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This is a division of application Ser. No. 423,436, filed Dec. 10, 1973, now U.S. Pat. No. 3,955,995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to calcination of preheated, pulverous, raw material, such as cement raw meal, consisting of or containing lime. The invention relates to an improved method of at least partially calcining such pulverous, raw material and improved calcination plants for treating such raw materials according to the improved method wherein heat is supplied before the material is subjected to any finishing calcination and/or other heat treatment, if any.
2. Description of the Prior Art
Calcination of pulverous raw materials such as cement raw meal is to be understood as an expulsion of carbon dioxide from calcium carbonate by an endothermic process (i.e. a process in which heat is absorbed) according to the equation:
CaCO.sub.3 → CaO + CO.sub.2
when the raw material is cement raw meal, a finishing heat treatment following the calcination is a sintering by which cement clinker is produced. Sintering is an exothermic process characterized by, or formed with, evolution of heat.
The heat necessary for carrying through the conversion of the cement raw meal to cement clinker is usually provided by burning fuel, which together with combustion air, is introduced into a combustion chamber and forms smoke gas. As a result, the energy contained in the fuel is released for heating the smoke gas to a high temperature. The hot smoke gas is then brought into contact with the raw meal to be heat treated. The heat is mainly used for preheating and calcining the raw meal, its sintering being as mentioned an exothermic process; in practice, however, heat must be supplied in order to start the sintering.
Owing, among other things, to the presence of alkalis in the raw meal and the consequent drawbacks it is sometimes preferred to carry through the preheating and calcining of the raw meal by hot gas from one source of heat and the initiation of its sintering by hot gas from another source of heat.
In the case of calcination of cement raw meal it is desirable to carry through this process at a low temperature. However, it is difficult to do that by means of smoke gases having a high temperature since there is then a great risk of excessive heating of the raw meal occurring locally and temporarily. Even excessive heating of a part of the raw meal for a short time may involve expulsion of alkali vapors or the production of melts which may give rise to cakings. Excessive heating of the raw meal at the calcination stage may also prevent chemical reactions intended to take place at a later stage of the whole process for the manufacture of cement clinker. For example, a clinker mineral formation at the stage of the total process at which the calcination is to take place will involve a disadvantageous development of the whole process.
U.S. Pat. No. 3,203,681 to Rosa, et al. relates to a process wherein heat for carrying through the calcination of preheated cement raw meal derives from hot gases having a temperature higher than the calcination temperature. The gases are produced in a separate chamber and are passed upwardly in a riser column in which the raw material is suspended and entrained by the gases thus produced. U.S. Pat. No. 3,452,968 to Shimizu et al. relates to a process for roasting fine ore wherein preheated raw meal and fuel are ejected individually into a rotating flow of gas ascending upwardly in a calcining chamber. Combustion and the roasting reaction are then caused in the violently diffusing turbulent flow. Neither of these prior art patents disclose or suggest a method of heat treating a pulverous, raw material or a plant for practicing the method such as I have invented. According to my invention, a raw material consisting entirely of, or at least containing a portion of, lime is at least partially calcined substantially isothermically (i.e. constant temperature conditions) at relatively low temperatures while substantially eliminating the disadvantages of the presently known systems.
SUMMARY OF THE INVENTION
According to the method of the invention a preheated, pulverous, raw material consisting entirely of, or at least containing a portion of, lime is at least partially calcined. The method comprises mixing at least a part of the preheated raw material intimately with a fuel capable of carrying out at least a partial calcination. The fuel is either a combustible gas itself or, one which is capable of producing a combustible gas upon coming into contact with the preheated raw material. The contacting relation thereby provides a suspension of the raw material in the combustible gas. The method further comprises providing a flow of oxygen-containing gas in contacting relation with the suspension of gas/material in such a manner that the combustible gas burns and the individual particles of raw material are calcined substantially isothermically (i.e. under conditions of substantially constant temperatures) and at relatively low temperatures. The raw material particles thus treated are entrained by the total of exit gases from the combustion and calcination processes and are finally separated from the stream of gases in which they are entrained.
Thus, while presently known methods utilize a fuel to produce a hot stream of smoke gas which is then passed to the raw material to be calcined, the heat is, according to the present invention, generated at the place where the solid particle, which is surrounded by gas, meets the oxygen necessary for the combustion. As far as each particle of raw material is concerned the heat is generated at the place where it is to be used. As a result, the particles of raw material, the oxygen, and the combustible gas, are mixed very intimately so that the calcination may be performed approximately isothermically and at a relatively low temperature.
The use of the expression "partial calcination" results from the fact that the whole cement burning process is often carried through in a manner in which only a partial calcination takes place at the calcination stage, whereas the finishing calcination is effected at the sintering state. It is, of course, also conceivable that the preheated raw meal which is passed to the calcination stage has, in fact, already been subjected to a certain amount of calcination during the preheating stage.
The fuel contemplated by the invention may be either a combustible gas, a liquid fuel such as oil, or a solid, pulverous fuel, such as coal powder. If the fuel is a gas, it is caused to mix intimately with the raw material. In the case of a liquid fuel, when such a fuel is introduced into the raw material, the fuel will evaporate upon meeting the hot raw material and produce a gas which behaves in a similar manner as if combustible gas had been supplied. Solid pulverous fuel has the same effect since it gives off combustible gases when it contacts the hot raw material. These gases then behave in the same manner as the gas which is supplied directly.
In certain cases the process may advantageously be modified by suspending a part of the preheated raw material in the oxygen-containing flow of gas before it is brought into contact with the suspension of gas/material.
Although the intimate mixture of fuel and raw material may be simply discharged into contact with the oxygen-containing gas to provide the contact with the gas/material suspension, there are advantages if an accumulation of an at least partly fluidised mixture of continually supplied fuel and preheated pulverous raw material is formed in a confined space and permitted to serve as a source for continuously providing the gas/material suspension which is to be brought into contact with the flow of oxygen-containing gas. In addition, the combustible gas mixed with the raw material, or the combustible gas formed upon mixture of the fuel with the raw material, will contribute to the at least partial fluidisation of the mixture. If the combustible gas supplied or produced is insufficient for the purpose, a supply of incombustible gas such as atmospheric air, for example, may also be introduced into the mixture. In practice the amount of atmospheric air will be small, and the oxygen content of the air will, therefore, be so small that any combustion of gas that takes place in the accumulation will be without significance.
In those applications in which the raw materials which have been at least partially calcined, are then to be subjected to a finishing calcination and/or other heat treatment, the incombustible gas introduced into the accumulation may be constituted by a part of the gases from the finishing calcination and/or other heat treatment process. This finishing or supplementary heat treatment of the raw material is often succeeded by a cooling of the final product by causing a moving layer thereof to be swept and/or traversed by cooling air in at least one of several known coolers, such as a grate cooler, a separate planetary cooler, or an underlying rotating drum cooler. Since the oxygen-containing gas used in the present invention is preferably atmospheric air which may be preheated to a temperature below the calcination temperature of the raw material, at least part of the used cooling air from the aforementioned cooling process may thus be used in the flow of oxygen-containing gas with which the gas/material suspension is to be brought into contact.
I have found that there are advantages if prior to being brought into contact with the flow of oxygen-containing gas, the preheated raw material passes downwardly and then upwardly along a V-shaped path and the fuel, or fuel and noncombustible gas, is introduced into the material as or after the material passes the lowest point of the path. With this procedure, the mixture downstream of the lowest point of the path is at least partly fluidised and less dense than the material upstream of the lowest point of the path. As a result there is an extensive tendency for the fluidised raw material mixture in the downstream branch of the V-shaped path to rise in that branch whilst the upstream branch of the V-shaped path remains full of unfluidised raw material. This mammoth pump effect produces a very intimate mixing of the raw material and fuel and allows an appreciable saving in the overall height of the construction.
The gas and material suspension may be brought into contact with one or more or all sides of an upwardly flowing stream of oxygen-containing gas. Thus, the suspension may be brought into contact with the outside of the gas stream. Alternatively, the gas/material suspension may be discharged upwardly within an upward flow of oxygen-containing gas. In either case, the gas stream may be exercising a helical swirling action.
Alternatively, a fluidised bed of the raw material may be advantageously utilized in which case the fluidized bed is maintained by introducing into the bottom of the bed, fuel, or fuel and non-combustible gas. In this embodiment the gas in the fluidised bed contributes to the fluidisation of the bed and entrains raw material particles in the space above the bed to form the suspension of gas/material adjacent to the oxygen-containing stream. Thus, there is maintained a liquid-like layer of raw material in the fluidised bed and a gaseous cloud on top of the bed. However, the boundary between them is, of course, not sharply defined. Between them there will be a transitional layer behaving something between a liquid and a gas. The mixture of raw material particles and gas present in this transitional layer may be caused to overflow an edge of the fluidised bed into the stream of oxygen-containing gas. In this case, the flow will be similar to that of a light flowing liquid.
The contact between the gas/materials suspension and the stream of oxygen-containing gas may be caused to take place along an imaginary mutual interface between the media so that the calcination of the raw material particles is at least initiated adjacent to the interface. The particles which are calcined to the greater extent are entrained by the passing oxygen-containing gas stream during calcination and, if desired, after calcination. In still other embodiments of the invention, the fluidised bed may surround or be surrounded by the oxygen-containing gas stream. The amount of material in the bed may then be kept to a minimum and the number of nozzles for the introduction of fuel or fuel and non-combustible gas may be reduced to a single circle of nozzles. In such a case, the fluidised bed may have an annular configuration and the cord of the annulus will have a triangular cross section with its apex downwards.
The invention also pertains to a calcination plant for treating a preheated, pulverous raw material consisting entirely of, or at least containing a portion of lime. Briefly, the plant comprises a conduit having its upper end portion connected to a particle/gas separator with means for passing a flow of oxygen-containing gas through the conduit. A means defines a mixing zone for mixing said preheated raw material and a fuel. The plant further comprises means for separately and continuously feeding fuel and raw material to the mixing zone for intimate mixing thereof to provide a suspension of fuel gas and raw material particles. The mixing zone and the conduit are so arranged in adjacent relation such that the suspension of fuel gas and raw material particles may pass from the mixing zone into contact with the oxygen-containing gas flowing upwardly through the conduit to provide at least a partial calcination of the raw materials.
In a preferred embodiment, the mixing zone is open to a calcination chamber. The conduit is in the form of a shaft, the top of which leads from the calcination chamber to the separator, and the means for passing a flow of oxygen-containing gas upwardly through the shaft is arranged to cause the gas to pass up into the calcination chamber through the bottom of the chamber.
The mixing zone may comprise one or more ducts leading into the calcination chamber with or without fluidisation, or a support arranged to form and maintain a fluidised bed adjacent to the side of the shaft or in the bottom of the calcination chamber as will be seen from the descriptions of the alternate embodiments hereinafter set forth.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described hereinbelow with reference to the drawings wherein:
FIG. 1 is a vertical, substantially cross-sectional view of a plant for calcination of cement raw meal according to the invention;
FIG. 2 is a side view of the plant shown in FIG. 1;
FIG. 3 is a modification of the plant shown in FIG. 1;
FIG. 4 is a side view of the plant shown in FIG. 3;
FIG. 5 is another modification of the plant of the invention;
FIG. 6 is a section taken along the line 6--6 of FIG. 5;
FIG. 7 is a cross-sectional view of still another modification of the plant shown in FIGS. 5 and 6;
FIG. 8 is a vertical, substantially cross-sectional view of still another modification of the plant of the invention;
FIG. 9 is a vertical, substantially cross-sectional view of still another modification of the plant of the invention;
FIG. 10 is a vertical, substantially cross-sectional view of still another modification of the plant of the invention;
FIG. 11 is a section taken along lines 11--11 of FIG. 10;
FIG. 12 is a vertical, substantially cross-sectional view of a portion of still another modification of the plant of the invention;
FIG. 13 is a sectional view taken along lines 13--13 of FIG. 12; and
FIG. 14 is a diagrammatic representation of a complete cement burning plant incorporating by way of example, the calcination plant of FIG. 3, but which may incorporate any of the modifications of the plants shown in the other Figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The calcination plant illustrated in FIGS. 1 and 2 has a conduit preferably in the form of a shaft 1 of square cross-section which is provided with a fire-resistant lining. During operation an oxygen-containing gas is fed to the shaft 1 from below.
The shaft 1 is associated with a V-shaped chamber 2 in the form of a fluidised bed support and two branches, one of which communicates through an opening 3 with the interior of the shaft. The other branch is connected with a pipe 4 the upper end of which joins the bottom of a cyclone 5, of which only the lower part is indicated in the drawing.
During operation preheated raw meal flows continually from the cyclone 5 through the pipe 4 down into the chamber 2 so as to form and maintain at the bottom of the chamber an accumulation 6 of preheated raw meal.
From the bottom of the chamber 2 the mouths of a number of uniformly distributed pipes 7A project. The other end of the pipes join transverse pipes which unite into a common supply pipe 7. Through the pipe 7 combustible gas or oil is being fed continually to the pipes 7A and hence into the raw meal accumulation 6.
If the feed is gas, this will penetrate that part of the raw meal accumulation that is located in the branch connected with the shaft 1, fluidising the part 9 of the accumulation, whereas the accumulation in the opposite branch will form a seal which effectively prevents the gas from passing up this way and into the pipe 4. As a consequence the fluidised part 9 will rise up the corresponding branch of the chamber 2.
If, however, the feed consists of oil supplied to pipes 7A through the pipe 7, the oil will evaporate when meeting the hot raw meal so that it will now behave as a combustible gas which fluidises that part of the raw meal accumulation which is denoted 9. Thus, the effect is the same, regardless of whether gas or oil is used.
Somtimes it may be found desirable to increase the fluidisation. There is, therefore, a supply pipe 8 for incombustible gas, which, for example, may be atmospheric air. The pipe 8 is branched off into a number of pipes 8A which open uniformly distributed above the bottom of the chamber as shown in FIG. 1. If the supplementary fluidisation is superfluous, the gas supply from the pipe 8 may simply be cut off. Simultaneously with the combustible gas at least contributing to the fluidisation of that part of the raw meal which is denoted 9, the gas also mixes intimately with the part 9. As long as no air or other oxygen-containing gas is fed through the pipe 8, no oxygen will be present in the part 9, and calcination of the raw meal, therefore, cannot take place. If, however, atmospheric air or another oxygen-containing gas is supplied from the pipe 8 through pipes 8A, this will have two effects; one will be that the raw meal seal in the left-hand branch of the chamber 2 is aerated to some extent so that the raw meal will more readily flow from the left-hand branch of the chamber 2. The other effect is that a certain amount of oxygen is introduced into the accumulation of the fuel-mixed raw meal, by which a certain calcination takes place sporadically, which, in itself, is undesirable, but owing to its small extent it is without importance in practice.
Simultaneously with penetrating the part 9 of the accumulation, thereby contributing to fluidise the part 9, the gas flow entrains raw material particles from the accumulation so as to form in the space above the accumulation, and using the accumulation as a source, the suspension of gas and material which by its contact with the passing oxygen-containing gas stream is to cause at least a partial calcination of the individual particles of the suspension. However, the calcination will only take place after the suspension has passed through the opening 3 between the chamber 2 and the shaft 1. The opening 3 is defined downwardly by an edge 11 which is formed where wall portion 11B of the shaft 1 and wall portion 11A of the chamber 2 join each other. Between the part 9 of the accumulation and the space in which the suspension of gas/raw meal is located there will be formed a transitional zone 10 in which the material behaves neither as a liquid nor as a gas, but partakes of the nature of a very lightly flowing liquid. It will overflow the edge 11 and form eddies 12 at this space, and these will at once be caught by the gas ascending through the shaft 1.
As indicated in FIG. 1, the contact between the suspension of gas and raw meal and the stream of oxygen-containing gas takes place along an imaginary boundary surface or boundary zone, denoted 13, between the media. The calcination of the raw meal particles will at least be initiated in the surface or zone 13, in which the particles and the combustible gas meet the oxygen from the oxygen-containing gas, and from which preferably those particles that are calcined to the larger extent are entrained by and, for example, after-calcined in the passing gas. The surface or the zone 13 is inclined, the oxygen of the oxygen-containing gas being consumed as the calcination proceeds, so that the gas will occupy less space. In return, the suspension of gas/raw meal on the left-hand side of the surface 13 will occupy more space since the calcination consists in expelling CO 2 gas from the lime of the raw meal.
Referring now to FIGS. 3 and 4, there is shown a modified plant for calcination of cement raw meal. The plant distinguishes in no essential way from the plant shown in FIGS. 1 and 2, and the reference numerals are, therefore, identical. The principal difference is that in this case the chamber 2 is not branched off into two sections and that there is, therefore, no formation of a seal as described with reference to FIG. 1. In addition, coal power is, as an example, contemplated for use in the calcination. The coal powder is supplied to the fluidised accumulation of raw meal by means of a worm conveyor 14 which forces the coal powder into the accumulation. When the coal powder meets the hot raw meal, combustible gases (carbon monoxide, methane, etc.) are expelled from the coal. When the fuel used is coal, extra fluidisation will usually be required, and also the plant according to FIG. 3 is, therefore, provided with a supply pipe 8 with appertaining pipes 8A and pipe openings for the supply of extra fluidisation gas. The mode of operation of the plant according to FIGS. 3 and 4 is the same as that of the plant first described.
FIGS. 5 and 6 show a calcination plant offering substantial advantages above those shown in FIGS. 1 through 4. The structure differs, however, little from those previously described and it has been possible to use the identical reference numerals to a wide extent. The shaft 1 used in this case is not a square, but of circular cross-section as will appear from FIG. 6, and it is provided with a calcination chamber formed by a wider part 15 of an upper portion of the shaft 1, the narrow and the wide parts of the shaft being connected by a part-conical section 16.
The form of the shaft 15 thus presented may be assumed to be arrived at by turning the section which represents the chamber 2 in FIG. 3 through an entire revolution about the axis of symmetry of the shaft 1. As a result, the support for the fluidised raw meal 9 is an annular trough open at its upper end, the egde 11 being annular too. Through the space surrounded by the trough the oxygen-containing gas flows into the shaft 15 through a pipe 17 which corresponds to the lower part of the shaft in FIGS. 1 and 3.
The preheated raw meal is fed to the shaft at two diametrically opposite points, each separately by one of the two cyclones 5 through its separate pipe 4. It will be evident from FIGS. 5 and 6 and the above description that the calcination with the use of the compact plant will be more intense and that the product obtained will be more homogenous than that obtained with the use of the plants previously described. The plane imaginary boundary surface 13 of the latter will, according to FIGS. 5 and 6 of the plant, be an imaginary conical boundary surface. Fundamentally, the mode of operation of the plant is, however, identical to that of the plants previously described.
In FIG. 5, as well as in FIGS. 1 and 3, closed curves in the shaft 1 or its enlargement 15, respectively, indicate the formation of eddy currents 19 by the suspension of gas/material. These eddies have axes of rotation which are substantially horizontal and may cause uncalcined particles to be continually passed to the boundary surface 13 so as to be calcined. In addition, the eddies 19 form a heat insulating cloud protecting the walls of the shaft or the enlargement portion 15 against the heat developed in and around the boundary surface.
Instead of using only one big supply pipe 17 for oxygen-containing gas, there may be a plurality of such smaller pipes mounted symmetrically. This is indicated in FIG. 7, which shows a horizontal, partial cross-sectional view of this embodiment of the plant shown in FIGS. 5 and 6, with the modification that there are three oxygen-containing supply pipes. In FIG. 7 only the upper ends of these pipes are visible in the form of the edge 11. This modification is used with advantage in very large production and provides in that case the suspension of gas and raw meal with increased contact surfaces for meeting the oxygen-containing gas.
The plant shown in FIG. 8 has, like the plant in FIG. 5, a calcination chamber formed by an enlargement 15 interposed between an upper portion 1 and a lower portion 17 of the shaft. However, the parts 15 and 17 are interconnected by a part-conical portion 18. In this example the fluidised bed is eliminated and the intimate mixing between the fuel and raw material takes place in the raw material feed pipes 4 for themselves, of which there may be one, two, or a ring of three or more; however, in FIG. 8 two feed pipes 4 are shown. The fuel is introduced directly into each pipe and FIG. 8 shows by way of example a worm conveyor 14 for coal powder on the right-hand side and, on the left-hand side, a number of separately valved feed pipes 7A connected to common pipe 7 for fuel oil or gas.
Notwithstanding the fact that this construction is simpler than those described so far, a very intimate mixing of the raw material and fuel is achieved. A suspension of gas and raw material is continuously discharged through the lower ends of the pipes 4 downwardly and radially inwardly towards the stream of oxygen-containing gas passing upwards through the centre of the calcination chamber. Also, here the suspension is caused to exhibit eddy currents rperesented by the curved arrows 19 so that a quick calcination is achieved at comparatively low temperature upon contact with the oxygen-containing gas stream. As in the other examples the particles of material, after calcination, are entrained and carried upwards through the upper part 1 of the shaft and are separated in the separator (not shown in FIG. 8).
The FIG. 9 modification differs from the modification of FIG. 8 in that the raw material feed pipes 4 are V-shaped having an upstream branch 4A and a downstream branch 4B. The fuel is introduced into the branch 4B and the fuel gas so introduced together, if necessary, with some incombustible gas introduced through pipes 8 at the lowest point of the V-shaped pipe, causes fluidisation of the raw material within the branch 4B. The raw material in the branch 4A forms a seal and a mammoth pump effect is produced similar to that in FIG. 1 whereby the mixture of raw material and fuel naturally rises through the branch 4B into the bottom of the calcination chamber. The advantages of particularly good mixing of raw material and fuel and the consequent efficient low temperature calcination are again obtained, together with that of a fast feed rate through the pipe 4 and the possibility of reducing the overall height of the equipment.
The modification illustrated in FIGS. 10 and 11 differs from the example of FIG. 9 in that the downstream branch 4B of the raw material feed pipe leads vertically and centrally up into the bottom of the calcination chamber 15 surrounded by the oxygen-containing supply pipe 17. Again, the fuel, with some incombustible gas, if necessary, is introduced into the bottom of the branch 4B through pipes 7, 8. In this example the oxygen-containing gas supply pipe 17 is fed laterally through a branch 17A which leads into a vortex producing manifold 17B which causes the gas to exercise a helical swirling action as it passes up through the chamber 15 as indicated by the arrowed line.
In this case eddy currents like those indicated by the curves or arrows 19 in the modifications shown in the previous Figures will not be formed, but the helical swirling motion of the gas will have the same effect as the eddies, although their common axis of rotation is vertical in this case instead of horizontal.
The example illustrated in FIGS. 12 and 13 utilizes a calcination chamber similar to that of FIGS. 8 to 11 but, like FIG. 5, an annular fluidised bed 9 is formed in the bottom of the chamber and is fed with raw material through a pipe or pipes 4. Owing to the part-conical shape of the bottom part 18 of the chamber, and an upwardly extending mouth 20 of the lower shaft portion 17 and corresponding to the edge 11 in FIG. 5, the fluidised bed has a triangular cross-section. This is a particularly efficient construction enabling efficient and quick calcination at low constant temperature to take place without the addition of any non-combustible fluidising air being necessary and with the use of only a single ring of oil feed pipes 7 for introducing the fuel through pipes 7A to be vaporized for fluidisation and combustion. Further, only comparatively small amounts of fluidised material need be maintained in the calcination chamber.
The mouth 20 is telescopically retractable downwards relatively to the lower part 17 of the shaft. The mouth 20 is sealed to the shaft 17 by sliding seals 21 and sealed to the calcination chamber by sliding seals 22. The advantage of this is that by lowering the mouth 20 slightly, the fluidised bed 9 can be caused partly and continuously to overflow the edge of the mouth with a weir effect into the oxygen-containing gas stream, similar to the examples in FIGS 1, 3 and 5.
A further advantage is that by lowering the mouth 20 until its upper edge is level with the bottom of the calcination chamber, the material in the fluidised bed is free to pour out of the bottom of the calcination chamber and down the shaft 17 into a hopper 23 forming a collecting chamber. This operation is carried out during a temporary stoppage when lumps of raw material or foreign bodies have settled in the fluidised bed. The mouth 20 is then raised again and operation is recommenced.
The material in the hopper 23 does not affect the supply of oxygen-containing gas up through the shaft 17 to the calcination chamber as the oxygen-containing gas supply is provided through a lateral pipe 24 which leads into the shaft 17 above the funnel 23. A blow pipe 25 leads into the funnel for use in blowing fine particles back up into the calcination chamber again. Lumps or foreign bodies then remaining in the funnel are removed, after cooling, by opening a damper 26.
FIG. 14 shows diagrammatically a complete cement burning plant, in which the calcination plant according to FIG. 3 constitutes an integral part. The plant according to FIG. 14 is assumed to be oil-fired; however, it should be emphasized that the other illustrated calcination plants could equally well be substituted. In this Figure there are shown certain numerals which are identical to those shown in the previous Figures and which are used to identify corresponding components. The shaft 1, the chamber 2, the opening 3, and the supply pipe 4 for preheated raw meal, and the entire cyclone 5 are shown. The supply pipe 7 for feeding oil to pipes 7A and the supply pipe 8 for feeding supplementary fluidising gas are also shown, as the edge 11. fluidising gas are shown, as well as the edge 11.
The upper end of the shaft 1 joins a horizontal pipe 27 through which the suspension of wholly or partially calcined raw meal is passed tangentially into a cyclone 28, in which gas and raw meal are separated from each other. The raw meal sinks through a pipe 29 directly down into a rotary kiln 30, in which the wholly or partially calcined raw meal is finish-calcined, if necessary, and burnt to cement clinker. The raw meal inlet end of the rotary kiln 30 is surrounded by a casing 31, and a similar casing 32 is located at the other end of the rotary kiln. The casing joins at its lower end a clinker cooler 33 of the grate type. This has a grate 34, onto which the clinker falls and along which the clinker is advanced from the right to the left, and cooled by a transverse current of air supplied through a pipe 35. Having passed the clinker layer, the air enters the casing 32 to the top of which the shaft 1 is connected, so that part of the used cooling air enters it and constitutes the oxygen-containing gas previously referred to. Another part is sucked into the rotary kiln 30 so as to serve as secondary combustion air for the formation of a flame at the end of a burner pipe 36 extending into the kiln, in which the sintering of the preheated and calcined raw meal takes place. The clinker cooler 33 need not necessarily be of the grate type to serve as a source of oxygen-containing gas to be supplied to the bottom of the shaft 1. Other types such as an independently rotating planetary cooler or an underlying rotating drum cooler might just as well be used.
In the cyclone 28 the wholly or partially calcined raw meal is separated from the gas in which it was suspended. The gas leaves the top of the cyclone through a riser pipe 37 which opens tangentially into the cyclone 5 previously referred to and which constitutes one cyclone of a two-stage cyclone preheater. From the top of the preheater a riser pipe 38 leads to the other cyclone, denoted 39. From the top of the cyclone again a pipe 40 leads to the suction side of a fan 41, which produces the sub-atmospheric pressure that causes atmospheric air to be drawn in through the intake 35, the air then flowing along the path indicated by the reference numerals 35-32-1-27-28-37-5-38-39-40-41. The fan 41 forces the gas into an electrostatic dust precipitator 42, in which the dust carried by the gases is separated off, and the cleaned gas leaves the precipitator through a pipe 43 leading to a vent (not shown).
The raw meal to be preheated in the cyclone preheater 37, 5, 38, 39, calcined in the shaft 1 and subsequently burnt to cement clinker in the rotary kiln 30, in order finally in the form of clinker to be cooled in the cooler 33, is passed to a hopper 44. The hopper 44 opens into a pipe 45 which contains a sluice 46, e.g. a gate valve of suitable design, which permits the raw meal to pass vertically down through the pipe 45, but prevents any passage of gas therethrough. The pipe 45 opens at some point further down in the vertical part of the riser pipe 38, where the raw meal meets the ascending stream of gas through the pipe, by which the raw meal is entrained and heated by the gas stream, whereas the gas itself is cooled.
In accordance with the principle known from cyclone preheaters the raw meal together with the gas is introduced into the cyclone 39, in which the two media are separated from each other, the gas as previously described ascending through the pipe 40, whereas the raw meal passes through a pipe 47 containing a sluice 48 of the identical kind as that denoted 46 into the interior of the riser pipe 37 near its lower end. As a result, the raw meal will be preheated still more, since the gas it meets in the riser pipe 37 is warmer than the gas flowing through the riser pipe 38. In the cyclone 5 the two media are again separated from each other, the gas as previously referred to passing up through the pipe 38, whereas the now finish-preheated raw meal is introduced through the pipe 4 into the chamber 2, in which it is treated as previously described and subsequently calcined in the shaft 1, with which the chamber 2 communicates.
It is worth observing again that the calcination and the preheating of the raw meal are not, as is conventionally the case, carried through by means of hot rotary kiln gases with the consequent drawbacks previously described, but by means of atmospheric air and fuel mixed with the raw meal. The exit gases from the sintering process performed in the rotary kiln 30 must, however, be disposed of in other manner, and preferably so that the heat contained therein may be utilized. The possibilities hereof are illustrated by additional pipelines in FIG. 14.
If extra fluidization of the raw meal in the chamber 2 is required, a part of the exit gases from the rotary kiln 30 may be used for this purpose such as indicated by the pipeline 8.
The remainder of the gases or the whole of the amount of gas may either follow the pipeline 50; that is, it may be introduced into the riser pipe 37 of the lower cyclone; or it may, following the pipeline 51, be introduced into the gas stream directly in front of the blower 41, as shown. In the latter case the heat of the exit gases will not, however, be utilized. On the contrary, it will often be necessary as indicated in the Figure to let the gases pass through a cooling tower 52. In this the gases are cooled before they enter the electrostatic precipitator 42, which cannot stand up to the passage of gas exceeding a certain temperature. Further, it would be unsatisfactory if the gas does not contain a certain amount of moisture. Moisture will automatically be added to it in the cooling tower 52.
Furthermore, in FIG. 14 there is indicated quite diagrammatically by means of the pipeline 53 a means whereby a part of the preheated raw meal may be fed to the bottom of the shaft 1, such that this part of the raw meal together with the oxygen-containing gas is passed up through the shaft. This is an alternative to passing the raw meal through the pipe 4 into the chamber 2 to be mixed with the fuel as previously described.
The overall height advantage which can be achieved by the V-shaped material feed pipe 4A and 4B in FIG. 9 may be appreciated by considering substitution of the FIG. 9 calcination plant in FIG. 14. In that case the upper end of each pipe branch 4B could be connected to the bottom of the shaft 1 in FIG. 14 so that the shaft 1 may be made shorter with a consequent possibility of lowering the level of parts 28, 5, 39 and 42, that is to say the whole of the plant. The bend at the interconnection of the branches 4A and 4B may then be located on a level with the mouth of the pipe 35 or even lower still. The other branch 4A being connected to the pipe 4.
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A method of heat treating a preheated, pulverous, raw material consisting of or containing lime, such as cement raw meal. By mixing at least part of the preheated raw material intimately with a fuel capable of carrying out at least a partial calcination, a suspension of raw material in a combustible gas is provided. Upon providing a flow of oxygen-containing gas in contacting relation with the suspension of gas/material, at least a partial calcination takes place according to an endothermic process in which calcium carbonate is dissociated into calcium oxide and carbon dioxide. A finishing calcination and/or other heat treatment may follow the calcination process. When the raw material is cement raw meal, the aforesaid finishing heat treatment following the calcination is a sintering by which cement clinker is produced according to an exothermic process. A unique calcination plant is disclosed for at least partially calcining a preheated pulverous, raw material according to the present method wherein by a supply of heat before the material is subjected to a finishing calcination and/or other heat treatment, if any, at least a partial calcination may be performed approximately isothermically and at a relatively low temperature.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of U.S. patent application No. 226,794, filed Aug. 1, 1988, now abandoned, which in turn was a continuation-in-part of U.S. patent application Ser. No. 163,795, now abandoned, filed Mar. 3, 1988, for "Ferrofluid Compositions", the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improved ferromagnetic fluid compositions commonly referred to as "ferrofluid compositions" in which fine particles of ferromagnetic material are dispersed in a very stable manner. More particularly, the present invention relates to ferrofluid compositions having low vapor pressure and low viscosity and which are suitable for use in seals under vacuum.
2. Prior Art
As conventional ferrofluids for a vacuum seal, there have been proposed two types of ferrofluids. One utilizes polyphenyl ether oil as its liquid carrier for dispersing therein the ferromagnetic particles, as disclosed by U.S. Pat. No. 4,315,827, and the other one utilizes alkylnaphthalene oil as disclosed by Japanese Laid-open (unexamined) Patent Publication No. Sho 59(1984)-168097.
Although the ferrofluid of the former is suitable for ultra low vacuum seals, due to its polyphenyl ether oil as a liquid carrier, having a very low vapor pressure of less than 10 -7 torr, it, adversely, has high viscosity, since the viscosity of polyphenyl ether oil is 120 cst at 40° C. This brings about high torque when the ferrofluid is used for a rotary shaft, and, thus, results in frictional heat within the ferrofluid itself, or at the peripheral machine parts or components to which the former ferrofluid is applied, thereby degrading the sealing power of the related machine parts.
On the other hand, as the latter utilizes alkylnaphthalene oil as its carrier, there exists no problem with respect to the viscosity. However, there arise other problems as explained below due to the fact that it uses petroleum sulfonic acid as a surfactant for dispersing fine ferromagnetic particles throughout the carrier.
More particularly, petroleum sulfonic acid has various portions of hydrophobic groups, among which there are contained some components which have poor affinity with the alkylnaphthalene oil carrier. Fine particles of ferromagnetic material which have adsorbed these components having poor affinity, naturally become poor in dispersion property and are liable to precipitate or settle within the carrier, thereby decreasing the yield in producing the same, and, further, it becomes impossible to obtain a ferrofluid in high concentration.
SUMMARY OF THE INVENTION
The present invention has been developed so as to obviate the above-mentioned drawbacks. The present invention has solved the aforesaid problems by providing ferrofluid compositions comprising fine particles of ferromagnetic materials being dispersed in a carrier selected from the group consisting essentially of alkylpolyphenyl ether oil and alkyl-naphthalene oil through the use of a surfactant having equivalent structure as its hydrophobic group portion.
Since the present invention uses as a carrier, for dispersing the ferromagnetic particles, either an alkylpolyphenyl ether oil or an alkylnaphthalene oil or both, having low viscosity, the ferrofluid, thus obtained, can satisfactorily suppress the frictional heat which is apt to be generated at the rotary shaft, during its rotation.
The viscosity of the subject ferrofluid can be adjusted, depending on the condition of the intended use, by admixing the above-mentioned two carriers in a suitable ratio and manner.
In addition, since the surfactant or surfactants used as a dispersing agent in accordance with the present invention comprise, at their hydrophobic group portion, chemical structure equivalent to that of the carrier, the surfactant or surfactants are able to have a high extent of chemical affinity with the carrier to be used in cooperation therewith, and thereby the dispersion property of the fine particles of the ferromagnetic material can be greatly stabilized.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The carriers in accordance with the present invention are comprised of synthetic oils having low viscosity, low vapor pressure and low pour point. Specifically, either an alkylpolyphenyl ether oil or an alkylnaphthalene oil or mixtures thereof, as shown in Table 1 are suitably used.
TABLE I__________________________________________________________________________ Viscosity Pour PointSynthetic Oil cst at 40° C. torr Vapor Pressure C° C.__________________________________________________________________________Octadecyldiphenyl ether (AP) 25 1 × 10.sup.-6 -40.0Hexadecyltriphenyl ether (AP) 60 1 × 10.sup.-6 -32.5Eicocylnaphthalene (AN) 38 less than less than 5 × 10.sup.-9 -5Tetraphenyl Ether (PE) 120 3 × 10.sup.-9 2.5Pentaphenyl Ether (PE) 280 1 × 10.sup.-11 2.5__________________________________________________________________________
In the Table, symbol (AP) denotes alkylpolyphenyl ether oil and symbol (AN) denotes alkylnaphthalene oil, respectively, while (PE) denotes polyphenyl ether oil shown for reference.
The introduction of an alkyl group into the hydrophobic group in the carrier fluid causes the viscosity and vapor pressure of the carrier fluid to decrease. Alkyl groups usable for attachment to the hydrophobic group of the carrier fluid are preferably those containing at least 12 carbons. Alkyl groups having between 12 and 20 carbons are particularly preferred.
The addition of the alkyl group to the carrier fluid brings the vapor pressure thereof below 10 -4 torr (at room temperature). The addition of the alkyl group also lowers the viscosity to a value below 80 cst at 40° C. Therefore the advantage of adding the alkyl group to the carrier fluid molecule is the benefit of lowered viscosity and lowered volatility.
In accordance with the present invention, either the listed alkylpolyphenyl ether oils or the alkylnaphthalene oil or a mixture of the two synthetic oils are used as a carrier, depending upon the intended use for the ferrofluid composition of this invention.
The surfactant or surfactants used in the present invention has in its structure both a nonpolar hydrophobic group portion and a polar hydrophilic group portion, one such among them having at its hydrophobic group portion a structure or structures equivalent to the carrier listed above.
In other words, in the case where an alkylpolyphenyl ether is selected as a carrier, a suitable dispersing agent can be one of the materials having an alkylpolyphenyl structure, such as a sodium salt of sulfonated octadecyldiphenyl ether, while when alkylnaphthalene is used as a carrier, a material(s) having an alkylnaphthalene structure, such as a sodium salt of sulfonated eicocylnaphthalene, is preferred to be used as a suitable dispersant.
In such cases where a mixture of alkylpolyphenyl ether oil and alkylnaphthalene oil is selected as a carrier, the surfactant to be suitably used is, also, a mixture of materials, each having a hydrophobic structure of the respective carrier component.
As to the hydrophilic group portion of the surfactant, it is required to render the molecule of the surfactant to be firmly adsorbed onto the surface of a ferromagnetic particle.
This can be accomplished by selecting such surfactant or surfactants that have, depending on the surface electric charge of the fine ferromagnetic particles, at least one such hydrophilic group that can be electrically bonded to ferromagnetic particles, for instance, acids, bases or the salt of a sulfonic group, sulfate ester group, phosphate ester group, carboxyl group, alcohol group, amino group or the like.
Ferromagnetic particles suitable for the present invention can be of such ones obtained as a colloidal suspension by the well-known wet method. Alternatively, they can be prepared by a so-called wet pulverizing technique, wherein magnetite particles are pulverized by a ball mill in water or in an organic solvent or by other methods such as a dry method.
It is also possible to use ferromagnetic particles other than magnetite, for example, manganese ferrite, nickel ferrite, cobalt ferrite, a composite ferrite of these ferrites with zinc, barium ferrite and the like. Alternatively, fine particles of metal such as iron or cobalt also can be used.
EXAMPLE I
6N of NaOH solution was added to 1 l of an aqueous solution containing 0.3 mol each of ferrous sulfate and ferric sulfate until the pH of the solution reached 11. Then the solution was aged at 60° C. for 30 minutes. Thus, there was obtained a slurry of a magnetite colloid. Next, the slurry was washed with water at room temperature and the remaining electrolyte was completely removed from the slurry. This is a process step for making fine magnetite particles by a wet method.
Thereafter, 14 grams of the sodium salt of sulfonated octadecyldiphenylether shown below was added, as a surfactant, to the thus obtained magnetite slurry. ##STR1##
Then an aqueous solution of 3N HCl was added to the slurry to adjust the pH of the slurry to 3 and, further, the slurry was agitated for 30 minutes at 60° C., thereby rendering the surfactant adsorbable on the surface of the fine magnetite particles. The slurry, thus treated, was held still so that the fine magnetite particles could be coagulated and settled, while the supernatant was poured out. Then a suitable amount of water was added and the slurry was agitated, again, then held still and the supernatant was poured out. Then a suitable amount of water was added and the slurry was agitated, again, then held still and the supernatant was poured out. Such water washing operations were repeated several times until the electrolyte in the solution was completely removed. Then the solution was filtered, and the magnetite was dehydrated and dried to obtain magnetite particles of desired size and properties.
Then a suitable amount of hexane was added to the magnetite particles with sufficient agitation so as to let the magnetite particles be dispersed in the hexane. The colloidal solution so obtained was transferred to a centrifugal separator for separating magnetite particles of unacceptable larger diameter under a centrifugal force of 8,000 G for 30 minutes. Fifteen grams of octadecyldiphenylether oil as a carrier, namely, a dispersing medium, expressed by the chemical formula shown below: ##STR2## was added to the colloidal solution obtained by the centrifugal separation explained above and was sufficiently admixed. Then the admixture was transferred to a rotary evaporator and held there at 90° C. so as to remove any remaining hexane, by evaporation.
The colloidal solution, after having gone through the evaporation step, was subjected to centrifugal separation for 30 minutes under a centrifugal force of 5,000 G. Thereby the undispersed solid particles were completely removed and the obtained ferrofluid was proven to be very stable showing saturation magnetization of about 180 Gauss.
EXAMPLE II
A magnetite slurry was obtained by the wet-method similar to that used for Example I. Then the slurry was filtered, degassed and dried at 70° C. to obtain magnetite powders. Then 1.5 grams of sodium salt of sulfonated hexadecyltetraphenyl ether, as a surfactant, as expressed by the chemical formula shown below: ##STR3## and a suitable amount of hexane were added to 5 grams of the magnetite powders and the admixture was ground and pulverized for 2 hours by using a ball mill.
Next, the thus treated mixture was transferred to a centrifugal separator, where the mixture was subjected to separation for 30 minutes under a centrifugal force of 8,000 G, thereby removing magnetite particles of larger particle diameter. Thereafter 5 grams of octadecyldiphenyl ether, as a carrier, was added to the mixture and was fully admixed. The resultant ferrofluid proved to be very stable and similar to that obtained in Example I.
EXAMPLE III
A very stable ferrofluid was obtained by using 15 grams of eicocylnaphthalene as a carrier, expressed by the chemical formula shown below: ##STR4## together with 25 grams of sodium salt of sulfonated eicocylnaphthalene as a surfactant acting as a dispersing agent expressed by the chemical formula shown below: ##STR5## and by treating the admixture of these components in a similar way as that applied to Example I.
EXAMPLE IV
A very stable ferrofluid was obtained by applying the same treatment as adopted in Example II and by using 5 grams of a carrier of eicocylnaphthalene and 2.25 grams of a sulfonated eicocylnaphthalene as a dispersing agent expressed by the chemical formula as follows: ##STR6##
EXAMPLE V
A comparison test was conducted to evaluate the difference between the lifetime of the ferrofluid compositions of the present invention and that of the prior art by using the test method explained below.
A ferrofluid composition of the prior art was prepared by using 5 grams of eicocylnaphthalene as a carrier and 2.25 grams of sodium salt of petroleum sulfonic acid by treating the admixture in the same manner as in Example II.
10 μl each of the two kinds of ferrofluids obtained by Example IV and that of prior art type, as explained above, were taken up and fixed on a slide glass placed on a sintered magnet piece, respectively. These samples were heated at 100° C. to observe the period of time until each sample had solidified or become viscous, which indicates thermal stability, namely, the life time of the two ferrofluid samples under comparison.
As the result, a clear difference was revealed between the two ferrofluids as can be seen from the following Table.
______________________________________Test Item Ferrofluid of Example IV Prior Art ferrofluid______________________________________Saturation 180 Gauss 180 GaussMagnetization No sign of solidification 825 hoursSolidifying nor increased viscosity wasTime observed even after 3000 hours.______________________________________
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A ferrofluid composition is defined by fine particles of ferromagnetic material, a liquid carrier for dispersing the ferromagnetic material and a surfactant or surfactants acting as a dispersant. The surfactant is required to have such relation to the carrier that the surfactant has, as its hydrophobic group portion, a structure equivalent to the carrier, and the carrier is selected to be either an alkylpolyphenyl ether oil, an alkylnaphthalene oil or both. By virtue of this structural feature, fine ferromagnetic particles are uniformly and stably dispersed throughout the carrier which has low viscosity and is thermally very stable.
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FIELD OF THE INVENTION
[0001] The present invention concerns novel diazo derivatives of general formula (I) hereafter reported, the process for their preparation and their use as deacidifying agents in the deacidification treatment of paper.
STATE OF THE ART
[0002] It is universally acknowledged that one of the causes of the too rapid deterioration of cultural materials on paper is the presence of acidity in the material. In modern paper, acidity is usually caused during the manufacture in the paper factory; however, acidity can often be found even in papers or books that are made from acid-free paper, as it comes from some types of ink for manuscripts, that was widely used in the past.
[0003] Experts agree that in order to prolong the life of books and documents that are stored in libraries and archives (according to the experts from three to five times as much) it is necessary to eliminate the acidity from the materials, by using a technique that in the specialised environment is known as “deacidification”. Obviously, in order to avoid the errors committed in the past, new documents and books to be stored should be made with acid-free paper (UNI n. 10332—Paper for documents. Requirements for the maximum duration and durability and UNI n. 10333—Paper for documents. Requirements for duration).
[0004] In the Italian public libraries there are currently 30 million books; an equal amount of paper documents are kept in public archives.
[0005] From fragmentary surveys carried out in some Italian preservation environments, in agreement with similar research carried out abroad on a wider scale, it has been found that 20-30% of library and archive materials are now so fragile that they cannot be made available for free consultation; the risk of further damage would be too high. Alongside this relatively low percentage however, it has been found that 60-80% of preserved books and documents need to be deacidified or in some way stabilised; otherwise, it would only be a matter of time before all the acid material would become fragile, and no longer consultable.
[0006] In view of what above said, it is evident that, in order to protect the Italian book and document heritage, it is necessary to be able to intervene with mass deacidification techniques, or however, with stabilisation techniques that would slow down deterioration; these would be techniques that allow the entire heritage to be restored in a time span of no more than ten, fifteen years.
[0007] It is therefore much felt the need for products that allow effective and persistent deacidification of paper, without secondary effects on the material treated.
SUMMARY
[0008] The Applicant has now found novel diazo derivatives of general formula (I) that are effective as deacidifying agents in the deacidification treatment of paper, without showing the drawbacks of the deacidification methods that have been used so far, and a process for their preparation.
[0009] Therefore subject of the present invention are the diazo derivatives of general formula (I)
[0010] wherein R′ is chosen from H and methyl, and R is the group
[0011] where n=1, 2, 3, 4, 5; and R 1 and R 2 , equal to one another, are chosen between methyl and ethyl, or R 1 and R 2 , taken together, form with N a piperidine ring or a 4-morpholine ring;
[0012] provided that, when n=2 and R″=H, R 1 and R 2 are different from methyl.
[0013] Further subject of the invention is the process for the preparation of the diazo derivatives of general formula (I)
[0014] wherein R′ is chosen from H and methyl, and R is the group
[0015] where n=1, 2, 3, 4, 5; and R 1 and R 2 , equal to one another, are chosen between methyl and ethyl, or R 1 and R 2 , taken together, form with N a piperidine ring or a 4-morpholine ring;
[0016] comprising the following steps:
[0017] a) reaction between the amine of formula (II) and ethyl chlorocarbonate of formula (III) to obtain carbamate (IV)
[0018] in which R is defined as above;
[0019] b) nitrosation of the carbamate (IV) obtained from the step a) to obtain N-nitroso-carbamate of formula (V):
[0020] wherein R is defined as above;
[0021] c) reduction of the N-nitroso-carbamate (V) obtained from step b) to obtain the desired formula (I) compound:
[0022] wherein R and R′ are defined as above.
[0023] Further subjects of this invention are the formula (IV) compounds and their N-nitroso derivatives of formula (V); and the use of the formula (I) compounds in the deacidification methods of paper material.
DETAILED DESCRIPTION OF THE INVENTION
[0024] According to a particular embodiment of the present invention, step a) of the present process is carried out at room temperature using CH 2 Cl 2 as a solvent, and with a large excess of K 2 CO 3 so as to completely neutralise the HCl that forms during the,reaction; the preferred stoichiometric ratio between amine (II), K 2 CO 3 and ethyl chlorocarbonate (III) is 1:4:3.
[0025] The reaction in step b) of the present process can be carried out at a temperature of 1-2° C. using HCl/NaNO 2 as reagent. A large excess of HCl/NaNO 2 is preferably used so as to achieve complete nitrosation of the formula (IV) product.
[0026] According to a particular embodiment of the invention, step c) of the present process is carried out at a temperature of 1-2° C. with a solution of sodium methoxide in methanol. By using a slight excess of sodium methoxide compared to the amount of the formula (V) compound, the formula (I) compound is obtained in which R′ is H, whereas with a large excess of sodium methoxide, the compound (I) is obtained in which R′ is methyl. Methanol, ethanol and Na 2 CO 3 are obtained as the only secondary reaction products.
[0027] The so obtained product is dissolved in a suitable inert stabilising solvent, preferably in diethyl ether, and the ether solution of the products is kept at a temperature of −18° C. and away from light, and it is used in this form without isolating the product.
[0028] The formula (I) compounds can be used for the deacidification of paper products according to techniques known in the art; preferably, these compounds can be used in mass deacidification techniques, where “mass deacidification techniques” means the technique described in the copending patent application in the name of the same Applicant, wherein an increase in the pH up to 9-10 of the paper material treated is obtained, and such an increase persists in time for at least 6 months. Following the treatment with compounds of general formula (I) prepared with the present process, no undesired side effects were noted, such as the formation of unpleasant odours or colouring caused by the treatment itself.
[0029] The present compound of formula (I) wherein R′ is H and R is the group
[0030] where n=1, and R 1 and R 2 , taken together, from with N a piperidine ring, has proved to be especially effective in obtaining a prolonged continuation of the basic pH obtained by the deacidification treatment.
[0031] The following examples are given to provide non-limiting illustrations of the present invention.
EXAMPLE 1
[0032] Synthesis of the Compound (III) wherein R is (1-piperidine)methyl
[0033] In a flask containing 3.9 g of K 2 CO 3 (MW=138.21, 28 mmol) 15 ml of CH 2 Cl 2 are added; the mixture is maintained under strong stirring for 10 min. at 20-25° C., and then 1 ml of 1-(2-aminoetil)piperidine (MW=128.22, d=0.899, 0.9 g, 7 mmol) is added. The mixture is kept under strong stirring at 5-6° C. for 5 min. Then 2 ml of ethyl chlorocarbonate (MW=108.52, 21 mmol) are added dropwise and the mixture is kept under strong stirring at 20-25° C. After 90 minutes the mixture is filtered onto paper to remove the non reacted K 2 CO 3 and is purified via crystallisation in diethyl ether.
[0034] 1.1 g of a white solid are obtained, that by means of GC-MS and 1 H-NMR analysis was found to be [2-(1-piperidine)ethyl]carbamate (MW=200.28, 5.5 mmol, yield=78%). The product is kept in the dark at 4° C.
EXAMPLE 2
[0035] Synthesis of the Compound (V) in which R is (1-piperidine)methyl
[0036] In a flask containing 2 ml of water, 1.7 ml of HCl 37% by weight (MW=36.46, 20 mmol) are added, and the temperature is brought up to 1-2° C. Under strong stirring, 1 g of [2-(1-piperidine)ethyl]ethylcarbamate (MW=200.28, 5 mmol) obtained as described in Example 1 is added, and 1 g of NaNO 2 (MW=69.00, 15 mmol) previously dissolved in 2 ml of water. Once the addition is completed, the reaction mixture is kept at the same temperature and under stirring for another 60 minutes, then the pH is brought to basic values by adding 15 ml of a saturated solution of Na 2 CO 3 , and the extraction with 40 ml of diethyl ether is carried out. Finally, the organic phase is dehydrated with anhydrous Na 2 SO 4 , then filtered onto paper, and the solvent is removed via distillation in a vacuum at 25° C. and away from the light.
[0037] 0.73 g of a yellow-orange oil are thus obtained, which is identified via 1 H-NMR and 13 C-NMR as N-nitroso-[2-(1-piperidine)ethyl]ethylcarbamate (MW=229.28, 3 mmol, yield=64%). The product is kept at a temperature below −18° C. and away from the light.
EXAMPLE 3
[0038] Synthesis of the Compound (I) in which R is (1-piperidine)methyl
[0039] 0.7 g of -N-nitroso-[2-(1-piperidine)ethyl]ethylcarbamate obtained as described in Example 2 are diluted with 5 ml of diethyl ether and added dropwise into a flask containing 0.2 g of sodium methoxide (MW=54.02, 4 mmol), 1 ml of diethyl ether and 1 ml of methanol; the reaction mixture is maintained under constant stirring and is kept at a temperature of 1-2° C.
[0040] Once the addition is completed, the mixture is diluted with additional 25 ml of diethyl ether, and the Na 2 CO 3 is removed by decantation. An ether solution of the desired product 2-(1-piperidine)diazoethane (MW=139.21) is thus obtained, having a concentration of 3 mmol/30 ml, i.e. 0.1 M.
[0041] This solution is kept at a temperature of −18° C. and away from the light.
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Novel diazo derivatives useful for the deacidification of paper material and the process for their preparation comprising three steps starting from an amine and ethyl chlorocarbonate, are described.
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This application is a division of application Ser. No. 709, 918, filed Mar. 8, 1985, which is now U.S. Pat. No. 4,606,401 issued Aug. 19, 1986.
FIELD OF THE INVENTION
This invention relates generally to electronic thermostats for providing temperature dependent control signals to one or more temperature modifying loads and more particularly to a digital programmable thermostat having a series of multifunction program input buttons and multimode display means, providing for fast, convenient user friendly operation of the device.
BACKGROUND OF THE INVENTION
Thermostat controlled systems for heating furnaces and/or air cooling systems (hereinafter collectively referred to as "furnaces") of the type employed in residences and many commercial and industrial buildings often include means for manually entering a desired temperature set point, means for measuring the actual temperature within the building, and means for switching the furnace on or off as a function of the difference between the set point temperature and actual temperature.
The availability of inexpensive integrated circuits incorporating large numbers of digital devices on a single semiconductor chip has led to the development of programmable electronic thermostats including means for storing a schedule of desired temperatures at specified times within a repetitive period such as a day or a week. For example, U.S. Pat. Nos. 4,206,872 and 4,314,665, disclose a thermostat for generating control signals for a furnace employing a digital memory for storing a desired temperature-time program for the thermostat for a repetitive period.
While electronic programmable thermostats enjoy both cost and reliability advantages over conventional mechanical thermostats, they are often limited in their operation and may be difficult or inconvenient for the average homeowner to program and operate.
In particular, the limited data entry means and limited displays often make it difficult for homeowners unfamiliar with simple computer device programming to successfully program the device or take advantage of all of the features offered by the device.
It is therefore an object of the present invention to provide a programmable thermostat including a display having simple, clear, graphic indications of the current mode and operable parameters, and simple, easy-to-understand program entry means to ensure efficient "user friendly" programming and operation by a typical homeowner.
It is another object of the present invention to provide a programmable thermostat including means for entering a desired temperature for the heating unit and a desired temperature for the cooling unit for each of the times in the time-temperature schedule.
It is another object of the invention to provide display means for displaying the two temperatures associated with the particular time-temperature point in a schedule as a range of temperatures, bounded at either end by the desired heating and cooling temperatures respectively.
It is yet another object of the present invention to provide an electronic programmable thermostat including means for entering an entire time-temperature schedule at one time.
SUMMARY OF THE INVENTION
The thermostat of the present invention employs means for generating an electrical signal which varies as a function of the ambient temperature on the thermostat, a clock for generating digital electrical signals representative of real time, a programmable, digital memory for retaining a schedule of times and temperature ranges for a particular repetitive time cycle, display means for indicating certain modes, time and temperature conditions during the programming and operation of the device, and control means for interrogating the current temperature range in the time-temperature schedule, determining whether the ambient temperature on the thermostat is within that range, and generating a control signal to the furnace or air conditioner when appropriate.
The device also employs a series of manual controls which, in concert with the display means, allow a user unskilled at programming digital electronic devices to program a set of time-temperature schedules, review those schedules, and/or override the scheduled temperature range at any particular time.
The display means in the preferred embodiment of the present invention may display one or more of the following parameters depending upon the current mode:
(a) a temperature range corresponding to the current temperature range in effect or corresponding to a particular selected time in the programmed schedule.
(b) the current real time or one of the programmed times in the time-temperatures schedule;
(c) the current day of the week or the day corresponding to a particular time-temperatures setting in the schedule; and
(d) a word description of the current mode.
The temperature ranges are displayed as a series of bar segments with each individual bar segment corresponding to a particular position on a preselected temperature scale. The end-most bar segments represent the lower and upper temperature limits for initiating operation of the heating and cooling units respectively. These bar segments preferably appear along one edge of the display screen.
A removable mask surrounds the display screen and includes a temperature scale with marked intervals corresponding to and in alignment with each of the bar segments on the display screen. Thus, a different temperature scale may be employed by simply removing the mask surrounding the display device and replacing it with a mask having the new scale.
The program input devices preferably take the form of a series of low cost push-buttons. In one embodiment of the invention, one button switches the device between the operating mode and one or more programming modes. A second set of one or more buttons are operable to increment the time register, and a third set of one or more buttons are operable to adjust the limits in the displayed temperature range.
Control means is provided for determining the length of time that any one of the above described buttons is being held in a depressed or "on" position, and generating a digital electrical signal which is a function of the length of time the button is being depressed. In this manner, "tapping" a button (holding it for less than a preselected time period) may cause the particular parameter affected by that button to decrement, while "holding" that button, (maintaining the button in a depressed condition for greater than a specified time period) will cause the displayed parameter affected by that button to increment. This control may also include logic which, after determining that a particular button is being "held", continues to increment the parameter affected by that button for each additional preselected time interval that the button is maintained in a depressed condition. This simple means for enabling a single push-button to perform a plurality of operations is advantageous because it reduces the number of program input components in the device and saves steps in the programming and operation of the device.
The preferred embodiment of the invention employs integrated semiconductor circuits to implement all of the digital functions including the oscillator, time base, memory and the comparators. This circuitry may take the form of one or more integrated circuit chips with interconnections to the display, the temperature sensing element, the programming input devices and the output switch. The output switch may take the form of a solid state switch or hard contact. If a solid state switch is employed it may or may not be formed as a part of the integrated circuit depending upon various economic and techincal factors. The logic circuitry in the thermostat is preferably implemented with a suitable programmed microprocessor.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which form an integral part of the specification and are to be read in conjunction therewith, and in which like reference numerals are employed to designate identical components in the various views:
FIG. 1 is a schematic diagram of the present invention;
FIG. 2 is a flow chart illustrating the preferred manner of operation of the hold/tap logic employed in the present invention;
FIG. 3 is a flow chart illustrating the preferred manner of operation of the function selector logic when the present invention is in PROGRAM mode;
FIG. 4 illustrates the preferred manner of allocating the program memory utilized in the present invention to accomodate the time-temperatures entries;
FIG. 5 is a partial front view of the face of the programmable thermostat;
FIG. 6 is a front view of the display and display mask of the thermostat when the device is in NORMAL mode; and
FIG. 7 is a front view of the display and display mask of the thermostat when the device is in PROGRAM mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the preferred embodiment of the present invention includes a stable periodic source 10 such as a stable crystal oscillator. The stable periodic source 10 may also take the form of a circuit which provides a periodically switching output using the alternating current power means as a timing source. The stable periodic source 10 should be insensitive to the ambient temperature at the thermostat over the normal operating range of the device and should output a bivalued electrical signal which periodically changes state.
The output of the stable periodic source is provided to a clock 12. The clock 12 preferably employs a dividing chain (not shown) which generates real time signals such as the type employed in digital clocks or watches. In the preferred embodiment, the clock 12 is capable of generating output signals that change state with each second, minute, hour, and day. However additional signals which change state with the month and year could be provided without departing from the spirit of the invention.
A temperature sensor 14 is provided for supplying a temperature dependent digital signal reflective of the ambient temperature on the thermostat. The temperature sensor 14 typically includes a variable frequency oscillator employing a thermally sensitive element having some electrical property that varies as a function of the ambient temperature.
Output from the clock 12 is provided to a memory scanner 16 which interrogates a programmed memory 18 to obtain the current desired temperature range from a programmed schedule of times and temperatures. The memory scanner 16 in cooperation with the schedules program controller 58 is also preferably operable to provide the current scheduled time and temperature settings to the active set time register 20 and active temperature registers 22. The active time and temperature registers 20-22 may be any suitable type of temporary storage device such as random access memory and are utilized to provide values corresponding to the current schedule time and temperatures information to various other components in the thermostat as will be described hereinafter.
A display device 24, preferably taking the form of a liquid crystal device, receives one or more binary signals from a display data selector 26 corresponding to current time, current ambient temperature, the active scheduled time and temperature range, or one of the programmed time and temperature ranges, and the current programming mode. Current time information is obtained by the display data selector 26 via input from the clock 12. The current ambient temperature information is obtained from the display data selector 26 from the temperature sensor 14. Mode information is input to the display data selector 26 from the current mode register 28, and time and temperature range information pertaining to the programmed schedule are obtained by the display data selector 26 via input from the appropriate memory locations 18, 20-22. During normal operation, the display data selector 26 provides signals to the display 24 which displays the current ambient temperature (see FIG. 6). In addition, the display data selector 26 may provide signals for the display of other of the above described information in various formats depending upon the current mode as will be described in further detail hereinafter.
Outputs of the minimum and maximum temperatures describing the current active temperature range is provided respectively to a pair of comparators 30-32. Each of the comparators 30-32 receives digital signals corresponding to the current ambient temperature from the temperature sensor 14. The comparators 30-32 each provide an output signal to a pair of outputs 34-36 which is dependent upon their respective input signals. For example, the output signal of comparator 30 may be a simple two-stage signal having one value when the actual temperature is greater than the desired temperature, and the opposite value when the actual temperature is less than the desired value. The output of comparator 32 could be a similar two-stage signal. Alternatively, the comparators 30-32 could generate a proportional output signal representative of the difference between the actual and desired temperatures, or could be modified in consideration of such factors as the lag time between the time the heater 38 or air conditioner 40 is energized and the time the temperature change actually reaches the thermostat.
It should be noted that a single comparator may be provided in place of comparators 30-32 which performs the function of determining whether the actual temperature is outside of the current programmed temperature range and outputting a signal to one of the outputs such as 34 or 36 dependent upon the results of that comparison without departing from the spirit of the present invention.
It should also be noted that additional details pertaining to the various components of the present invention as described herein and their function may be obtained by reference to either of Applicant's aforementioned patents which are incorporated herein.
Power for the circuit is preferably obtained from the source 42 by tapping across the switch contacts when they are opened, or across the series resistor (not shown) in the output circuit when the switch contacts are closed. An auxiliary power source 44 is also provided, preferably in the form of a 5-year, 1,000 hour alkaline 9-volt battery. This auxiliary power source 44 provides sufficient power to the thermostat to prevent destruction of the programmed time-temperatures schedules stored in RAM during temporary power outages and allows the user to program the thermostat prior to its installation.
Program input means in the form of a plurality of push-buttons 46-54 are provided for inputting the desired time-temperatures schedule into the program memory 18, setting the clock 12, and receiving any of the above described information on the display. Conventional, low cost push-buttons of the type used with digital watches may be employed for this purpose. In the preferred embodiment, five program input buttons labeled MODE, SLOW, FAST, HEAT, and A/C are provided.
Function selector logic 56 is connected to each of the buttons 46-54 in order to monitor their respective states (i.e. open or closed) and provide output signals to various components of the system as a function of the state of the program input buttons 46-54 and the current mode of the system, as will be described in more detail hereinafter.
It should be noted that hold/tap logic 66 is preferably provided for monitoring the state of each of the program input buttons 46-54 and providing information to the appropriate function selector module 56-64 which is dependent upon that state. In particular, the hold/tap logic 66 interrogates the condition of each of the program input buttons 46-54 to determine if any one of the buttons is in a depressed position. If one of the program input buttons 46-54 is found to be in a depressed position, the hold/tap logic outputs one of two signals to the appropriate input button function selector 56-64 which is a function of the duration of time that that button remains in the depressed position.
Referring now to FIG. 2, the hold/tap logic 66 in the preferred embodiment interrogates each of the program input buttons 46-54 to determine if one of them is in the depressed position. If one of the buttons is found to be in the depressed position a period of time is counted, preferably 0.25 seconds and that button is then again interrogated. If the button is no longer in the depressed position, the logic sends a signal to the function selector logic for that button which indicates that the button has been "tapped." If the button is still in the depressed position after the initial 0.25 second count, an additional 0.75 seconds is counted and a "hold" signal is sent to the appropriate function selector logic. Another second is counted and that same button is interrogated and a "hold" signal is issued for each additional second that the button is found to have remained in the depressed position. In this manner, each of the buttons can perform a specific operation when tapped and a different operation when held. In the preferred embodiment the function affected by the particular program input button 46-54 is decremented one unit each time the button is tapped and is incremented for one unit for each second that it is held.
FIG. 3 is a flow chart illustrating the operation of the function selector logic 56 when the thermostat is in PROGRAM mode. In this mode, the function selector logic 56 will output a signal to the schedules program controller 58 to increment the displayed time by 30 minutes for each second that the SLOW button 48 is held and decrement the displayed time by 30 minutes for each time that the SLOW button 48 is tapped. Similarly, the function selector logic 56 will adjust the lower temperature limit in the displayed range when the HEAT button 52 is depressed, and adjust the upper temperature limit in the displayed temperature range when the A/C button 54 is depressed. Thus, by operating the SLOW, HEAT, and A/C buttons 48,52,54 in PROGRAM mode, a particular time and temperature range may be displayed.
Additional time-temperature ranges may be programmed by depressing the SLOW button 48 to change this displayed time and subsequently adjusting the temperature range associated with that time by operation of the HEAT and A/C buttons 52,54. Each of the time-temperatures input during the programming stage are stored by the scheduled program controller 58 in a temporary buffer 60. The user may review any of the time-temperatures by depressing the FAST button 50. In PROGRAM mode, this button can be tapped or held to display the previous or subsequent time-temperatures entries in the schedule respectively. Thus, by maintaining the fast button 50 depressed, the user can quickly review all of the time-temperature entries that have been programmed in a rapid and convenient manner. The time-temperature settings may be stored into program memory 18 by the user by tapping the MODE button 46.
In the preferred embodiment, six different times and corresponding heat/cooling temperatures can be entered for a particular one-day schedule. When the MODE button 46 is tapped, the schedules program controller 58 causes the initial time-temperatures schedule to be automatically entered into all seven days of the program memory 18. Once the initial schedule is entered into program memory 18 for the entire cycle (seven days), time-temperatures entries may be added, deleted, or changed for any particular day of the week.
If a particular time-temperatures entry is to be added to a particular day, the FAST, SLOW, HEAT, and A/C buttons may be operated in the above described fashion to change the display to reflect the time-temperatures entry desired. This new displayed time-temperatures entry is automatically stored by the schedules program controller 58 in the program memory 18 for that particular day and time.
A particular time-temperatures entry may be deleted from program memory 18 by the schedules program controller 58 by holding either the HEAT and A/C buttons until the line of segments defining the range appearing on the display all disappear.
A particular time-temperatures setting may be changed in program, memory 18 by the schedules program controller 58 by operating the FAST button until that time-temperatures setting is displayed and subsequently altering the temperature range by operation of the HEAT and A/C buttons.
The preferred embodiment has WAITING, SET CLOCK, HOLD, and HOLD UNTIL modes in addition to the PROGRAM and normal operating modes. The MODE button 46 displays each of the last five modes when it is held in a depressed position. To enter any one of these modes, the MODE button 46 should be depressed until the desired mode is displayed and then released. It should be noted that the function selector logic 56 is operable to monitor the program input buttons 46-54 and provide signals to the appropriate system component depending on the current mode. It will be understood by those skilled in the art that the described operation of the various program input buttons 46-54 in each of the described modes is accomplished by suitably programming the function selector logic 56 to perform the described functions.
In the SET CLOCK mode, the FAST and SLOW buttons 48,40 may be utilized to set the real time clock 12 on the thermostat. The FAST button causes the display data selector 26 to increment or to decrement the displayed time in four hour steps. The SLOW button similarly increments or decrements the displayed time in ten minute steps. When the correct real time is shown on the display, the MODE button should be tapped to store the displayed time in the system clock 12.
HOLD mode allows the user to suspend the programmed time-temperatures schedule and hold the thermostat in a specified temperature range until further notice. To program this feature, the user holds the MODE button 46 until the word HOLD is displayed. The HEAT and/or A/C buttons may then be operated to display the held temperature range. When in this mode, the display data selector 26 causes the display 24 to show the HOLD temperature range and the words PROGRAM HOLD. The schedules program logic 58 then causes the HOLD temperature range to replace the active registers 20-22. To end HOLD mode and resume the programmed time-temperatures settings, the user may depress the MODE button 46 until the words PROGRAM HOLD disappear. At this point, the schedules program logic 58 causes the appropriate scheduled time-temperatures entry to be loaded into the active registers 20-22.
The MODE button 46 may also be depressed to display HOLD UNTIL. This mode allows the user to enter a particular temperature range by operation of the HEAT and A/C buttons 52,54. The FAST button 50 is operated to select the future time-temperatures set point where the user wants to resume the programmed schedule. The MODE button may then be tapped to display the current room temperature and the words HOLD UNTIL. The schedules program controller will store the HOLD UNTIL entries in the active regularly programmed schedule registers 20-22 until the indicated future time temperatures set point is scheduled to become active. At this time the logic will load these into the active registers 20-22 and HOLD UNTIL will then disappear from the display 24.
If the user attempts to manually program the thermostat to start the air conditioner during the period immediately following a power shutdown, the word WAITING will appear on the display 24 to indicate that the thermostat is in waiting mode, and will remain displayed until the six-minute waiting period has elasped.
In this mode, the thermostat will not allow the air conditioner to be restarted for six minutes after it has been shut-off. Since some of the liquid in the compressor may have vaporized during the power failure, this automatic six-minute delay allows for that vapor to return to the liquid state, thereby insuring that the compressor pump will be pumping liquid when the air conditioning unit is restarted after the six-minute delay.
The logic necessary to implement the programming and operation of each of the above described modes has been illustrated as function selector logic 56, hold tap logic 66, schedules program controller 58, memory scanner 16, and display data selector 26. The means for performing these functions is a combination of simple hardware logic devices and/or micro code which may be duplicated by one skilled in the art to perform the above described functions.
Referring to FIG. 4, the program memory 18 of the present invention is allocated in an efficient manner allowing for a relatively large number of time-temperatures entries and temperature ranges to be programmed into a relatively small amount of memory. The portion of program memory 18 allocated for the time-temperatures schedule consists of seven blocks. Each of the seven blocks contains six 9-bit words with each word corresponding to a particular time-temperatures entry. Each of the blocks 70 corresponds to a day in the week. Each of the words 72 is a particular time-temperatures entry. Thus, the preferred embodiment allows for six time-temperatures entries for each of seven days of the week or forty-two entries.
Since the time entries may be at half hour increments, there are forty-eight different times identifiable for each day. The first six bits 74 of each word are utilized to indicate which of the forty-eight times has been programmed for this entry. The last three bits indicate which of eight different temperature ranges are associated with this time entry. These three bits correspond to an address in a 64-bit temperature range table consisting of eight 8-bit words each corresponding to a particular temperature range. Each of the upper and lower temperatures defining the range may be any one of the sixteen possible temperature values, so 4 bits are allocated for each of the temperatures. The temperature range for a particular time-temperatures entry is then indicated in the word corresponding to that entry by 3 bits which identify the address of the range found in the temperature range table 80. Since 3 bits rather than 8 bits is used for each of the words 72 in the time-temperatures entry table 71, the memory requirements for the system have been reduced by about 25% or a total of 146 bits.
Referring to FIG. 5, the face 82 of the thermostat includes a display device 24 and a display mask 86. As previously described, the display 24 is preferably a liquid crystal device. The temperature range is displayed as an energized linear segment, preferably a series of discrete bars 88 spaced side-by-side in a linear fashion, across one edge of the display 24. To display a particular temperature pair, the indicia corresponding to each of the temperatures, as well as all those temperature settings therebetween, are energized in contrasting color to the remaining temperatures indica along the scale. A selected temperature scale 90 is marked along the adjoining edge of the mask 86 and contains markings corresponding to each of the segments 88 on the display 24 which indicate the temperature value of each of the segments on the scale. In the preferred embodiment, the mask 86 is removably secured to the face 82 of the thermostat so that a mask employing a different temperature scale may be easily substituted in the device. As will be appreciated by those skilled in the art of human factors design, the temperature bar display format of the present invention provides the user with an instant impact relating to the operating range resulting from the selected temperature pair.
A second series of indicia in the form of discrete energizable markings or segments 92, corresponding to each of the seven days of the week is preferably located along a different edge of the display 24. A second scale corresponding to these segments is marked along the edge of the mask 86 adjacent to the edge of the screen 24 containing the segments and preferably includes letters 92 corresponding to abbreviations for each day of the week. Again it should be noted that abbreviations for days of the week in different languages may be substituted by simply removing the mask 86 surrounding the display 24 from the face 82 of the thermostat. A twelve hour digital display and A.M. and P.M. designations 96 are provided for displaying either the real time or a time corresponding to a particular time-temperatures entry. Lastly, the words "SET CLOCK", "PROGRAM", "HOLD UNTIL", and "WAITING" are also displayed, depending on the current mode.
While FIG. 5 shows all of the information that may be displayed on the face 82 of the thermostat, in the preferred format only selected portions of the information are provided to the display 24 by the display data selector 26 in any particular mode. As shown in FIG. 6, indicia in the form of an energizable segment corresponding to the current temperature is the only information displayed in the normal operating mode of the device. FIG. 7 shows the information displayed while in PROGRAM mode. This information includes the temperature range 100 corresponding to one of the time-temperatures entries, the time 102 including the day 104 for that time-temperatures entry, and the word PROGRAM indicating that the device is currently in PROGRAM mode.
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The present invention is an apparatus and method for bidirectional alteration of a multivalue parameter from an initial value using a two-state manual input. In accordance with the present invention, the multivalue parameter is altered from its initial value in a first direction if the manual input is in a preselected state for less than a predetermined period of time. If the manual input is in the preselected state for a period of time longer than this first interval of time, then the multivalue parameter is altered from its initial value in the opposite direction. Additionally, if the manual input remains in the preselected state for additional periods of time, the value of the multivalue parameter is further altered in the opposite direction for each such additional interval. This invention is taught as useful in providing programs for programmable memory devices, in particular programmable thermostats.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present disclosure is related to U.S. patent application Ser. No. 14/137,277, entitled “Suture Passer with Tissue Reinforcement Positioner”, filed Dec. 20, 2013. The entire disclosure of the application referenced above is incorporated herein by reference.
FIELD
The present disclosure relates to a suture passer with tissue reinforcement positioner.
BACKGROUND
This section provides background information related to the present disclosure which is not necessarily prior art.
Various devices and methods are known for suturing soft tissue in connection with arthroscopic, endoscopic, or other surgical procedures. These and other small-incision or less invasive surgical procedures generally require that suturing and the associated manipulation of suturing are performed in confined areas which are not easily accessible.
Although the existing devices can be satisfactory for their intended purposes, there is still a need for procedures and devices that provide greater control in the passage of sutures, greater control in the passage of delicate sutures, and increased flexibility in the types and thicknesses of tissues that can be sutured in ordinary and in less invasive procedures.
SUMMARY
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
The present disclosure describes a suture passer device that includes a handle, a shaft extending from the handle, a suture carrier secured to the handle and extending through the shaft, and a suturing head extending from the shaft and configured to retain tissue. The handle is operable to advance the suture carrier through the suturing head to pass a suture through tissue retained in the suturing head. According to one aspect of the present disclosure, the suture passer device includes a quick-connect mechanism releasably connecting the shaft to the handle. According to another aspect of the present disclosure, the shaft includes a first shaft and a second shaft pivotally coupled to the first shaft, and the first shaft defines a first channel for receiving the second shaft. Methods of disassembling a suture passer device are also described.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
FIG. 1 is a side view of a suture passer device according to the principles of the present disclosure;
FIG. 2 is an exploded isometric view of the suture passer device shown in FIG. 1 ;
FIG. 3A is an isometric view of a suturing head of the suture passer device with an upper jaw in an open position and a suture carrier in a retracted position;
FIG. 3B is a section view taken along line 3 B shown in FIG. 3A ;
FIG. 4A is an isometric view of the suturing head with the upper jaw in a closed position and the suture carrier in an extended position;
FIG. 4B is a section view taken along line 4 B shown in FIG. 4A ;
FIG. 5 is an isometric view of a handle assembly of the suture passer device with a trigger and a rear handle in released positions;
FIG. 6 is a side view of the handle assembly with the trigger and the rear handle in applied positions;
FIG. 7 is an isometric view of a proximal end of a shaft assembly of the suture passer device disconnected from a distal end of the handle assembly;
FIG. 8 is a side view of the proximal end of the shaft assembly connected to the distal end of the handle assembly;
FIG. 9 is a side view of an alternative embodiment of the shaft assembly and the handle assembly with a proximal end of the shaft assembly disconnected from a distal end of the handle assembly;
FIG. 10 is a side view of the alternative embodiment of the shaft assembly and the handle assembly with the proximal end of the shaft assembly connected to the distal end of the handle assembly;
FIG. 11 is an isometric view of the proximal end of the shaft assembly with an inner shaft inserted into an outer shaft;
FIG. 12 is an isometric view of a proximal end of a shaft assembly with the inner shaft removed from the outer shaft;
FIG. 13 is an isometric view of the suturing head with the upper jaw in the open position and positioning a tissue reinforcement construct, the suture carrier in the retracted position, a suture extending through a lower jaw, and soft tissue disposed between the lower jaw and the upper jaw;
FIG. 14 is an isometric view of the suturing head in the closed position, the soft tissue being held between the upper and lower jaws, and the suture carrier in the extended position and passing a portion of the suture through the soft tissue and the tissue reinforcement construct;
FIG. 15A is an end view of the suturing head passing two portions of a suture through soft tissue and the tissue reinforcement construct, the suture extending through a suture anchor secured in a hole in bone;
FIG. 15B is an end view of the two portions of the suture tied in a knot to form an adjustable loop that secures the soft tissue to the bone;
FIG. 16A is an end view of the suturing head passing adjustable loops of a suture construct through soft tissue and the tissue reinforcement construct, the suture construct extending through a suture anchor secured in a hole in bone, and a locking member position adjacent to the loops;
FIG. 16B is an end view of the locking member extending through the loops and preventing the loops from being pulled through the soft tissue and the tissue reinforcement member as the loops are tightened;
FIG. 17A is an isometric view of the suturing head with the upper jaw in the open position and positioning a tissue reinforcement construct, the suture carrier in the retracted position, and a first end of a flexible suture anchor of a suture construct extending through the lower jaw;
FIG. 17B is an isometric view of the suturing head in the closed position, the soft tissue being held between the upper and lower jaws, and the suture carrier in the extended position and passing the first end of the flexible suture anchor through the soft tissue and the tissue reinforcement construct;
FIG. 17C is an isometric view of a plurality of suture constructs extending through soft tissue and the tissue reinforcement construct, with the suturing head passing a portion of one of the suture constructs through the soft tissue and the tissue reinforcement construct as illustrated in FIG. 17B ;
FIG. 18A is an isometric view similar to that shown in FIG. 13 but illustrating an alternative embodiment of a suturing head having teeth for positioning the tissue reinforcement construct instead of a slot; and
FIG. 18B is a side view similar to that shown in FIG. 14 but illustrating the alternative embodiment of the suturing head.
FIG. 19A is an isometric view similar to that shown in FIG. 13 but illustrating a second alternative embodiment of a suturing head for positioning the tissue reinforcement construct instead of a slot; and
FIG. 19B is a side view similar to that shown in FIG. 14 but illustrating a second alternative embodiment of the suturing head.
FIG. 20A is an isometric view similar to that shown in FIG. 13 but illustrating a third alternative embodiment of a suturing head having teeth for positioning the tissue reinforcement construct instead of a slot; and
FIG. 20B is a side view similar to that shown in FIG. 14 but illustrating a third alternative embodiment of the suturing head.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
Example embodiments will now be described more fully with reference to the accompanying drawings.
Referring now to FIGS. 1, 2, 3A, 3B, 4A, and 4B , a suture passer device 10 includes a handle assembly 12 , a suture carrier 14 , a shaft assembly 16 , and a suturing head 18 . The handle assembly 12 includes a front handle 20 , a rear handle 22 , a trigger 24 , and a handle spring 26 . The shaft assembly 16 includes an outer shaft 28 , an inner shaft 30 , a shaft spring 32 , and a washer 34 . The spring 32 and the washer 34 can be welded to the inner shaft 30 . The suturing head 18 includes an upper jaw 36 and a lower jaw 38 . The handle assembly 12 is operable to actuate the upper jaw 36 of the suturing head 18 from an open position ( FIG. 3 ) to a closed position ( FIG. 4 ) in order to clamp or engage soft tissue between the upper and lower jaws 36 , 38 . The handle assembly 12 is also operable to actuate the suture carrier 14 from a retracted position ( FIG. 3 ) to an extended position ( FIG. 4 ) to pass a suture 40 through soft tissue that is clamped or held between the upper and lower jaws 36 , 38 .
The suture carrier 14 includes a proximal body 42 having a round plinth, disk, or hockey puck shape, a cylindrical body 44 , and a flat, elongate body 45 . The proximal body 42 is disposed at the proximal end of the suture carrier 14 and is configured to be retained within a pocket 46 in the rear handle 22 . The cylindrical body 44 is attached to the proximal body 42 and extends from the proximal body 42 to the elongate body 45 . The elongate body 45 is attached to the cylindrical body 44 using, for example, a weld 47 , and extends from the cylindrical body 44 to the distal end of the suture carrier 14 . The elongate body 45 has a notch 48 adjacent to its distal end for holding the suture 40 and a pointed tip 50 at its distal end for piercing a hole in soft tissue so that the suture carrier 14 and the suture 40 can be passed through the tissue. The proximal body 42 can be made from plastic, and the cylindrical and elongate bodies 44 , 45 can be made from a flexible material such as Nitinol or a flexible polymer.
With particular reference to FIGS. 3A, 3B, 4A, and 4B , the upper jaw 36 of the suturing head 18 includes teeth 52 , a tissue reinforcement member holder 54 , a suture carrier receptacle 56 , and a suture retaining mechanism 58 . The teeth 52 are configured to bite into or grip soft tissue when the upper jaw 36 is in the closed position. The tissue reinforcement member holder 54 is configured to position a tissue reinforcement member 60 ( FIGS. 13 and 14 ) so that the suture carrier 14 and the suture 40 pass through the tissue reinforcement member 60 after passing through soft tissue held between the upper and lower jaws 36 , 38 . In various implementations, the tissue reinforcement member holder 54 can also or alternatively be included in the lower jaw 38 .
The tissue reinforcement member holder 54 can be a slot 61 having open lateral sides 61 a , 61 b , an open distal end 61 c , and a closed proximal end 61 d . The tissue reinforcement member 60 can be inserted into the slot 61 . In turn, the slot 61 can hold the tissue reinforcement member 60 while allowing the tissue reinforcement member 60 to be slidably adjustable in a lateral direction through the open sides 61 a , 61 b.
The tissue reinforcement member 60 can be made from a flexible material such as woven, knitted, or braided polyester tape or a non-woven or non-braided material (such as felt), collagen fiber, or other reinforcement member. The tissue reinforcement member 60 is configured to increase the strength of a repair by reinforcing soft tissue. For example, a portion of the suture 40 may be passed through soft tissue and tied in a knot, and the tissue reinforcement member 60 may increase the force required to pull the knot through the soft tissue. The tissue reinforcement member 60 can be one of the example locking members described in U.S. Pat. Pub. No. 2011/0208240 (see, e.g., FIGS. 4 through 9), the disclosure of which is incorporated herein by reference in its entirety. The tissue reinforcement member 60 can be a mesh such as a SportMesh™ Soft Tissue Reinforcement, available from Arthrotek®, a Biomet® company of Warsaw, Ind.
The suture carrier receptacle 56 can be an opening in the upper jaw 36 . The suture carrier receptacle 56 can extend through portions of the upper jaw 36 disposed above and below the slot 61 . The suture carrier 14 and the suture 40 can be passed through the suture carrier receptacle 56 after passing through soft tissue held between the upper and lower jaws 36 , 38 .
The suture retaining mechanism 58 prevents unintentional movement of the suture 40 out of the upper jaw 36 by maintaining the suture 40 at or near the suturing head 18 . In one embodiment, the suture retaining mechanism 58 can be a flap 62 that fits over the suture carrier receptacle 56 . The flap 62 can be made of a resilient and flexible material, such as spring steel, Nitinol, or a flexible polymer. The suture carrier 14 can be passed into the receptacle 56 , temporarily disrupting a suture engaging portion 64 of the flap 62 from a closed position in contact with the upper jaw 36 to an open position spaced apart from the upper jaw 36 . In turn, the flap 62 can pull the suture 40 through soft tissue held between the upper and lower jaws 36 , 38 . The suture carrier 14 can then be retracted through the suture carrier receptacle 56 , allowing the suture engaging portion 64 to return to the closed position. In turn, the flap 62 biases the suture 40 against the receptacle 56 to prevent the suture 40 from being pulled back through the receptacle 56 .
The upper jaw 36 can be rotatably or pivotally coupled to the outer shaft 28 of the shaft assembly 16 using a pin 80 , and the lower jaw 38 of the suturing head 18 can be integrally formed with the outer shaft 28 . The shaft assembly 16 and the suturing head 18 can be made from metal. The lower jaw 38 can include a suture carrier channel 82 and a suture receptacle 84 . The suture carrier channel 82 can guide the suture carrier 14 as the suture carrier 14 is advanced and retracted through the lower jaw 38 . The suture carrier channel 82 includes a ramped portion 86 that directs the suture carrier 14 through the suture carrier receptacle 56 in the upper jaw 36 . The suture receptacle 84 can be an opening or slot formed into the lower jaw 38 . The suture 40 can be passed through the receptacle 84 before being received in the notch 48 in the suture carrier 14 .
With particular reference to FIGS. 3B and 4B , the inner shaft 30 can also be rotatably or pivotally coupled to the outer shaft 28 using the pin 80 . The inner shaft 30 can define an elongate slot 88 , and the pin 80 can extend through the slot 88 . The slot 88 allows the inner shaft 30 to move distally or proximally relative to the outer shaft 28 . The length of the slot 88 can correspond to the amount of longitudinal movement of the inner shaft 30 required to actuate the upper jaw 36 between the open position and the closed position.
The upper jaw 36 can be rotatably or pivotally coupled to the inner shaft 30 using a pin 90 . Thus, as the inner shaft 30 axially moves distally relative to the outer shaft 28 , the upper jaw 36 rotates or pivots from the open position to the closed position. In this regard, the connections at the pins 80 , 90 convert linear movement of the inner shaft 30 into rotational movement of the upper jaw 36 .
Referring now to FIGS. 5 and 6 , the trigger 24 of the handle assembly 12 can be actuated from a released position ( FIG. 5 ) to an applied position ( FIG. 6 ) in order to actuate the upper jaw 36 from the open position to the closed position. In this regard, the trigger 24 can be rotatably or pivotally coupled to the front handle 20 using a pin 100 , and the trigger 24 can include a hammer portion 102 that is received within a slot 104 ( FIG. 2 ) in the inner shaft 30 . As the trigger 24 is actuated from the released position to the applied position, the hammer portion 102 pushes the inner shaft 30 distally relative to the outer shaft 28 . Then, as discussed above, the distal movement of the inner shaft 30 causes the upper jaw 36 to rotate or pivot from the open position to the closed position.
The shaft spring 32 can be captured between a proximal end 106 of the outer shaft 28 and the washer 34 . The washer 34 can define a slot 108 ( FIG. 2 ) configured to receive the inner shaft 30 . The width of the slot 108 can be less than the width of the inner shaft 30 to yield a press fit between the washer 34 and the inner shaft 30 that fixes the washer 34 onto the inner shaft 30 . Thus, when the trigger 24 is released, the biasing force of the shaft spring 32 acting on the washer 34 axially moves the inner shaft 30 proximally. Since the hammer portion 102 of the trigger 24 is received within the slot 104 in the inner shaft 30 , the proximal movement of the inner shaft 30 moves the hammer portion 102 proximally and returns the trigger 24 to the released position.
The rear handle 22 can be actuated from a released position ( FIG. 5 ) to an applied position ( FIG. 6 ) in order to actuate the suture carrier 14 from the retracted position to the extended position. In this regard, the rear handle 22 can be rotatably or pivotally coupled to the front handle 20 using a pin 110 , and the handle spring 26 can bias the rear handle 22 toward the released position. As the rear handle 22 is actuated from the released position to the applied position, the engagement between the proximal body 42 of the suture carrier 14 and the rear handle 22 moves the suture carrier 14 from the retracted position to the extended position.
The handle spring 26 can be a leaf spring and the shaft spring 32 can be a coil spring, as shown. Alternatively, both the handle spring 26 and the shaft spring 32 can be coil springs. In various embodiments, the spring rate of the handle spring 26 is less than the spring rate of the shaft spring 32 . Thus, if the rear handle 22 and the trigger 24 are applied at the same time, the upper jaw 36 rotates or pivots to the closed position before the suture carrier 14 advances to the extended position. This facilitates clamping soft tissue between the upper and lower jaws 36 , 38 before passing the suture carrier 14 and the suture 40 through the soft tissue.
Referring again to FIGS. 1 and 2 , a proximal end 112 of the shaft assembly 16 can be easily disconnected from a distal end 114 of the handle assembly 12 , and the outer shaft 28 can be rotated or pivoted away from the inner shaft 30 . This facilitates cleaning, disinfecting, and sterilizing the suture passer device 10 . In various implementations, the front handle 20 , the rear handle 22 , and the trigger 24 can be made from plastic. In these implementations, after a surgery, the shaft assembly 16 can be disconnected from the handle assembly 12 , and the handle assembly 12 can be discarded.
Referring now to FIGS. 7 and 8 , the proximal end 112 of the shaft assembly 16 can be inserted into a cylindrical channel 120 in the front handle 20 and releasably connected to the handle assembly 12 using a quick-connect mechanism such as a bayonet mount. In this regard, the outer shaft 28 can define a pair of J-shaped slots 122 (only one shown) disposed on opposite sides of the outer shaft 28 , and the front handle 20 can include pins 124 extending into the cylindrical channel 120 . To connect the shaft assembly 16 to the handle assembly 12 , the open ends 126 of the J-shaped slots 122 can be aligned with the pins 124 . The proximal end 112 of the shaft assembly 16 can then be inserted into the cylindrical channel 120 until the pins 124 contact radial surfaces 128 of the J-shaped slots 122 . The shaft assembly 16 can then be rotated relative to the handle assembly 12 until the pins 124 contact closed ends 130 of the J-shaped slots 122 .
As discussed above, the shaft spring 32 may be captured between the proximal end 106 of the outer shaft 28 and the washer 34 . The biasing force of the shaft spring 32 may urge the outer shaft 28 distally, thereby engaging the pins 124 with the closed ends 130 of the J-shaped slots 122 . Thus, to disconnect the shaft assembly 16 from the handle assembly 12 , the outer shaft 28 can be moved by hand further into the cylindrical channel 120 to overcome the biasing force of the shaft spring 32 and disengage the pins 124 from the closed ends 130 of the J-shaped slots 122 . The shaft assembly 16 can then be rotated relative to the handle assembly 12 until the pins 124 contact longitudinal surfaces 132 of the J-shaped slots 122 . The proximal end 112 of the shaft assembly 16 can then be withdrawn from the cylindrical channel 120 .
Referring to FIGS. 9 and 10 , an alternative embodiment of a releasable connection between the shaft assembly 16 and the handle assembly 12 is illustrated. In this embodiment, the proximal end 112 of the shaft assembly 16 includes pins 134 (only one shown) disposed on opposite sides thereof, and the distal end 114 of the handle assembly 12 defines L-shaped slots 136 . To connect the shaft assembly 16 to the handle assembly 12 , the pins 134 are aligned with open ends 138 of the L-shaped slots 136 . The proximal end 112 of the shaft assembly 16 can then be inserted into the cylindrical channel 120 until the pins 134 contact radial surfaces 140 of the L-shaped slots 136 . The shaft assembly 16 can then be rotated relative to the handle assembly 12 until the pins 134 contact closed ends 142 of the L-shaped slots 136 . Although not shown in FIGS. 9 and 10 , the shaft spring 32 may bias the outer shaft 28 distally, thereby maintaining the engagement between the pins 134 and the closed ends 142 of the L-shaped slots 136 .
To disconnect the shaft assembly 16 from the handle assembly 12 , the shaft assembly 16 can be rotated relative to the handle assembly 12 until the pins 134 contact longitudinal surfaces 144 of the L-shaped slots 136 . The proximal end 112 of the shaft assembly 16 can then be withdrawn from the cylindrical channel 120 in the front handle 20 . Although not shown in FIGS. 9 and 10 , the shaft spring 32 may bias the outer shaft 28 distally, thereby forcing the proximal end 112 of the shaft assembly 16 out of the cylindrical channel 120 in the front handle 20 .
Referring now to FIGS. 11 and 12 , the proximal end 112 of the shaft assembly 16 is illustrated with the inner shaft 30 inserted into the outer shaft 28 ( FIG. 11 ) and the inner shaft 30 rotated or pivoted away from the outer shaft 28 ( FIG. 12 ). The embodiment shown in FIGS. 11 and 12 is the same embodiment that is shown in FIGS. 7 and 8 with the J-shaped slots 122 defined in the outer shaft 28 near the proximal end 112 of the shaft assembly 16 . The outer shaft 28 can also define a U-shaped channel 150 that is configured to receive the inner shaft 30 . The inner shaft 30 can also define a U-shaped channel 152 . When the inner shaft 30 is inserted into the U-shaped channel 150 in the outer shaft 28 , the U-shaped channels 150 , 152 can cooperate to define a fully enclosed channel for guiding the suture carrier 14 . The ability to pivot the inner shaft 30 away from the outer shaft 28 exposes interior features, such as the U-shaped channels 150 , 152 , and makes it easier to disassemble and assemble components of the shaft assembly 16 . In turn, the shaft assembly 16 can be easily cleaned, disinfected, and sterilized.
As discussed above, the shaft spring 32 may be captured between the proximal end 106 of the outer shaft 28 and the washer 34 . Thus, when the shaft assembly 16 is disconnected from the handle assembly 12 , the biasing force of the shaft spring 32 can hold the inner shaft 30 in the U-shaped channel 150 of the outer shaft 28 , as shown in FIG. 11 . However, the proximal end 106 of the outer shaft 28 may be pulled upward by hand to rotate the outer shaft 28 away from the inner shaft 30 . When the outer shaft 28 is rotated away from the inner shaft 30 , as shown in FIG. 12 , the shaft spring 32 is allowed to relax. Thus, before rotating the outer shaft 28 back toward the inner shaft 30 , the shaft spring 32 may be compressed by hand to avoid interference between the shaft spring 32 and the U-shaped channel 150 in the outer shaft 28 .
Referring now to FIGS. 13 and 14 , the suture passer 10 is illustrated with the tissue reinforcement member 60 positioned or slidably received in the slot 61 in the upper jaw 36 , and soft tissue 160 positioned between the upper and lower jaws 36 , 38 . The slot 61 in the upper jaw 36 of the suture passer 10 can aid in the positioning of the tissue reinforcement member 60 before, during, and after passing the suture 40 through the soft tissue 160 . The suture passer 10 can be used to pass the suture 40 through the soft tissue 160 and the tissue reinforcement member 60 substantially simultaneously. For example, using only one hand placed on the handle assembly 12 , the suture carrier 14 can be advanced to pass the suture 40 through the soft tissue 160 and the tissue reinforcement member 60 in a single, continuous operation or motion. In addition, using only the suture passer 10 , the tissue reinforcement member 60 can be positioned in the path of the suture carrier 14 , and the suture carrier 14 can be advanced to pass the suture 40 through the soft tissue 160 and the tissue reinforcement member 60 . Thus, a second instrument is not required to hold the tissue reinforcement member 60 . Since the suture passer 10 accomplishes the functions of multiple tools while requiring minimal space, the suture passer 10 can be used in an arthroscopic surgery or an open surgery.
In an example method of using the suture passer 10 , the reinforcement member 60 is slidably inserted into the slot 61 in the upper jaw 36 , and the suture 40 is inserted into the suture receptacle 84 in the lower jaw 38 , as shown in FIG. 13 . The upper jaw 36 is then closed to clamp and retain the soft tissue 160 between the upper and lower jaws 36 , 38 while simultaneously positioning the tissue reinforcement member 60 . The suture carrier 14 is then advanced through the suture carrier channel 82 in the lower jaw 38 and the receptacle 56 in the upper jaw 36 . As the suture carrier 14 advances through the lower jaw 38 , the notch 48 in the suture carrier 14 catches the suture 40 . Thus, as the suture carrier 14 advances through the receptacle 56 in the upper jaw 36 , the suture carrier 14 passes the suture 40 through both the soft tissue 160 and the tissue reinforcement member 60 substantially simultaneously, as shown in FIG. 14 . The suture carrier 14 passes the suture 40 from a first side 160 a of the soft tissue 160 to a second side 160 b of the soft tissue 160 . As the suture carrier 14 retracts through the receptacle 56 in the upper jaw 36 , the suture retention mechanism 58 prevents the suture 40 from retracting with the suture carrier 14 and maintains the suture 40 on the second side 160 b of the soft tissue 160 .
Referring now to FIGS. 15A and 15B , an example method of using the suture passer 10 and the suture 40 to attach the soft tissue 160 to bone 162 is illustrated. First, a suture anchor 164 can be secured within a hole 166 formed in the bone 162 . The suture anchor 164 can be a hard, rigid anchor or a soft, deformable anchor. The hole 166 can be pre-formed or formed by external threads 168 on the anchor 164 . The suture 40 can be passed through a hole 170 in the anchor 164 before or after the anchor 164 is secured to the bone 162 .
The tissue reinforcement member 60 can then be inserted into the slot 61 in the upper jaw 36 of the suture passer 10 , and a first end 172 of the suture 40 can be inserted into the suture receptacle 84 in the lower jaw 38 . The upper jaw 36 can then be closed to clamp or retain the soft tissue 160 between the upper and lower jaws 36 , 38 . The suture carrier 14 can then be advanced to pass the first end 172 of the suture 40 through both the soft tissue 160 and the tissue reinforcement member 60 substantially simultaneously. The suture carrier 14 can then be retracted.
The suture passer 10 can then be moved along the length of tissue reinforcement member 60 in a direction X without removing the member 60 from the slot 61 in the upper jaw 36 since the slot 61 has the open sides 61 a , 61 b . The suture passer 10 can then be used to pass a second end 174 of the suture 40 through the soft tissue 160 and the tissue reinforcement member 60 . After the first and second ends 172 , 174 of the suture 40 are passed through the soft tissue 160 and the tissue reinforcement member 60 , the first and second ends 172 , 174 can be tied in a slip knot 176 to form an adjustable loop 178 . The size of the loop 178 can be decreased to bring the soft tissue 160 closer to the bone 162 . The tissue reinforcement member 60 prevents the knot 176 and the suture 40 from being pulled through the soft tissue 160 while the suture 40 is under tension.
Referring now to FIGS. 16A and 16B , an example method of using the suture passer 10 and a suture construct 180 to attach the soft tissue 160 to bone 162 is illustrated. First, the suture construct 180 can be passed through the hole 170 in the suture anchor 164 , and the anchor 164 can be secured within the hole 166 in the bone 162 . The suture construct 180 can be formed of a monofilament, a braided fiber or strand, or other flexible material. The suture construct 180 can include a first end 182 , a second end 184 , a first adjustable loop 186 , a second adjustable loop 188 , and a braided body 200 . The braided body 200 of the suture construct 180 can define a longitudinal passage 202 extending between a first opening 204 and a second opening 206 .
The first and second ends 182 , 184 and the braided body 200 can be integrally formed as a single braided construct using a braiding process for braiding fibers composed of a biocompatible material. The openings 204 , 206 can be created during the braiding process as loose portions between pairs of fibers. The longitudinal passage 202 can be a portion of a longitudinal passage that extends along the entire length of the suture construct 180 .
Before forming the adjustable loops 186 , 188 , the braided body 200 can be positioned within the hole 170 in the anchor 164 . The first adjustable loop 186 can then be formed by passing the first end 182 through the longitudinal passage 202 in the direction from the second opening 206 to the first opening 204 . Similarly, the second adjustable loop 188 can be formed by passing the second end 184 through the longitudinal passage 202 in the direction from the first opening 204 to the second opening 206 .
A second suture anchor 164 ′ can also be secured within a hole 166 ′ in the bone 162 , and a suture construct 180 ′ can be passed through a hole 170 ′ in the anchor 164 ′ and arranged to form two adjustable loops 186 ′, 188 ′ as described above. The suture passer 10 can then be used to pass the adjustable loops 186 , 188 , 186 ′, 188 ′ through the soft tissue 160 and the single, elongated tissue reinforcement member 60 as shown in FIG. 16A . The suture passer 10 can be moved along the length of the tissue reinforcement member 60 in the direction X without removing the member 60 from the slot 61 in the upper jaw 36 since the slot 61 has the open sides 61 a , 61 b . To this end, the suture passer 10 can be slid axially along the length of the tissue reinforcement member 60 as the member 60 passes through the open sides 61 a , 61 b of the slot 61 .
After the adjustable loops 186 , 188 , 186 ′, 188 ′ are passed through the soft tissue 160 and the tissue reinforcement member 60 , a locking member 208 can be passed through and positioned within the adjustable loops 186 , 188 , 186 ′, 188 ′. The locking member 208 can be one of the example locking members described in the U.S. Pat. Pub. No. 2011/0208240 (see, e.g., FIGS. 4 through 9), the disclosure of which is incorporated herein by reference in its entirety. The adjustable loops 186 , 188 , 186 ′, 188 ′ can be self-locking adjustable loops (e.g., self-locking adjustable loops that have no knots). Examples of self-locking adjustable loops are disclosed in U.S. Pat. No. 7,658,751 and U.S. Pat. No. 7,601,165, the disclosures of which are incorporated herein by reference in their entirety.
When the locking member 208 is positioned within the adjustable loops 186 , 188 , 186 ′, 188 ′, the ends 182 , 184 , 182 ′, 184 ′ can be pulled to decrease the sizes of the adjustable loops 186 , 188 , 186 ′, 188 ′, respectively, and thereby bring the soft tissue 160 closer to the bone 162 . The size of the adjustable loops 186 , 188 , 186 ′, 188 ′ can be decreased until the soft tissue 160 is in contact with the bone 162 as shown in FIG. 16B . The tissue reinforcement member 60 and the locking member 208 prevent the adjustable loops 186 , 188 , 186 ′, 188 ′ from being pulled through the soft tissue 160 as the size of the adjustable loops 186 , 188 , 186 ′, 188 ′ is decreased and after the repair is made.
Referring now to FIGS. 17A, 17B, and 17C , an example method of using the suture passer 10 and a flexible loop construct 210 to attach the soft tissue 160 to bone 162 is illustrated. The flexible loop construct 210 can include a first flexible anchor 212 , a second flexible anchor 214 , and a suture construct 216 . Examples of flexible anchors and suture constructs are disclosed in U.S. Pat. Pub. No. 2011/0098727, the disclosure of which is incorporated herein by reference in its entirety. The flexible anchors 212 , 214 may be a JuggerKnot™ Soft Anchor, available from Biomet® of Warsaw, Ind. The first flexible anchor 212 has a first end 218 , a second end 220 , a first opening 222 , a second opening 224 , and a longitudinal passage 226 extending between the first and second openings 222 , 224 . The first end 218 can be longer than the second end 220 . The second flexible anchor 214 has a first end 228 , a second end 230 , a first opening 232 , a second opening 234 , and a longitudinal passage 236 extending between the openings 232 , 234 .
The suture construct 216 can include a first end 237 , a second end 238 , adjustable loops 240 , 241 , and a braided body 242 . The braided body 242 can define a first opening 244 , a second opening 246 , and a longitudinal passage 248 extending between the first and second openings 244 , 246 . The first and second ends 237 , 238 and the braided body 242 can be integrally formed as a single braided construct using a braiding process for braiding fibers composed of a biocompatible material. The openings 244 , 246 can be created during the braiding process as loose portions between pairs of fibers. The longitudinal passage 248 can be a portion of a longitudinal passage that extends along the entire length of the suture construct 216 .
To form the flexible loop construct 210 , the suture construct 216 can be inserted through the longitudinal passage 236 in the second flexible anchor 214 until the braided body 242 is positioned within the longitudinal passage 236 . To form the adjustable loop 240 , the first end 237 of the suture construct 216 can be inserted through the longitudinal passage 226 in the first flexible anchor 212 in the direction from the first opening 222 to the second opening 224 . The first end 237 can then be inserted through the longitudinal passage 248 in the braided body 242 in the direction from the second opening 246 to the first opening 244 . To form the adjustable loop 241 , the second end 238 of the suture construct 216 can be inserted through the longitudinal passage 226 in the first flexible anchor 212 in the direction from the second opening 224 to the first opening 222 . The first end 237 can then be inserted through the longitudinal passage 248 in the braided body 242 in the direction from the first opening 244 to the second opening 246 .
After the flexible loop construct 210 is formed, the first end or tail 218 of the first flexible anchor 212 can be inserted through the suture receptacle 84 in the lower jaw 38 , as shown in FIG. 17A . The upper jaw 36 can then be closed, and the suture carrier 14 can be advanced using only one hand to pass the tail 218 of the first flexible anchor 212 through both the soft tissue 160 and the tissue reinforcement member 60 simultaneously, as shown in FIG. 17B . An instrument such as forceps can then be used to grab the tail 218 and pull the remainder of the first flexible anchor 212 through the soft tissue 160 and the tissue reinforcement member 60 .
Before or after the first flexible anchor 212 is passed through the soft tissue 160 and the tissue reinforcement member 60 , the second flexible anchor 214 can be inserted into the hole 166 in the bone 162 . Tension can then be applied to the first and second ends 237 , 238 of the suture construct 216 to decrease the size of the adjustable loops 240 , 241 and thereby bring the soft tissue 160 closer to the bone 162 . As tension in the adjustable loops 240 , 241 increases, the flexible anchors 212 , 214 deform as shown in FIG. 17C . This prevents the first flexible anchor 212 from being pulled through the tissue reinforcement member 60 and prevents the second flexible anchor 214 from being pulled out of the hole 166 in the bone 162 .
After the suture passer 10 is used to pass the first flexible anchor 212 through the soft tissue 160 and the tissue reinforcement member 60 , the suture passer 10 can be moved in a direction X without removing the member 60 from the slot 61 in the upper jaw 36 . The suture passer 10 can then be used to pass first flexible anchors 212 ′, 212 ″, 212 ′″ of flexible loop constructs 210 ′, 210 ″, 210 ′″ through the soft tissue 160 and the tissue reinforcement member 60 in the manner described above. The bone 162 may be a humerus, and FIG. 17C may illustrate a rotator cuff repair. The suture passer 10 can also be used to repair an Achilles tendon or to attach soft tissue to soft tissue.
Referring now to FIGS. 18A and 18B , a suturing head 250 is illustrated that is similar to the suturing head 18 except that the suturing head 250 includes an upper jaw 252 instead of the upper jaw 36 . The upper jaw 252 is similar to the upper jaw 36 except the upper jaw 252 includes a tissue reinforcement member holder 253 formed as teeth 254 on the underside of the upper jaw 252 . The teeth 254 are configured to bite into or grip the tissue reinforcement member 60 when the tissue reinforcement member 60 is positioned on the teeth 254 as shown in FIG. 18A . Thereafter, the teeth 254 hold or retain the tissue reinforcement member 60 to fix the tissue reinforcement member 60 to the upper jaw 252 . The teeth 254 can have barbed or hooked ends that enable the teeth 254 to hold the tissue reinforcement member 60 . The teeth 254 can also be configured to bite into or grip the soft tissue 160 when the upper jaw 252 is closed while the soft tissue is position between the upper and lower jaws 252 , 38 . For example, the length of the teeth 254 can be greater than the thickness of the tissue reinforcement member 60 . The teeth 254 can position or hold the tissue reinforcement member 60 in the path of the suture carrier 14 so that, when the upper jaw 252 is closed and the suture carrier 14 is advanced, the suture carrier 14 is passed through the tissue reinforcement member 60 as shown in FIG. 18B .
Referring now to FIGS. 19A and 19B , a suturing head 260 is illustrated that is similar to the suturing head 18 except that the suturing head 250 includes an upper jaw 262 instead of the upper jaw 36 . The upper jaw 262 includes teeth 264 , a suture carrier receptacle 266 , and a suture retaining mechanism 268 . The teeth 264 are configured to bite into or grip the soft tissue 160 when the upper jaw 262 is in its closed position.
In various implementations, the upper jaw 262 can also include a tissue reinforcement member holder 270 . The tissue reinforcement member holder 270 is configured to position the tissue reinforcement member 60 so that the suture carrier 14 and the suture 40 pass through the tissue reinforcement member 60 after passing through soft tissue held between the upper and lower jaws 262 , 38 . The tissue reinforcement member holder 270 may be a slot 272 , as shown, which is similar to the slot 61 in the upper jaw 36 of the suturing head 18 .
The suture carrier receptacle 266 can be an opening in the upper jaw 36 . The suture carrier receptacle 266 can extend through portions of the upper jaw 262 disposed above and below the slot 272 . The suture carrier 14 and the suture 40 can be passed through the suture carrier receptacle 266 after passing through soft tissue held between the upper and lower jaws 262 , 38 .
The suture retaining mechanism 268 prevents unintentional movement of the suture 40 out of the upper jaw 262 by maintaining the suture 40 at or near the suturing head 18 . The suture retaining mechanism 268 can be made of a resilient and flexible material, such as spring steel, Nitinol, or a flexible polymer. The suture retaining mechanism 268 can include a distal end 274 , a proximal end 276 , teeth 278 , a wide, substantially flat, rectangular body 280 , a narrow, substantially flat, rectangular body 282 , a first pin-receiving portion 284 , and a second pin-receiving portion 286 . The teeth 278 can be disposed at the distal end 274 and can be configured to engage the suture 40 to maintain the suture 40 at or near the suturing head 18 .
The suture carrier 14 can be passed into the receptacle 266 , temporarily disrupting the distal end 274 of the suture retaining mechanism 268 from a closed position ( FIG. 19A ) in contact with the upper jaw 262 to an open position ( FIG. 19B ) spaced apart from the upper jaw 262 . The suture carrier 14 can then be retracted through the receptacle 266 , allowing the distal end 274 to return to its closed position. In turn, the suture retaining mechanism 268 biases the suture 40 against the receptacle 266 to prevent the suture 40 from being pulled back through the receptacle 266 . The suture retaining mechanism 268 can include ears 288 extending from the rectangular body 280 and configured to engage stops 290 on the upper jaw 262 disposed on opposite sides of the receptacle 266 as the distal end 274 returns to its closed position.
The first pin-receiving portion 284 includes a first cylindrical portion 292 defining a first pin hole 294 , a neck portion 296 extending from the rectangular body 280 to the first cylindrical portion 292 , and a tail 298 extending from the first cylindrical portion 292 . The second pin-receiving portion 286 includes a second cylindrical portion 300 attached to the rectangular body 280 and defining a second pin hole 302 . A first pin 304 can be inserted into a first pin hole 306 in the upper jaw 262 and into the first pin hole 294 in the suture retaining mechanism 268 to couple the suture retaining mechanism 268 to the upper jaw 262 adjacent to the distal end 274 of the mechanism 268 . A second pin 308 can be inserted into a second pin hole 310 in the upper jaw 262 and into the second pin hole 302 in the suture retaining mechanism 268 to couple the proximal end 276 of the mechanism 268 to the upper jaw 262 .
Thus, the suture retaining mechanism 268 can be coupled to the upper jaw 262 using two pin connections disposed at or near the distal and proximal ends 274 , 276 of the mechanism 268 . In turn, if the suture retaining mechanism 268 fractures at a location between the two pin connections, such as at the junction between the rectangular bodies 280 , 282 , the two portions of the suture retaining mechanism 268 on opposite sides of the fracture remain coupled to the upper jaw 262 . Therefore, the design of the upper jaw 262 ensures that no portion of the suture retaining mechanism 268 is left inside of a patient in the event of a fracture.
As the distal end 274 moves from its closed position to its open position, the first pin-receiving portion 284 rotates counterclockwise about the first pin 304 , the rectangular body 282 flexes downward, and the second pin-receiving portion 286 moves distally. The first pin-receiving portion 284 can rotate counterclockwise about the first pin 304 until the tail 298 on the first pin-receiving portion 284 contacts a ledge 312 on the upper jaw 262 . In this regard, the ledge 312 on the upper jaw 262 can act as a stop that limits counterclockwise rotation of the first pin-receiving portion 284 . Conversely, as the distal end 274 moves from its open position to its closed position, the first pin-receiving portion 284 rotates clockwise about the first pin 304 , the rectangular body 282 returns to its relaxed state, and the second pin-receiving portion 286 moves proximally. The second pin hole 310 can be a slot rather than a cylindrical hole such that the second pin 308 can move distally or proximally in the second pin hole 310 to allow the distal or proximal movement of the second pin-receiving portion 286 .
Referring now to FIGS. 20A and 20B , a suturing head 320 is illustrated that is similar to the suturing head 18 except that the suturing head 320 includes an upper jaw 322 instead of the upper jaw 36 . The upper jaw 322 includes teeth 324 , a suture carrier receptacle 326 , and a suture retaining mechanism 328 . The teeth 324 are configured to bite into or grip soft tissue when the upper jaw 322 is in its closed position.
In various implementations, the upper jaw 322 can also include a tissue reinforcement member holder 330 . The tissue reinforcement member holder 330 is configured to position the tissue reinforcement member 60 so that the suture carrier 14 and the suture 40 pass through the tissue reinforcement member 60 after passing through soft tissue held between the upper and lower jaws 322 , 38 . The tissue reinforcement member holder 330 may be a slot 332 , as shown, which is similar to the slot 61 in the upper jaw 36 of the suturing head 18 .
The suture carrier receptacle 326 can be an opening in the upper jaw 322 . The suture carrier receptacle 326 can extend through portions of the upper jaw 262 disposed above and below the slot 332 . The suture carrier 14 and the suture 40 can be passed through the suture carrier receptacle 326 after passing through soft tissue held between the upper and lower jaws 322 , 38 .
The suture retaining mechanism 328 prevents unintentional movement of the suture 40 out of the upper jaw 322 by maintaining the suture 40 at or near the suturing head 18 . The suture retaining mechanism 268 can be made of a resilient and flexible material, such as spring steel, Nitinol, or a flexible polymer. The suture retaining mechanism 328 can include a distal end 334 , a proximal end 336 , teeth 338 , a flat rectangular body 340 , a first pin-receiving portion 342 , and a second pin-receiving portion 344 . The teeth 338 can be disposed at the distal end 334 and can be configured to engage the suture 40 to maintain the suture 40 at or near the suturing head 18 .
The suture carrier 14 can be passed into the receptacle 326 , temporarily disrupting the distal end 334 of the suture retaining mechanism 328 from a closed position ( FIG. 20A ) in contact with the upper jaw 322 to an open position ( FIG. 19B ) spaced apart from the upper jaw 322 . The suture carrier 14 can then be retracted through the receptacle 326 , allowing the distal end 334 to return to its closed position. In turn, the suture retaining mechanism 328 biases the suture 40 against the receptacle 326 to prevent the suture 40 from being pulled back through the receptacle 326 . The suture retaining mechanism 328 can include ears 346 extending from the rectangular body 340 and configured to engage stops 348 on the upper jaw 322 disposed on opposite sides of the receptacle 326 as the distal end 334 returns to its closed position.
The first pin-receiving portion 342 includes a first cylindrical portion 350 defining a first pin hole 352 , a distal fillet 354 extending between first cylindrical portion 350 and the rectangular body 340 , and a proximal fillet 356 extending between first cylindrical portion 350 and the rectangular body 340 . The second pin-receiving portion 344 includes a second cylindrical portion 358 defining a second pin hole 360 , and a curved spring portion 362 extending from the rectangular body 340 to the second cylindrical portion 358 . A first pin 364 can be inserted into a first pin hole 366 in the upper jaw 322 and into the first pin hole 352 in the suture retaining mechanism 328 to couple the mechanism 328 to the upper jaw 322 adjacent to the distal end 334 of the mechanism 328 . A second pin 368 can be inserted into a second pin hole 370 in the upper jaw 322 and into the second pin hole 360 in the suture retaining mechanism 328 to couple the proximal end 336 of the mechanism 328 to the upper jaw 322 .
Thus, the suture retaining mechanism 328 can be coupled to the upper jaw 322 using two pin connections. In turn, if the suture retaining mechanism 328 fractures at a location between the two pin connections, such as across the width of the spring portion 362 , the two portions of the mechanism 268 on opposite sides of the fracture remain coupled to the upper jaw 322 . Therefore, the design of the upper jaw 322 ensures that no portion of the suture retaining mechanism 328 is left inside of a patient in the event of a fracture.
As the distal end 334 moves from its closed position to its open position, the first pin-receiving portion 342 rotates counterclockwise about the first pin 364 and the spring portion 362 flexes downward through a bottom opening 372 in the upper jaw 322 . Conversely, as the distal end 274 moves from its open position to its closed position, the first pin-receiving portion 284 rotates clockwise about the first pin 364 and the spring portion 362 returns to its relaxed state. In various implementations, the spring portion 362 may be configured to flex downward without extending through the bottom opening 372 in the upper jaw 322 to avoid contact between the spring portion 362 and the soft tissue 160 . For example, the flexibility of the spring portion 362 can be adjusted by altering the geometry and/or material of the spring portion 362 .
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
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The present disclosure describes a suture passer device that includes a handle, a shaft extending from the handle, a suture carrier secured to the handle and extending through the shaft, and a suturing head extending from the shaft and configured to retain tissue. The handle is operable to advance the suture carrier through the suturing head to pass a suture through tissue retained in the suturing head. According to one aspect of the present disclosure, the suture passer device includes a quick-connect mechanism releasably connecting the shaft to the handle. According to another aspect of the present disclosure, the shaft includes a first shaft and a second shaft pivotally coupled to the first shaft, and the first shaft defines a first channel for receiving the second shaft. Methods of disassembling the suture passer device are also described.
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FIELD OF THE INVENTION
The field of this invention relates to running tools, particularly those useful in running liners into wellbores on coiled tubing units.
BACKGROUND OF THE INVENTION
In the recent past, to save well operator time and money, coiled tubing units have been used in more applications as a substitute for rigid tubing. The coiled tubing facilitates shorter trips into and out of the wellbore, thus reducing rig time required for given operations. One of the operations that are now desirable for use with coiled tubing units is to run casing or liner into a wellbore. When using a coiled tubing unit to accomplish this operation, it is desirable to have a running tool which has features which retain a grip on the liner or casing, regardless of whether the liner or casing is in tension or compression. It is also desirable to be able to transmit torque to the liner to facilitate its advancement or retrieval from the wellbore. Another desirable feature is to be able to be sure that once there has been release from the liner that it does not again accidentally become reattached to the running tool. These desirable features have been combined into the apparatus which is the subject of the present invention.
In the past, various tools for gripping and releasing have been employed. Various tools have had a feature for mechanical actuation of engagement but were designed in such a manner so that if the object to which the running tool or fishing tool was engaged was put into compression, there would be a release. Typical of such tools is that disclosed in U.S. Pat. No. 5,242,201, which illustrates mechanical engagement by physical displacement of the collets against an object to be retrieved but which as well indicates a design which will release when placed in compression. The fishing tool illustrated in U.S. Pat. No. 5,242,201 also indicates the state of the known art regarding transmission of torque through the collets. In the design illustrated in U.S. Pat. No. 5,242,201, the collets are reinforced with lugs so that they can better withstand transmitted torque. On the other hand, the apparatus of the present invention makes it possible to transmit torque without involving the collets, which differs from the prior designs which put a torsional stress through the collets. Since the design in U.S. Pat. No. 5,242,201 is for a fishing tool where release and relatching to a stuck object to be retrieved is desirable, it did not provide for a feature that positively prevents relatching once there has been release from the object. In running liner on coiled tubing, relatching would be undesirable because it is industry standard to be free from your liner prior to pumping cement. Upon releasing the running tool, the drillpipe and running tool are picked up to verify its release and then set back down and put in compression. Then cement is displaced down through the drillpipe and up around the outside of the liner. If cement is overdisplaced, the cement can get up around the running tool. If the running tool is not released, this could cause a problem.
Accordingly, the apparatus of the present invention represents an improvement over known devices. Particularly for operations involving running liner with coiled tubing, the apparatus provides a mechanism to retain the liner whether it is in tension or compression under application of fluid pressure to the tool, to transmit torque directly through the liner outside the collets, and to positively stay released from the liner once steps have been taken to deliberately release from the liner.
SUMMARY OF THE INVENTION
A running tool particularly useful for running liners on coiled tubing is disclosed. A torque-transmitting outer sleeve is employed which initially traps the collets. The collets are engaged to the liner by relative mechanical movement and thereafter lock in a secured position to the liner, regardless of whether the liner is placed in tension or compression by the running tool. Release is accomplished by letting down weight on the running tool, coupled with hydraulic pressure to shear a pin securing the collet mechanism. Upon such a hydraulic release with the pin sheared, the outer torque sleeve shifts downwardly to prevent relatching. Torque is transmitted through the outer torque sleeve and not through the latching collets.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevational view of the apparatus in the run-in position upon initial engagement with the liner.
FIG. 2 is the apparatus of FIG. 1 showing the collets becoming unsupported.
FIG. 3 is the view of FIG. 2 showing the collets engaging the groove in the liner and locking against it.
FIG. 4 is the view of FIG. 3 with weight shifted down on the apparatus, showing how the collets continue to retain their locking engagement with the liner.
FIG. 5 is the view of FIG. 4 with hydraulic pressure applied to the apparatus to obtain release of the collets from the liner.
FIG. 6 is the view of FIG. 5 with an upward force applied to the apparatus, illustrating how the collets cannot relatch against the liner.
FIG. 7 is a detailed view showing how pressure is built up in the apparatus by dropping a ball against the seat.
FIG. 8 is a detail showing the guide mechanism for the torque sleeve to transmit torque from the apparatus directly to the liner.
FIG. 9 is a detailed view of the castellations which appear at the lower end of the torque sleeve as well as the upper end of the liner section which are used to transmit torque through the apparatus and into the liner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus A is illustrated in FIG. 1. A top sub 10 is connected to a mandrel 12 at thread 14, with the connection sealed by seal 16. Mandrel 12 is connected to bottom sub 18 at thread 20 which is sealed by seal 22. A guide lug 24 is secured to top sub 10 and extends into groove 26 of mandrel 12.
A torque sleeve 28 has a window 30 in the form of a long longitudinal slot, through which extends lug 24. Accordingly, rotational forces applied to top sub 10 are transmitted to torque sleeve 28 through lug 24. At the same time, relative longitudinal motion is possible between top sub 10 and torque sleeve 28 as will be described below. It should be noted that FIG. 8 illustrates a detail of the arrangement, showing torque sleeve 28 with its window 30 and lug 24 extending therethrough.
A spring 32 bears on lower end 34 of top sub 10. Ring 36 is mounted between mandrel 12 and torque sleeve 28. Its relative position is secured due to a lug 38 extending through bore 40, which is oriented radially in ring 36. Since, as shown in FIG. 1 lug 38 extends into window 30, the lug 38 can travel no further than the position shown in position la when lug 38 hits the bottom 40 of window 30. Accordingly, spring 32 exerts a downward force on torque sleeve by pushing down on ring 36 when lug 38 is bottomed on window 30.
Mounted over mandrel 12 is sleeve 42. Sleeve 42 forms a variable-volume cavity 44, which is in turn sealed by seals 46 and 48. A passageway 50 connects the central bore 52 with variable-volume cavity 44. Sleeve 42 is connected to ring 54 at thread 56. Ring 54 is connected to sleeve 58 at thread 60. Sleeve 58 has an outwardly oriented shoulder 62 which is at times engageable with ring 64, as will be described below. The collet assembly 66 is connected to ring 64 at thread 68. The collet assembly 66 features an inwardly oriented shoulder 70, a plurality of collet fingers 72, each of which terminate in a collet head 74. The collet heads 74 are formed by surfaces 76-86. The torque sleeve 28 has a lower end 88, which has a series of castellations 90. Castellations 90 can be better seen in FIG. 9.
The casing or liner is shown in dotted lines in FIG. 1c as 91. It has an upper end 92 with castellations 94. The castellations 94 can be better seen in FIG. 9. Those skilled in the art will appreciate that when the torque sleeve 28 engages the liner or casing 91, there is an interengagement between the castellations 90 and 94 to allow for transmission of torque therethrough.
It should be noted that the position of ring 54 illustrated in FIG. 1b is maintained by a shear pin 96 which extends through ring 54 and into groove 98 of mandrel 12. As will be explained below, when the shear pin 96 is sheared, ring 54 is able to move relatively with respect to mandrel 12 to facilitate release from the liner 91. Finally, as shown in FIG. 1c, the mandrel 12 is secured to the bottom sub 18 by the engagement of thread 20. A lug 100 extends through bottom sub 18 and into mandrel 12 into groove 102.
All the major components now having been described, the operation of the apparatus A of the present invention will be explained. The apparatus A is aligned and inserted into the liner 91 to be run in the wellbore. At that time, as illustrated in FIG. 1c, the torque sleeve 28 is biased downwardly by spring 32. The torque sleeve 28 in turn bears down on surface 76 of the collet heads 74, while at the same time mandrel 12 presents raised surface 104 adjacent surface 84 of the collet heads 74 to effectively trap the collet heads 74. Upon the increase in force exerted on top sub 10, as illustrated by comparing FIG. 2 to FIG. 1, the mandrel 12 with bottom sub 18 move downwardly, while the collet heads 74 remain immobilized due to torque sleeve 28 bearing down on surface 76 of collet heads 74, while at the same time the upper end 92 of liner 91 is in contact with surface 80 of the collet heads 74, thus further preventing their downward movement. In order to allow the mandrel 12 to move downwardly while the collet heads 74 remain in a stationary position, spring 106 is compressed between shoulders 70 and 108 (see FIG. 2b). In effect, shoulder 108 moves closer to shoulder 70 to compress spring 106, while at the same time shoulder 110 advances toward upper end 112 of torque sleeve 28 (see FIG. 2a). By comparing the positions in FIGS. 1 and 2, it can be seen that the downward shifting of the assembly of top sub 10, mandrel 12, and bottom sub 18, results in movement of raised surface 104 away from surface 84, thus making the collet heads 74 unsupported. As soon as that occurs, spring 106 is able to move the collet assembly 66 by pushing on shoulder 70. The collet heads 74 move inwardly temporarily toward depressed surface 114, which is a recessed surface on mandrel 12 which is now presenting itself opposite surface 84 (see FIG. 2c). Spring 106 further translates the collet heads 74 longitudinally around the upper end 94 of the liner 91 until the surface 78 of the collet heads 74 enters groove 116 of liner 91. At that time, as shown in FIG. 3c, the collet heads 74 once again become trapped, this time in groove 116 when raised surface 104 is once again presented against surface 84 on the collet heads 74. A lifting force, such as applied in the position shown in FIG. 3, will allow lifting of the liner 91 since the collet heads 74 are firmly engaged in groove 116. Similarly, a downward force on the top sub 10, as shown in FIG. 4, will still not result in a release of the collet heads 74 from groove 116 since they will still remain trapped by the juxtaposition of raised surface 104 with surface 84.
As shown in FIG. 3a, gap 118 between shoulder 110 and upper end 112 is a predetermined distance shorter than the length of groove 116. Accordingly, when downward weight is put on top sub 10, as shown in FIG. 4, shoulder 110 bottoms on torque sleeve 28 at its upper end 112. However, throughout the movement which brings shoulder 110 closer to top end 112, collet heads 74 move in tandem with mandrel 12 due to shear pin 96, which ties the movement of mandrel 12 to ring 54. While the movement is occurring, which is shown in FIG. 4, there is no resistance to advancement of collet heads 74 within groove 116. Accordingly, when ring 54 moves downwardly with mandrel 12, it pushes down on sleeve 58, which in turn transmits the movement through spring 106 to collet assembly 66. As a result, by looking at FIGS. 3c and 4c, the relative positions of collet heads 74 and raised surface 104 remain unchanged in the movement from the position shown in FIG. 3 to the position shown in FIG. 4.
When it is desired to release from the liner 91, a downward force is applied to top sub 10. At that time, a ball 120 (see FIG. 7) is dropped into sealing engagement with seat 122. Seat 122 is located at or below bottom sub 18 in bore 52. Once ball 120 is seated against seat 122, pressure from the surface can be built up in bore 52. Other pressure build-up techniques can be used, such as an orifice which creates backpressure when sufficient flow is pumped through it. This pressure is communicated through passage 50 to increase the volume of variable-volume cavity 44. In so doing, the shear pin 96 is sheared while the hydraulic pressure pulls up sleeve 42, which takes up with it ring 54 as well as sleeve 58. Eventually, shoulder 62 bottoms on ring 64, thus applying an upward pull to the collet assembly 66 because ring 64 is threadedly connected to collet assembly 66 at thread 68. Because a downward force on top sub 10 is applied from the surface while at the same time hydraulic pressure increases the volume of variable-volume cavity 44, collet heads 74 can escape the groove 116 because once again in that position, the recessed surface 114 presents itself in opposition to groove 116. The upward force which is ultimately transmitted to the collet heads 74 retracts them to the position shown in FIG. 5c. Thereafter, the downward force on top sub 10 is removed and an upward force is placed on top sub 10. When this occurs, shoulder 110 moves away from top end 112 while spring 32, which had been previously compressed in the view shown in FIG. 5a, now relaxes, pushing downwardly on torque sleeve 28. Torque sleeve 28, as shown in FIG. 6c, moves downwardly so that its lower end 88 comes into alignment with raised surface 104, while the collet heads 74 are further retracted against recessed surface 114. With the shear pin 96 having already been sheared, any further setdown force on top sub 10 will only accomplish retraction of torque sleeve 28. Seals 46 and 48 create sufficient resistance to downward movement of sleeve 42 so that collet heads 74 remain within torque sleeve 28 to prevent reengagement. Gap 124 is also sufficiently narrow to prevent escape of collet heads 74 with torque sleeve 28 in a fully biased position by spring 32.
It should be noted that when the torque sleeve 28 engages the liner 91, the castellations 90 and 94 can engage in an offset manner as shown in FIG. 9, which is the preferred mode to allow the transmission of torque therethrough. If desired and the transmission of torque is for any reason not important, the torque sleeve 28 can engage the liner 91 in such a manner that the castellations 90 and 94 are in alignment as opposed to the offset in which they are shown in FIG. 9. Engagement can still occur between the apparatus A and the liner 91 with the castellations 90 and 94 in alignment. However, upon application of any torque, the castellations 90 and 94 will snap into an interengaging orientation, as shown in FIG. 9. While a ball 120 dropping against a seat 122 has been shown as the mechanism to obstruct the central bore 52, other ways to close off this bore or to build up hydraulic pressure can be employed without departing from the spirit of the invention.
Those skilled in the art will now appreciate that with the components and movements described above, an apparatus A is revealed which can engage a liner and retain the engagement, regardless of whether the running tool is subjected to a pulling or a pushing force with respect to the liner. Additionally, torque can be transmitted to the liner 91 outside the locking mechanism or the collet heads 74. The torque sleeve 28 transmits the torque directly from the top sub 10 to the liner 91. A provision is made for relative movement between torque sleeve 28 and top sub 10, which is smaller than the length of the groove in the liner 91 which is to be engaged. Therefore, regardless of whether the collet heads 74 are in tension or compression, as shown in FIGS. 3 and 4, respectively, the engagement is retained. The fluid pressure release, once accomplished, becomes permanent as the torque sleeve 28 is repositioned by the force of spring 32 downwardly a sufficient distance to juxtapose itself next to raised surface 104 on the mandrel, effectively creating a gap 124 small enough to prevent collet heads 74 from getting any further engagement into groove 116. Torque sleeve 28 actually covers collet heads 74 in this released position to further ensure that liner 91 is not teengaged. It should be noted that until the bore 52 is obstructed with ball 120, the engagement to the liner 91 is retained. It is only when it is deliberately decided that it is time to let go of the liner 91 that the bore 52 is obstructed, allowing pressure build-up in cavity 44 to effectuate the shearing of shear pin 96 for the release and subsequent lock-out feature which will prevent reengagement. Accordingly, in one simple, low-profile tool, a variety of functions are accomplished. Compact design is important due to the small size requirements for such running tools, particularly in deviated well-bores. Those skilled in the art will appreciate that the apparatus A can, of course, also be used as a retrieving tool or a fishing tool. The unique layout of parts illustrated in the preferred embodiment allows all these features to be present in the apparatus A while still allowing the tool to fit through openings as small as 31/2" or smaller.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the spirit of the invention.
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A running tool particularly useful for running liners on coiled tubing is disclosed. A torque-transmitting outer sleeve is employed which initially traps the collets. The collets are engaged to the liner by relative mechanical movement and thereafter lock in a secured position to the liner, regardless of whether the liner is placed in tension or compression by the running tool. Release is accomplished by letting down weight on the running tool, coupled with hydraulic pressure to shear a pin securing the collet mechanism. Upon such a hydraulic release with the pin sheared, the outer torque sleeve shifts downwardly to prevent relatching. Torque is transmitted through the outer torque sleeved and not through the latching collets.
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BACKGROUND OF THE INVENTION
The present invention relates to a method for modifying one surface of a textile fabric or a nonwoven fabric in which properties which are different from those of the above-mentioned textile fabric or nonwoven fabric itself are imparted to one surface of the fabric.
The above-mentioned method of the present invention is that in order to obtain a textile fabric or a nonwoven fabric suitable as a material of sportswear which is excellent in the perspiration treatment owing to an excellent function of moving a moisture from one surface to another in the fabric and has wash and wear properties, only one surface of the textile fabric or the nonwoven fabric is improved.
More specifically, the present invention relates to a method for modifying one surface of a textile fabric or a nonwoven fabric which is excellent in water permeability and diffusibility and which has a durability, wherein one surface maintains a hydrophobic nature inherent in the fibers and only the other surface is modified to have a hydrophilic nature (water absorption and sweat absorption) without accompanying an external change, a change in air permeability and the like.
In the human body, a moisture is always evaporated from the skin at normal state for regulation of the body temperature and due to a physiological perspiration function. In the vigorous sport, an amount of sweat is increased to prevent an abrupt increase of the body temperature.
Accordingly, a humidity within the clothing is also increased in taking part in a vigorous sport. It is said that when a temperature is 33° C. and a humidity is 65% or more, sweat which reaches the body surface from the sweat gland cannot be gasified and perspiration in a liquid phase starts.
The increase in the amount of sweat inherently serves to decrease the increasing body temperature with evaporation heat. However, when sweat remains on the skin surface or retains on the clothing surface in contact with the skin, the regulation of the body temperature with evaporation heat does not function effectively, with the result that the temperature in the clothing and the amount of sweat are all the more increased.
On the contrary, when the body temperature starts to decrease after the sport, sweat which is present on the body surface or on the clothing surface in contact with the skin is evaporated to make one feel chill.
In order to prevent the uncomfortable feelings such as <stuffy feeling>, <sticky feeling> and <chill feeling> in or after the sport, the clothing is required which has such a comfort that sweat on the body surface can be absorbed quickly and released rapidly into the outside environment from the portion in contact with the skin.
When the conventional fiber materials are evaluated from this standpoint, a fiber material made of 100% of natural fibers of cotton, wool or the like absorbs sweat well because of the excellent water absorption. However, since this has an excellent water retention, sweat once absorbed is hardly evaporated, and a considerable amount of a moisture is left inside the fibers, so that drying takes much time. Meanwhile, a fiber material made of 100% of synthetic fibers has a low rate of water absorption when it is brought into contact with water, and has thus a poor water permeability. Accordingly, absorption or shifting of sweat is not conducted, inviting an uncomfortable feeling due to wetting with sweat.
A mixed fabric of natural fibers and synthetic fibers has also a defect that sweat absorbed is absorbed in natural fibers and a hydrous state is maintained, with the result that sweat (moisture) is hardly evaporated.
In order to solve these defects, a fabric in which one surface is hydrophobic and another is hydrophilic has been proposed.
FIGS. 1 (A) through 1 (C) are model views showing a water absorption and a water permeability of a hydrophobic textile fabric, a textile fabric in which both surfaces are hydrophilic, or a textile fabric in which one surface is hydrophobic and another is hydrophilic.
In the hydrophobic textile fabric of a fiber material made of 100% of synthetic fibers, a moisture permeation layer does not reach the outside as shown in FIG. 1 (A). In the textile fabric of a fiber material made of 100% of natural fibers in which both surfaces are hydrophilic, a moisture permeation layer reaches the outside, and is uniformly distributed in the inside and the outside as shown in FIG. 1 (B). In the textile fabric having the hydrophilic surface and the hydrophobic surface, the moisture permeation layer is enlarged from the hydrophobic surface to the hydrophilic surface as shown in FIG. 1 (C).
With respect to the behavior of sweat truly required in the textile fabric for sportswear, working clothes entraining a large amount of sweat and the like, as mentioned above, what is important is not that sweat is absorbed into the textile fabric, but rather that sweat is moved from the hydrophobic surface in contact with the skin to the hydrophilic surface always in contact with open air without absorption into the textile fabric and is diffused and released into the surface layer. A fabric having a water absorption and a water permeability as shown in FIG. 1 (C), namely, a fabric in which one surface is hydrophobic and another is hydrophilic can achieve such a behavior.
A variety of methods have been so far proposed for obtaining a textile fabric in which one surface is a hydrophobic surface and another is a hydrophilic surface. For example, it is known that in a post-treatment method in which a hydrophilic agent or a water-repellent agent is coated on one surface of a textile fabric, a textile fabric that does not give a stuffy feeling, a sticky feeling or the like can easily be produced. However, the textile fabric obtained by such a method has a poor washing resistance because the agent is simply coated thereon, and the textile fabric causes clogging by the agent coated, decreasing an air permeability.
A method has been also reported in which a textile fabric of synthetic fibers having a difference in function between front and back surfaces is obtained by imparting a hydrophilic nature to one surface of the textile fabric through plasma treatment using a low-temperature plasma method (for example, Japanese Patent Laid-Open Nos. 59-106,570 and 59-106,569). In this method, the textile fabric of synthetic fibers is fixed on an electrode surface in an inner electrode-type plasma device to treat one surface of the fabric. However, this method involves a problem that since the textile fabric has an air permeability, the overall fabric (both front and back surfaces) is plasma-treated in the plasma irradiation. Accordingly, no textile fabric having a satisfactory difference in function between front and back surfaces is obtained by such a method.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for modifying one surface of a textile fabric or a nonwoven fabric having a practical difference in function between front and back surfaces.
The present inventor has assiduously conducted investigations, and has consequently found that the above problem can be achieved by coating a sizing agent as a plasma reaction-preventing layer on one surface of a textile fabric or a nonwoven fabric before conducting low-temperature plasma treatment. This finding has led to the completion of the present invention.
That is, the present invention relates to a method for modifying one surface of a textile surface or a nonwoven fabric, which comprises coating a sizing agent on the whole or at least a part of one surface of the textile fabric or the nonwoven fabric, subjecting another surface of the textile fabric or the nonwoven fabric to low-temperature plasma treatment to form an active seed, then graft-polymerizing this active seed with a polymerizable monomer, and thereafter removing the sizing agent coated on one surface of the textile fabric or the nonwoven fabric.
The sizing agent is usually coated on the whole of one surface. It is possible that the sizing agent is coated partially, for example, in a pattern so that the surface not coated with the sizing agent is wholly modified and the coated surface is partially modified. Therefore, the field of application of the present invention can be widened by the above-mentioned perspiration treatment as well as by variously changing properties of a material to be graft-polymerized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 (A) through 1 (C) are model views of a water absorption and diffusion mechanism of a textile fabric.
FIG. 2 (A) is a model view of a test for water absorption of a modified textile fabric in Example 8.
FIG. 2 (B) is a view in which a wet state of ink is traced on a striped surface in contact with ink. FIG. 2 (C) is a view in which a wet state of ink is traced on the wholly modified surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is described in detail below.
A method for processing a textile fabric or a nonwoven fabric in the present invention includes four steps. The first step is a step of coating a sizing agent as a plasma reaction-preventing layer on one surface of a textile fabric or a nonwoven fabric; a second step is a step of activating another surface of the textile fabric or the nonwoven fabric through low-temperature plasma treatment; a third step is a step of graft-polymerizing a polymerizable monomer using a polymerizable active seed activated through the low-temperature plasma treatment; and a fourth step is a step of removing the sizing agent or the like coated on one surface of the textile fabric or the nonwoven fabric having a difference in function between front and back surfaces.
[First step]
In the first step of coating the sizing agent, the sizing agent is coated as the plasma reaction-preventing layer on one surface of the textile fabric or the nonwoven fabric.
The textile fabric or the nonwoven fabric intended by the present invention may be hydrophilic or hydrophobic. The hydrophobic fiber is preferable.
A textile fabric or a nonwoven fabric made of various synthetic fibers of a polyester, polypropylene, polyamide or polyacrylonitrile type as hydrophobic fibers can be mentioned. Further, a textile fabric or a nonwoven fabric made of blended fibers including polyester, polypropylene, polyamide or polyacrylonitrile fibers and 50% of cotton, flax, silk or wool fibers as at least hydrophilic fibers can be mentioned.
As the hydrophilic fibers, cotton, flax, silk or wool fibers can be mentioned.
The sizing agent which is used as the plasma reaction-preventing layer in the present invention is not particularly limited unless it has a direct influence on the textile fabric or the nonwoven fabric even if activated.
As a water-soluble sizing agent, for example, sodium alginate, starch, processed starch (dextrin, carboxymethyl starch or the like), a cellulose derivative (methyl cellulose, ethyl cellulose, carboxymethyl cellulose or the like), a synthetic paste (polyvinyl alcohol, polyacrylic acid or the like) and so forth can be mentioned.
In the method of the present invention, the sizing agents may be used either singly or in combination.
The water-soluble sizing agent is used in a paste form by adding water thereto. In this case, the concentration of the sizing agent can be changed, as required, depending on the type of the textile fabric or the nonwoven fabric to be coated. However, when the concentration is low and the permeability in the textile fabric or the nonwoven fabric is high, the sizing agent is permeated into the opposite surface when it is coated, and this is undesired. For example, the concentration of the above-mentioned sizing agent is preferably at least 0.5% by weight and at most 20% by weight, more preferably at least 0.5% by weight and at most 10% by weight.
A method for coating the sizing agent on the textile fabric or the nonwoven fabric is not particularly limited so long as it can uniformly be coated only on one surface of the textile fabric or the nonwoven fabric. For example, a coating method using a bar coater, a knife coater, a doctor coater or the like and a printing method using a screen or the like are mentioned.
The coating amount of the sizing agent is not particularly limited so long as it acts as a plasma reaction-preventing layer. For example, it can be coated such that the amount becomes between 40 μm and 60 μm after drying.
The sizing agent coated is dried by being allowed to stand, for example, in an atmosphere of 60° C. for from 15 to 20 minutes or in air for from 5 to 8 hours. Further, baking may be conducted as required.
[Second step]
In the second step, the textile fabric or the nonwoven fabric in which one surface is coated with the sizing agent as obtained in the first step is subjected to low-temperature plasma treatment.
Since the sizing agent becomes a plasma reaction-preventing layer, no active seed is formed in the surface coated with the sizing agent by the plasma treatment. Accordingly, it is possible to obtain the textile fabric or the nonwoven fabric in which only the other surface not coated with the sizing agent has a uniform, radical-polymerizable active seed (hereinafter simply referred to as an “active seed”) by such a low-temperature plasma treatment.
The low-temperature plasma treatment is conducted by, for example, placing the textile fabric or the nonwoven fabric having one surface coated with the sizing agent in an inner electrode-type plasma device, continuously introducing a gas for low-temperature plasma treatment, and applying a voltage between electrodes.
The gas used in the low-temperature plasma treatment in the method of the present invention includes a gas free from an oxygen gas and capable of forming an active seed, an oxygen gas and an oxygen gas-containing mixed gas.
As the gas free from an oxygen gas and capable of forming an active seed, an argon gas, a helium gas, a nitrogen gas, a hydrogen gas, carbon dioxide and a mixed gas thereof are mentioned.
As the oxygen gas-containing mixed gas, air and the like are mentioned.
Further, the gas forming the “oxygen gas-containing mixed gas” along with the oxygen gas is not particularly limited. The above-mentioned argon gas and the like and the mixed gas thereof may be used.
When the gas free from the oxygen gas and capable of forming the active seed is used in the low-temperature plasma treatment, the surface of the textile fabric or the nonwoven fabric having one surface coated with the sizing agent is subjected to the low-temperature plasma treatment, and the oxygen gas or the oxygen gas-containing mixed gas is introduced into the plasma device whereby the resulting active seed is reacted with oxygen. Alternatively, after the plasma treatment, the textile fabric or the nonwoven fabric is taken out into ambient atmosphere, and the active seed formed on the surface is reacted with oxygen.
When the low-temperature plasma treatment is conducted in the oxygen gas or the oxygen gas-containing mixed gas, the above-mentioned procedure is not needed.
The thus-obtained active seed is one which is stable for a long period of time.
The conditions for the low-temperature plasma treatment are not particularly limited so long as the textile fabric or the nonwoven fabric in which only the other surface not coated with the sizing agent has the uniform active seed is obtained. For example, preferable conditions when using an ordinary inner electrode-type plasma device are described below.
A power source to which a voltage is applied is not particularly limited if a frequency capable of discharge is provided. In the experiment of the present invention, 13.56 MHz was used.
A discharge output is preferably between 0.1 W/cm 2 and 1 W/cm 2 . A discharge time is 1 second or more, especially preferably between 5 and 60 seconds.
A gas pressure in the discharge is preferably between 0.1 mmHg and 20 mmHg, especially preferably between 0.1 mmHg and 10 mmHg, further preferably between 0.1 mmHg and 1 mmHg.
A flow rate of a gas is preferably between 30 ml/min and 300 ml/min, especially preferably between 100 ml/min and 200 ml/min.
When the low-temperature plasma treatment is conducted under the above-mentioned conditions, the largest amount of the active seed can preferably be formed without damaging the textile fabric or the nonwoven fabric.
[Third step]
In the third step, the surface of the textile fabric or the nonwoven fabric having the active seed as obtained in the second step is contacted with the radical-polymerizable monomer to conduct graft polymerization.
When the surface of the textile fabric or the nonwoven fabric having the active seed is contacted with the monomer, the surface of the textile fabric or the nonwoven fabric has been deaerated to 0.1 mmHg or less in vacuo to remove an oxygen gas and the like contained in the textile fabric or the nonwoven fabric, whereby the graft polymerization reaction proceeds more easily. Further, the vacuum deaeration may be conducted while the textile fabric or the nonwoven fabric is contacted with the monomer.
In the method of the present invention, the graft polymerization reaction of one surface of the textile fabric or the nonwoven fabric may be conducted in a liquid phase or in a gaseous phase.
However, when the reaction is conducted in the liquid phase, namely in the monomer solution, a homopolymer tends to be formed. A homopolymer formed is adhered to the textile fabric or the nonwoven fabric, and is difficult to remove in some cases. Further, in the liquid phase reaction, the polymerization tends to proceed, and an amount of the graft polymer to the textile fabric or the nonwoven fabric is increased. When the amount of the graft polymer is too large, the texture of the final textile fabric or nonwoven fabric is sometimes decreased.
Meanwhile, when the graft polymerization reaction is conducted in the gaseous phase, formation of the homopolymer is inhibited in comparison with the liquid phase reaction, and the amount of the graft polymer is easily controlled. In this case, the texture of the textile fabric or the nonwoven fabric is hard to decrease. Accordingly, in the method of the present invention, it is advisable to conduct the graft polymerization by the gaseous phase reaction.
The temperature of the graft polymerization reaction is selected, as required, in relation to the reactivity of the monomer and the reaction time, and it is not particularly limited so long as a desired amount of a graft polymer is obtained. It is preferably at least 40° C. and at most 80° C.
The reaction time is selected, as required, in relation to the reaction method, the reaction temperature, the type of the monomer and the like, and it is not particularly limited so long as a desired amount of a graft polymer is obtained. The reaction can be conducted, for example, for at least 30 minutes and at most 10 hours.
The radical-polymerizable monomer used in the present invention can be selected, as required, depending on the use of the textile fabric or the nonwoven fabric. When the textile fabric or the nonwoven fabric is hydrophobic, a hydrophilic monomer is used. When the textile fabric or the nonwoven fabric is hydrophilic, a hydrophobic monomer is used.
The radical-polymerizable monomer here refers to a monomer which has a carbon-carbon double bond and in which the polymerization reaction proceeds through chain polymerization.
Examples of the hydrophilic monomer include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and N-vinyl-2-pyrrolidone.
Examples of the hydrophobic monomer include perfluorooctylethyl acrylate and perfluorooctylethyl methacrylate.
The combination of the textile fabric or the nonwoven fabric and the radical-polymerizable monomer can be selected, as required, depending on the use purpose. Especially, the textile fabric or the nonwoven fabric obtained from the following combination of the textile fabric or the nonwoven fabric and the monomer is preferable because a function to shift a moisture from one surface to another of the textile fabric or the nonwoven fabric is excellent.
Preferable examples of a combination of a hydrophobic textile fabric or nonwoven fabric and a hydrophilic monomer include a combination of a polyester-type textile fabric or nonwoven fabric and acrylic acid, a combination of a polyester-type textile fabric or nonwoven fabric and methacrylic acid, a combination of a polyester-type textile fabric or nonwoven fabric and 2-hydroxyethyl acrylate, a combination of a polyester-type textile fabric or non-woven fabric and 2-hydroxyethyl methacrylate, a polyester-type textile fabric or nonwoven fabric and N-vinyl-2-pyrrolidone, a polyamide-type textile fabric or nonwoven fabric and acrylic acid, a combination of a polyamide-type textile fabric or nonwoven fabric and methacrylic acid, a combination of a polyamide-type textile fabric or nonwoven fabric and 2-hydroxyethyl acrylate, a polyamide-type textile fabric or nonwoven fabric and 2-hydroxyethyl methacrylate, a combination of a polyamide-type textile fabric or nonwoven fabric and N-vinyl-2-pyrrolidone, a combination of a polypropylene-type textile fabric or nonwoven fabric and acrylic acid, a combination of a polypropylene-type textile fabric or nonwoven fabric and methacrylic acid, a combination of a polypropylene-type textile fabric or nonwoven fabric and 2-hydroxyethyl acrylate, a combination of a polypropylene-type textile fabric or nonwoven fabric and 2-hydroxyethyl methacrylate, and a combination of a polypropylene-type textile fabric or nonwoven fabric and N-vinyl-2-pyrrolidone. Of these combinations, the combination of the polyester-type textile fabric or nonwoven fabric and acrylic acid is especially preferable.
Preferable examples of a hydrophilic textile fabric or nonwoven fabric and a hydrophobic monomer include a combination of a cotton-type textile fabric or nonwoven fabric and perfluorooctylethyl acrylate, and a combination of a cotton-type textile fabric or nonwoven fabric and perfluorooctylethyl methacrylate.
The amount of the monomer can be selected, as required, depending on the reaction conditions and the like, and it is not particularly limited if it is an amount by which a hydrophilic nature corresponding to the use can be imparted to another surface of the textile fabric or the nonwoven fabric. For example, it is between 0.3% by weight and 2.0% by weight, especially preferably between 0.5% by weight and 1.2% by weight based on the total amount of the textile fabric or the nonwoven fabric.
[Fourth step]
In the textile fabric or the nonwoven fabric obtained in the third step, the sizing agent remains while being coated on one surface. Accordingly, this sizing agent is removed in the fourth step. Since the homopolymer of the monomer and the unreacted monomer are adhered to the other surface, these can be removed simultaneously.
The removal can be conducted by an ordinary method for removing a sizing agent, an unreacted monomer and the like from the textile fabric or the nonwoven fabric. For example, it can be achieved by washing the same with warm water of at least 40° C. and at most 60° C. The sizing agent and the like may be removed, as required, through ultrasonic washing.
In this manner, the textile fabric or the nonwoven fabric in which only one surface is modified, namely which has a difference in function between front and back surfaces is obtained.
The case of partially coating one surface of the textile fabric or the nonwoven fabric with the sizing agent in practicing the present invention is described as follows. That is, the shape in partially coating the sizing agent is not particularly limited. It can be arranged in various patterns such as a striped pattern, a lattice pattern, a circular pattern, an elliptical pattern and the like, or in any optional pattern. The surface other than the surface wholly or partially coated with the sizing agent in the textile fabric or the nonwoven fabric is subjected to the low-temperature plasma treatment to form the active seed, and this active seed is partially graft-polymerized with the polymerizable monomer, after which the sizing agent can be removed.
EXAMPLES
The present invention is illustrated more specifically by referring to the following Examples.
Example 1
As a water-soluble sizing agent, sodium alginate was adjusted to 10% by weight with water. The sizing agent was coated on one surface of a polyester jersey by a screen method such that the thickness after drying was between 50 μm and 60 μm, and allowed to stand in an atmosphere of 60° C. for 15 minutes for drying. The polyester jersey used had a thickness of 0.85 mm and a weight of 272.4 g/m 2 . Subsequently, the above-mentioned textile fabric was placed on a sample stand between inner parallel flat electrodes in an inner electrode-type plasma device (plasma treatment device supplied by Hirano Koon K.K.) for low-temperature plasma treatment. The low-temperature plasma treatment was conducted under such conditions that an inner pressure of the plasma device was 0.4 mmHg, an argon gas flow rate 100 ml/min, a plasma irradiation time 30 seconds and a discharge output 0.15 W/cm 2 . After the completion of the plasma treatment, air was charged into the device which was under reduced pressure. The textile fabric was then withdrawn from the inside of the device.
The graft polymerization reaction was conducted in a gaseous phase. In a reaction device, a hydrophilic monomer was charged into a detachable, bottomed, vertical polymerization pipe having a capacity of 160 ml, and 3 or 4 tubes cut to from 2 to 3 cm were placed in this polymerization pipe in order not to bring the sample into contact with the above-mentioned monomer. And 2 ml of acrylic acid were collected as a hydrophilic monomer, and charged into the polymerization pipe. Subsequently, the textile fabric which had been subjected to the low-temperature plasma treatment was inserted into the polymerization pipe, and put on the glass tubes. The inside of the polymerization pipe was purged with a nitrogen gas, and deaerated to reduce the pressure to 0.1 mmHg. During the reaction, the reduced pressure was maintained. The reaction was conducted at a temperature of 60° C. for 8 hours.
After the completion of the polymerization, the textile fabric was withdrawn from the polymerization pipe, and dipped overnight in warm water to remove the sizing agent and the like. Then, the resulting fabric was dried.
The amount of the graft polymer of the resulting textile fabric was 0.5% by weight based on the total amount of the textile fabric, and the texture such as an appearance, a touch or the like was the same as that of the untreated textile fabric.
Example 2
As a water-soluble sizing agent, sodium alginate was adjusted to 10% by weight with water. The sizing agent was coated on one surface of the same polyester jersey as that used in Example 1 by a screen method such that the thickness after drying was between 50 μm and 60 μm, and allowed to stand at room temperature for 5 hours for drying.
Subsequently, the plasma treatment was conducted as in Example 1, and the graft polymerization reaction was conducted as in example 1 except that 2 ml of 2-hydroxyethyl acrylate were used instead of 2 ml of acrylic acid as a polymerizable monomer.
After the completion of the polymerization, the sizing agent and the like were removed, and the textile fabric was then dried, as in Example 1. The amount of the graft polymer of the resulting textile fabric was 0.5% by weight based on the total amount of the textile fabric.
Example 3
A grafted polyester jersey was obtained in the same manner as in Example 2 except that 2 ml of N-vinyl-2-pyrrolidone were used as a polymerizable monomer.
The amount of the graft polymer of the resulting textile fabric was 0.8% by weight based on the total amount of the textile fabric.
Comparative Example 1
A grafted polyester jersey was obtained in the same manner as in Example 1 except that a sizing agent was not coated as a plasma reaction-preventing layer. The amount of the graft polymer of the jersey was 0.8% by weight based on the total amount of the textile fabric.
Comparative Example 2
Since the plasma device used in the present invention uses inner parallel flat electrodes, it is impossible to protect one surface of a textile fabric by spreading the same on the electrode plates as described in the above-mentioned document in which the drum-type electrode is used. Accordingly, in Comparative Example 2, the textile fabric was fixed on a curved glass plate instead of the electrode plates using a cotton yarn, and the plasma treatment was conducted.
That is, a grafted polyester jersey was obtained in the same manner as in Example 1 except that the low-temperature plasma treatment was conducted such that the above-mentioned polyester jersey fixed on the curved glass plate with the cotton yarn without using the sizing agent as the plasma reaction-preventing layer was placed on the sample stand between the inner parallel flat electrodes in the plasma device.
The amount of the graft polymer of the resulting textile fabric was 0.6% by weight based on the total amount of the textile fabric.
[Tests for water absorption and water permeability]
The grafted polyester jerseys obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were washed by a simple method according to JIS-0217-104. After the washing was repeated ten times, the tests for water absorption and water permeability were conducted with respect to each of the textile fabrics.
The water absorption and the water permeability were measured by the following method. First, exactly 0.1 cc of an ink solution (hereinafter referred to as “droplets”) obtained by diluting commercial ink (blue black) to 2.0 times with water were added dropwise to a glass plate coated with a Teflon resin. Each of the polyester jerseys was put on droplets, and allowed to stand for 60 seconds. Subsequently, each of the polyester jerseys was moved to another glass plate coated with a Teflon resin, and allowed to stand for 3 minutes. Then, wet areas of both surfaces of each of the polyester jerseys were measured. The results are shown in Table 1.
TABLE 1
Surface area
Hydrophilic
Wet area (cm 2 )
(outside/droplet
monomer
Outside
Droplet side
side)
Ex. 1
Acrylic acid
21.9
1.1
19.91
Ex. 2
2-Hydroxyethyl
10.8
1.2
9.00
acrylate
Ex. 3
N-vinyl-2-
15.0
1.5
10.00
pyrrolidone
Com. Ex. 1
Acrylic acid
6.7
6.5
1.03
Com. Ex. 2
Acrylic acid
6.5
5.7
1.14
In the polyester jerseys obtained in Examples 1 to 3, the wet areas of the outside are increased to approximately 20 times, approximately 9 times and approximately 10 times relative to the wet areas of the droplet side respectively. This is consistent with the model view (C) of the textile fabric having both the hydrophobic surface and the hydrophilic surface in FIG. 1 . Accordingly, it is found that in the polyester jerseys obtained in Examples 1 to 3, only one surface is modified to have a hydrophilic nature, and the fabrics have a difference in function between front and back surfaces.
On the other hand, with respect to the polyester jersey obtained in Comparative Example 1, the wet area of the droplet side is approximately consistent with that of the outside, and it is not enlarged. This is consistent with the model view (B) of the textile fabric having both hydrophilic surfaces in FIG. 1 . Accordingly, it is found that when the graft polymerization is conducted with the plasma treatment without coating the sizing agent, both surfaces are modified to have a hydrophilic nature.
With respect to the polyester jersey obtained in Comparative Example 2, the same water absorption and water permeability as in the model view (B) are shown although the wet area of the outside is slightly larger than that of the droplet side. Accordingly, in the polyester jersey obtained by the method of Comparative Example 2, both surfaces are modified to have a hydrophilic nature in exactly the same manner.
Example 4 and Comparative Example 3
In Example 4 and Comparative Example 3, the grafting was conducted as in Example 1 and Comparative Example 1 except that a commercial polyamide jersey was used. With respect to the resulting grafted textile fabrics, the tests for water absorption and water permeability were conducted in the above-mentioned manner.
In the textile fabric obtained in Example 4, the wet area of the outside was larger than that of the droplet side. Accordingly, it was found that only one surface was modified to have a hydrophilic nature, and the fabric had a difference in function between front and back surfaces. Meanwhile, in the textile fabric obtained in Comparative Example 3, the wet area of the droplet side was approximately consistent with that of the outside. Thus, the wet area was not enlarged. Accordingly, it was found that in the textile fabric obtained in Comparative Example 3, both surfaces were modified to have a hydrophilic nature.
Examples 5 to 8 and Comparative Examples 4 to 7
In Examples 5 to 8 and Comparative Examples 4 to 7, one surface or both surfaces were grafted in the same manner as in Example 1 and Comparative example 1 except that the textile fabric used was replaced with a textile fabric of a polyester taffeta, a polypropylene plain weave, a polyamide taffeta and a polyacrylonitrile plain weave in this order.
In these textile fabrics, the thickness of the fabric was not satisfactory, and the dot of ink on the front surface was overlapped with the dot of ink on the back surface. Therefore, it was impossible to evaluate the difference in function between the front and back surfaces by the tests for water absorption and water permeability.
Then, with respect to these textile fabrics, the difference in function between the front and back surfaces was evaluated by a dyeing method with a cationic dye (Estrol dye: Estrol Red N-GSL, made by Sumitomo Chemical Co., Ltd.).
In the textile fabrics of the polyester taffeta, the polypropylene plain weave, the polyamide taffeta and the polyacrylonitrile plain weave obtained by the grafting as in Example 1 and Comparative Example 1, the graft polymerization with the acrylic acid monomer was conducted, and the acidic group (—COOH) of acrylic acid was present on the surfaces of the textile fabrics. In the cationic dye, dyeing was conducted with a salting bond between the cationic ion of the dye and the acidic group on the surface of the textile fabric, and the larger the number of the acidic group present on the surface, the fabric is dyed deeper. Accordingly, the difference in function between the front and back surfaces was evaluated in terms of the extent of the dyeing.
In the textile fabrics in Examples 5 to 8 in which the grafting was conducted in the same manner as in Example 1, one surface was dyed light, and the other surface was dyed deep.
On the other hand, in the textile fabrics in Comparative Examples 4 to 7 in which the grafting was conducted in the same manner as in Comparative Example 1, both surfaces were uniformly dyed deep.
Accordingly, in the textile fabrics of the polyester taffeta, the polypropylene plain weave, the polyamide taffeta and the polyacrylonitrile plain weave obtained in the same manner as in Comparative Example 1, the acidic group is present on both surfaces. It is said that both surfaces are modified to have a hydrophilic nature. On the other hand, in the textile fabrics of the polyester taffeta and the like obtained in the same manner as in Example 1, the acidic group is found to be present on one surface alone. It is said that only one surface is modified and the fabrics have the difference in function between the front and back surfaces.
Example 9
As a water-soluble sizing agent, sodium alginate was adjusted to 10% by weight with water. One surface of the same polyester jersey as that used in Example 1 was partially coated with a sizing agent in a striped pattern by a screen method such that the thickness of the sizing agent after drying was between 50 μm and 60 μm. Specifically, in the hydrophobic surface (1) shown in FIG. 1 (C), the patterning was conducted such that the hydrophilic portion was arranged between the hydrophobic surfaces at intervals of 5 mm or less and the area ratio between the hydrophobic portion and the hydrophilic portion was between 30:1 and 1:1.
In the above-mentioned manner, the sizing agent was coated, and the fabric was then allowed to stand in an atmosphere of 60° C. for 15 minutes for drying. The same dry condition can also be obtained by the other drying method in which the fabric is allowed to stand at room temperature for 5 hours.
Subsequently, the plasma treatment was conducted as in Example 1, and the graft polymerization reaction was conducted as in Example 1 using 2 milliliters of acrylic acid as a polymerizable monomer.
After the completion of the polymerization reaction, the sizing agent and the like were removed, and the textile fabric was dried, in the same manner as in Example 1. The amount of the graft polymer of the resulting textile fabric was 0.5% by weight based on the total amount of the textile fabric.
[Tests for water absorption and water permeability]
The partially grafted polyester jersey obtained in Example 9 was repeatedly washed ten times by the above-mentioned simple method according to JIS-0217-104. Subsequently, the textile fabric was subjected to the tests for water absorption and water permeability in the above-mentioned manner. The results are shown in FIG. 2 .
As shown in FIG. 2 (A), the textile fabric was placed such that the surface modified in the striped pattern was brought in contact with the ink solution. The textile fabric was caused to absorb ink, and then dried. FIG. 2 (B) shows a state where the wholly modified surface was caused to absorb ink. FIG. 2 (C) shows a state where the surface modified in the striped pattern was caused to absorb ink. According to the drawings, it is observed that the wet area of the surface in contact with ink [FIG. 2 (C)] and the wet area of the opposite surface [FIG. 2 (B)] are approximately the same, while the wet amount of the hydrophobic region ( 1 ) is small.
As mentioned above, the sizing agent is coated not wholly but partially, making it possible to conduct modification in various manners. Consequently, the field of use in the present invention can be widened by variously selecting chemical and physical properties of the graft polymer.
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Provided is a method for modifying one surface of a textile fabric or a nonwoven fabric, which comprises coating a sizing agent inactive to plasma treatment on one surface of a hydrophobic or hydrophilic textile fabric or nonwoven fabric, subjecting another surface of the textile fabric or the nonwoven fabric to low-temperature plasma treatment to form an active seed for a graft polymerization reaction, then graft-polymerizing this active seed with a polymerizable monomer, and thereafter removing the sizing agent coated on one surface of the textile fabric or the nonwoven fabric. Clothing in which sweat given in sports or the like can easily be shifted from one surface to another thereof and can easily be evaporated and which has wash and wear properties is obtained.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and claims the benefit of U.S. Provisional Application No. 61/306,030, filed Feb. 19, 2010, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates in general to certain new and useful and required improvements in the protection of pipe insulated materials from outdoor physical and degradation damage as well as efficient and aesthetic methods to prevent atmospheric air leakage from entering a building. In particular, the invention relates to a pipe and duct installation system which seeks to improve long term optimal energy efficiencies in residential and commercial buildings and to follow the new 2012 Energy Model Codes.
BACKGROUND
There are many challenges with long term optimal energy efficient installations of outdoor insulated pipe and conduit, including the protection of these from ultraviolet exposure, weather, wind, physical and material degradation or both. The degradation of these pipe insulated materials is very important to maintain energy efficiency as the heating or cooling systems depend on the conveyed fluids and the maintaining of temperatures being controlled. These temperatures can be negatively affected by extreme outdoor temperatures and in turn, make the systems work harder and longer than would otherwise be necessary, therefore adding energy consumption.
In addition, building fenestration has also become an important energy efficient issue. The stoppage of outdoor atmospheric air coming into the buildings is a very important issue, as this negatively affects the controlled indoor building temperature and will make the cooling and heating mechanical systems work harder and longer than would otherwise be necessary, and again therefore adding energy consumption.
There are also many associated installation challenges when exterior wall penetration is required including sealing, connecting, aesthetics, maintenance, and flexibility. Many times the multiple amount of Air Conditioning or Heating unit systems and the respective line sets are ganged up in one central location making it difficult for the installer to install, seal, and protect each and every line set. Therefore, there is a need for a receiver that can accommodate the line sets in a quick, efficient, aesthetic, and a systematic battery or gang method. These installations are common in apartment buildings, office buildings and where more than one system is installed in the same area.
There are many different ways that these installations are taking place. More specifically pipe insulation is generally not being protected and the weather exposure causes the degradation of the soft foamed polymers used as insulation. When the pipe insulation is protected, in many instances, adhesive tapes are used. The weather exposure eventually causes the tape adhesives to either fail due to unraveling or fusing to the polymer causing material permeation issues, corrosion, mold, and maintenance issues.
Among the many different methods presently being used is the recess boxing method. This is done by the installer having a metal box fabricated and embedded into the exterior wall and having the line set passing through the box and then sealing all around with a urethane foam or other kind of sealant. In this method, aesthetics and proper long term sealing are inadequate, as the installations look unsightly with unaesthetic unfinished cavities in the wall and the hardened urethane foam materials fail and become cracked therefore leaving air leakage gaps.
There are installations presently being used that make use of single inlet roof flashings which are attached and are embedded to the rough membrane of the exterior wall and which are made of sheet metal, plastic or a combination of both. The flashing is used to contain an area for the line set to go thru a single metal area and other flashings contain a neoprene resilient single area for the seal of the line set that stretches to accommodate different diameters. However there are several set backs to these installation methods. When metal only flashings are used, not only does it become a necessity to seal the line set gap left between the annular metal area of the flashing and the line set to seal for air leakage, but a very difficult to seal hollow area is created. This area is presently being sealed by the usage of adhesive tapes that fail or foam sealers that also eventually fail. The roof flashing is also limited in that it does not allow the installer an option of attachment as the installation always has to be made on the rough wall while construction is taking place. Therefore if the installer misses or forgets to do the installation during construction, it will be difficult to correct the problem later. The other limitation is that the single passageway holds a very thin area that requires a difficult angle to accommodate and lacks surface area continuance, making an efficient installation impossible. This is due to for the most part the extreme directional angles of the piping to be accepted. In addition, whether a plastic or a metal flashing is used or not, the non-supported exterior wall finish material that is terminated at the single neck area radius of the flashing, creates a difficult and unsupported surface area for application of the finish materials. This will leave areas with unfinished material gaps, crevasses, and cracks that cause air leakage. The other limitation of roof flashings is the lack of flexibility of the single opening as the line sets address the wall, from many different angles, before going into or out of the exterior walls. U.S. Pat. No. 5,588,267 to Rodriguez and U.S. Pat. No. 7,730,681 B2 to Gilleran show examples of roof and wall flashings.
In addition there is another installation method that uses an exterior rigid plastic wall shield that is not always economically feasible. Most of the linear line sets are installed in the cavity of the exterior walls. Sealing to prevent air leakage is not a feature in this system. In addition there is a limitation with rigid shields as flexibility has become a challenge and an important requirement for full enclosure of these hard to follow line set patterns.
There has been a need for a complete insulated pipe and duct mounting arrangement in the marketplace. The installer has been having to depend on make shift custom fabrications that leave much room for improvement and are limited on sealing, aesthetics, attachment, and that are time consuming to install. Therefore there is a need for an improved system which is easy to install and highly efficient in operation.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a wall duct receiver assembly adapted to fit together with a flexible protective cover to provide a long term energy efficient line set installation that will not depend on adhesives, tape, or foam fillers.
It is also an object of the invention to provide a wall duct receiver assembly that incorporates mechanical attachments with improved aesthetics for single and multiple inlets and connections to accommodate insulated pipes and ducts of different sizes.
It is another object of the invention to protect pipe insulation line set materials from physical or ultraviolet degradation, and to provide a wall receiver assembly which is easily removable and reusable for maintenance and with flexible capabilities for full enclosure without the use of adhesive tape.
It is another further object of the invention to mechanically connect a single insulated line set or a multiple insulated line set or a battery of insulated line sets to a single wall receiver that has the ability to seal and secure a single inlet or multiple inlets against air leakage and accommodate different diameters and to include one or more inlets within the same wall receiver.
It is an additional object of the present invention that the wall receiver inlets have a high degree of flexibility that allows for sealing at an extreme angle and offer a 360 degree of high flexibility to accommodate difficult to seal line set patterns.
It is also an object of the present invention that the wall receiver allow for an economic installation solution to allow the longest linear part of the line set to be installed in the exterior wall cavity and yet allow for the soft copper piping bending radius required, to exit at the equipment service point without the need for extra pipe joints or fittings.
It is still a further object of the present invention that the wall receiver be insulated and will seal the area between the wall surface and the receiver to prevent air leakage and that allows for the installation to be directly installed to the finished surface of the exterior wall with mechanical fasteners that are directly anchored or attached to the wall surface.
It is yet another object of the present invention that the wall receiver allows for the utility of an interior wall bracket that will not utilize or perforate the exterior finished wall surface for mechanical fastening attachments but rather will be attached to the rough interior wall by use of nails or screws and in turn will be the attachment or support for the wall receiver with all the required fasteners pre-arranged and for the proper receipt or mounting of the wall receiver.
With the above and other objects in view, my invention resides in the novel features of construction, form, arrangement, and combination of parts and components presently described and pointed out in the claims.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to an insulated pipe mounting arrangement system that fits over a section of an air conditioning line set and receives it at the service point where the mechanical equipment is installed outdoors. This combined system uses two main components each with its own separate components and features. A protective cover that goes over the exposed insulated line set, and a wall receiver that is installed as the connector or transition between the building envelope or exposed insulated line set and the exterior wall penetration.
The line set protective cover can be made of resilient materials like poly vinyl chloride (PVC) or the like, and can be injection molded or plastic sheeting as these materials have been found to contain resistant degradation qualities when exposed in outdoor use. The other materials that can withstand outdoor use for this specific purpose are metal and canvas. However, metal has flexibility, corrosion and cost disadvantages and canvas has issues with moisture rot and attachment limitations. Therefore flexible plastic and the usage of fasteners such as hook and loop or other type of mechanical fastener is ideal for this specific usage. Since wind or tamper resistance is also desirable these protectors will also integrate an extra tamper resistant fastening method with the installation as optional for the installer.
The cover can be made for easy on and off use with a slit and fasteners that are attached for ease of installation or it can be more of a conduit construction with a flexible design. The importance of a service person having access to the line set copper lines is important as this is an area that requires constant repair and maintenance and requires the copper lines to be repaired for leaks. This invention also intends to relate to and accomplish improved and incorporated methods on how to protect insulated pipe for easy, quick and more efficient installations and to make service maintenance inspections quicker and more efficient with removable and replaceable features.
Regardless of the protectors having a slit or non-slit construction, one area of importance is the point of connection with the wall receiver. The wall receiver can be plastic injection molded and made of rigid poly vinyl chloride (PVC) or acrylic butylenes styrene (ABS) or the like and can also be either fabricated or molded and made out of metal. These plastic materials can resist long term outdoor exposure by the use of additives. The inlet that will be receiving the line set and that is mounted on the wall receiver has a radius construction made of plastic that is highly resilient flexible material such as neoprene, silicone or the like. The importance of this material to be highly flexible and resilient is that the specific point of connection is best suited with these features to accommodate different line set diameter sizes so the requirement for highly resilient material is important for multiple size fit capabilities. In addition the radius construction has a tapered design that allows added flexibility to ensure air leakage sealing even when extreme angled line set fitting is required. A tight and flexible fit can then be utilized to prevent building atmospheric air leakage from the inlet. In addition, a secondary holding fastener is also utilized to ensure continued connection security and long term sealing.
Also important is the method of wall attachment that the wall receiver offers. The receiver can be installed with the wall receiver directly bolted to the wall whether backing is used or not. The preferred installation is the combination housing receiver with the wall bracket as this will not require the use of wall penetration for fasteners. The wall bracket is preferably made out of 18 gauge galvanize sheet metal, the bracket can also be made out of rigid plastic and can be injection molded or fabricated.
The wall bracket installs to the rough wall membrane and has apertures for direct nailing or bolting to the rough wall to make the installation quick and easy. The wall bracket has integral fastener receivers that allow the wall receiver to be attached. Once the finish surface is complete, the bracket will then serve as a support and help enhance the sealing with a sandwiching effect as a weather gasket is placed between the wall surface and the back side rim of the wall bracket. Fasteners are also part of the wall receiver assembly and may come in different lengths depending on the wall membrane thickness requirement. The wall receiver also includes fastener openings or apertures that will allow easy installation either directly to the wall or to the wall bracket. The preferred fastener openings are scored with knockout capabilities so that the installer has the option of installation with or without the bracket. The knockout feature prevents air leakage through the fastener apertures which will not be needed to accommodate the fasteners. Caps can also be used to cover the fastener opening areas as well.
This invention possesses many other advantages and has other purposes which may be made more clearly apparent from a consideration of the forms in which it may be embodied. These forms are shown in the drawings forming a part of and accompanying the present specification. For purposes of illustrating the basic principles they will now be described in detail. It is to be understood that the following detailed description and the accompanying drawings are not to be taken in a limiting sense.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1A is a front exploded perspective view showing a complete front view of the wall retainer housing and the wall bracket used with and connected to the insulated pipe line set with a protector;
FIG. 1B is an enlarged and detailed sectional side view showing an outdoor exposed installation including a conventional insulated and protected air conditioning or heating exchanger line set and the wall receiver mounting assembly;
FIG. 2A is a back view of a wall receiver housing only;
FIG. 2B is a side view of an insulated wall receiver housing;
FIG. 2C is a back side view of an insulated wall receiver housing;
FIG. 2D is a partially cutaway side view of a wall receiver with a threaded mechanical connection construction;
FIG. 3A is a front view of the wall receiver housing with elastic neck inlets;
FIG. 3B is a sectional side view of an insulated wall receiver housing with the front elastic neck inlets of FIG. 3A showing a gasket abutted to the back edge at the perimeter of the wall receiver;
FIG. 3C is a back side view of the insulated wall receiver of FIG. 3A showing the back side of the perimeter of the wall receiver that abuts with the gasket including the tapered inlet neck areas and the fastener passageways 127 .
FIG. 4A is a front view of an exterior elastic inlet neck area and its open passageway;
FIG. 4B is a side view of the exterior of the elastic inlet neck area of FIG. 4A with raised areas for secure clamp area and the tapered diaphragm attachment area that allows the wall area of the wall receiver to be accommodated in the tapered area for attachment;
FIG. 4C is a front view of an angled neck inlet;
FIG. 4D is a side view of the angled neck inlet of FIG. 4C ;
FIG. 5A is a front view of an exterior elastic inlet neck area with a closed or sealed passageway and an end cap area with a score line cutting area to accommodate and seal smaller diameter pipe, conduit or wiring;
FIG. 5B is a side view of the exterior elastic inlet neck area of FIG. 5A showing the cut score lines, tapered attachment area and the end cap area, including the raised area to secure clamping;
FIG. 6A is a front view of an optional rough wall bracket for attachment of the wall receiver housing to a wall;
FIG. 6B is a side view of the rough wall bracket of FIG. 6A showing a channel area between the large flanged perimeter area that is directly abutted to the rough wall and the smaller flanged perimeter area that abuts to the gasket and the finish surface area;
FIG. 7A is a front view of the wall gasket that abuts between the finish surface of the exterior wall and the back side of the perimeter edge flange within the back side of the wall receiver housing;
FIG. 7B is a side view of the gasket of FIG. 7A ;
FIG. 8A is a front and enlarged sectional view of the pipe, pipe insulation, and pipe insulation protector;
FIG. 8B is a side sectional view of the pipe, pipe insulation and pipe insulation protector line set assembly of FIG. 8A ;
FIG. 8C is a front view of a non-slit protector or conduit construction with the pipe and pipe insulation inside;
FIG. 8D is a side sectional view of the protector or conduit with an enlarged fastening joint area line set assembly;
FIG. 8E is a front view of the protector or a conduit for pipe insulation with a slit construction:
FIG. 8F is a front view of a protector or a conduit for pipe insulation with an overlapping edge construction;
FIG. 9A is a front view of a clamp or ring type securing fastener;
FIG. 9B is a side view of a clamp or ring type securing fastener of FIG. 9A ; and
FIG. 9C is a front perspective view of a threaded type securing fastener.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The preferred embodiments described herein are only for purposes of illustration and are not to be understood to be any limitations on the inventive subject matter being described.
The preferred embodiment of the insulated pipe ducting and mounting arrangement is a system of FIG. 1A that incorporates a wall receiver 100 with one or more attached continuous inlet ducts 400 and 500 for receiving a pipe or piping 900 covered by insulation 800 and that includes a protector system 700 for the insulated pipe or piping 900 that has been adopted by the new 2012 Energy Codes for the Residential and Commercial Building Energy Model Code Requirements. The codes require that the exposed insulated piping 900 be protected from the outdoor weather exposure and physical damage without the use of adhesive tape. The preferred embodiment described below incorporates many detailed solutions for the many challenges associated with this requirement.
In the preferred embodiment shown in FIG. 1A , the wall receiver 100 has a predetermined and configured angle making it possible to accommodate the piping 900 within a wall cavity defined between adjacent 2×4 studs 1200 , and enabling the pipe to be bent to the exterior without kinking. Installations using the least possible fittings are the most desirable ones, as this is a way to minimize friction within the fluids for better efficiency in the running of the equipment that will result in energy efficiencies as well. The refrigerant fluids are carried by the piping 900 which is made of soft copper. The copper piping 900 can be bent by the installer up to a certain degree, which is the standard practice in the plumbing, heating and cooling industry.
The Residential and Commercial Building Energy Model Codes are gravitating into improved and increased pipe insulation, outdoor protected insulation, and fenestration, which is the elimination of heat or cold from atmospheric air leakage and entering into the building and negatively affecting the energy consumption. Therefore in another preferred embodiment, the wall receiver 100 is insulated by a layer of insulation 130 on the back side of the cavity area of the wall receiver 100 as shown in FIG. 2C . The wall receiver 100 in another preferred embodiment has a respective wall bracket 300 shown in FIG. 6A and FIG. 6B that is attached to the rough 2×4 wall studs 1200 of a building as shown in FIG. 1A , by use of nails 1100 or screws which pass through apertures 302 shown in FIG. 6A . The bracket 300 receives a finish wall receiver housing 100 shown in FIG. 1A , assisted and held by fasteners which pass through apertures 301 shown in FIG. 6A that are threaded housings.
In a preferred embodiment shown in FIG. 7A , a gasket 200 is provided for sealing between the wall receiver 100 and the bracket 300 to prevent air leakage. The gasket 200 is assisted by the use of fasteners 1000 shown in FIG. 1A , that engage with threaded apertures 301 as shown in FIG. 6A and threaded housings or fastener receivers 303 shown in FIG. 6B . The wall bracket 300 has a channel 304 shown in FIG. 6B that is formed between the large flange 305 that is nailed or screwed to the rough wall and the small flange 306 shown in FIG. 6A that holds the wall receiver 100 . The channel 304 can be changed in dimension, made either wider or narrower, to accommodate thicker or thinner exterior wall thicknesses and the combined wall membrane thicknesses required. In a preferred embodiment the large flange 305 of the wall bracket shown in FIG. 6A can also be formed, bent or constructed into different shapes such as extended ear-like shapes to assist in installing the bracket 300 and to make it easy and efficient to accommodate for different exterior construction types such as masonry exterior wall construction and the like.
The preferred embodiment shown in FIG. 18 incorporates the bracket 300 and the finish wall receiver housing 100 , the gasket 200 and the exterior wall membrane 1300 that creates a pressure system to not only seal from air leakage but also offers a fully pressure supported distributed system that creates clamping pressure applied inside and outside the wall to prevent long term cracking, spacing, and a more efficient, uniform, consistent wall surface finished gap and sealed installation. The wall receiver housing 120 shown in FIG. 2A incorporates apertures 121 for fasteners and has a finish edge or rim 124 that supports and allows for any added sealing that may be applied such as weatherproof silicone material caulking around the narrow edge perimeter of the receiver 100 . An entry point 122 or points 123 are formed as openings in the slanted front panel 125 the wall receiver 100 . As shown in FIG. 1B , the front panel 125 is slanted to provide a cavity area 126 inside the wall receiver 100 . The wall receiver 100 shown in FIG. 1A and the respective wall bracket 300 can also accommodate different exterior wall thicknesses with the simple use of either longer or shorter bolts 1000 , or threaded rods and threaded nuts, or other type of anchoring fasteners. FIG. 2C shows that the wall receiver 100 can also be insulated by providing a layer of insulation 130 on the back side of the cavity area 126 defined by the slanted front panel 125 .
The wall receiver 100 , shown in FIG. 1A in a preferred embodiment can also be installed on its own without the use of the rough wall bracket 300 . The wall receiver 100 has apertures 121 shown in FIG. 2A to accommodate different types of fasteners that are available to the installers and that are capable of passing through the receiver and wall area, such as bolts, anchor fasteners, toggle fasteners or any combination thereof.
In a preferred embodiment the wall receiver 100 may have one or more inlets 400 and 500 with different sizes that are mounted over the wall receiver openings of 122 and 123 shown in FIG. 2A . The inlets may be attached with the wall receiver 100 by the use of elastic material over molding or an attached molded sandwich type insert. As shown in FIG. 5B , a molded plastic insert 404 can be inserted at the back of the inlet 400 to attach the insert 500 to the front panel 125 of the wall receiver 100 . The molded plastic insert 404 has a back face or flange 405 which together with a back face or flange 408 of the inlet 400 provides a channel to receive the material of the wall receiver housing 100 in a sandwich-like fashion between the flanges 405 and 408 . A molded plastic insert 503 shown in FIG. 4B can be inserted at the back of the inlet 500 to attach the inlet 500 to the front panel 125 of the wall receiver 100 . The molded plastic insert 503 has a flange 506 which together with a flange 508 of the inlet 500 provides a channel to receive the material of the wall receiver housing 100 in a sandwich-like fashion between the flanges between the flanges 506 and 508 .
In the preferred embodiment, the inlets 400 and 500 of FIG. 1A can be constructed to accommodate pipes of different sizes. Each of the inlets 400 shown in FIG. 1A can have an integral cap 401 or end point with score lines 402 in the end areas so the installer can cut the opening to the desired fit size on the job. Therefore the installer will have a choice of the desired inlet to be opened and used. The inlets shown in FIG. 5A not to be utilized can be air leak sealed within the integral end cap area 406 . The end cap area 406 can also contain score lines 407 within different sized diameter areas which can be cut by the installer to accommodate different sizes of pipe conduit and the like. The inlet 500 can be provided with a similar end cap and score lines to allow the size of the opening to be adjusted to accommodate different sizes of pipe conduit.
In a preferred embodiment shown in FIG. 4B , the inlet 500 has raised lines or guides 502 which are spaced apart to provide an area for a clamp or ring fastener. Also, as shown in FIG. 5B , the inlet 400 has raised lines or guides 402 and 403 which are spaced apart to designate the area for the clamp or ring fastener. The raised lines 402 , 403 and 502 can also be used as cutting line guides or score lines with integral weakened or exterior or internal thinner material lines for cutting to required size, diameter and or length that can be integrated for multiple sizes with a taper or graduated form.
The inlet 500 shown in FIG. 1A , that is attached to the wall receiver 100 has several unique features in its preferred embodiment. The inlet 500 provides a flexible 360 degree universal entry angle capability which is important as the direction of the entry point will be different for the installer in different installations. The receiver inlet 500 may also have a housing that will be integrated into the wall receiver or attached by mechanical means, allowing the inlet 500 to be fully rotatable or to swivel to accommodate any angle that the insulated piping 900 is to be received from shown in FIG. 4C and FIG. 4D .
The preferred embodiment inlet shown in FIG. 4C and FIG. 4D can combine an integral angled inlet 504 that can have a built-in orientation in the approximate range of 45, 60, or 90 degrees. The angled inlet embodiment provides for easier accommodation of the insulated piping 900 and the protector 700 that are connected with the inlet 500 , mostly from a lower or higher elevation position but most importantly away from the exterior wall. The angled inlet 504 shown in FIG. 4D can easily be rotatable to accommodate piping 900 from different directions. The angled inlet 504 can be cut along the angled score line 505 shown in FIG. 4D for a straighter directional installation.
The preferred embodiment of the inlet 500 has a continuous elongated neck area shown in FIG. 1B and has an inlet continuance that conventional roof flashing of the prior art do not have. The inlet 500 incorporates an internal passageway area 501 shown in FIG. 4A for a higher degree of air leakage deterrence. At the same time the exterior inlet neck area 500 allows for a weather resistant or tamper-resistant connection with the pipe insulated protector, by the added security of a mechanical clamping means 600 shown in FIG. 1A either secured to the wall receiver 100 and or the inlet 500 or both.
The preferred embodiment of the inlet neck 500 shown in FIG. 1A can be made of a highly resilient and resistant plastic. The inlet neck 500 can be an exposed part or it can be a protected part with a respective housing cover or shade directly attached to the inlet neck 500 or to the wall receiver base or both by means of mechanical attachment. The inlet neck cover 500 shown in FIG. 4B is attached preferably by plastic over molding snap on fastening, bolted, threaded, inserted, or other co-acting fastening components 503 . In a preferred embodiment the wall receiver 100 , as shown in FIG. 2D , can have a threaded connection 101 , which can be integrally molded or attached as a separate part to the construction, to assist in connecting the arranged pipe insulated protector with the wall receiver 100 and also serving as an inlet passageway 102 .
In a preferred embodiment shown in FIG. 4A of the exterior neck inlet base area 500 , a universally directional and adjustable housing or cover can be provided to cover the highly resilient plastic to prevent atmospheric air leakage into the building. The adjustable housing or cover can be attached to the inlet neck area base 500 or the wall receiver base 100 shown in FIG. 1A or both by means of mechanical attachment. The inlet, its respective cover, or a combination can be both preferably attached or connected by a snap on, bolted or other co-acting mechanical fastening elements.
In the preferred embodiment of the inlets 400 and 500 shown in FIG. 3A , the score lines can be arranged with different diameters to allow the selection of multiple diameter sizes by cutting along the score lines to provide the desired diameter needed to be fitted into and or connected to the piping 900 .
In a preferred embodiment FIG. 1A both of the inlet neck internal areas 500 and 400 are able to be sized for a multiple diameter passageway of pipe and or conduit types or wiring with score lines 407 for air leak sealing. In a preferred embodiment this can also be used by a step down or tapered diameter down sized constructed inlet. This can also be accomplished in a preferred embodiment by the use of an end cap 406 or an accommodating ring end cap.
The preferred embodiment of the pipe insulated protector 700 shown in FIG. 1A , that connects to the wall receiver inlets 400 and 500 , is made of a plastic molded or extruded material that has a flexible construction and is sized to accommodate a multiple and combined amounts of insulated pipe, pipe, wiring, conduit and can be cut to the desired length needed.
In the embodiment shown in FIG. 8A and FIG. 8B , the insulated pipe protector 700 can be a larger conduit with an internal hollow core passage or a hose-like flexible conduit with a non-slit design, that fits over the pipe 900 and the pipe insulation 800 . The installer simply slips or feeds the non-slit protector 700 over the insulated pipe or conduit 900 . The protector 700 is then connected with the assistance of a mechanical fastening member shown in FIGS. 9A and 9B which can be embodied as a fastener ring 600 having an integral means of locking and hinging that assist in connecting and securing the ring 600 to the inlet neck 500 that is attached to the wall receiver 100 . In a preferred embodiment shown in FIG. 9A , the ring 600 includes a hinge 601 which allows the ring 600 to be clamped to the inlet 500 and to the pipe insulated protector 700 . In a preferred embodiment shown in FIG. 9C , the ring 600 has an internal threaded area 602 that co-acts with the threaded area 101 shown in FIG. 2D on the wall receiver housing 100 and allows for the full rotation of the inlet 500 to accommodate the different angles associated with the installation. The flexible hose-like duct 700 can also have an end connection ring or fastener 701 to assist with the co-acting connection as shown in FIG. 8D . In a preferred embodiment a cap fits on the opposite end of the arranged pipe insulation protector 700 to assist in air sealing the passageway from the opposite end.
In another preferred embodiment of the pipe insulated protector 700 shown in FIG. 1A that connects to the wall receiver inlet 500 , the protector 700 can be embodied as an elongated sleeve 701 of a plastic material that is molded or sheeted and flexible and has a longitudinal slit 703 as shown in FIG. 8E . In a preferred embodiment shown in FIG. 8F , the protector 700 is a protective cover arrangement 702 with an overlapping construction 704 , that wraps around the pipe insulation 800 shown in FIG. 1A . The overlapping sections 704 are attached to each other by the use of mechanical fastening such as bolts and apertures, snap on co-acting plastic or metal molded fasteners, or self contacting fiber fasteners or self contacting molded fasteners. The snap on or nut and bolt fasteners can also be installed with the use of eyelets.
In another preferred embodiment the pipe insulation protector 700 shown in FIG. 1A , the protector 700 can be constructed with self contact fasteners such as hook and loop and can also be arranged to accommodate a universal fit for different diameters of insulated pipe by applying a thicker fastening strip or strips on a horizontal manner or a perpendicular manner adjacent to the matching slit closed edges or the over lapped edge closure. The fasteners can be bonded and preloaded with use of molded, sonic welding, radio frequency welding, hot air welding and non adhesive bonding. If hook and loop fasteners are to be used the non adhesive bonding can also be reinforced with threaded stitching for extra weather resistant security. The protective cover 700 can then also be cut to fit and can be cut to the desired length needed.
The invention in its broader aspects is not limited to the specific details of the preferred embodiments shown and described, and it will be appreciated that variations and modifications can be made without departing from the scope of the invention.
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An outdoor insulated pipe and duct mounting system includes a wall mounted receiver arranged to receive an insulated pipe or duct provided with an insulation pipe protector which connects and seals to the receiver. The combined system is able to accommodate insulated pipes of different sized diameters and can accommodate one or more inlets within the same receiver with a high degree of flexibility and unique mechanical connection security. The mounted wall receiver system is arranged to receive the insulated piping from any directional angle with a unique full rotation inlet capability. The system serves buildings with outdoor installed air conditioning line sets, insulated pipes, and conduit that have the need to penetrate the building envelope in order to be connected to the buildings indoor mechanical, plumbing, or electrical systems. The system is designed to be installed as an option for new construction applications, to upgrade existing installations, to replace existing installations and for addition to existing installations, but all in an aesthetic and efficient way.
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BACKGROUND
[0001] Running user processes with an administrator access level is often not optimal for users. When processes run within the context of an administrative access level, they forfeit many of the security features provided by the operating system, especially when using a web browser or reading email. Yet despite this, currently many user accounts on computer systems are configured to have users login as the administrator.
[0002] Having users run applications as Least-Privileged User Account (“LUA”) is desired but is often a problem for certain applications. LUA users are those that can perform common computer tasks but typically cannot install programs or change system settings. LUA users typically do not have the authority to perform operations that can compromise system security. Corporations that have their users run as LUA are occasionally called upon to perform significant and costly work to make their applications run for LUA users. In some cases, the corporations have to loosen security, e.g., give users permission to write to areas that are typically off-limits for LUA, to allow applications to run as LUA, thus losing many of the benefits of running as LUA.
SUMMARY
[0003] Certain applications, especially legacy applications, try to write to areas of the system that require administrator privileges and, lacking sufficient privilege, fail to run successfully for LUA users. The disclosed system redirects certain file writes, i.e., globally impactful file writes to specific locations that require administrator privileges and would otherwise fail for LUA users, so as to allow the same file writes to succeed by redirecting them to happen in the LUA context of the user, i.e., in a per-user virtualization location. However, such virtual files are only created upon actual file modifications or writes, not just file reads or opens (“delayed virtualization”).
[0004] Prior applications of the assignee of the present invention have disclosed methods for non-delayed virtualization, e.g., virtualization that occurs when a file is requested to just be opened. The current system discloses methods for delayed virtualization, in which rather than occurring at the time the file is requested to be opened, a virtual file is only created when the file is actually written to. Thus, the use of the term “delay” here is intended to mean that if virtualization actually occurs, it occurs later than it would in a non-delayed or immediate virtualization situation. Indeed, not all files planned for virtualization will actually have virtual files thus created in a delayed virtualization system.
[0005] Advantages may include one or more of the following. By only creating virtual files upon an actual write, performance is improved because virtual files are not created unnecessarily. This may be particularly important for applications such as antivirus programs and Windows® Media Player that have substantial “open-for-write” operations on files but end up not performing write operations on many of those files.
[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
[0007] Additional advantages will become apparent from the description that follows, including the figures and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows the logical placement of a virtual store within a computing system.
[0009] FIG. 2 shows a flow chart indicating a method used by the system.
[0010] FIG. 3 shows a computing system that may include the system.
DETAILED DESCRIPTION
[0011] Throughout this specification, “file virtualization” generally refers to the act of transparently creating a virtual file that a user's application running with lessened privileges, such as a LUA user, and not administrator, may transparently access in lieu of accessing the corresponding non-virtual file. In particular, in many cases, the lack of administrator privileges may prevent the user's application from accessing the non-virtual file, and the act of attempting to do so will result in an error message. By allowing the user to access the virtual file instead, such errors are prevented.
[0012] In more detail, at the time of virtualization, a file virtualization filter copies the original file (the “global file”) to a location in a “virtual store” to create a “virtual file”. This virtual file is then accessed whenever a virtualization-enabled application opens the global file. If the filter creates the virtual file when the application opens the global file for write access, this is “non-delayed”, “immediate”, or “copy-on-open” virtualization. If the filter instead waits until the application actually writes to the file, this is “delayed” or “copy-on-write” virtualization. In other words, virtualization occurs when the application is actually going to write to the file, not just when file access is requested (i.e., the file is opened) without an immediate need to write to or otherwise actually alter the file.
[0013] In more detail, the default file system behavior when an application asks for write access to files, e.g., by using a file open flag such as FILE_GENERIC_WRITE, is to open the file, even though in many scenarios the application may not actually write to the file. When the user is running as LUA, and the user is denied access to a file due to lack of privilege, and the file is a candidate for virtualization, the system in part lessens or minimizes the set of files that get virtualized, so virtual files are only created when it is absolutely necessary, i.e. when the file write actually occurs. This eliminates unnecessary creation of virtual files. For example, sometimes a file is opened to record errors, but if no errors occur then the file is not actually written to. In some cases, a developer will code a procedure to first open all files that could potentially be needed by the procedure, even though most invocations of the procedure will not actually use all of those files. In these cases, and others, unused files might not be virtualized merely as a result of their being opened.
[0014] Referring to FIG. 1 , a portion 20 of a computer system is shown. A volume 61 , i.e., a specific data storage device, is shown having a virtual store 64 , explained in more detail below. The volume 61 is accessed via a file system driver 74 . The file system driver 74 accesses files from a filter manager 68 within which is a mini-file-system filter driver for LUA file virtualization 72 . An I/O system 66 accesses the file system driver 74 .
[0015] The virtual store 64 is a directory that is organized on a per-user and per-volume basis in the root directory. In other words, each volume has its own virtual directory for storing virtual files, and this directory is broken down into subdirectories for each user. The file and folder hierarchy may mimic that of the global file system.
[0016] If the virtual directory has already been created, the same may be available when the volume is available. Alternatively, the virtual directory may also be created dynamically upon demand, and is generally not roamed. In other words, the virtual directory is generally not available for server-based user profiles that are downloaded to a local computer when a user logs on.
[0017] Virtual stores may be created as needed per-volume within the root and may be partitioned per-user, e.g., by the security identification number “SID”. The appropriate security descriptors may be applied to each virtual directory or subdirectory to ensure the privacy and integrity of the user data. The same or similar security descriptors may be used as are known for user profile directories (account directories or “home” directories). As a user's virtual directory may have the same permissions as the user's profile directory, it may be fully accessible to applications and tools running in the context of the user. Virtualization is preferably not recursive; virtual stores may be excluded from virtualization if necessary or desired. Virtual namespaces, the root directory for a specific user's virtual file hierarchy within the virtual store, may be viewed as a logical file layer above the global layer. The following example shows the file layout for a virtual “WINDOWS\win.ini” file for a user:
<Volume Root> +---System Volume Information | \---Virtual Store | \---<Virtual Namespace> | \---WINDOWS | win.ini | \---WINDOWS win.ini
[0018] Also shown in FIG. 1 is the logical separation of the user mode and the kernel mode within the operating system. User mode is the non-privileged processor mode in which application code, including protected subsystem code, executes. User mode applications cannot gain access to system data except by calling subsystem-supplied functions, which, in turn, call system services. Kernel mode is the privileged processor mode in which certain operating system executable code runs. A driver or thread running in kernel mode has low-level access to system memory and hardware.
[0019] Steps of one embodiment will now be described. It is noted that much of the flowchart, up to step 54 and also including step 58 , is also present in a non-delayed virtualization system. Steps 56 and 62 comprise much of the delayed virtualization functionality. Referring to FIG. 2 , the method begins when a call is made by an application program or process to open a file or CREATE PROCESS (step 12 ). At this point, the application program is generally requesting write access to a file. Note that in this regard all file opens, whether for read access or write access, are referred to as “create” operations. Further, a caller is defined as any component running above the level of the file virtualization filter that perform file operations. The caller is usually the user application.
[0020] The next step “Is Virtualization Enabled?” (step 14 ) determines whether or not the scheme of file virtualization is enabled and usable by the operating system. The result of this step may be determined by a function call from a component within the kernel, i.e., the operating system, such as:
[0021] Return QueryVirtualizationMode(EffectiveToken);
[0022] This decision depends on the virtualization token, in this case “EffectiveToken”. Tokens such as Effective Token are token flags that are set per process. This flag may be defined, e.g., only for interactive logons, and may expose a new token information class, e.g., TokenVirtualization that allows callers to set and query this flag. If the token is set, file-writes that meet the criteria of being virtualized will be redirected to the virtual store 64 . In another embodiment, virtualization may be restricted to primary token (instead of effective) and user mode callers.
[0023] In one embodiment, the default situation for a user running as LUA would be to have virtualization enabled upon start-up, creating a restricted token. This may be set at a system/domain/per-user level. In another embodiment, if virtualization is turned off globally (for the entire machine) then no virtualization occurs. In this case, no LUA object virtualization will be performed. Existing virtual files are ignored, and can only be accessed directly in the virtual store.
[0024] Virtualization may also be turned off for a specific application. For example, some applications are designed to be only run at the administrator level. Such applications may be marked in an application database as not using virtualization. That is, virtualization may be turned off for full token users, e.g., the local administrator and users elevated to administrator privilege. When an application is started, the application may query an application database to determine if the application is so marked. If so, virtualization is not enabled and the virtualization token is not set. If virtualization is off for a given process, the files already in the virtual store 64 may not be visible to that process, i.e., read-though to the virtual store 64 may not be afforded.
[0025] However it may happen, if virtualization is not enabled then program flow proceeds to pass-through (step 18 ) which accesses the filesystem as needed (step 22 ). In particular, pass-through (step 18 ) passes the request for file access to the FILESYSTEM without allowing direct access. In this case, if the user running as LUA attempts to access a file accessible only to administrator-level users, without a virtual file available to access instead, and there would be none if virtualization was not enabled, an error message would result.
[0026] If virtualization is enabled, however, a number of criteria may be checked to determine if the particular file is a proper candidate for virtualization and disposition in the virtual store 64 .
[0027] First, if virtualization is enabled, then the system checks to see if the caller, i.e., the user application, is running in user mode as described above or is running in an impersonated profile (step 16 ). If the caller is in user mode, i.e., at an unprivileged access level, then the virtualization procedure may continue.
[0028] If the caller is not in user mode or is an impersonated caller, then the program again branches to pass-through (step 18 ) and further accesses the filesystem (step 22 ). In any case, as above, if the user running as LUA attempts to access a file accessible to users running with administrator access privileges, and a corresponding virtual file is not available to access instead, an error message results.
[0029] This “NO” branch from decision step 16 eliminates the security issues raised by impersonated and kernel mode callers. In particular, allowing virtualization for such users may allow global data to be overwritten; an act such callers ordinarily would not be allowed to do. For example, when a DLL is loaded under impersonation, such as in winlogon.exe processes, users may provide their own malicious virtual DLL and take control of the process. The current method prevents virtualization of system DLLs. In the case of kernel mode callers, drivers inspecting global data, including loading modules, may do so under impersonation. With virtualization, such callers may no longer be sure they are accessing the global version. For this reason as well, virtualization is only allowed for user mode calls.
[0030] The method then checks if the action is a re-parse (step 24 ). That is, when an application calls for a file write operation it generally initially calls for a file write operation on the global file. If the application has been re-parsed to a virtual file, however, then the remainder of the virtualization logic can be skipped, saving significant time. Thus, this step performs that check. In other words, this step is used to distinguish between a case of a direct open using the full virtual path (i.e., a file-open command with the full path such as “\Virtual Store\username\somefile”) and an open via the virtualization logic that has reparsed to the virtual file. If the action is a re-parse, then any necessary context for the virtual file is built (step 26 ) and the filesystem is accessed as before (step 22 ).
[0031] In this context, it is noted that the term reparse is used to mean that an application has been redirected to use a file different from the originally-intended file.
[0032] If the action is not a re-parse, then the process of virtualization continues. The file name may be normalized (step 28 ). In particular, the underlying file system filter driver 72 sets the short names for virtual files as the same as that for normal files. As the file system filter driver 72 is unaware of the relationship between the global and virtual directories, it may not synchronize the short names.
[0033] A difficulty may arise when a file having a short filename associated with a file in the global location may not match the equivalent short filename in the virtualized location. Moreover, if only a virtual file exists, and later a global file is created with a different long name but the same short name, then if the global file is virtualized, its virtual short name may differ from its global short name.
[0034] For example, a user may be running as LUA and the global file system location\program files\common files\appdir contains a file:
Long File Name Short File Name This is test 1.txt THISIS˜1.TXT
[0035] If an application creates a virtual file in the same location, and if a global file has not been created for this specific user, then the short file name in the virtual folder will be the same as that in the global location although the long filenames are different.
[0036] The virtual location\program files\common files\appdir then contains a file:
Long File Name Short File Name This is test 2.txt THISIS˜1.TXT
[0037] Certain rules help to resolve issues surrounding the handling of short file names. In particular, if an application requests file access, then the long file name should be used if possible. In such cases the long file name will always map to the correct location. In any case, virtualization should be ensured to occur on the correct volume, and to the same file, regardless of what name form is used to reference the same.
[0038] The next check is whether the file-write is excluded from virtualization (step 32 ). Certain filesperse are excluded from virtualization. In particular, operating system and other such files may be specifically excluded from virtualization on grounds of security and system stability. Files may be excluded from virtualization by setting an attribute on the global file, or by checking if the file is listed in an inclusion/exclusion criteria list or database.
[0039] For example, one criteria may be that if a virtualized file exists, it takes precedence over the global file unless the global file is an operating system file or other such file. Another criterion may be that only files that an administrator would have had privileges to change may be virtualized.
[0040] File virtualization should not result in additional security issues, e.g., via elevation of privileges. To this end, kernel mode calls and impersonated calls may be excluded from virtualization. Moreover, operating system and other such files may be excluded from virtualization, and only specific areas of the system where applications commonly write may be redirected.
[0041] In any case, if the file is excluded from virtualization, then the system passes through (step 18 ) to the filesystem as before.
[0042] The next check may be whether a user with heightened or administrator privileges would have had permission to change the file (step 34 ). If not, the test fails and the system passes through (step 18 ) to the filesystem as before. If so, then the file continues to be a proper candidate for virtualization and the next set of criteria may be checked.
[0043] Step 36 refers to whether the file has already been virtualized. In particular, this step focuses on whether the application is already directly accessing a virtual file in the virtual store. If the user is already directly accessing the virtual file in the virtual store, then no further virtualization is necessary and the system can continue to transparently access the virtual file via the filesystem (step 22 ). If the application is not directly accessing a virtual file in the virtual store, then the process continues to the creation of the virtual file. Note that step 36 is a check to see if the application is accessing the virtual store for the file, not a check to see if an appropriate file virtual already exists, which is the subject of a later step.
[0044] The first step in this creation is a building of a virtual path to the virtual file (step 38 ). This step connects the virtual file, to be created within the virtual store 64 , with the application requesting creation or modification of the corresponding file.
[0045] The next step solves the problem of multiple creation of a same virtual file. Once the virtual path has been constructed, the virtual path (including filename) can be checked against the virtual store 64 to determine if a virtual file for that virtual path already exists (step 42 ). If the virtual file already exists, then the application can be reparsed to the virtual file (step 44 ). The I/O system 66 is then accessed as appropriate (step 46 ).
[0046] If there is no virtual file for the virtual path, i.e., if the “does virtual exist?” (step 42 ) test fails, then the “NO” branch is followed and a global file is created (step 48 ).
[0047] The next step is to determine if access to the global file is allowed or denied (step 52 ). If access to the global file is not denied, then the action is allowed to pass through to the filesystem, as no virtualization is necessary if a global file is allowed to be created or modified. If access is denied, i.e., no access to a global file is allowed, then the next test is to determine if a global file already exists (step 54 ). If the global file does not already exist, then the application program can reparse to the virtual file (step 44 ), and access is made to the I/O system 66 , as described in more detail below in connection with FIG. 3 .
[0048] The results of steps 42 through 54 are summarized in TABLE I.
TABLE I COULD CHECK OF CHECK OF ADMIN VIRTUAL GLOBAL CHANGE STORE FILESYSTEM FILE? RESULT FILE EXISTS FILE EXISTS YES APPLICATION USES VIRTUAL FILE IN VIRTUAL STORE FILE EXISTS FILE DOES N/A APPLICATION USES NOT EXIST VIRTUAL FILE IN VIRTUAL STORE FILE EXISTS FILE EXISTS NO APPLICATION DOES NOT USE VIRTUAL FILE IN VIRTUAL STORE - PASS THROUGH TO FILE- SYSTEM FILE DOES FILE DOES N/A FILE IS A CANDIDATE NOT EXIST NOT EXIST FOR VIRTUALIZATION FILE DOES FILE EXISTS NO PASS THROUGH TO NOT EXIST FILE-SYSTEM FILE DOES FILE EXISTS YES FILE IS A CANDIDATE NOT EXIST FOR VIRTUALIZATION
[0049] If a global file already exists, then a determination is made as to whether the call is to write to a file that is not an allowed operation for delayed virtualization (step 56 ). In more detail, “Is CreateDisposition an implied write operation?” (step 56 ) refers to certain cases where delayed virtualization may not happen. In these cases, an entire file is being completely overwritten or created with new content (an implicit write) and thus delayed virtualization is preferably not used. Such operations include the following (as denoted by their corresponding operation flags): FILE_CREATE, FILE_SUPERSEDE, FILE_OVERWRITE, FILE_OVERWRITE_IF, and the like. If the call is for such an operation, then a virtual file may still be created, but in a non-delayed fashion. Virtualization is immediate in those instances because there is an implied write operation in the next operation. In general, delayed virtualization may not occur upon write or other file-altering operations, or for those which change or replace attributes, file times, data, etc. and thus non-delayed virtualization occurs instead.
[0050] It is noted that in certain other cases the file is not actually changed and yet virtualization is again not delayed. For example, if a section object on a file is being mapped for write access, e.g., as if it were memory instead of a file, then a block of memory is reserved that can be changed. For these individual writes, delayed virtualization may or may not be employed. If not, then virtualization may occur immediately rather than when changes to memory occur.
[0051] Delayed virtualization may occur for operations that do not change the file or replace the same, such as file-open, file-open-if, and the like. In the former, if the file already exists, then the operation calls for opening it instead of creating a new file. If the file does not exist, the operation fails the requests and does not create a new file. In the latter, the operation calls for opening the file if it exists. If it does not, the operation creates the file.
[0052] In these delayed virtualization cases, however, a file object is generated that is referred to here, e.g., as the delayed virtualization file. However, it should be noted that this file object is and continues to be just a link or pointer to the global file until such time as actual virtualization occurs, at which point a copy of the global file is created in the user's virtual store (step 62 ). That is, if the virtual file is created through delayed virtualization, the virtual file is not initially created per se-just a handle or pointer to the global file is created. If there later occurs a reason to create the physical file (e.g., an actual write to the file), then all existing virtual handles are synchronized and switched over to use the virtual file. In other words, the handle provides a placeholder file object whose target can be switched. All operations to the placeholder file object can be redirected to the target. Initially, the target is the global file. When a write is made, the global file is virtualized (step 62 ) and the target is switched from the global file to the newly created virtual file. The application then reparses (step 44 ) to the so-created virtualized file.
[0053] FIG. 3 illustrates an example of a suitable computing system environment 100 . The computing system environment 100 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the system. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100 .
[0054] The system as described is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
[0055] The system may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The system and method may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.
[0056] With reference to FIG. 3 , an exemplary system for implementing the system includes a general purpose computing device in the form of a computer 110 . Components of computer 110 may include, but are not limited to, a processing unit 120 , a system memory 130 , and a system bus 121 that couples various system components including the system memory to the processing unit 120 . The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.
[0057] Computer 110 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer 110 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by computer 110 . Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of the any of the above should also be included within the scope of computer readable media.
[0058] The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132 . A basic input/output system 133 (BIOS), containing the basic routines that help to transfer information between elements within computer 110 , such as during start-up, is typically stored in ROM 131 . RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 120 . By way of example, and not limitation, FIG. 3 illustrates operating system 134 , application programs 135 , other program modules 136 , and program data 137 .
[0059] The computer 110 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 3 illustrates a hard disk drive 140 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152 , and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 such as a CD ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a non-removable memory interface such as interface 140 , and magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as interface 150 .
[0060] The drives and their associated computer storage media discussed above and illustrated in FIG. 3 , provide storage of computer readable instructions, data structures, program modules and other data for the computer 110 . In FIG. 3 , for example, hard disk drive 141 is illustrated as storing operating system 144 , application programs 145 , other program modules 146 , and program data 147 . Note that these components can either be the same as or different from operating system 134 , application programs 135 , other program modules 136 , and program data 137 . Operating system 144 , application programs 145 , other program modules 146 , and program data 147 are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 20 through input devices such as a keyboard 162 and pointing device 161 , commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 120 through a user input interface 160 that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190 . In addition to the monitor, computers may also include other peripheral output devices such as speakers 197 and printer 196 , which may be connected through a output peripheral interface 190 .
[0061] The computer 110 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 180 . The remote computer 180 may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 110 , although only a memory storage device 181 has been illustrated in FIG. 3 . The logical connections depicted in FIG. 3 include a local area network (LAN) 171 and a wide area network (WAN) 173 , but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
[0062] When used in a LAN networking environment, the computer 110 is connected to the LAN 171 through a network interface or adapter 170 . When used in a WAN networking environment, the computer 110 typically includes a modem 172 or other means for establishing communications over the WAN 173 , such as the Internet. The modem 172 , which may be internal or external, may be connected to the system bus 121 via the user input interface 160 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer 110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 3 illustrates remote application programs 185 as residing on memory device 181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.
[0063] Generally, the data processors of computer 130 are programmed by means of instructions stored at different times in the various computer-readable storage media of the computer. Programs and operating systems are typically distributed, for example, on floppy disks or CD-ROMs. From there, they are installed or loaded into the secondary memory of a computer. At execution, they are loaded at least partially into the computer's primary electronic memory. The system described herein includes these and other various types of computer-readable storage media when such media contain instructions or programs for implementing the steps described below in conjunction with a microprocessor or other data processor. The system also includes the computer itself when programmed according to the methods and techniques described herein.
[0064] For purposes of illustration, programs and other executable program components, such as the operating system, are illustrated herein as discrete blocks. It is recognized, however, that such programs and components reside at various times in different storage components of the computer, and are executed by the data processor(s) of the computer.
[0065] Although described in connection with an exemplary computing system environment, including computer 130 , the system is operational with numerous other general purpose or special purpose computing system environments or configurations. The computing system environment is not intended to suggest any limitation as to the scope of use or functionality. Moreover, the computing system environment should not be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment. Examples of well known computing systems, environments, and/or configurations that may be suitable that may be used include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, mobile telephones, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
[0066] An interface in the context of a software architecture includes a software module, component, code portion, or other sequence of computer-executable instructions. The interface includes, for example, a first module accessing a second module to perform computing tasks on behalf of the first module. The first and second modules include, in one example, application programming interfaces (APIs) such as provided by operating systems, component object model (COM) interfaces (e.g., for peer-to-peer application communication), and extensible markup language metadata interchange format (XMI) interfaces (e.g., for communication between web services).
[0067] The interface may be a tightly coupled, synchronous implementation such as in Java 2 Platform Enterprise Edition (J2EE), COM, or distributed COM (DCOM) examples. Alternatively or in addition, the interface may be a loosely coupled, asynchronous implementation such as in a web service (e.g., using the simple object access protocol). In general, the interface includes any combination of the following characteristics: tightly coupled, loosely coupled, synchronous, and asynchronous. Further, the interface may conform to a standard protocol, a proprietary protocol, or any combination of standard and proprietary protocols.
[0068] The interfaces described herein may all be part of a single interface or may be implemented as separate interfaces or any combination therein. The interfaces may execute locally or remotely to provide functionality. Further, the interfaces may include additional or less functionality than illustrated or described herein.
[0069] In operation, computer 130 executes computer-executable instructions such as those illustrated in the figures to grant an application program access to a resource according to a privilege associated with the application program and with the resource.
[0070] The systems and methods illustrated in the figures and described herein may be implemented in software or hardware or both using techniques some of which are well known in the art.
[0071] The order of execution or performance of the methods illustrated and described herein is not essential, unless otherwise specified. That is, elements of the methods may be performed in any order, unless otherwise specified, and that the methods may include more or less elements than those disclosed herein.
[0072] When introducing elements of the present invention or the embodiment(s) thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
[0073] As various changes could be made in the above constructions, products, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
[0074] For example, the methods and techniques described here may be applied to a number of areas in which a virtual file is desired to be created within the context of a specific user and for a specific file. In particular, the technique of employing virtualized files that are only created when necessary may be used in combination with application isolation and other similar areas. As another example, the methods and techniques described here may be applied to partial virtualization for a specific application. In particular, certain files in an application may be virtualized while others are not virtualized.
[0075] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
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Certain applications, especially legacy applications, try to write to areas of the system that require administrator privileges and hence fail to run successfully for users with lessened privileges. The disclosed system redirects certain file writes, i.e., globally impactful file writes to specific locations that require administrator privileges and would otherwise fail for others users, so as to allow the same file writes to succeed by redirecting them to happen in the context of the user, i.e., in a per-user virtualization location. In particular, virtualization only occurs when the application is actually going to write to the file, not just when file access is requested without an intention of writing to or otherwise actually altering the file. Following virtualization, applications are redirected to use the virtualized files. The system thus allows users to run applications that otherwise would not be enabled, and to maintain a higher level of security when doing so.
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BACKGROUND OF THE INVENTION AND RELATED ART
The invention relates to trolleys and more particularly to trolleys for transporting or conveying prepared foods with cooling and/or warming thereof. The trolleys are ud, for example, in hospitals and retirement homes and in various means of public transportation.
A trolley of this type is already known from FR-A-2 684281 and from WO-97/09575. The trolley comprises a casing with a heat insulating wall inside which the food dishes are mounted. Means are provided for defining a first zone and a second zone, and these defining means may be a heat insulating partition or may be a virtual partition represented by the fact that the food dishes are covered with a dish-cover made of a heat insulating material, all the parts under the dish-cover on the one side of the trolley representing the first zone and on the other side the second zone. The first zone is generally designed to receive part of the dishes on which food is deposited intended to be consumed cold. It consists of a zone which must be kept at a low temperature, usually at around 3° C. On the other hand, the second zone is intended to receive food which must be consumed hot. This zone is first of all kept at a cold temperature of 3° C. for example, and then before the meal is consumed, is brought to a higher temperature, in particular 65° C. so that the food is reheated and may be served hot. To this end, the trolley includes a first device for cooling the first zone, a second device for cooling the second zone and a device for heating the second zone.
The disadvantage of trolleys known up to now is that devices for cooling by a refrigerating fluid or by absorption, both for the first zone as well as for the second zone, are operating as soon as they are put onto the trolley, even though they are not to be used at this time. As they can only provide a limited cooling capacity, they must be put on the trolley at the last moment or adapted to have the capacity to provide less cooling, so that the trolley can only keep food cold for a shorter time.
SUMMARY OF THE INVENTION
According to the invention, each cooling device comprises a first container for a gas, and optionally a first solid reagent capable of reacting with the gas, and a second container for a second solid reagent capable of reacting with the gas and which, if a first solid reagent is provided, is able to react more vigorously with the gas than the first solid reagent. The containers communicate with each other via a conduit provided with a valve. The first container of the first cooling device is placed in the first zone, while the second container of the first cooling device is placed outside the two zones. The first container of the second cooling device is placed in the second zone, while the second container of the second cooling device is placed outside the two zones.
The cooling devices operate by a thermochemical process, and they are actuated when the valve is opened. In this manner, the capacity of the cooling devices to produce cooling is only used deliberately and selectively.
According to one particularly preferred embodiment, the heating device comprises a first reservoir for a gas and optionally a first solid product able to react with the gas and a second reservoir for a second solid product able to react which, if a first solid product is provided, is able to react more vigorously with the gas than the first solid product, communicating with each other via a conduit provided with a valve, the first reservoir being placed outside the two zones, while the second reservoir is placed in the second zone.
The same advantages are thus obtained for the heating device as for the cooling devices, with the supplementary advantage that since the heating device is in this case entirely self contained and mounted on board the trolley, it is possible to operate it in at any moment whatsoever without being dependent on a source of electrical power at a fixed point. The heating can be started while the food dishes are carried in the trolleys. This enables the waiting time to be reduced.
In accordance with a second embodiment, it is possible to individualize more satisfactorily the cooling and/or heating of prepared dishes placed on the various plates. To that end, individual cooling and/or heating zones are provided for each prepared dish in order to obtain individual cooling or individual cooling and/or heating.
The gas may be ammonia or its derivatives, in particular alkylamines with C 1 to C 8 , for example monomethylamine, dimethylamine, but also water, CO 2 , SO 2 , SO 3 or H 2 . The solid adsorbent reagent may be a salt, such as a halide, a pseudohalide, a carbonate, a sulfate, a nitrate, an oxide or a metallic nitride, which, preferably, is in a natural expanded graphite matrix. The endothermicity of the reaction gives the desired cooling. As metals of salts constituting the solid reagents, use may in particular be made of the salts of the alkaline earth metals, zinc salts, manganese salts, iron salts and nickel salts. As a salt, reference may in particular be made to MnCl 2 , SrCl 2 , SrBr 2 to maintain the temperature at 3° C. and NiCl 2 , MgCl 2 , MgBr 2 and NiBr 2 to maintain the temperature at −20° C. When couples of reagents or solid products are provided, these may be for example NICl 2 , MgCl 2 , MgBr 2 , NiBr 2 , NiCl 2 , NiBr 2 according to the desired temperatures.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, given solely by way of example:
FIG. 1 is a sectional view of a trolley according to the invention;
FIG. 2 is a partial sectional view of a variant of the trolley according to the invention;
FIG. 3 is a sectional view along the line III—III of FIG. 2;
FIG. 4 is a top plan view of the cooling device used in the variant of FIG. 2; and
FIG. 5 is a top plan view of the combined cooling and heating device used in the variant of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The trolley shown in FIG. 1 has a casing 1 with an interior heat insulating partition 3 on which are mounted food dishes or plates 2 . The plates 2 are spread out horizontally while being superimposed. They pass through the heat insulating partition 3 so that each plate includes a depression situated in a cold zone 4 and a depression situated in a zone 5 , referred to as the cold/hot zone since it must be kept initially at a cold temperature and then brought, for example, to 65° C.
To this end, cooling devices are provided at each side of the casing 1 , which extend outside the plane of FIG. 1 .
The cooling device of the cold zone 4 includes a first container 7 filled with NH 3 and BaCl 2 . This first container communicates via a conduit 8 provided with a valve 9 with a second container 10 filled with MnCl 2 .
Similarly there is a first container 11 , filled with BaCl 2 , in the zone 5 and a second container 12 , filled with MnCl 2 , located remote of the zone 5 . The containers 11 and 12 communicate with each other via a conduit 13 provided with a valve 14 to provide the second cooling device. A heating device is also situated beside this cooling device, only on the side of the zone 5 , having a reservoir 15 filled with MnCl 2 communicating with a reservoir 16 filled with BaCl 2 via a conduit 17 provided with a valve 18 . The zone 4 is farther away from the container 10 than from the container 7 . The zone 5 is farther away from the container 12 than from the container 11 and is farther away from the reservoir 16 than from the reservoir 15 . The containers 10 and 12 and the reservoir 16 are located outside the casing, whereas the other containers and reservoir are located inside the casing.
In the embodiment of FIG. 1, each first container and/or first reservoir extends substantially perpendicularly to the plates. In accordance with another aspect of the invention, it is possible to stop the heating means by turning a valve.
In FIG. 2, the trolley comprises a casing 20 with a heat insulating wall enclosing mounted food dishes or plates 21 , only two of these plates being represented. Each depression in a given plate is covered with a dish-cover 22 made of heat insulating material. The dish-covers 22 determine a cold zone and a warm zone, on the one hand for the cold depressions and on the other hand for the warm depressions of the plate. More particularly, a sub-container 23 is provided under each cold depression of the plate 21 . Under each hot depression of the plate 21 , both a sub-container 24 and a sub-reservoir 25 are provided and interlaced as shown in FIG. 5 for respectively providing cooling and heating.
FIG. 4 represents one of the sub-containers 23 . The sub-container 23 has seven fingers 26 connected by a manifold 27 . The manifold 27 extends to a conduit 28 having a valve 29 and arranged to communicate with a reservoir 30 . The reservoir 30 contains MnCl 2 and the sub-container 23 contains BaCl 2 .
As shown in FIG. 5, the sub-container 24 has only six fingers 26 , but it is otherwise similar to the sub-container 23 . Accordingly, the fingers 26 are connected by the manifold 27 and conduit 28 including valve 29 to the reservoir 30 .
As also shown in FIG. 5, the sub-reservoir 25 has five fingers 31 connected to a common collector 32 . The collector 32 is connected by a conduit 33 having a valve 34 to a reservoir 35 . The fingers 31 contain MnCl 2 and the reservoir 35 contains BaCl 2 . The fingers 26 are interlaced with the fingers 31 .
FIG. 3 is a sectional view along the line III—III of FIG. 2 . The food dishes or plates 21 are stacked to either side of a service duct 36 in which the reservoirs 30 and 35 are housed. This service duct is separated from the zones where the plates are situated by heat insulating partitions 37 .
Another embodiment consists of positioning the reservoir 16 in the zone 4 and the reservoir 15 in the zone 5 . This enables the zone 4 to be kept cold provided the operation of the device 7 , 10 is shut down, which prevents heat from being discharged to the environment, when the temperature is raised again.
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A meal trolley has an insulated casing and food dishes or plates supported therein for cooling and heating by thermochemical reactions. The reagents of the chemical reactions are stored in containers and reservoirs carried by the trolley and selectively connected to provide the self-contained cooling or heating.
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CLAIM OF PRIORITY
This application claims a priority benefit of U.S. Provisional Application Ser. No. 61/744,980, entitled, “Retractable-Screen Systems and Methods for Curb-Opening Storm Drain Catch Basins,” filed Oct. 9, 2012, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
The present disclosure relates generally to storm drain catch basins, and more specifically to retractable screen systems and methods for catch basins.
BACKGROUND
Typical curbed storm drain catch basins are designed as a primary entry point for urban water runoff. The curb openings provide nuisance water, low flow storm water, and high flow storm water into the catch basin as well as trash and/or debris that emanates from the streets and curbsides.
Trash and/or debris such as bottles, cans, plastic wrappers, leaves, grass cuttings, sediments, manure, hydrocarbons, and other pollutants frequently find their way into these catch basins and may travel through storm drain outlet pipes and into rivers, lakes, oceans, and other bodies of water.
A vast majority of screened covers that have been inserted into curb opening catch basins stay closed during the dry season and swing open through mechanical trip devices when the storm water reaches a predetermined curb height.
During heavy rainfall events, due to storms or water main pipeline breakage, it is imperative that water flow from the streets into the curb openings containing these retractable screens open up significantly in order to prevent street flooding.
Trash and/or debris accumulate in front of these screened devices and along the curbs and gutters from the streets. Street sweeper trucks often provide cleaning service to remove and collect this debris build-up during planned maintenance schedules, which can be performed periodically (e.g., weekly, monthly, etc.). The screened devices that have debris build-up will typically remain closed during the street sweeper brush pass, as well as stay closed during nuisance water and low flow storm water events.
Typical storm drain screened gate systems designed to remain closed during the dry season or low flow storm water events and open during heavy storm water events are disclosed in, for example, U.S. Pat. No. 7,491,338 to Nino, U.S. Pat. No. 6,869,523 to Martinez, U.S. Pat. No. 8,277,645 to Jarvis, U.S. Pat. No. 7,234,894 to Flury, U.S. Pat. No. 6,972,088 to Yehuda, U.S. Patent Publication No. 2012/0103883 to Friezner, and U.S. Pat. No. 7,238,279 to Saurenman. The disadvantage of such systems is that some of these screen devices incorporate locking pin components, which can malfunction due to trash and/or debris fouling, which prevent opening of the screen device. Additionally, some devices may be too complex in design, with many moving parts that can prevent opening and/or closing due to trash and/or debris entanglement.
BRIEF DESCRIPTION OF DRAWINGS
The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals indicate similar elements and in which will become better understood with regard to the following description, appended claims, and accompanying figures wherein:
FIG. 1 is a schematic diagram depicting an example curb-opening retractable screen system installed across a curb opening storm drain catch basin, according to some embodiments;
FIG. 2 is a schematic diagram depicting the example curb-opening retractable screen system from the front left side perspective, according to some embodiments;
FIG. 3 is a schematic diagram depicting the example curb-opening retractable screen system from the front right perspective, according to some embodiments;
FIG. 4 is a schematic diagram depicting another example curb-opening retractable screen system from the front right perspective, according to some embodiments;
FIG. 5 is a schematic diagram depicting the example curb-opening retractable screen system from the rear view with the winged screens in an open position, according to some embodiments;
FIG. 6 is a schematic diagram depicting the example curb-opening retractable screen system from the rear view with the winged screens in a closed position, according to some embodiments;
FIG. 7 is a schematic diagram depicting the example curb-opening retractable screen system from the left side view with the winged screens in a closed position, according to some embodiments;
FIG. 8 is a schematic diagram depicting the example curb-opening retractable screen system from the left side view with the winged screens in an open position, according to some embodiments;
FIG. 9 is a schematic diagram depicting the example curb-opening retractable screen system from the right side view with the winged screens in an open position, according to some embodiments;
FIG. 10 is a schematic diagram depicting the example curb-opening retractable screen system from the right side view with the winged screens in a closed position, according to some embodiments;
FIG. 11 is a schematic diagram depicting the example curb-opening retractable screen system from the top view with the winged screens in a closed position, according to some embodiments;
FIG. 12 is a schematic diagram depicting the example curb-opening retractable screen system from the bottom view with the winged screens in an open position, according to some embodiments;
FIG. 13 is a schematic diagram depicting the example curb-opening retractable screen system from the bottom view with the winged screens in a closed position, according to some embodiments;
FIG. 14 is a schematic diagram depicting the example curb-opening retractable screen system from the top view with the winged screens in an open position, according to some embodiments;
FIG. 15 is a schematic diagram depicting an example unassembled curb-opening retractable screen system, according to some embodiments;
FIG. 16 is a schematic diagram depicting the example curb-opening retractable screen system from the front view with the winged screens in an open position, according to some embodiments;
FIG. 17 is a schematic diagram depicting the example curb-opening retractable screen system from the front view with the winged screens in a closed position, according to some embodiments; and
FIG. 18 is a schematic diagram depicting another example of a curb-opening retractable screen system, according to some embodiments.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details are set forth to provide a thorough understanding of claimed subject matter. However, it will be understood by those skilled in the art that claimed subject matter may be practiced without these specific details. In other instances, methods, apparatuses, or systems that would be known by one of ordinary skill have not been described in detail so as not to obscure the claimed subject matter.
In the following detailed description, the terms “left” and “right” are intended to indicate such directions as viewed from the upstream side of the curb-view from the street. The terms “vertical” and “horizontal” are intended to include directions that are substantially vertical and substantially horizontal, respectively.
The present disclosure relates to retractable screen systems, apparatuses, and/or devices that include mechanical components allowing the retractable screen system, apparatus, and/or device to be in various positions. For example, the retractable screen system may be in a closed, unlocked position, which may prevent street sweeping trucks from pushing trash, debris, and/or litter into, through, and/or past the screened system into the catch basin that may lead into a storm drain system. In another example, the retractable screen system may open to a predetermined level based on a water level (e.g., during storm water curb flow).
In some embodiments, the retractable screen system may operate in a horizontal manner (e.g., as opposed to a vertical manner). For example, a winged screen affixed to both sides of a center screen on the retractable screen system may open horizontally toward the inside of a curb opening.
The present technology described herein provides the ability to prevent street flooding and clogging of the front of the retractable screen system due to the multiple screen openings of the retractable screen system. The retractable screen system may provide storm water flow opening of a hinged, spring loaded, winged screen on both ends of a central screen, where the winged screens may open horizontally into the storm drain catch basin (e.g., during storm water flow overriding the spring pressure of the screen openings). In some embodiments, the present technology may avoid using locking and unlocking devices, while preventing trash and debris from bypassing the winged screens. In other embodiments, locking and unlocking devices may be used.
FIG. 1 is a schematic diagram depicting an example curb-opening retractable screen system installed across a curb opening storm drain catch basin 12 . FIG. 2 is a schematic diagram depicting the example curb-opening retractable screen system from the front left side perspective. The screen system may be installed for the catch basin 12 across a curb opening 11 of the curb 21 on a street 15 . The catch basin 12 may be accessed using a manhole 13 in the sidewalk 14 . A winged screen 18 may be connected to both sides of a center screen 10 (e.g., by weld) using piano hinge 17 (e.g., ⅜″ tube), which may allow the winged screens 18 to open into the curb opening 11 in a horizontal manner. Screen mounting bracket 37 (shown in FIG. 15 ) is secured to center screen 10 using component 20 , which may be any suitable component for affixing compression tube 35 to center screen 10 , such as any one or combination of a cap screw (e.g., ⅜″×¾″), nut, flat washer, lock washer, and the like. The compression tube 35 may mount to screen mounting bracket 37 . Component 23 may mount to the ceiling of the catch basin 12 to secure the screen system.
FIG. 3 is a schematic diagram depicting the example curb-opening retractable screen system from the front right perspective. FIG. 4 is a schematic diagram depicting another example curb-opening retractable screen system from the front right perspective. FIGS. 3 and 4 show embodiments of the winged screens 18 in an open position (e.g., horizontally open) while the center screen 10 remains unopened. Since storm water curb flow is typically flow directional, this technology allows curbed water to flow into either the right or left winged screens 18 .
FIG. 5 is a schematic diagram depicting the example curb-opening retractable screen system from the rear view with the winged screens 18 in an open position. FIG. 6 is a schematic diagram depicting the example curb-opening retractable screen system from the rear view with the winged screens 18 in a closed position. Mounted (e.g., by weld) on the top lip area of the winged screens 18 is a tube 33 of an appropriate size (e.g., ¾″×3″) that has a tension spring 30 mounted over the tube 33 in which one end of the spring 30 is placed to rest by tension against the winged screen 18 , and the other end of the spring 30 is placed to rest by tension through a hole in spring holder 32 secured (e.g., by weld) to the center screen 10 .
FIG. 7 is a schematic diagram depicting the example curb-opening retractable screen system from the left side view with the winged screens 18 in a closed position. FIG. 8 is a schematic diagram depicting the example curb-opening retractable screen system from the left side view with the winged screens 18 in an open position. FIG. 9 is a schematic diagram depicting the example curb-opening retractable screen system from the right side view with the winged screens 18 in an open position. FIG. 10 is a schematic diagram depicting the example curb-opening retractable screen system from the right side view with the winged screens 18 in a closed position.
In FIGS. 7-10 , winged screens 18 connects with a center screen 10 using piano hinge 17 . One or more cap screws 20 secures the center screen 10 to mounting plate 26 (as shown in FIG. 15 ), wherein one or more cap screws and nuts secures the screen assembly to traveling tube 35 and traveling tube 19 , which may allow the screen system to move backward into the catch basin 12 away from the curb opening 11 . The winged screens 18 have springs 30 that are attached to spring holder tubes 33 , as shown in FIGS. 5 and 6 . One side of spring 30 may be placed near the hinge 17 onto the center screen 10 , and the other end of the spring may be placed near the hinge 17 onto the winged screen 18 . The spring tension may be set to allow the winged screens 18 to open at a predetermined storm water curb flow rate. In some embodiments, the spring tension may be set to allow medium to high curb water flow. Referring to FIGS. 7 and 10 , the retractable screen system may be closed, whereas in FIGS. 8 and 9 , the coil spring 34 (as shown in FIG. 15 ) within traveling tube 19 may be at a minimum or compressed length for maximum storm water flow capacity into the storm water catch basin 12 (e.g., maximum open position during a major storm water event). Anchor 25 may be any suitable component that may be used to secure bracket 23 to the catch basin wall, such as a concrete anchor cap screw. Washer 38 may be any suitable component that may be used to keep traveling tube 19 on track to slide in and out of tube 35 without little to no wobbling effect.
FIG. 11 is a schematic diagram depicting the example curb-opening retractable screen system from the top view with the winged screens 18 in a closed position. FIG. 12 is a schematic diagram depicting the example curb-opening retractable screen system from the bottom view with the winged screens 18 in an open position. FIG. 13 is a schematic diagram depicting the example curb-opening retractable screen system from the bottom view with the winged screens 18 in a closed position. FIG. 14 is a schematic diagram depicting the example curb-opening retractable screen system from the top view with the winged screens 18 in an open position. The slotted stationary tube 19 contains a coil spring 34 which when fitted with tube 35 , is kept from coming apart under compression by a cap screw and nut 24 which is secured (e.g., by weld) next to the slot end of tube 19 .
FIG. 15 is a schematic diagram depicting an example unassembled curb-opening retractable screen system. A coil spring 34 may be set inside a spring mounting tube 19 that is slotted to hold a smaller tube 35 that has a guide 38 fitting into the slot in the mounting tube 19 , allowing the spring to be compressed and decompressed such that the retractable screen system is able to open or close based on predetermined storm water flow rates. To hold the spring in place, a cap screw and nut 24 may be mounted (e.g., by weld) to the end of the slot on the mounting tube 19 . The guide 38 may rest against the cap screw and nut 24 , preventing the retractable screen system from exiting the slot.
The mounting tube 19 has adjustable mounting brackets 22 that may be secured (e.g., by weld) and may have additional adjustable positioning brackets 23 secured by cap screws 24 for mounting and securing the screens, mounting tube 19 , and concrete wedge anchors 23 to the concrete ceiling, back wall, and/or side walls of the storm drain catch basin 12 .
At the end of the tube 35 is a flat bar 39 of appropriate size (e.g., ½″×125″×2″) that is secured (e.g., by weld) and may contain a spring compression stop. Mounted (e.g., by weld) at one end of tube 35 is a guide washer 38 of appropriate size (e.g., 5/16″), which may fit into the slot of tube 19 , keeping the screens aligned into the curb opening 11 of the storm drain catch basin 12 during compression and decompression of spring 34 , and/or opening and closing of the winged screens 18 .
Two mounting brackets 22 are secured (e.g., by weld) to the spring holder tube 19 , and one mounting bracket 22 is secured by a cap screw and nut 24 to the back of the spring holder tube 19 . Attached to the mounting bracket 22 is an adjustable anchoring bracket 23 , which allows adjustment to the screens inside the storm drain catch basin 12 . Concrete wedge anchors 25 are inserted through the tops of the adjustable anchoring brackets and inserted into the ceiling, side walls, and/or back wall of the storm drain catch basin 12 to secure the embodiment of the technology.
The center screen 16 may be secured to the slider tube 35 by the screen mounting bracket 37 , which is secured to the slider tube 35 (e.g., by weld). Inserted horizontally through the screen mounting bracket 37 is a cap screw and nut 24 that will secure the center screen 10 to the slider tube 35 .
FIG. 16 is a schematic diagram depicting the example curb-opening retractable screen system from the front view with the winged screens 18 in an open position. FIG. 17 is a schematic diagram depicting the example curb-opening retractable screen system from the front view with the winged screens 18 in a closed position.
The winged screens 18 as well as the center screen 10 may remain closed when no fluids and/or low-flow fluids enter the screens (e.g., when the fluid flow rate is zero). As fluid begins to enter the system, the winged screens 18 open based upon the tension set for the spring loaded assembly. As the fluid rate increases, the winged screens 18 may accordingly open wider. The center screen spring may compress during extreme storm flow events to allow the retractable screen system to open (e.g., both the winged screens 18 and the center screen 10 ), preventing street flooding. When the fluid flow rate decreases, the winged screens 18 and center spring may accordingly begin to close. The retractable screen system may divert trash and/or debris from entering the storm drain catch basin 12 during zero to low fluid flow conditions (e.g., nuisance water flow from lawn watering). Trash and/or debris build-up in front of the retractable screen system may be collected by street sweeping trucks as they patrol their scheduled street routes.
FIG. 18 is a schematic diagram depicting another example of a curb-opening retractable screen system. As shown in FIG. 18 , the winged screens may open in the same direction, which may be effective for streets that have an incline and/or decline. In some embodiments, the winged screens may open in unison.
While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the embodiments is not limited to them. Many variations, modifications, additions, and improvements are possible.
Plural instances may be provided for components, operations, or structures described herein as a single instance. Finally, boundaries between various components, operations, and structures are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of the embodiment(s). In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the embodiment(s).
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Retractable screen systems and methods for catch basins are disclosed. In an example embodiment, a retractable screen apparatus includes a retractable center screen coupled to a retracting spring-loaded tube assembly secured to a portion of the catch basin. Two independently-operating side screens may each be coupled to the retractable center screen. Each side screen may be spring loaded such that each side screen is capable of opening and closing horizontally based on a predetermined fluid flow rate of water flowing into the catch basin.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of provisional application No. 60/211,603, filed Jun. 15, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compositions that are useful as polishing compositions for chemical-mechanical polishing of semiconductors. More specifically, the polishing compositions of the present invention include an aqueous medium, an oxidizing agent, an inhibitor and a pH buffer.
2. Description of Related Art
Methods for chemical mechanical polishing and planarization of substrates used in the formation of semiconductors using abrasive slurries are shown in Sandhu et al U.S. Pat. Nos. 5,994,224 issued Nov. 30, 1999, Streinz et al 5,993,686 issued Nov. 30, 1999, Kaufman et al 6,039,891 issued Mar. 21, 2000, Sandhu et al 6,040,245 issued Mar. 21, 2000. Chemical mechanical polishing methods using non-abrasive containing polishing compositions are shown in Hudson U.S. Pat. No. 5,927,792 issued Oct. 26, 1999 and in WO 99/61540 published Dec. 2, 1999.
In chemical mechanical polishing of semiconductors comprising silica having circuits therein of aluminum, titanium or titanium nitride, a polishing composition is required that results in a very low level of defects and provides a higher level of polishing performance than can be achieved with prior art polishing compositions that contain abrasives or that do not contain abrasives but other combinations of polishing components. Dishing of the metallic circuit of the semiconductor has been a problem with conventional polishing composition particularly those containing abrasives. Dishing of the metallic circuit occurs when significantly more of the center portion of a metallic circuit of a semiconductor is removed than is removed from the sides resulting in a dip in the circuit that is below the level of the surface of the semiconductor. A polishing composition and method are required that has an acceptable removal rate of material, does not result in scratching the surface of the semiconductor or in dishing of the metallic circuit of a semiconductor and provides excellent planarization of the surface of the semiconductor that is being polished.
SUMMARY OF THE INVENTION
An aqueous polishing composition for chemical mechanical polishing of semiconductor devices comprising silica and circuits of aluminum, titanium or titanium nitride; wherein said aqueous composition comprises
an oxidizing agent such as an alkali metal chlorate or hydrogen peroxide,
an inhibitor of a polyalkyleneimine, and
a pH buffer such as ammonium phosphate or an alkali metal carbonate and optionally, a complexing agent, oxide suppressants and other inhibitors can be added.
A further aspect of this invention is a method for polishing a semiconductor device comprised of silica and circuits of aluminum, titanium or titanium nitride by applying the novel aqueous a polishing composition at an interface between a polishing pad and the semiconductor device.
DETAILED DESCRIPTION
The aqueous polishing composition of this invention is used to polish semiconductor devices of a silica wafer having circuits therein of aluminum, titanium or titanium nitride. The composition when used in a typical polishing process provides excellent planarization of the surface, does not scratch the surface and in particular does not dish the metallic circuit but polishes it evenly and at about the same level as the silica substrate. The composition can be used in combination with a variety of conventional polishing pads that are used on typical polishing machines.
The novel aqueous polishing composition contains about 0.0001-30%, based on the weight of the composition, of an oxidizing agent; about 0.0001-15% by weight, based on the weight of the composition, of an inhibitor; and 0.0001-5.0% by weight, based on the weight of the composition, of a pH buffer to provide the composition with a pH in the range of about 2-11. Optionally, a complexing agent, oxide suppressants and other inhibitors can be added to the composition.
Typical oxidizing agents that can be used are alkali metal chlorates such as potassium chlorate; and other oxidizing agents can be used such as ammonium chlorate, potassium iodate, ammonium perchlorate, potassium hyperchlorite, ammonium hyperchlorite, potassium chlorite, ammonium chlorite and the like. Hydrogen peroxide also is a useful oxidizing agent. The oxidizing agent oxidizes the surface of the metal circuit so that the metal is readily removed in the polishing process.
The inhibitor is a polyalkyleneimine having a weight average molecular weight of about 1,000-1,000,000. Preferably, polyethyleneimine is used. The inhibitor forms an inhibitor layer or a passivation layer on a metal substrate being polished such a aluminum and protects the substrate from dissolution during polishing and reducing dishing of the substrate. Depending on the pH of the polishing composition, the inhibitor layer can be a layer of aluminum oxide or a layer of an aluminum inhibitor polymeric film. At pH 4-9, the inhibitor layer is mainly aluminum oxide. When the pH is less than 2 or higher than 9, this inhibitor layer is an aluminum inhibitor polymeric film. The inhibitor layer is formed by the adsorption of inhibitor onto the aluminum surface through chemical bonding. When an organic inhibitor is used, such as polyethyleneimine, a polymeric inhibitor layer is formed and the thickness of the layer is built up by hydrogen bonding. The inhibitor layer can only be removed by mechanical abrasion and the removal rate of material during polishing is very low which results in a low level of dishing of the aluminum. Similar results occur when polishing titanium and titanium nitride since the surface of these compounds mainly is titanium oxide.
A pH buffer is used to keep the polishing composition at a pH of 2-11, preferably in the range of 4-9. Typical compounds that can be used are ammonium phosphate, ammonium hydrogen phosphate, potassium carbonate, ammonium tetraborate and potassium tetraborate.
About 0.0001-10% by weight, based on the weight of the composition, of an oxide suppressant can be added to the polishing composition. Typical oxide suppressants that can be used are organic bromides such as dodecyl trimethylammonium bromide. Under some circumstances, a polyalkyleneimines such as polyethyleneimine can function as an oxide suppressant. For example, when silicon dioxide is polished the polyalkyleneimine functions as an oxide suppressant.
Other inhibitors can be added to the polishing composition so long as the total amount of inhibitor including the polyalkyleneimine does not exceed 15% by weight of the polishing composition. Typical inhibitors that can be added to the polishing composition are inorganic compounds like phosphoric acid, phosphoric acid salts, carbonate salts, boric acid, boric acid salts, chromate salts, silicate salts, or organic compounds containing nitrogen, silicon, and or oxygen. Organic compounds also can be used. Typical organic compounds are benzoic acid and salts of benzoic acid. By using these inhibitors, the pH of the slurry can be extended to 2-11. Some of the above compositions like salts of acids can function as pH buffers in particular the salts of phosphoric and boric acids.
Optionally, about 0.0001-30% by weight, based on the weight of the composition, of a complexing agent can be added to the composition. Typical complexing agents that can be used are citric acid, ethylenetetraacetic acid, imnodiacetic acid, and nitrilotriacetic acid. The complexing agent dissolves the metal oxide formed by the oxidizing agent and it is readily removed in the dissolved state during the polishing process. A complexing agent is not required for composition having a high pH such as 10 and above since the hydroxy ions in the composition act as a complexing agent and no additional complexing agent is required.
In the formulation of the polishing composition, the constituents can be blended together in any order. A variety of polishing pads can be used with the polishing composition that are conventionally used in polishing semiconductors. One preferred polishing pad is a fixed abrasive pad SWR 159 manufactured by the 3 M Company. Also, a wide variety of polishing machines can be used. One typically useful machine is a Westech 372.
The following examples illustrate the invention. All parts and percentages are on a weight basis unless otherwise indicated.
EXAMPLES
Example 1
Polishing Composition 1
The following constituents were blended together to form the polishing composition:
3 parts ammonium hydrogen phosphate
1 part polyethyleneimine (PEI) weight average molecular weight 750,000
7.5 parts hydrogen peroxide
88.5 parts water.
The resulting composition has a pH of 10.
Polishing Composition 2—identical to Polishing Composition 1 except PEI was omitted.
Each of the above Polishing Compositions was used to polish (1) a test TEOS wafer and (2) an aluminum wafer. An aluminum wafer consists of a sputtered aluminum film deposited on a thermally grown silicon dioxide on a silicon substrate. A TEOS wafer is a test wafer that consists of silicon dioxide deposited on a silicon substrate by chemical vapor deposition.
For polishing, a Westech 372 polishing machine was used and the following polishing conditions were used: 4 psi down force, 2 psi back pressure, 40 rpm polishing platen speed. The polishing pad used was a fixed abrasive pad SWR 159 manufactured by 3 M Company.
The polishing results of the Polishing Compositions 1 and 2 were as follows:
Polishing Composition 1 (Invention)
Aluminum Wafer
Removal rate of aluminum for 3 continuous polishing runs was 1404, 1113, and 1163 A/min., respectively. The average removal rate of aluminum was 1227 A/min.
TEOS Wafer
TEOS removal rate is 0 A/min. of silicon dioxide.
Finish of Surface—no visible scratches were observed on either the aluminum wafer or the TEOS wafer.
Polishing Composition 2 (PEI Omitted)
Aluminum Wafer
Removal rate was about 4 microns/min.
TEOS Wafer
TEOS removal rate is 0 A/min. of silicon dioxide
Finish of Surface—unacceptable for both wafers, since many surface scratches were present due to high friction. PEI is required as in Polishing Composition 1 to reduce friction and provide scratch free polishing.
Although embodiments of the invention have been described, other embodiments and modifications are intended to be covered by the spririt and scope of the appended claims.
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An aqueous polishing composition for chemical mechanical polishing of semiconductor devices of silica and circuits of aluminum, titanium or titanium nitride; wherein said aqueous composition includes, an oxidizing agent, an inhibitor of a polyalkyleneimine, and a pH buffer, and a method for polishing a semiconductor device by applying the polishing composition at an interface between a polishing pad and the semiconductor device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an air detector for use in an infusion device, and more particularly, to an air detector designed to detect air bubbles or columns in an infusion solution flowing through a tube from a supply bag, etc. into a human body in the medical infusion device or the like, which facilitates easy and reliable loading of said tube into the infusion device.
2. Description of the Prior Art
Prior art infusion devices of the kind referred to above include an air detector using a ultrasonic or an optical sensor for detecting air bubbles or columns in the liquid flowing through a tube. The air detector is loaded in a part of the tube.
Two types of the air detectors are known. More specifically, in the separate type as shown in FIG. 5, a signal emitting member 1 and a signal receiving member 3 of the sensor are separate components in such structure that the former is mounted on a stationary unit 2 of a pumping station, while the latter is carried by a movable unit 4 such as a door. When the door 4 is closed, a channel 6 is defined between an upper surface of the signal emitting member 1 of the stationary unit 2 and a lower surface of the signal receiving member 3 of the movable unit 4, into which a tube 5 is accommodated. Accordingly, when the movable unit 4 is closed while the tube 5 is loaded into an upper recess 7 defined in the signal emitting member 1 of the unit 2, the tube 5 is deformed into a flattened configuration within the channel 6 to provide an enlarged surface area 5a to be in contact with the signal emitting and receiving members 1 and 3.
On the other hand, in the unitary type of the air detector as shown in FIGS. 6 and 7, a tube-receiving groove 8 is defined in the stationary unit 2. Both the signal emitting and receiving members 1 and 3 are embedded in the opposing walls of the groove 8. The unitary type is mainly used for detecting relatively short air bubbles or columns and therefore the length of tube-receiving groove 8 is relatively short, exerting less resistance in contact between the groove and the tube. Accordingly, the tube may be fitted into the groove 8 by pushing by fingers.
In the above-described separate type, it is difficult to maintain a constant distance between the signal emitting and receiving members so as to stabilize the performance of the detector.
In the unitary type, it is necessary for the tube-receiving groove 8 to have a relatively narrow width in order to obtain a high sensitivity in the detector. In order that relatively elongated air bubbles or columns can be detected in the narrow groove 8, it is necessary to correspondingly elongate the inter-sensor distance in a lengthwise direction of the tube as indicated in FIG. 7. This necessarily increases the frictional resistance of the groove and makes it difficult to place the tube in the groove. In other words, when the air bubbles or columns of a size corresponding to L1 are to be detected, the inter-sensor distance between sensors 1 and 1, and 3 and 3 is necessary to be L1 as shown in FIG. 6. Meanwhile, when the air columns of a size corresponding to L2 are to be detected, the inter-sensor distance should be set L2 as shown in FIG. 7.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been devised with a view to substantially solve the above-described problems inherent in the prior art, and has for its essential object to provide an air detector which utilizes a unitary type sensor assuring a constant distance between signal emitting and receiving members and correspondingly a stable detecting efficiency. The conventional difficulty in loading a tube encountered with the use of unitary type sensor is obviated by employing a unique design for a tube-receiving groove, whereby elongated air bubbles or columns can be detected.
In accomplishing the above-described object, according to the present invention, an air detector is provided which is designed to detect air bubbles or columns in an infusion solution flowing through a tube loaded in a pumping station. The tube extends from a supply bag, etc. to a patient through the detector between a signal emitting member and a signal receiving member thereof. The detector of the present invention is characterized in that the tube is fitted into a groove defined in a stationary unit of the pumping station, the groove having a tube-fixing section of a width narrower than the outer diameter of the tube defined at the lower side of the groove, the signal emitting member and the signal receiving member being disposed on the opposing side walls of the tube-fixing section, the upper section of the groove being defined by one side wall which flares outwardly from the tube-fixing section and the other side wall which is perpendicular and continues to the tube-fixing section. The detector is further characterized in that a tube-abutting member is provided on a movable unit rotating to the stationary unit such as a door whereby the tube is pushed into the groove and further into the tube-fixing section by the tube-abutting member when the door is closed while the dislodgement of the tube from the groove is prevented.
Accordingly, since the present invention utilizes a unitary type sensor which is stable in the detecting accuracy, and the difficulty in loading a tube conventionally encountered with the use of unitary type sensor is obviated by the tube-abutting member provided in the movable unit, the tube is easily loaded into the detector by forcible pushing of the tube with the tube abutting-member.
BRIEF DESCRIPTION OF THE DRAWINGS
This and other objects and features of the present invention will become apparent from the following description taken in conjunction with one preferred embodiment thereof with reference to the accompanying drawings, in which:
FIG. 1 is a schematic front elevational view of an air detector according to a preferred embodiment of the present invention;
FIGS. 2 and 3 are cross sectional views showing the loading process of a tube;
FIG. 4 is a cross sectional view explanatory of a problem in loading the tube;
FIG. 5 is a schematic front elevational view of a prior art air detector of the separate type; and
FIGS. 6 and 7 are schematic views of a prior art air detector of the unitary type.
DETAILED DESCRIPTION OF THE INVENTION
Before the description of the present invention proceeds, it is to be noted here that like parts are designated by like reference numerals throughout the accompanying drawings.
A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
Referring to FIG. 1, an air detector according to the preferred embodiment of the present invention shown therein consists of a stationary unit 10 of an infusion device and a movable unit 11, i.e., a door of the pump. The door 11 is pivotable about its axis 12 in a direction indicated by an arrow to close and open the stationary unit 10. A body 14 formed of synthetic resin of an air detector generally indicated at 13 is embedded in the stationary unit 10. The body 14 defines a groove 15 opening upwards for receiving a tube. As shown in FIG. 1, the groove 15 has an upper section 16 thereof defined by two side walls, one of which 17 is flared outwardly and the other of which 30 extends in a plane perpendicular to the upper surface of the stationary unit 10. The groove 15 further defines a tube-fixing section 20 adjacent its base defined by opposing side walls 18, 19 which extend in parallel to each other and perpendicularly to the tube-fixing section 20. The side wall 19 is flush with the side wall 30 of the upper section 16. Therefore, the tube-fixing section 20 has rectangular cross section. A signal emitting member 21 and a signal receiving member 22 of an ultrasonic sensor are embedded within the body 14 adjacent the side walls 18 and 19, respectively.
The width a of the tube-fixing section 20 is set smaller than the outer diameter w of a tube 23 to be inserted in the groove 15 (a<w). This provides a large contact area between the tube 23 and the side walls 18, 19 respectively provided with signal emitting and signal receiving members of the sensor as desired for detecting air bubbles or columns passing through the tube 23. The tube 23 is fitted within the tube-fixing section 20 of the small width a along the outwardly flared outer section 16. Thus, the tube 23 is deformed from a circular configuration into an oval configuration in cross section.
As discussed above, in order to detect a relatively long air bubbles or columns, it is required to extend the inter-sensor distance (in an axial direction of the tube) thereby making it necessary for the tube-receiving groove 15 to have a corresponding extended length. Thus, the length of the groove 15 in this embodiment is rendered considerably longer than that of the conventional design of unitary type in proportion to the length of air bubbles or columns to be detected. However, the use of an elongated groove 15 may develop a problem of difficulty in loading of the tube 23 in the fixing section 20 because of the increased resistance in contact between the outer wall of the tube 23 and the inner wall of the groove.
In order to obviate the above problem, according to the present invention, a tube-abutting member 25 is provided on the lower surface of the door 11 corresponding to the position where the tube 23 is pushed into the tube-fixing section 20 in the groove 15. The abutting member 25 has a configuration complementary to, but smaller than the upper section 16. In other words, one of the side walls of the abutting member 25 flares outwardly, while the other projects at right angles to the movable unit 11. When the door 11 is pivoted about its axis 12, the abutting member 25 is inserted into the groove 15 from above while exerting a clockwise force on the tube 23. On the contrary, if the side walls 17 and 30 in the upper section 16 of the groove 15 are both notched and sloped outwardly as indicated by a hatch S in FIG. 4, the tube 23 would stably rest on the upper section 16. However, when the tube 23 is pushed by the projecting abutting member 25 into the fixing section, the tube 23 would be dislodged from the groove 15 as shown by an arrow in FIG. 4. This rotational or rolling displacement of the tube 23 may be prevented by making the side wall 19 of the upper section 16 in the groove 15 flush with the side wall 30 thereby to push the tube 23 forcibly in the fixing section 20 by the abutting member 25.
Consequently, in the above-described structure, the tube 23 may be simply loaded in position of the air detector 13 by placing it first in the upper section 16 of the groove 15 and then closing the door 11. In other words, when the door 11 is closed, the tube-abutting member 25 enters the groove 15, forcing the tube 23 from the upper section 16 into the tube fixing section 20. This process allows the tube to be fitted into the fixing section 20 in an automatic and reliable fashion even if a large frictional resistance is encountered between the outer surface of the tube 23 and the inner surface of the groove 15.
As will be clear from the foregoing description, according to the present invention, the air detector utilizes the sensor of unitary type with the signal emitting and receiving members embedded in the opposing side walls defining the tube-receiving groove formed in the stationary unit. Once the tube has been loaded in the tube fixing section in the groove, the tube can be placed in constant position to the sensor, namely, between the opposing signal emitting and receiving members spaced a constant distance, making it possible to obtain a stable and reliable performance in the air detector. Furthermore, since the abutting member carried by the door assists the loading of the tube into the fixing section, the tube may be easily inserted even into a relatively long groove. This permits for the detector to detect air bubbles or columns of various sizes without developing any difficulty in loading the tube into the detector. Moreover, the use of unitary type sensor having both the signal emitting and receiving members mounted in the stationary unit is advantageous because it does not require recalibration of the relative distance between the signal emitting and receiving members in order to stabilize its air detecting performance.
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An air detector according to the present invention utilizes a unitary type sensor for detecting air bubbles or columns in an infusion solution flowing through a tube. Because of a unique design for a tube-receiving groove and a cooperating abutting member, the difficulty in loading a tube heretofore encountered with the use of unitary type sensor is obviated. Thus, the tube can be loaded in the air detector easily with good reliability.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This invention claims the benefit of provisional application Ser. No. 62/189,559, filed Jul. 7, 2015, the disclosure of which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] This invention relates to a clamp for hoses or flexible tubing. More particularly, this invention relates to tubing clamps commonly used in the medical industry.
[0004] Description of the Background Art
[0005] Presently, there exist many types of clamps for clamping onto a tubing or other flexible member to at least partially obstruct fluid flow through the tubing or to completely close-off fluid flow through the tubing. One particular industry that requires the use of tubing clamps is the medical industry wherein clamps are used widely as tubing clamps in intravenous administration sets, catheterization kits, and many other medical assemblies.
[0006] One of the most common types of tubing clamp in the medical industry comprises a clam-shell design having upper and lower arms joined together by a living hinge. The medical tubing is positioned between the upper and lower arms which are allowed to clamp onto the tubing by means of the living hinge. Typically, the upper arm includes a pointed end that engages into teeth formed in the end of the lower arm to achieve a complementary ratchet mechanism such that the anvils of upper and lower body portions may be clamped onto the medical tubing to reduce fluid flow or to entirely close off all fluid flow. Further, the most widely used tubing clamp comprises a longitudinal hole formed through the living hinge and the ratcheting portions of the lower arm such that the tubing is threaded therethrough in alignment with mating clamping anvils to squeeze closed the tubing therebetween.
[0007] Importantly, surgical micro-tubing had led to the development of lateral opposing sidewalls that confine the micro tubing to rest between the unclamped anvils thereby precluding the micro tubing from otherwise creeping out between the anvils before they are clamped together.
[0008] The entirety of the tubing clamp is typically manufactured as a one-piece injection-molded assembly. Accordingly, conventional molding techniques are preferably employed with minimal slides. As shown in FIG. 1 , known tubing clamps with opposing sidewalls require too many slides and other complex molding techniques.
[0009] Therefore, an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the tubing clamp art.
[0010] Another object of this invention is to provide a tubing clamp having non-opposing sidewalls that may be injection molded without slides.
[0011] Another object of this invention is to provide a tubing clamp having non-opposing sidewalls emanating from one clamp arm that engage into slots form in the other clamp arm to minimize twisting of the clamp arms relative to one another during squeezing of the clamp closed.
[0012] The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
[0013] For the purpose of summarizing the invention, this invention comprises a clamp for flexible tubing such as medical tubing or micro-tubing. The clamp comprises a clam-shell design having lateral non-opposing sidewalls that prevent the micro-tubing from bending out from under the mating clamping anvils when closed. Unlike the lateral opposing sidewalls of prior art clamps such as is shown in FIG. 1 , the lateral non-opposing sidewalls of the clamp of the present invention are non-opposing lateral sidewalls that may be injection molded without the use of additional slides that are otherwise needed to injection mold the prior art opposing sidewalls shown in FIG. 1 .
[0014] The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
[0016] FIG. 1 is a perspective view of a prior art tubing clamp having lateral sidewalls that are directly opposing one another;
[0017] FIG. 2A is a right perspective view of a first embodiment of the tubing clamp of the invention having two lateral sidewalls that are not directly opposing one another;
[0018] FIG. 2B is a right perspective view of a second embodiment the tubing clamp of the invention having three lateral sidewalls that are not directly opposing one another; and
[0019] FIG. 3A is a left perspective view of a first embodiment of the tubing clamp of the invention having two lateral sidewalls that are not directly opposing one another;
[0020] FIG. 3B is a left perspective view of a second embodiment the tubing clamp of the invention having three lateral sidewalls that are not directly opposing one another;
[0021] FIG. 4A is a right side view of a first embodiment of the tubing clamp of the invention having two lateral sidewalls that are not directly opposing one another;
[0022] FIG. 4B is a right side view of a second embodiment the tubing clamp of the invention having three lateral sidewalls that are not directly opposing one another;
[0023] FIG. 5A is a left side view of a first embodiment of the tubing clamp of the invention having two lateral sidewalls that are not directly opposing one another;
[0024] FIG. 5B is a left side view of a second embodiment the tubing clamp of the invention having three lateral sidewalls that are not directly opposing one another; and
[0025] FIG. 6 is a right perspective view of a third embodiment of the tubing clamp of the invention having two lateral sidewalls that are not directly opposing one another;
[0026] Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to FIGS. 2-5 , the tubing clamp 10 of the invention comprises an upper arm 12 and a lower arm 14 flexibly hinged together by a living hinge 16 to define a clam-shell design.
[0028] The upper arm 12 comprises a generally flat top configuration 18 with a terminal portion 20 . Extending downwardly underneath the flat upper configuration 18 is a generally triangular-in-cross-section upper portion 22 defining a transverse upper anvil 24 , preferably with a cross-sectional rounded edge in the form of a circular segment CS. Similarly, the lower arm 14 comprises a generally flat bottom configuration 26 with a terminal portion 28 extending upwardly for removable engagement with the terminal portion 20 of the upper arm 12 . Extending upwardly from the flat lower configuration 26 is a generally triangular-in-cross-section lower portion 30 defining a transverse lower anvil 32 , preferably with a cross-sectional rounded edge in the form of a circular segment CS.
[0029] The living hinge 16 comprises an aperture 34 and the terminal portion 28 of the lower arm 14 comprises another aperture 36 in alignment with one another allowing the tubing (shown in phantom as reference numeral 38 ) to be clamped threaded therethrough and positioned between the anvils 24 and 32 .
[0030] The anvils 24 and 32 move generally parallel to one another when the upper arm 12 and lower arm 14 are squeezed together against the inherent resilient memory of the living hinge 16 whereupon the tubing 38 is squeezed between the anvils 24 and 32 to obstruct, or completely close-off, fluid flow through the tubing 38 . It is noted that the circular segments CS of the anvils 24 and 32 are preferably aligned parallel with one another such that the tubing 38 is squeezed precisely closed between the anvils 24 and 32 .
[0031] Without departing from the spirit and scope of the invention, the terminal portions 20 and 28 may comprise a variety of configurations to completely or partially obstruct fluid flow through the tubing 38 . As shown, for complete obstruction, the lower terminal portion 28 may comprise a single toothed rack 40 formed on the inward portion of the lower terminal portion 28 of the lower arm 14 . The upper terminal portion 22 comprises a pawl 42 . The leading edge of the pawl 42 is aligned for engagement with the tooth of the rack 40 . When the upper and lower arms 12 and 14 are grasped by a person's hand and squeezed together such that the anvils 24 and 32 tightly squeeze the tubing 38 to close-off fluid flow, the leading edge of the pawl 42 removeably snaps under the tooth of the rack 40 to secure the anvils 24 and 32 is their closed position.
[0032] Alternatively, for partial to complete obstruction of fluid flow, the inward portion of the lower terminal portion 28 may comprise a plurality of teeth (not shown) along the rack 40 for sequential engagement by the leading edge of the pawl 42 such that the anvils 24 and 32 gradually squeeze the tubing 38 to initially partially then completely obstruct fluid flow as the anvils 24 and 32 are ratcheted toward one another upon sequential engagement of the leading edge of the pawl 42 along the teeth of the rack 40 .
[0033] It is noted that the upper configuration 18 may comprise a series of parallel transverse ridges 44 on the upper surface thereof to facilitate better gripping by the person's thumb during such squeezing of the arms 12 and 14 together.
[0034] To open the clamp 10 , the terminal portion 28 is pushed forwardly by a person's thumb to disengage the leading edge of the pawl 42 from the tooth of the rack 40 whereupon the inherent resilient memory of the living hinge 16 causes the upper and lower arms 12 and 14 (and their respective anvils 24 and 32 ) to move apart and no longer squeeze the tubing 38 .
[0035] The clamp 10 of the present invention may be used with different-sized tubings 38 so long as the diameter of the tubing 38 is smaller than the diameter of the apertures 34 and 36 and is therefore capable of being threaded therethrough. Moreover, micro-tubings 38 (i.e., tubing of a very small diameter) may likewise be used. However, it is known that micro-tubing 38 has the tendency to easily flex and bend and may inadvertently easily bend outside of clamp 10 and away from in between the anvils 24 and 32 .
[0036] In order to better constrain the micro-tubing 38 between the anvils 24 and 32 , the clamp 10 of the invention comprise at least one first sidewall 46 on one side (e.g., right) of the clamp 10 and at least one second sidewall 48 on the other side (e.g., left) of the clamp 10 . FIGS. 2A, 3A, 4A and 5A illustrate one embodiment of the clamp 10 wherein only one first sidewall 46 and only one second sidewall 48 are employed whereas FIGS. 2B, 3B, 4B and 5B illustrate another embodiment of the clamp 10 wherein only one first sidewall 46 but two second sidewalls 48 are employed.
[0037] The sidewalls 46 and 48 in one embodiment emanate from the lower triangular portion 30 . Alternatively, in another embodiment (not shown) the sidewalls 46 and 48 may emanate from the upper triangular portion 22 . Still alternatively, in other embodiments (not shown), the first sidewall(s) 46 (e.g., the right sidewall) may emanate from the lower triangular portion 30 and the second sidewall(s) 48 (e.g., the left sidewall) may emanate from the upper triangular portion 22 , or vice versa.
[0038] The sidewalls 46 and 48 in one embodiment each comprise a generally flat rectangular configuration to define a tubing path between the apertures 34 and 36 such that when clamping micro-tubing 38 , the micro-tubing 38 is constrained to be in proper transverse alignment between the anvils 24 and 32 and is prevented from inadvertently bending out from between the anvils 24 and 32 where they would not be properly squeezed closed between the anvils 24 and 32 .
[0039] In the first embodiment as shown in FIGS. 2A, 3A, 4A and 5A , the single first sidewall 46 emanates upwardly from the side end of the anvil 32 of the triangular portion 30 whereas the single second sidewall 48 emanates upwardly from the side end of the forward sloped surface 30 FS of the triangular portion 30 . Alternatively, in the third embodiment shown in FIG. 6 , the single first sidewall 46 emanates upwardly from the anvil 32 of the triangular portion 30 and the single second sidewall 48 emanates upwardly from the rearward sloped surface 30 RS of the triangular portion 30 .
[0040] Unlike the prior art clamps employing opposing sidewalls (see for example FIG. 1 ), the first and second sidewall(s) 46 and 48 of the clamp 10 of the present invention are not directly aligned opposite one another (i.e., the left first sidewall(s) 46 is not aligned directly across from the right second sidewall(s)). Rather, as best shown in FIGS. 4 and 5 , the first and second sidewalls 46 and 48 are non-opposing from one another such that no portion of the first sidewall(s) 46 is directly opposite to any portion of the second sidewall(s) 48 to form a gap G when the clamp 10 is viewed from the side. Importantly, the gap G formed between the non-opposed first and second sidewalls 46 and 48 facilitate injection molding of the clamp 10 by the two halves of a conventional injection mold without the use of slides that would otherwise be necessary were the sidewalls were opposing one another as taught by the prior art (see FIG. 1 ).
[0041] The upper arm 12 may comprise first and second side slots 50 and 52 into which the respective first and second sidewalls 46 and 48 may move into as the clamp 10 is squeezed closed by moving the arms 12 and 14 together. Advantageously, the slots 50 and 52 function to better align the upper triangular portion 22 relative to the lower triangular portion 30 upon movement of the arms 12 and 14 together such that the arms 12 and 14 do not otherwise twist during closing and otherwise misalign the anvils 24 and 32 as they are clamped together. A more complete closure of the micro-tubing 38 may therefore be achieved since the anvils 24 and 32 will be more accurately aligned parallel during clamping to more completely obstruct fluid flow through the micro-tubing.
[0042] In another embodiment of the invention (not shown), the first and second sidewalls 46 and 48 may emanate from the upper triangular portion 22 whereupon the lower triangular portion 30 may comprise first and second side slots into which the respective first and second sidewalls 46 and 48 may move into as the clamp 10 is squeezed closed.
[0043] The present invention includes that contained in the appended claims as well as that of the foregoing description. Although this description has been described in its preferred form with a certain degree of particularity, it should be understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction, combination, or arrangement of parts thereof may be resorted to without departing from the spirit and scope of the invention.
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A clamp for flexible tubing such as medical tubing or micro-tubing. The clamp comprises a clam-shell design having lateral non-opposing sidewalls that prevent the micro-tubing from bending out from under the mating clamping anvils when closed. The lateral non-opposing sidewalls of the clamp are non-opposing in order to facilitate injection molded in two halves of an injection mold without the use of additional slides.
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BACKGROUND OF THE INVENTION
This is a continuation of pending PCT/EP99/08179, filed Oct. 28, 1999.
The invention concerns a rubber article composed of at least two vulcanized mixes having different composition and properties, and having between them a lap joint. More particularly, it concerns a tire whose various constituent mixes are joined by superposition of an edge of one of the mixes over another mix.
Junctions between mixes such as those mentioned above, when subjected to stresses (whether tension, compression or shear), represent a particularly vulnerable area of the article considered, the life of the article being greatly limited by the destruction of the joint, whether this destruction be due to adhesion failure or to stress concentration at the location of the joint, or even to external aggression in the case of some junctions.
The purpose of the invention is to improve the life of the article considered by causing the junction(s) between rubber mixes constituting the said article to be less influenced by the known causes of its/their destruction.
SUMMARY OF THE INVENTION
The vulcanized rubber article according to the invention, which consists of at least two rubber mixes having different composition and properties, the said two mixes having between them a lap joint, is characterized in that at least one of the edges of at least one of the two mixes has an end whose trace-line resembles an oscillating movement, namely an oscillating trace-line.
The thickness of the edge of the mix in question is preferably constant over a width at least equal to the desired trace-line amplitude: the said thickness being in any case less than 2 mm in the non-vulcanized condition such that the molding and vulcanization of the finished article obliterates the surface irregularities created at the junction of the two mixes.
Any trace-line may be suitable (trace-lines of stationary or non-stationary oscillations), the preferred trace-lines being the sinusoidal trace-line of a harmonic oscillation and the circular trace-line (in which the line corresponding to a half-period is a semicircle).
The preferred application of the crenellated or serrated edge(s) relates to the joining of two rubber mixes constituting a tire, whether this junction emerges on an external wall of the tire or is totally internal. The application is particularly advantageous for junctions on the sidewall of the tire between the mix used for the tread and that used for the sidewall.
An oscillatory trace-line can be characterized by an amplitude and a wavelength. The amplitude measured crest to crest, whether variable or not, is in the case of tire applications preferably between 3 mm and 15 mm. As for the wavelength, this is preferably between 0.1% and 2% of the circumferential extension of the tire measured in the equatorial plane.
DESCRIPTION OF THE DRAWINGS
The characteristics and advantages of the invention will be better understood from the description below, which refers to the drawings illustrating non-limiting example embodiments and in which:
FIGS. 1A and 1B show schematically a first variant of a junction between two rubber mixes, respectively seen in cross-section and in plan view,
FIGS. 2A and 2B show the junction between a tread mix and a sidewall mix in a touring vehicle tire, respectively seen in cross-section and in plan view, and
FIGS. 3A to 3 C show an internal junction between the upper edge of the quasi-triangular section above the bead wire of a tire and the mix used to line the carcass ply of the said tire.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A vulcanized rubber plate (FIG. 1A) seen in cross-section, is composed of two rubber mixes A and B, whose composition and consequently whose properties are different. The said two mixes, in the non-vulcanized condition, are shaped by passing between the rollers of a calendering roll or by passing into a blade of an extruder, and the edges of each section have a thickness e that decreases regularly from the maximum thickness down to a thickness of at most 2 mm and in the case described is equal to 0.6 mm, the said thickness remaining constant as far as the edges of the section. The junction of the two mixes is formed by the two sloping edges and the tongues of constant thickness and width equal 1 to 7 mm. The said tongues have an undulating shape (FIG. 1 B), such that the end of the edge of each mix has a sinusoidal trace-line with crest to crest amplitude a equal to 5 mm and wavelength λ equal to 10 mm.
FIGS. 2A and 2B concern the preferential application of the principle described above and show a partial view of the upper part of a cross-section through a tire of size 175/70.R.13. The said tire comprises a radial carcass reinforcement 1 surmounted radially by a crown reinforcement 2 consisting of two plies of metallic cables crossed from one ply to the next and making with the circumferential direction an angle of 22°. The edges of the said crown 2 are joined to the carcass reinforcement 1 by sections 3 . A tread 4 covers the reinforcement 2 radially and is connected to a sidewall rubber 5 . The junction between the tread 4 and the sidewall rubber 5 is formed by the edge of the said tread with a portion 4 ′ whose thickness decreases as far as the point C and a portion 4 ″ or tongue with constant thickness equal to 0.6 mm between the points C and D on the outer wall of the tire. The said tongue 4 ″ is shown in section in FIG. 2 B: the oscillating trace-line at its end is formed of a succession of triangles with rounded peaks on either side of a central axis XX′. The amplitude a is equal to 5 mm and the wavelength λ to 10 mm, the latter representing 0.55% of the circumferential extension of the tire measured in the equatorial plane ZZ′.
The last example, shown in FIGS. 3A to 3 C, concerns an internal junction of the tire and more particularly the junction between the radially uppermost point of the section 7 of rubber mix located radially above the anchoring bead-wire 6 of the carcass reinforcement 1 and on the one hand the layer of rubber mix covering the cables of the carcass reinforcement 1 (lining of the ply) and on the other hand the rubber mix located axially outside the said point. As described earlier, the section 7 has an edge with a part whose thickness decreases and a part EF with constant thickness equal in this case to 0.5 mm and width equal to 5 mm. The part EF has an end which describes a periodic trace-line said to be semicircular as shown in FIG. 3B, with an amplitude a of a 3.0 mm and a wavelength λ of 6.0 mm. The said trace-line may also be a periodic trapezoidal trace as shown in FIG. 3C, with the same values of amplitude and wavelength, without compromising the junction between the mixes.
Comparison tests between tires having junctions with straight edges between tread and sidewall rubber and tires having junctions between the some mixes with periodic trace-lines as described in the part of the description relating to the junction concerned, demonstrate the very clear superiority of the solution according to the invention, since tires designed in that way have covered distances, before the appearance of any initiation of degradation, twice as far as those covered by tires having junctions with a straight trace-line between the tread and the sidewall rubber, both when rolling under overload and when rolling in an ozonated environment. Similarly, junctions according to the invention used in the lower portion of a tire between the section above the bead-wire and the lining of the carcass reinforcement, make it possible to use for the section 7 mixes which, in terms of their composition, are not very compatible in adhesion with the lining mixes customarily used.
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A rubber article, such as a tire, composed of at least two rubber mixes with different composition and properties, the said two mixes having a lap joint characterized in that at least one edge of at least one of the two mixes has an end with an oscillatory trace-line.
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RELATED APPLICATION
This application is a divisional of patent application U.S. Ser. No. 09/988,792, filed Nov. 20, 2001 now abandoned, which claims the benefit of provisional application U.S. Ser. No. 60/252,369, filed Nov. 21, 2000, which is hereby incorporated hereby by reference.
GOVERNMENT FUNDING
This invention made with U.S. Government support under DA06284 awarded by the National Institute of Health. The Government has certain rights in the invention.
TECHNICAL FIELD
This invention relates to novel antimicrobial compounds derived from peptides.
BACKGROUND
Widespread use of antibiotics in recent decades has led to proliferation of pathogens having multiple drug resistance, often encoded by transmissible plasmids, and therefore capable of spreading rapidly between species. Many previously useful antibiotics are no longer effective against infectious organisms isolated from human and animal subjects. The specter of epidemic forms of bacterial diseases such as tuberculosis and fungal diseases, which are refractory to known antibiotic agents, may be realized in the near future. Development of novel antimicrobial compounds is a continuing urgent public health need.
SUMMARY OF THE INVENTION
The invention features an antimicrobial composition comprising a substance P (SP) peptide or peptide mimetic thereof. The amino acid sequence of the peptide contains at least residues 1-8 of Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met (SEQ ID No:1), or the amino acid sequence of the peptide contains at least residues 1-8 of Arg-D-Pro-Lys-Pro-Gln-Gln-D-Trp-Phe-D-Trp-Leu-Met (SEQ ID No: 2). A SP peptide is a peptide with antimicrobial activity, which contains an amino acid sequence that is at least 50% identical to the amino acid sequence of SEQ ID NO:1.
The peptide contains levorotatory (L) and/or dextrorotatory (D) forms of an amino acid. For example, the peptide has at least one D amino acid. The antimicrobial composition further contains one or more additional antimicrobial agents such as tetracycline, penicillin, doxycycline, ampicillin, or CIPRO™.
Antimicrobial peptides contain the amino acid sequence Xaa 1 -Pro-Xaa 2 -Pro-Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 (SEQ ID NO:12). Referring to SEQ ID NO:12, Xaa 1 and Xaa 2 are positively charged amino acids, Xaa 3 and Xaa 4 are any amino acids other than Pro, and Xaa 5 and Xaa 6 are hydrophobic amino acids. Xaa 5 and Xaa 6 are preferably aromatic amino acids. For example, Xaa 5 and Xaa 6 are Phe or Trp. Preferably, the composition does not contain Saporin (U.S. Pat. No. 6,063,758), neither in a free form, nor conjugated to to the antimicrobial peptide.
The amino terminal portion of a SP peptide associates with a membrane component of a microbe. Preferably, the SP peptide associates with a microbial membrane component but does not associate with an SP receptor, e.g., a tachykinin receptor. Accordingly, the peptide contains amino acids 1-5, 1-6, 1-7, 1-8, 1-9, or 1-10 of SEQ ID NO:1 or 2, and lacks 1, 2, 3, 4, or 5 amino acids from the carboxy-terminal end of SEQ ID NO:1 or 2. The amino acid sequence of the peptide contains residues 1-10 of SEQ ID Nos: 1 or 2. For example, the amino acid sequence of the peptide comprises Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Xaa (SEQ ID NO:13), wherein Xaa is not a methionine residue.
The antimicrobial composition inhibits growth of a bacteria (e.g., cutaneous, mucosal, or enteric bacteria), fungus, or virus. For example with respect to bacteria, the peptide inhibits growth of a cell selected from the genera consisting of Staphylococcus, Streptococcus, Bacillus, Clostridium, Escherichia, Shigella, Campylobacter, Hemophilus, Proteus, Yersinia, Klebsiella, Pseudomonas , and Serratia . For example with respect to fungi, the peptide inhibits growth of a cell selected from the genera consisting of Aspergillus, Candida, Cryptococcus, Epidermophyton, Histoplasma, Microsporum , and Trichophyton.
The invention also includes a method for inhibiting growth or survival of a microorganism, by directly contacting the microorganism (e.g., a membrane component of the microbe) with a SP peptide or a peptide mimetic thereof. A peptide mimetic is an SP analog in which one or more peptide bonds have been replaced with an alternative type of covalent bond, and which is not susceptible to cleavage by peptidases elaborated by the subject or by the target microorganism. The peptide contains at least 8 consecutive residues, e.g., residues 1-8, of the amino acid sequence of SEQ ID Nos: 1 or 2. For example, the peptide contains at least positions 1-10 of the amino acid sequence of SEQ ID Nos: 1 or 2.
The invention also provides a method of inhibiting a microbial infection by carrying out the following steps: identifying a mammal suffering from or at risk of developing a microbial infection and administering to the mammal a SP peptide or peptide mimetic thereof. The peptide or peptide mimetic is administered topically. In an alternative embodiment, the invention provides a method of inhibiting a microbial infection, by introducing directly into an articulating joint of an animal a SP peptide or peptide mimetic thereof. The method is also carried out by introducing the SP peptide or mimetic directly into an abscess.
Also within the invention is a kit containing at least one unit dose of an antimicrobial SP peptide or mimetic packaged together with a label, instructions for use, or means of administering the compound
“Antimicrobial” activity of an agent or composition shall mean ability to inhibit growth of one or more microorganism. For example, the antimicrobial compositions described herein inhibit the growth of or kill bacterial, algal, fungal, protozoan, and viral genera and species thereof.
It is well known to one of skill in the art of antibiotics development that an agent that causes inhibition of growth can also be lethal to the microorganism (bacteriocidal, for example in the case of a microorganism that is a bacterium). The SP peptide or mimetic is lethal, growth inhibitory, or both.
“Broad spectrum” antimicrobial activity means to ability to inhibit growth of organisms that are relatively unrelated. For example, ability of an agent to inhibit growth of both a Gram positive and a Gram negative bacterial species is considered a broad spectrum activity.
Various compositions and methods herein are useful for preventing and treating Gram positive and Gram negative bacterial infections in human and animal subjects. Gram positive bacterial species are exemplified by, but not limited to, genera including: Staphylococcus , such as S. epidermis and S. aureus; Micrococcus; Streptococcus , such as S. pyogenes, S. equis, S. zooepidemicus, S. equisimilis, S. pneumoniae and S. agalactiae; Corynebacterium , such as C. pyogenes and C. pseudotuberculosis; Erysipelothrix such as E. rhusiopathiae; Listeria , such as L. monocytogenes; Bacillus , such as B. anthracis; Clostridium , such as C. perfringens ; and Mycobacterium , such as M. tuberculosis and M. leprae.
Gram negative bacterial species are exemplified by, but not limited to genera including: Escherichia , such as E. coli O157:H7; Salmonella , such as S. typhi and S. gallinarum; Shigella , such as S. dysenteriae; Vibrio , such as V. cholerae; Yersinia , such as Y. pestis and Y. enterocolitica; Proteus , such as P. mirabilis; Bordetella , such as B. bronchiseptica; Pseudomonas , such as P. aeruginosa; Klebsiella , such as K. pneumoniae; Pasteurella , such as P. multocida; Moraxella , such as M. bovis; Serratia , such as S. marcescens; Hemophilus , such as H. influenza ; and Campylobacter species. Further examples of bacterial pathogenic species that are inhibited according to the invention are obtained by reference to standard taxonomic and descriptive works such as Bergey's Manual of Determinative Bacteriology, 9 th Ed., 1994, Williams and Wilkins, Baltimore, Md.
Prevention and treatment of fungal infections are embodied by various compositions and methods provided herein. Suitable fungal genera are exempflied, but not limited to: Candida , such as C. albicans; Cryptococcus , such as C. neoformans; Malassezia ( Pityrosporum ); Histoplasma , such as H. capsulatum; Coccidioides , such as C. immitis; Hyphomyces , such as H. destruens; Blastomyces , such as B. dermatiditis; Aspergillus , such as A. fumigatus; Penicillium , such as P. marneffei ; and Pneumocystis , such as P. carinii . Subcutaneous fungi, such as species of Rhinosporidium and Sporothrix , and dermatophytes, such as Microsporum and Trichophyton species, are amenable to prevention and treatment by embodiments of the invention herein.
Prevention and treatment of viral infections that are topically manifested are embodied by various compositions and methods provided herein. Suitable viral infections include but are not limited to: viral warts (papilloma virus), Herpes simplex type I and type II, varicella zoster (chicken pox), Molluscum contagiosum (a pox virus), rubeola (measles), and rubella (German measles).
A subject to be treated is an animal, preferably a warm-blooded animal, including any bird or mammal species. Methods and compositions embodied herein are envisioned for human and veterinary use. Veterinary use includes application to cows, horses, sheep, goats, pigs, dogs, cats, rabbits, and all rodents. The methods of the invention are also useful to agricultural workers and pet owners to combat infections contracted by exposure to livestock or pet animals.
A subject is diagnosed as having a microbial infection by inspection of a bodily tissue, e.g., epidermal and mucosal tissue, including such tissue present in surfaces of oral, buccal, anal, and vaginal cavities and glans penis. Diagnosis of infection is made according to criteria known to one of skill in the medical arts, including but not limited to, areas of inflammation or unusual patches with respect to color, dryness, exfoliation, exudation, prurulence, streaks, or damage to integrity of surface. Conditions exemplary of those treated by the compositions and methods herein, such as abscess, meningitis, cutaneous anthrax, septic arthritis, emphysema, impetigo, cellulitis, pneumonia, sinus infection and tubercular disease are accompanied by elevated temperature. Diagnosis can be confirmed using standard ELISA-based kits, and by culture, and by traditional stains and microscopic examination of direct samples, or of organisms cultured from an inoculum from the subject.
Other features and advantages of the invention will be apparent from the following description of embodiments thereof, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the chemical structure of SP.
DETAILED DESCRIPTION
Naturally-occurring SP, a member of the tachykinin family, is an undecapeptide (SEQ ID NO:1, FIG. 1 ). SP plays a key role in pain signal transmission. As it is widely distributed not only in the central and peripheral nervous systems, but in other tissues as well, it also mediates multiple homeostatic functions. Some classes of immune cells, such as T and B cells, endothelial cells, and macrophages, have the ability to express SP receptors; and some classes of immune cells such as macrophages, eosinophils, and endothelial cells, have the ability to produce SP.
The concentration of SP increases in inflamed tissues, consistent with a role in mammalian host defense system. Naturally-occurring SP is involved in direct stimulation of lymphocytes and regulation of tissue repair via enhancement of proliferation of fibroblasts and endothelial cells. In addition, immune cells can be induced by SP to produce cytokines that modulate hematopoiesis. SP is involved in activation of multiple endogenous defense systems.
Surprisingly, the data herein show that compositions such as SP peptides, SP-related molecules, SP fragments, and SP peptide derivative compositions having a particular consensus amino acid sequence, possess broad spectrum antimicrobial activities.
Determination of SP-Mediated Antimicrobial Activity
Inhibition of growth (bacteriostasis, for example in the case of a microorganism that is a bacterium) is determined by turbidometric analysis of a liquid culture. For example, such that a culture having a particular titer of cells per unit volume in the presence of one or more concentrations of the agent fails to increase in density as measured by light scattering in a spectrophotometer or calorimeter, in comparison to the culture in the absence of the agent or at a lower concentration of the agent. Inhibition of growth is also determined using solid medium containing a concentration of the agent, such that a reduced ability to form a number of visible colonies (reduced titer of bacterial cells) is observed in the presence of that concentration of agent, in comparison to the absence of the agent or a lower concentration. The assays are standardized by using a predictable predetermined number of cells, and the lowest observed concentration of the agent that inhibits growth is defined as the minimum inhibitory concentration (MIC). With this parameter, an agent having a lower MIC than another has a greater antimicrobial activity for the organism used in the assay.
Anti-fungal activity is similarly assayed, using log phase vegetative fungal cells. Vegetative cells of a model non-pathogenic species such as Saccharomyces cerevisiae , a Kluyveromyces or a Pichia species, or a pathogenic species such as Candida albicans are grown in a nutrient broth such as a standard yeast medium, to log phase, and then assayed by liquid or solid medium methods, as described above for bacteria.
Methods of assay for antiviral activity are also known in the art. A first method is direct measurement of lethality for virions, such as mixing various concentrations of the antiviral agent, e.g., for a fixed time, or as a function of time, with a known number of “plaque forming units” (PFU) of the virus strain. The treated virus PFUs are then diluted and mixed with an appropriate number of sensitive cells, and the number of plaques obtained in comparison to the same number of PFUs that have been identically treated, in the absence of the antimicrobial compound. This assay detects activity that directly disrupts virion structure or initial function of interaction with a sensitive host cell.
A second method detects inhibition by the agent of ability of the virus to successfully replicate in a sensitive cell. In this method, a sample from each of a range of concentrations of the antiviral agent is added to infected cells at a particular time following the infection, e.g., simultaneous to infection, or within 10 min or one hour of infection. Progeny viruses are collected at the end of the replication cycle, e.g., at 20 h after infection and incubation of the infected cells. The reduction yield of progeny viruses from infected cells in the presence of the agent, and as a function of concentration of the agent, compared to the yield in the absence of the agent, indicates that the agent, e.g., a SP peptide, possesses antiviral activity.
SP Peptides
SP peptides contain an amino acid sequence related to that of positions 1-8 of the amino terminal amino acids in the sequence of SP or SP antagonist (as shown in SEQ ID No: 1 or 2). The peptide of SEQ ID NO:2 is referred to as an SP antagonist because it interferes with SP receptor-mediated SP activity. The antimicrobial activity of an SP peptide is unrelated to SP receptor binding. SP receptor binding involves the carboxy-terminal end of SP. The carboxy-terminal 1, 2, or 3 amino acids of SP are not required for antimicrobial activity.
SP peptides are at least 50% identical to the sequences of SEQ ID NO:1 or 2. Further, they are at least 75% identical, 85%, 95%, and 99% identical to the sequences of SEQ ID NO:1 or 2. Nucleotide and amino acid comparisons described herein are carried out using the Lasergene software package (DNASTAR, Inc., Madison, Wis.). The MegAlign module used is the Clustal V method (Higgins et al., 1989, CABIOS 5(2):151-153). The parameter used is gap penalty 10, gap length penalty 10.
The one letter and three letter codes for the 20 naturally occurring amino acids are well known to one of skill in the art, and are indicated herein as appropriate. Amino acids which are positively charged are lysine (lys, K) and arginine (arg, R). Aromatic amino acids are tyrosine (tyr, Y), phenylalanine (phe, F) and tryptophan (trp, W). The aromatic amino acids are classified further as hydrophobic amino acids, a group which further includes valine (val, V), leucine (leu, L), and isoleucine (ile, I). A conservative substitution of one amino acid for another is a replacement by an amino acid having a similar chemical functional side group, e.g., replacement of a positively charged amino acid by another positively charged amino acid, or replacement of a hydrophobic amino acid by another hydrophobic amino acid.
The antimicrobial activity of the SP peptides and peptide mimetics thereof are associated with the residues located at the amino terminus. The amino-terminal four amino acids of SP peptides are alternately basic residues, i.e., the positively charged amino acids lysine (lys, K) and arginine (arg, R), and proline residues. Reference to Table 1 shows that a consensus amino acid sequence among the SP peptides in these first four positions is an alternation of two basic amino acids and two proline residues. The alternation of basic positively charged residues and proline residues confers a particular structure to the SP peptide.
Peptide modification techniques are used in the manufacture of drug analogs of biological compounds and are known to one of ordinary skill in the art. Synthetic peptides having an antimicrobial activity that is at least 50% of that of SP are produced by either of two general approaches. In a first approach, the peptides are produced by the well-known Merrifield solid-phase chemical synthesis method wherein amino acids are sequentially added to a growing chain. See, Merrifield (1963) J. Am. Chem. Soc. 85:2149-2156. Systems for manually synthesizing peptides on polyethylene pegs are available from Cambridge Research Biochemicals, Cambridge, Mass. Automatic peptide synthesis equipment is available from several commercial suppliers, including Applied Biosystems, Inc., Foster City, Calif.; Beckman Instruments, Inc., Waldwick, N.J., and Biosearch, Inc., San Raphael, Calif. Using such automatic synthesizers according to manufacturer's instructions, peptides are produced in gram quantities for use in the present invention. This method is preferred as yielding an SP peptide in a substantially purified condition, free of contaminating cell components, and substantially free of contaminating chemicals used in the synthetic procedure.
A polypeptide is substantially pure when it constitutes at least about 60%, by weight, of the protein in the preparation. Preferably, the peptide in the preparation is at least about 75%, more preferably at least about 90%, and most preferably at least about 99%, by weight, of SP peptide or mimetic. Purity is measured by any appropriate method, e.g., column chromatography, polyacrylamide gel electrophoresis, or HPLC analysis. Accordingly, substantially pure peptides include peptides purified from natural sources, recombinant peptides derived from a eucaryote but produced in E. coli or another procaryote, or in a eucaryote other than that from which the peptide was originally derived as well as chemically-synthesized peptides.
In a second approach, the synthetic SP peptides of the present invention are prepared by recombinant techniques involving the expression in cultured cells of recombinant DNA molecules encoding a gene for a desired portion of a natural or analog SP molecule. The gene encoding the peptide is natural or synthetic. Polynucleotides are synthesized by well known techniques based on the desired amino acid sequence. For example, short single-stranded DNA fragments are prepared by the phosphoramidite method described by Beaucage et al. (1981) Tetra. Lett. 22:1859-1862. A double-stranded fragment is obtained either by synthesizing the complementary strand using DNA polymerase under appropriate conditions or by adding the complementary strand using DNA polymerase with an appropriate primer sequence. The natural or synthetic DNA fragments coding for the desired SP peptide is incorporated into a suitable DNA construct capable of introduction to and expression in an in vitro cell culture. A particular technique for the recombinant DNA production of SP is described in Yokota et al. (1989) J. Biol. Chem. 264:17649, the disclosure of which is incorporated herein by reference. According to this method, the peptide must be further purified away from contaminating cellular materials. A peptide is considered purified if it is at least about 90% free of material having a different chemical composition, e.g., at least about 95% free, and at least about 98-99% free of contaminating material, by weight.
The methods and the SP compositions in certain embodiments of the present invention employ synthetic SP peptide derivative compounds, which can comprise amino acid analogs such as D-amino acids, or which can be non-peptide compositions or peptide mimetics as described herein. The SP peptide derivative compounds and peptide mimetics have functional antimicrobial activity comparable to that of a known SP peptide. The antimicrobial activity is for example, from about one-half of activity of SP peptide, to about two-fold, about four-fold, or about ten-fold greater than that of SP Peptide.
The derivative compounds have a shape, size, flexibility, and electronic configuration such that the antimicrobial activity of the molecule is similar to a natural antimicrobial peptide. Such non-peptide molecules will typically be small molecules having a molecular weight in the range from about 100 to about 1000 daltons. The use of such small molecules is frequently advantageous both in preparation of pharmacological compositions, and in pharmacological properties such as bioavailability, permeability into the microbial target, rate of metabolism by the subject and the target microorganism, and stability.
The invention includes analogs in which one or more peptide bonds have been replaced with an alternative type of covalent bond (a “peptide mimetic”) which is not susceptible to cleavage by peptidases elaborated by the subject or by the target microorganism. Where proteolytic degradation of a peptide composition is encountered following administration to the subject, replacement of a particularly sensitive peptide bond with a noncleavable peptide mimetic renders the resulting peptide derivative compound more stable and thus more useful as a therapeutic. Such mimetics, and methods of incorporating them into peptides, are well known in the art.
Similarly, the replacement of an L-amino acid residue by a D-amino acid residue is a standard method for rendering the compound less sensitive to enzymatic destruction. Other amino acid analogs are known in the art, such as norleucine, norvaline, homocysteine, homoserine, ethionine, and the like. Also useful is derivatizing the compound with an amino-terminal blocking group such as a t-butyloxycarbonyl, acetyl, methyl, succinyl, methoxysuccinyl, suberyl, adipyl, azelayl, dansyl, benzyloxycarbonyl, fluorenylmethoxycarbonyl, methoxyaselayl, methoxyadipyl, methoxysuberyl, and a 2,3-dinitrophenyl group. Blocking the charged amino- and carboxy-termini of the peptide derived compound would have the additional benefit of enhancing solubility of the compound in the hydrophobic environment of the cell membrane of the target microorganism.
The design of such peptide mimetic SP compounds is performed using techniques known in the art of drug design. Such techniques include, but are not limited to, self-consistent field (SCF) analysis, configuration interaction (CI) analysis, and normal mode dynamics computer analysis, all of which are well described in the scientific literature. See, e.g., Rein et al., Computer-Assisted Modeling of Receptor-Ligand Interactions, Alan Liss, NY (1989). Preparation of the identified compounds will depend on the desired characteristics of the compounds and will involve standard chemical synthetic techniques. See, Cary et al. Advanced Organic Chemistry, part B, Plenum Press, NY (1983).
Antimicrobial Formulations and Therapeutic Administration Thereof
The SP peptides, peptide analogs, and peptide mimetics are incorporated in a physiologically acceptable carrier or salt, suitable for topical application to the affected area, or for direct injection into the affected areas such as a soft tissue abscess or an infected joint, or for diffusion from a surgically implanted device. Topical applications include lavage of body cavities or lumens, e.g., pre- or post-surgical peritoneal lavage or pulmonary lavage. Topical applications include use of gels, creams, lotions, supposities, and use of devices and dressings such as dissolving patches and bandages impregnated prior to use with the antimicrobial peptide. Additional routes of delivery include oral, and injection or infusion that is intramuscular, intravenous, subcutaneous, intraperitoneal, intraspinal, and epidural. Meningitis for example is treated by administration of an SP peptide by several routes, including direct intraspinal injection.
The compositions contain from about 0.1 nM to about 10 mM peptide, usually containing from about 0.01 μM to about 1 mM compound, and more usually containing from about 0.1 μM to about 100 μM of SP peptide or peptide derived compound. The nature of the carrier depends on the intended area of application. For application to the skin, a cream lotion, or ointment base is usually preferred, with suitable bases including lanolin, SILVADENE™, particularly for the treatment of burns; AOUAPHOR™ (Duke Laboratories, South Norwalk, Conn.), and the like. The peptides or derivative compounds are incorporated into or onto natural and synthetic bandages and other wound dressings to provide for continuous exposure of a wound to the peptide. Aerosol applicators and inhaler devices are used, for delivery to sinuses and deeper portions of the respiratory system. Peptides and derivative compounds are also incorporated in or coated on implantable devices, such as heart pacemakers, intralumenal stents, and the like where the antimicrobial activity would be of benefit. Coating is achieved by non-specific adsorption or covalent attachment. Optionally, an anti-pruritic agent such as an opioid is added to a antimicrobial composition to relieve pain at an infected site. Additional antimicrobial agents can be combined with the SP peptides, including but not limited to one or more of beta-lactam antibiotics such as penicillin, macrolides such as erythromycin, aminoglycosides such as lincomycin, tetracyclines such as doxycycline, semi-synthetic antibiotics such as Ceclor, and bacterially-derived peptide antibiotics such as gramicidin and tyrocidin.
The contents of all cited patents and papers are hereby incorporated by reference herein.
Example 1
Structure of SP and Derivatives Thereof
Peptides were synthesized by respective Boc- or Fmoc-chemistry in solid phase by methods known in the art, e.g., Misicka, et al., Biochemical & Biophysical Research Communications 1991:180(3):1290-7. Crude peptides were purified by gel filtration on Sephadex LH-20 (in methanol), followed by preparative HPLC. All peptides were confirmed to have correct amino acid analyses and molecular weights by FAB-MS. For microbiological study, peptides in acetate form were used. The sequences of the peptides are: SP, Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-MetNH2 ( FIG. 1 , SEQ ID NO:1); SP antagonist, Arg-D-Pro-Lys-Pro-Gln-Gln-D-Trp-Phe-D-Trp-Leu-MetNH2 (SEQ ID NO:2); bradykinin, Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg (SEQ ID NO:3); neurotensin, Glu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu (SEQ ID NO:4) or Xaa-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu (SEQ ID NO:14; where Xaa is Pyr or Tyr); and indolicidin, Ile-Leu-Pro-Trp-Lys-Trp-Pro-Trp-Trp-Pro-Trp-Arg-Arg-NH2 (SEQ ID NO: 5).
SP is expressed in a variety of different animals. Analysis of the sequences of these homologues, in comparison to that of humans (SEQ ID NO:1) yields insight into design of SP peptides embodied herein. The sequence of SP native to the following organisms has been reported:
TABLE 1
SEQ ID NO:6
spotted dogfish
Lys-Pro-Arg-Pro-Gly-Gln-Phe-Phe-Gly-Leu-Met
SEQ ID NO:7
guinea pig, horse, cow
Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met
SEQ ID NO:8
alligator, chicken
Arg-Pro-Arg-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met
SEQ ID NO:9
Atlantic cod
Lys-Pro-Arg-Pro-Gln-Gln-Phe-Ile-Gly-Leu-Met
SEQ ID NO:10
rainbow trout
Lys-Pro-Arg-Pro-His-Gln-Phe-Phe-Gly-Leu-Met
SEQ ID NO:11
sea lamprey
Ala-Lys-His-Asp-Lys-Phe-Tyr-Gly-Leu-Met
SEQ ID NO:1
human
Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met
These data indicate a fully conserved consensus from prevertebrate chordate animals to humans, located in the three C-terminal residues. These three residues confer on the SP the ability to interact with a specific SP receptor on immune cells. Further, a consensus in the 8 N-terminal positions is found to be: Xaa 1 -Pro-Xaa 2 -Pro-Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 (SEQ ID NO:12) where Xaa 1 and Xaa 2 are positively charged amino acids, Xaa 3 and Xaa 4 are Gln or Gly, and Xaa 5 and Xaa 6 are aromatic amino acids, particularly Phe. This 8-residue fragment of SP has antimicrobial activity but cannot bind to an SP receptor on a cell of a subject, since the fragment lacks the portion of the peptide that confers affinity to that receptor.
Without being bound by any particular mechanism, antimicrobial activity of SP peptides requires the above 8-residue consensus sequence. The aromatic residues confer solubility on the peptide for the hydrophobic lipids of the membrane of target microbe cells, and also confer the ability for self-aggregation and multimerization of the SP peptide. The alternating positive residues and prolines at positions 1-4 of the 8-mer peptide confer a particular three dimensional configuration, for example, a helical configuration, to the monomer, so that the monomer assoicates with a lipid moiety of a cell membrane. SP peptides interact with one another and with a component of a microbial membrane to form a supramolecular structure, e.g., a pore.
Peptides having the above consensus offer advantages for use as a novel antimicrobial agent. As SP is an endogenous peptide, found in humans and other chordate and vertebrate animals, it is not antigenic. Therefore continued administration of this agent over time does not provoke an immune response. Further, deletion or substitution one or more of the three carboxy-terminal residues (Gly-Leu-Met) associated with affinity of the SP peptides to a specific SP receptor on cells of the immune system assures that possible undesired side affects of systemic SP administration (e.g., SP-receptor mediated activities such as pain, inflammation, and swelling) are reduced or eliminated. In addition, the antimicrobial activity of SP peptides has a broad antimicrobial spectrum as shown herein, including Gram positive and Gram negative bacteria, and fungi. These data indicate that traditional targets for antimicrobial agents, such as the prokaryotic ribosome or the murein cross-bridges of a bacterial cell wall are not involved as macromolecular targets. Therefore, the compounds described herein cannot be evaded by enzymes associated with multiple drug resistance factors. Topical administration of an SP peptide to an epithelium of a subject offers the advantage that the peptide remains external and does not become systemic.
Example 2
Antimicrobial Activity of SP and Derivatives Using Bacterial Test Species
Antimicrobial activity, specifically antibacterial activity, was assayed using cells of each of Staphylococcus aureus NCTC 4163, Escherichia coli NCTC 8196, Pseudomonas aeruginosa NCTC 6749, Proteus vulgaris NCTC 4635, and Enterococcus faecalis ATCC 19212. To determine the minimum inhibitory concentration (MIC), the microdilution broth method, well-known to one of ordinary skill in the art of microbiology, was used. Cells of each bacterial strain were collected in the logarithmic phase of growth, and resuspended in nutrient broth. The concentration of colony-forming units (CFU) per milliliter was quantified by measuring absorption of light at 600 nm (A 600 ).
Peptide samples were dissolved in nutrient broth (pH 7.0) and diluted serially. The sample solution (100 μl) was mixed with the diluted bacterial suspension (100 μl). Mixtures containing 105 bacterial CFU, and from 1% to 0.003% of test peptides, were incubated for 24 h at 37° C. Antimicrobial activities were expressed as the minimal inhibitory concentration (MIC), which is defined as the concentration at which 100% inhibition of growth of this number of cells was observed (Table 2). The indolicidin antibacterial property with cells of S. aureus was used as a positive control reference.
TABLE 2
Antimicrobial activities of SP peptides, neurotensin and bradykinin
Minimal Inhibitory Concentration MIC (%)
S. aureus
E. coli
E. faecalis
P. vulgaris
P. aeruginosa
C. albicans
SEQ ID NO: 1
0.007
0.06
0.13
0.13
0.13
0.25
SEQ ID NO: 2
0.13
0.13
0.13
0.13
0.13
0.03
Neurotensin
0.25
1.0
1.0
0.5
1.0
>1
Bradykinin
0.5
0.5
>1
0.5
1.0
0.25
Indolicidin
0.003
0.007
n.t*
n.t.
n.t.
0.015
*n.t.—not tested
Naturally-occurring SP binds to a specific SP receptor on certain cells and plays an active role in the host defense system. This peptide, and other regulatory peptides such as neurotensin and bradykinin, exhibit coordinated actions in protecting mammals from microbial infection. Previously, all activities of substance P have been related to its effects on endogenous mechanisms activated by NK receptors, such as antibody stimulation (Maszczynska, et al., Analgesia 2000; 3:259-68; Hartung, et al., Journal of Immunology 1986; 136(10):3856-63; Jeon, et al., Immunopharmacology 1999; 41 (3):219-26; Pascual and Bost, Immunology 1990; 71(1)52-5; Linnik and Moskowitz, Peptides 1989; 10(5):957-62; Payan, Annual Review of Medicine 1989; 40:341-52); histamine release; (Shibata, et al., Biochimica et Biophysica Acta 1985; 846(1): 1-7); induction of NO synthesis (Hartung, et al., Journal of Immunology 1986; 41(3):219-26); vasodilation, and so on (Joos and Pauwels, Trends in Pharmacological Sciences 2000; 21(4): 131-3).
In addition to SP, other peptides (e.g., neurotensin, bradykinin), which are expressed also at sites and injured tissues that form the frontiers of the host defense system, were tested. Surprisingly, a variety of pathogenic microorganisms were found to be inhibited by SP peptides with the amino acid sequence of SEQ ID NO:1 and 2. Bradykinin and neurotensin had significantly lower antibacterial potency than either SP or SP antagonist against nearly all microorganisms tested.
Data obtained using cells of S. aureus demonstrate that SP and SP derivatives thereof have substantial antimicrobial activity. The level of activity was comparable to that of indolicidin. The antimicrobial property of SP was found to be very strong (Table 2), i.e., equally potent to indolicidin for cells of the Gram positive bacterial species S. aureus . Further, SP antagonist activity is comparable to that of indolicidin for cells of the fungal pathogen C. albicans.
The antimicrobial potencies of SP antagonist on the other bacteria tested were weaker than SP (MIC was 10- to 20-fold higher), but still significant. Observed differences in activity correlate with endogenous recognition of pathogenic ( S. aureus ) and symbiotic bacteria ( E. coli ). S. aureus is widely and normally found on skin and so is “symbiotic” species, whereas infection by some strains of E. coli , such as the enterotoxic strain O157:H7, can be fatal.
Example 3
Antifungal Activity of SP and SP Antagonist
Antifungal activity was assayed using Candida albicans NCTC 10231 as a target fungus. Candida cells in the logarithmic phase of growth were suspended in dextrose broth medium at a density of 10 5 CFU/ml. A mixture of the sample solution (100 μl) and the fungal suspension (100 μl) was incubated for 24 h at 37° C. Antifungal activity was assessed using turbidity measurement as described above (Table 2).
SP was found to have antifungal properties against C. albicans . Further, the SP antagonist was found to have approximately 10 times higher potency against C. albicans than either SP or bradykinin.
Example 4
SP Antagonist does not Affect the Antimicrobial Activity of SP
Using mixing experiments, the antimicrobial effect of SP was found not to be blocked by the presence of a SP antagonist. This finding confirms the data in Table 2, and indicates that the antimicrobial effect in vivo is not mediated by the SP receptor, but is rather a direct effect on the microorganism. Data herein indicate that substance P possesses previously unreported, direct antimicrobial potency.
Other embodiments are within the following claims.
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The invention features an antimicrobial composition comprising a substance P peptide and methods of inhibiting growth of a microorganism by contacting the microorganism with a substance P peptide. Bacterial and fungal pathogens are inhibited by the substance P compositions.
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This application is a continuation of Ser. No. 08/345,934 filed Nov. 28, 1994, now abandoned; which is a continuation in part of Ser. No. 08/012,412 filed Feb. 16, 1993, now U.S. Pat. No. 5,403,552; which is a continuation in part of Ser. No. 07/843,409 filed Feb. 28, 1992, now abandoned; which is a continuation in part of Ser. No. 07/504,910 filed Apr. 4, 1990, now U.S. Pat. No. 5,051,940; which is a continuation in part of Ser. No. 07/352,689 filed May 10, 1989, now abandoned; which is a continuation in part of Ser. No. 07/139,075 filed Dec. 28, 1987, now abandoned; which is a continuation in part of Ser. No. 06/871,066 filed Jun. 5, 1986, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates, in general, to optical analyzers for liquids and liquids containing hydrocarbon and polymer gel constituents, and more particularly to analyzer modules which are capable of automatically monitoring and controlling aqueous polymer compositions with hydrocarbon concentrations of polymer or polymer gel constituents produced through a polymer processing and delivery system.
For convenience of expression, the word "polymer" is used herein to cover all suitable systems without regard as to what they can do or are actually processing. In greater detail, while the inventive analyzer may be used in many fields, to test and analyze many products, it is particularly useful for analyzing polymers. These polymers include--but are not necessarily limited to--synthetically and naturally occurring polymers used in charge neutralization, coagulation, flocculation, and emulsification applications. Another particularly useful application of the invention is in the dairy industry where butter fat is first removed and then back blended into milk. These and similar polymers are blended, activated or otherwise processed in many different system, a few of which are shown in the above-identified patents, patent applications, and similar disclosures.
As a general description, a polymer can be defined as a chemical compound made up of repeating structural units which are comprised mainly of carbon and hydrogen. The structural units, or monomers, are linked together to form long chains in a process called "polymerization". If the monomers are positively charged, the polymer is referred to as "cationic" because it migrates to a cathode. A typical cationic polymer contains positively charged nitrogen ions on some or all of its repeating units. When the polymer is comprised of negatively charged units, it is termed "anionic", again because it migrates to an anode. An anionic polymer, for example, may get its charge from negatively charged oxygen ions. If the net charge on the polymer is zero, it is described as "nonionic". A nonionic polymer can result from either an equal combination of negative and positive units or from an absence of charged groups along its chain.
If a polymer is made up of only one type of repeating unit, or monomer, it is a "homopolymer". If two types of monomer uniformly alternate along a polymer backbone, it is a "copolymer". The number and type of repeating units comprising a polymer molecule determine its molecular weight. Since many monomer units are required to make up a polymer, these weights may be very high, ranging from ten thousand to more than ten million.
"Gels" are colloidal suspensions in which the dispersed, natural or synthetic polymer phase, has combined with the continuous, aqueous, phase to produce a semi-solid material. Gels are also fluid-like colloidal systems having long-chain, nitrogen-containing, macromolecules in a semi-solid form. "Emulsions" are dispersions of high-solids synthetic polymer gels in hydrocarbon oil. All solid synthetic polyelectrolytes result from differences in a processing of a polymer prepared in aqueous solutions, or in an aqueous phase of suspension. The synthesis results in a rigid, tough, rubbery gel. Processing the tacky gel particles, with heat, produces the "dry" or "powder" solid polyelectrolyte product.
In general, an activation of liquid polymers is a compound/complex continuum of multistage organic chemical reactions. Depending on the characteristic of the polymer, the activation may require one or more distinctive and successive stages.
Liquid emulsion polymer or micro emulsion polymer (whether 25% to 40% active inverse-emulsions, or 50% to 70% active dispersions) require two distinct processing steps to completely activate the aqueous polymer solution product. These two steps are inversion and aging, similar to the systems described in the above-identified patent applications. In the inversion phase, polymer processing systems "break" the emulsion by subjecting the mixture of high-active-solids polymer gel particles to high-energy, high shear, pressure and mixing gradient forces which instantaneously disperse the continuous oil phase and release the discontinuous polymer gel particles, thereby freeing the polymer to dissolve in the dilution water through hydration and molecular diffusion. In the aging step, the liberated polymer particles are allowed to hydrate and diffuse, in-line or in specially designed holding tanks.
Solution polymers (whether 2% to 7% high molecular weight active or 5% to 60% low molecular weight active) may require only one processing step. The high turbulence high energy blending associated with the above-mentioned systems are usually enough to provide an active in-line homogenous aqueous polymer solution.
The ideal polymer processing system should perform at least two functions. (1) It should provide an active and homogenous polymer solution and; (2) should maintain a desirable relationship (ratio) between the volume of solvent or diluent (water) and the volume of polymer (solute). Additionally this relationship or ratio should be adjustable over a usable range. The polymer particles and associated constituents in a ratio with the aqueous diluent, form a polymer composition which is the "concentration" of the solution.
The concentration of the polymer solution is an important aspect. Too great a concentration causes a polymer overdose result with a negative effect. Too small a concentration causes a polymer underdose that has a similar negative effect. Therefore, it is extremely important to maintain the proper dosage range when applying a polymer. Controlling the concentration of the polymer is one important variable.
Another aspect of maintaining proper polymer concentration involves the "breaking" or inversion of an emulsion type polymer. Too great a dilution results in a low concentration which might wash away necessary inverting agents called "activators" or "surfactants" which are useful in emulsifying hydrocarbon carriers. At the start of the polymer processing procedure, the concentration of a polymer solution is established by setting the diluent flow rate and the polymer flow rate at a desired ratio. For example, a 1% solution concentration set point is established by rationing 1 part of polymer to 100 parts of diluent. (Polymer to Water 1:100)
An ideal analyzer should continuously sense the polymer particles and associated constituents freed in the aqueous medium and should provide pertinent concentration information. If the sensed concentration begins to depart from the desired setpoint, signals from the analyzer should be fed back to adjust the polymer processing system. While the system is being so adjusted, the analyzer should monitor to avoid over correction. When the polymer mixture approaches the desired concentration setpoint, the process should be stabilized and then maintained there.
Other fluids, liquids, gels and the like have similar problems which may be addressed by the invention. For example, milk and milk products may also be monitored continuously by the invention. Thus, for example, during processing, milk is first separated from its butter fat and then the butter fat is blended back into the milk at the appropriate concentrations. This process may be monitored or controlled by the invention.
In the inventive system, a sensor manifold assembly or sample block or sample chamber (hereinafter "sample chamber") may be either a stand alone component or a part of another assembly, such as a premix manifold. The sample chamber can be installed to accept either a full process flow or a partial process or a bypass flow. These alternatives give great flexibility as, for example, when adding the inventive module for automatically controlling polymer processing to an existing system while retrofitting an installation.
In one instance the sample chamber may be placed downstream of the polymer processing system at a cascaded location after the primary solution has been blended or inverted, etc. and where there may be further dilution by way of secondary or tertiary dilutions. Also, by way of another example, the module for automatically controlling the polymer processing system can be used in the well known cascade control fashion by monitoring the polymer solution as it exits a holding vessel or aging tank in order to provide a consistence of polymer concentration which heretofore has been unheard of. This is particularly useful in processes like paper making where the polymer is critical to the wet end chemistry of the paper machines.
In the structure set forth in U.S. patent application Ser. No. 08/012,412, filed Feb. 16, 1993, the system was operated with a set point. For example, in order to provide the 1% solution concentration described above, the input of polymer is set at some value in terms of gallons per minute. Then, the input of diluent electrolyte is set at 100 times that value, again in terms of gallons per minute. Hence, the output solution will be 1 part polymer and 100 parts diluent.
When the system reaches equilibrium, a suitable command is given. Thereafter, the system automatically operates at a 1% solution concentration which existed when the command was given. If the user wishes to operate the system at, say 0.5 parts polymer and 100 parts diluent, the set point procedure is repeated. Thereafter, the system operates at a ratio of 0.5 polymer per 100 parts diluent. However, now the system can no longer operate at the ratio of 1 part polymer, per 100 parts diluent unless the reset procedure is followed. This means that the system Ser. No. 08/012,412 is always dedicated to operate at some fixed ratio. It can not operate at any other ratio unless the preset procedure is repeated.
This problem occurs because polymers do not have linear response functions. In fact, each polymer has its own characteristic profile curve. Few of the polymers share the same characteristic curve. Therefore, unless there is a very unusual situation, the users of the inventive system almost always have to refer to a different unique characteristic curve each time that a new polymer is processed.
Accordingly, an object of the invention is to provide new and novel concentration analyzers which do not require resetting in order to process many different concentrations of a polymer in a liquid. Here, an object is to provide a continuous sensing of the concentration of a polymer or other liquid, semi-liquid, gel or the like and to relate that concentration to a non-linear relationship. In this connection, an object is to provide for operating a polymer processing system with anyone of many solution concentrations which are automatically maintained without requiring the calibration of a new set point each time that the ratio of polymer to electrolyte is changed.
Another object of the invention is to provide a production system which may be monitored and automatically adjusted, continuously.
In keeping with an aspect of the invention, these and other objects are accomplished by first "profiling" a characteristic curve or table of information into a computer memory in order to describe a particular polymer. In greater detail, a light source emits a controlled amplitude and frequency of coherent light (laser) energy which is scattered and absorbed by the polymer material dispersed throughout an instantaneous aqueous sample of a monitored material flowing continuously through a sample chamber. The source of light energy is located at an adjustable distance from one side of the sample chamber. An optical receiver (a photoresistor with a selectable filter) measures the amount of light received on the other side of the sample chamber and generates an output signal which may be converted into a usable process control signal.
In order to profile the curve, the operator repeatedly sets the inflows of polymer and an electrolyte, such as water, and then, after each such setting, stores a memory of the relationship between the set inflows and the process control signal, thereby producing a curve or a table of information for the particular polymer being processed. A process controller (microprocessor or microcomputer) compares the usable process signal generated responsive to the received light to the stored characteristic curve in order to detect any deviation of the actual concentration or ratio of polymer to electrolyte to the theoretical ratio described by the characteristic curve or table of information.
The process controller display can be configured to read in any suitable terms, such as percent concentration, active polymer solids or any other relevant engineering unit or scale.
When the monitored system has feedback, the receiver output may be applied through a feedback control loop so that the process controller may be programmed to proportionally monitor and adjust a processing system such as a polyelectrolyte concentration by automatically controlling the polymer processing and delivery system itself.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is shown in the attached drawing, wherein:
FIG. 1 is a pictorial representation of the mechanical aspects of a system incorporating the invention;
FIG. 2 is a cross sectional view of the inventive sensor in connection with a sample chamber;
FIG. 3 pictorially shows how the inventive sensor and sample chamber is connected into a polymer processing system, such as that shown in FIG. 1;
FIG. 4 is a block diagram of the inventive system;
FIG. 5 schematically shows alternative ways of connecting the inventive module into a polymer flow system;
FIG. 6 schematically shows a cascade coupling of the inventive module;
FIG. 7 graphically illustrates how the angular displacement between a laser light source and a detector may be varied;
FIG. 8 is an exemplary graph showing a hypothetical non-linear relationship between the laser signal output and polymer concentration; and
FIG. 9 is a flow chart showing the operation of the inventive programmable controller.
DETAILED DESCRIPTION OF THE INVENTION
Broadly, a polymer processing system (FIG. 1) has polymer and any suitable electrolyte (hereinafter called "water" for convenience of expression) which are introduced via intake ports 20, 22, respectively. A polymer pump is shown at 23. If one part of polymer is introduced via port 20 while one hundred parts of water are introduced via port 22, the concentration is 1% polymer. The polymer and water are mixed in any suitable and known way and then fed through a mixing pressure regulator 24. Various mechanical control handles 26, 28, 30 may be manually adjusted as may be required. These adjustments may be purely mechanical (as opening or closing valves); or, they may be settings of adjustments on electrical controls/actuators.
On control panel 32, various electrical switches or the like may be used to program the system. As here shown, by way of example only, the panel provides a variable speed control. Almost any kind of adjustable device may be accommodated. The inventive sensor sample chamber 34 is here shown, by way of example at the inlet port of the mixing pressure regulator 24 to continuously monitor the solids content of the fluid flowing to the mixing pressure regulator 24. Alternative locations 36, 36 might place the inventive controller/sensor at the output of the system while another location might be on the recycle leg of the polymer mixing loop. The controller/sensor may also be located at any other suitable location in the system.
FIG. 4 shows a block diagram of the electronic controls for the inventive system. The electronic modules depicted in FIG. 4 are located in the main control panel 32 of the system described in FIG. 1. Most of the polymer processing system of FIG. 1 is generally shown in the lower left-hand corner of FIG. 4.
Three elements form the essence of the automatic polymer solution controller system:
a sample chamber, sensor manifold assembly or sample block;
an electronic module; and
a process controller.
The sample chamber or sensor manifold assembly 34 (FIG. 2) has a flow chamber 40, in a housing with a transparent viewing port 42, a selective light filter 44, a cadmium sulfide (CdS) photoresistor 46, and a coherent light source (semiconductor laser) emitter 49. The assembly of FIG. 2 has threaded ports which accept diode assembly 48, and resistor lens detector assembly 50.
FIG. 4 shows the assembly of FIG. 2 built in a modular design which incorporates the components of FIG. 2 and a laser drive means 62 built into a single housing 51 which offers a more compact size and reduces the chances for a diode failure. This module 51 is a commercial product (Model VLM 2-5C) sold by Applied Laser Systems, 2160 N.W. Vine Street, Grants Pass, Oreg. 97526.
The laser diode assembly 48 incorporates a semiconductor diode 49, heat sink, lens, static shielding and pin connector housed in a cylindrical threaded body designed for ease of removal from the sample cell. One exemplary laser diode 49 produces light which has a visible light wave length of λ=670 nm. Depending on the type of laser used, wavelengths can vary from approximately 300 nm through infrared (>700 nm). In one example, a laser diode with a wavelength of 780 nm may be used in conjunction with a photodiode detector (i.e., a silicon photocell) to take full advantage of polymer compositions that respond favorably to the infrared spectrum. In another example, an ion laser operating at 514 nm may be used for polymer compositions which respond favorably to this wavelength. For both examples, the appropriate lasers would be fitted for use in the module for automatically controlling the polymer system.
The laser light is by far the most efficient way of reading through the polymer solution. However, at the margin of utility and for some polymer solutions, white light may be used instead of the laser light. Therefore, for the convenience of expression, the term "coherent" light is to be construed as any light suitable for a particular polymer solution.
The sample chamber (FIG. 2) may be installed to use either a bypass (FIG. 5A), a partial flow (FIG. 5B) or a full and unrestricted solution flow (FIG. 5C), depending on its relative location in and the nature of the polymer processing system (FIG. 1). FIG. 6 shows the inventive module at a cascaded location downstream of a mixing tank. The output in any of the connections of FIG. 5 or 6 may be either part of a feedback loop or the output of the system. The flow of a polymer solution through sample chamber 34 (FIG. 2) has to be fast enough to respond to process changes and slow enough so as not to cause an undue turbulence and thus to prevent an efficacious reading.
FIG. 3 shows one example of a connection of the sample chamber assembly into the polymer processing system. In greater detail, a pipe 54 leads from a polymer mixing chamber 53 (FIG. 1) into the sample chamber housing 34 and pipe 52 leads from the housing 34 to the pressure regulator 24 so that the polymer solution flows through the sensor chamber housing 34 during normal processing. The inside diameter of the flow chamber 34 can range from 0.302" to more than 12.0" and flows can range from 0.25 gpm to 5000 gpm. Typically, a sample cell will be designed for a flow velocity of 1 to 10/ft sec. However, a range of 0.3 to 25.0 ft/sec, or more, is possible depending on the rheology of the fluids.
During the flow, a light from laser source 49 (FIG. 2) shines coherent light through the solution in chamber 40 toward the receiver assembly 50. The characteristics of the solution flowing through housing 34 are detected by the differences in the readings taken at the receiver assembly 50.
The sample chamber 34 is designed for a direct opposing scan of the light emitter and detector which seems to be the most efficient arrangement for most polymer solutions. However, there are cases where an off axis scanning is preferred. Basically, the light emitter diode 49 and detector 46 may be set at any suitable angle with respect to each other. This setting tends to emphasize a certain type of particle reflection which is not typically enhanced in direct opposition scanning. The angle of particle reflection A (FIG. 7) may be in the range from 0° to 60°; however, sometimes greater angles may be used if testing warrants it.
In many cases, the level of partial hydration of certain polymers with respect to efficiencies of invention and on blending, aging, etc., may lend itself to angles greater than 60°. Where this is the case, the lenses can be set at 70°, 90°, 120°, 180° or any angle in between. In this arrangement, the optical output of the emitter cell could be adjusted to compensate for the more radical off axis lens angles.
The automatic polymer solution controller electronic module (FIG. 4) integrates several functions into a single unit. The first function of the module is to provide an adjustable power supply 60 to power a semiconductor laser diode driver 62 and resistance transmitter 68. A special feature is included to protect the semiconductor laser in that power from the power supply 60 is routed to an external connection 64 on the sensor housing 34. A lead from another external connection 66 is connected to the laser driver 62.
In this inventive example, the semiconductor laser diode 49 (FIG. 2) is powered by a laser driver circuit 62 rated to deliver up to 150 mA of power. An on board potentiometer enables this driver to be adjusted to the desired output power. The driver can either provide a constant light or optical output via a pin diode feedback or provide a constant current source for the laser diode. This is a selectable feature. The optical feedback loop is designed to maintain a constant light output which is independent of temperature variations at the diode. The feedback loop remedies this temperature caused problem by compensating the amount of drive current delivered to the diode so that the driver current is automatically adjusted to maintain the same light output level.
Through the use of a plug 69 (FIG. 2) on the diode lens assembly, the connection is made to diode 49 before the diode drive board connection is made. This important feature protects the diode 49 from destructive voltage spikes if the diode connector should be removed while it is receiving power. Additionally, the power supply lead pins on the printed circuit board holding the module of FIG. 4 are mechanically shortened to prevent supply problems caused by spikes if the module is removed or replaced while the processing unit is powered.
The delivery of power to the diode automatically shuts down within milliseconds after the detection of a destructive voltage spike. This feature is built into a laser driver circuit. This is particularly useful when attempting to disconnect or reconnect a diode with the power on. This circuit enhancement both prevents the diode from failing due to a sudden spike, and eliminates the need for special connectors designed to prevent this. This circuit also prevents a user from removing the light emitting diode from the sample chamber while the laser is operating. This is also an important consideration in meeting certain classes of regulating compliance codes.
The module for automatically controlling the polymer solution also includes a resistance transmitter signal conditioning device 68 (FIG. 4) which has separate zero and span settings. The resistance transmitter 68 accepts a resistance signal from the receiving sensor 46 and converts it into a proportional analog output. In effect, resistance transmitter 68 is a translator for converting the "language" of sensor 46 into the "language" of PID (proportional integral derivative) controller 70. The PID controller 70 is a standard commercial electronic product, such as those sold by Yokagawa (Model UT 40) and by Powers, Model 535.
Because semiconductor lasers are sensitive to heat from many sources, one has to be particularly careful when monitoring processes that are carried out at a temperature which is higher than ambient temperatures. When running a high temperature solution (above 50° C.) through the sample chamber 34, remoting the emitter and detector cells prevents conductive heat damage to the diode. In the inventive system, fiber optic cables may be fitted to adapter lens housings at the sample chamber and then routed into another enclosure (i.e., control panel) where the emitter and detector are placed away from the heat source. The fiber optic cables are then terminated at ends of the emitter and detector assemblies.
The losses experienced through fiber optic transmission inefficiencies are compensated by increasing the optical output of the laser. Most laser diodes are operated at or above their threshold current values. This is often 70% to 90% of their maximum current value. Thus, for a diode with a maximum operating current value of 100 mA, the threshold current might reasonably reside somewhere around 80 mA. The threshold current is defined as the point in the radiant power output curve where the diode exhibits the special laser light qualities. For most applications, this is where the inventive system seeks to operate.
The electronic PID controller receives the output from the resistance transmitter 68 and displays it at 76 as a process value. The output from the PID controller is then used to control the speed (in this example) of a neat polymer injection pump 23 (FIG. 1) via variable speed drive 77. Hence, there is a feedback control loop from PID controller 70 to the polymer processing system (FIG. 1), sample chamber 34, resistance transmitter 68, and back to controller 70, which continuously adjusts the polymer processing system.
In operation, the polymer solution passes continuously through the housing of the sensor chamber 36 (FIG. 2). The laser light source 49, operating in this example at a wavelength of 670 nm, is positioned inside the housing of sensor chamber 34 and behind a suitable lens assembly 72 located on one side of the monitored solution stream. The light passes from the laser source through the lens 72 and then through the polymer solution. After passing through the polymer solution, it enters a second lens assembly 74 on the opposite side of the solution stream. Located inside and behind the second lens assembly is a light selective filter (approximately 670 nm) and a CdS photoresistor 46.
The frequency which is selected for the laser depends on the type of polymer that is being monitored. Most synthetic polyelectrolytes, such as dispersions, emulsions, and natural polymers (corn starches, for example) respond well at the 670 nm wavelength. Solution polymers work best at or near infra-red wavelengths. However, for the entire range from visible light through infrared, all frequencies can be used to take advantage of unique molecular footprints and equivalent weights.
The light intensity which is received at the resistor lens assembly 74 (FIG. 2) passes through a light selective filter prior to entering the CdS cell 46. By matching the light selective filter with the laser frequency, ambient light entering the sample chamber 34 through the viewing window 42 does not have a disruptive effect on the reading from CdS cell 46. Any small percent of the ambient light that has wavelengths that pass through the light selective filter are considered background noise which may be calibrated out of the reading, under almost all conditions.
The intensity of the light which is received at the resistor lens assembly 74 varies with the concentration of the polymer solution.
The resistance of the CdS cell 46 is variable with the intensity of the light. Due to these two relationships acting in conjunction with each other, the output resistance becomes directly proportional to the concentration of the polymer solution.
The resistance of the CdS cell 46 is measured and converted into a process control signal by resistance transmitter 68 and PID controller 70. This signal may become a manually selected setpoint which is entered into the PID or the programmable logic controller ("PLC") 100, which is a standard commercial item (FANUC Series 90-30) manufactured and sold by the General Electric Company. The PID controller 70 output signal is a control signal for adjusting the processing system of FIG. 1.
Since it has been assumed for descriptive purposes that the controlled device 32 (FIG. 1) is a variable speed drive in FIG. 1, the usable output signal varies the speed of a positive displacement polymer injection pump 23. As the concentration of the polymer solution tends to decrease (i.e., water flow increases), neat polymer solids decrease, etc., the PID controller 70 (FIG. 4) increases its output signal, thus increasing the speed of a positive displacement pump 23. This causes more polymer to be metered to the polymer processing unit, thus increasing the concentration of the polymer solution. The usable output signal may cause the percent of polymer concentrate and active polymer solids to be displayed at 76.
Another example would incorporate the use of a water flow control valve at a location where the polymer injection pump stays constant and the water flow is adjusted for concentration control.
The system of FIG. 4 includes the programmable logic controller ("PLC") 100 which is connected to the polymer processing system of FIG. 1 in order to send at 101 and receive at 102 information relating primarily to flow rates of polymer at inlet 20 and water at inlet 22, expressed in terms of gallons per minute, or the equivalent. The laser sensor 34 sends its reading to the PLC via the resistance transmitter 68 and PID controller 76. The PLC stores information which it receives or generates in an EPROM 104.
FIG. 8 is a graph which shows a characteristic curve for an exemplary and hypothetical polymer. The same information could be stored in a look-up table. Each polymer has its own individual curve which should be used when that particular polymer is being processed. This information could be stored in many different ways.
On the other hand, one desirable characteristic of the invention is that it is adapted to be controlled by a person such as computer terminal operator, or the like, who is skilled at working on a computer terminal; however, it is, perhaps unlikely that the operator will know very much about characteristic curves of a polymer. Therefore, an object of the invention is to enable the terminal operator to enter a curve or table of information, such as in FIG. 8, without being familiar with the polymer.
In greater detail, the curve of FIG. 8 is "profiled" into the computer. In this case, custom "profiling" is a technique for entering information responsive to the use of an internal computer construction without requiring the operator to know the specifics of the information that is being entered. That is, the information is entered as if it were being "profiled" by the computer itself.
FIG. 8 has the laser produced output readings (i.e. the milliamp reading on wire 79, FIG. 4) on the vertical scale and the polymer concentration (read in tenths of a percent) on the horizontal scale. Therefore, the vertical scale is 0-25 milliamps and the horizontal scale is from 0.3% to 2% concentration of polymers in the output solution.
In order to profile or paint the curve into the computer, the operator first adjusts, in incremental steps, the polymer inflow at inlet port 20 to have an inflow rate of 0.3 GPM (gallons per minute) and the water inflow at inlet port 22 has 100 GPM. As soon as the two inflows are mixed and equilibrium occurs, the PLC 100 computer or alternatively the PID stores a memory of the ratio of inflow rates and the laser output in an EPROM 104. This ratio is the first recorded point on the curve of FIG. 8, representing the first incremental adjustment of the inflows to 0.3% polymer concentration in the output solution. Then, the operator resets the inflows at inlet ports 20 and 22 in the next incremental step and the PLC stores a memory of the next point on the curve of FIG. 8 in the EPROM 104, representing the second incremental adjustment of the inflows, i.e. the milliamp reading at 0.4% polymer concentration in the output solution.
The process is repeated in incremental steps which may be as fine or as coarse, per step, of the adjustments as the operator may wish to make.
Depending upon the nature of the user needs, the memory stored in EPROM 104 may be any suitable number of points to generate a curve that is profiled into memory. Also, depending upon user needs, one or more curves may be stored at addresses so that, in the future, the operator only has to enter an address code to recall any curve that has been stored in the past. This way, it is only necessary to enter a code which identified the polymer that is being processed.
Or, the EPROM 104 may be adapted to store a single curve which is erased and replaced each time that a new polymer is introduced into the system of FIG. 1. If a user does not change the polymer being processed very often, this record, erase, and re-record may be the most economical.
Once the curve of FIG. 8 is profiled into the memory at EPROM 104, the PLC 100 or alternatively the PID generates and sends process control signals at 101 which controls and adjusts the inflows of polymer and electrolyte at the two input ports at 20 and 22. This control holds a selected level of polymer concentration in the solution delivered at the outflow port, as read by the laser sensor of FIG. 3. For example, if a polymer concentration of 1% is desired in the out flowing solution, the computer terminal may be adapted so that operator only has to push "1". For, say, a 0.75 concentration, the operator pushes "0.75". Of course, any suitable arrangement including words (such as "skim milk", "lo fat", "whole milk", etc.) may also be provided for an operator to punch when a process begins.
For better performance, there are instances where the module for automatically controlling the polymer system can be tuned to operate below the threshold value of the laser. This is particularly true for polymer solutions with lower densities. In this case, the laser acts as a light emitting diode of a monochromatic nature with marginal coherency at a much lower energy level. In the inventive system, the laser driver can be adjusted to operate below the threshold current in order to accommodate such an application. This is useful when applying the unit to a broad range of applications. The flexibility inherent in this feature provides a means for processing different solutions of different concentrations, within the capability of the module for automatically controlling a polymer system.
One such application involves the use of the module for automatically controlling a system in the dairy industry. The module can be used as a standard component for evaluating the butter fat content in milk where the dairy industry typically back blends butter fat into milk. The module enables dairies to measure and adjust the milk/butter fat ratios to determine whether the milk is skim; <1%, low fat; 1-2%, whole 3-4%, etc. When used in a feedback loop, the module interfaces with a dairy central process computer in order to control and adjust butter fat content on a continuous production basis.
The procedure for profiling a polymer processing curve is shown by the flow chart in FIG. 9, which is written in terms of a manual procedure. However, it should be understood that much of the procedure may be performed by a microprocessor operating under human supervision.
First, the inventive polymer processing system is switched on and brought up to speed. Then, the electrolyte or water flow rate is adjusted at 120 to a maximum volume for the system. A digital readout on the machine is then adjusted at 122 to give a base line reading of "000" at the maximum water flow.
The display 76 of PID 70 (FIG. 4) is transferred at 124 to an output mode which will allow the user to manually adjust the speed of pump 23.
The neat polymer pump is adjusted at 126 until the desired concentration is reached. For the first point or lowest concentrated ratio on the curve of FIG. 8, the first concentration of polymer will be set (128). For example, in the case of the graph of FIG. 8, the first setting is at 0.3% polymer (99.7% water).
The value being displayed at 76 on PID controller 70 is recorded at 130 while the system is operating at the set concentration (0.3% in this example) of the first setting which was made at step 128. This recorded value may be adjusted at 132 to reflect any suitable scale that is being used. If the graph is such that the point 0.3% is offset from either the vertical or the horizontal axes by some distance, a calculation to provide such offset is made at 134.
The user may or may not be satisfied by any given reading. As with all laboratory test readings, it may be desirable to take repeated readings and then average out the errors. Also, there are rounding errors, which might leave the user with an unacceptable level of possible errors. Stated another way, a redundancy of reading brings greater reliability.
Therefore, at 136, the program of the FIG. 9 flow chart provides for a reiteration of the program calculation results. On each iteration, reliability is increased by, in effect, dividing a calculation error in half. The repeated computations are made to divide a desired target value by the current PID display 76 and then multiply the resulting value by a range value, thereby reducing the error by one-half on each iteration.
At 140, the polymer pump is adjusted to the next higher level of polymer concentration. Assuming that the user wishes to profile every point on the graph of FIG. 8, the user next sets the concentration of the outflowing solution to 0.4% polymer. The steps 130-136 are repeated at 142.
In like manner, as shown at 144, steps 140, 142 are repeated for each resetting of the polymer concentration shown in FIG. 8 which is to be recorded.
As shown at 146, the system is designed to record any desired number of points from 2 to 20 on the curve of FIG. 8. The computer will draw the best and smoothest curve through the recorded points, as shown in FIG. 8.
Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention.
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A polymer processing system has a polymer input and an electrolyte input which may be varied independently of each other. The polymer and electrolyte are combined and mixed to provide an out flowing solution which flows through a sensor cell that gives an output signal indicating the concentration of polymer in the solution leaving the processing system. The user repeatedly and incrementally sets the inflows of polymer and electrolyte to provide a preselected variety of concentrations of polymer in the out flowing solution. On each incremental setting, a memory stores information relating the concentration to the output signal. Thereafter, the processing system automatically maintains any desired polymer concentration in joint response to the output signal and the stored information.
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BACKGROUND
The present invention relates to a method for detecting a turning situation with a view, notably, to generating a setpoint for a transmission of an automobile vehicle drive train. It also relates to a device implementing such a detection method.
An automobile vehicle automatic transmission conventionally comprises a control unit receiving one or more input parameters representing, amongst others, the state of the road: slope, change of slope, curvature, etc. Then, depending on the values of these parameters, the control unit delivers a transmission ratio setpoint to be applied, with interposition, where necessary, of “disable” commands temporarily prohibiting gear-ratio up-shift or down-shift changes for an enhanced driving comfort, for example in certain cases where the vehicle is in a turning situation. In a turning phase, a driver driving an automobile vehicle equipped with a conventional automatic transmission is indeed subjected to uncomfortable driving situations.
For example, going into a turn, the driver generally releases the accelerator pedal. The automatic gearbox that was initially on a given ratio then goes directly to the higher ratio owing to the conventional gear-change rules for an automatic gearbox. The vehicle thus no longer benefits from the engine braking effect. The switch to a higher gear ratio then causes an unpleasant swerving sensation for the automobile vehicle.
Methods and associated devices are already known from the prior art that allow adaptations to be applied to try and improve the comfort of the driver and the passengers in a turning phase.
The patent FR 2 779 793 filed by the applicant describes a system for automatic adaptation of a vehicle gearbox in a turning situation. The system detects a turning situation according to the transverse acceleration of the vehicle, then adapts the gear ratio change strategy as a function of the engine speed and the resistive forces applied to the vehicle.
The transverse acceleration may be determined either by accelerometers or calculated from the rotational speeds of a right and of a left non-driven wheel of the vehicle, such as described in the patent FR 2802 646 filed by the applicant. The calculation proposed by the patent FR 2802 646 assumes that the wheels adhere to the road without slipping and therefore requires the speed sensors to measure the rotation of non-driven wheels of the vehicle.
The patent GB 2 381 873 (Robert Bosch GmbH) involves the simultaneous use of a transverse acceleration calculation from the speeds of the wheels of the vehicles, and the results of measurement from a transverse accelerometer, in order to evaluate the transverse acceleration with more reliability. This patent proposes that the values of transverse acceleration exceeding a predefined threshold are put aside as non-valid, that this acceleration comes from the accelerometer measurement or deduced from the speeds of the wheels. This patent proposes that the interpretation of the transverse acceleration be suspended in the case of excessive skidding, defined by a wheel speed on the inside of the turning circle greater than the forward speed of the vehicle, or by a wheel speed on the outside of the turning circle less than the forward speed of the vehicle. This method requires the simultaneous presence of wheel speed sensors and of a transverse accelerometer, with the associated costs and operational issues.
BRIEF SUMMARY
The present invention aims to overcome the shortcomings of the aforementioned documents. The subject of the present invention is a method allowing the detection of the phases during which the slipping of the drive wheels with respect to the ground is too great which leads to an overestimation of the transverse acceleration. Such an overestimation may indeed lead to an up-shift gear change being inadvertently prevented in the absence of a curve in the road that would justify such a prevention.
The subjects of the present invention are a device and a method for evaluating the transverse acceleration of the vehicle that uses sensors already installed on the vehicle for other purposes. The invention notably allows the data from drive wheel speed sensors on the vehicle to be utilized, and in this respect is particularly advantageous for improving the driving comfort for vehicles that do not dispose of means of measuring the speed of the non-driven wheels of the vehicle.
The principle of the invention consists in carrying out a first estimation of the transverse acceleration of the vehicle based on the rotational speeds of a right wheel and of a left wheel, then in carrying out a series of tests in order to verify whether this estimated value is reliable or not. If the reliability of the estimated value is not confirmed, an arbitrary value is assigned to the transverse acceleration, for example a zero value, or another constant identifiable by the control processes that use this transverse acceleration. The reliability tests are carried out depending on other operating parameters of the vehicle which are also accessible in the “series” configuration of the vehicle, in other words without any sensor specific to the invention.
In one embodiment, a device for evaluating the transverse acceleration of an automobile vehicle comprises means of measuring the rotational speeds of two wheels of the vehicle and a module for estimating the transverse acceleration of the vehicle from these speeds. The device also comprises a validation module capable of calculating, as a function of operating parameters of the vehicle, notably of the rotational speeds of said wheels and of the transmission ratio engaged, a Boolean skidding variable which is negative if the transverse acceleration estimated by the module is relevant for detecting a turn, and which is positive if the reverse is true.
Advantageously, said wheels are a right drive wheel and a left drive wheel belonging to one and the same wheel set of the vehicle.
In one variant embodiment, the device also comprises a correction module capable of delivering a corrected value of the transverse acceleration in such a manner that said corrected value is equal to the previous estimated value of the transverse acceleration if the Boolean skidding variable is negative, and that this corrected value is equal to an arbitrary constant if the reverse is true.
This variant can comprise a delay device inducing a time delay either for the change in value, from positive to negative, of the skidding variable, or for the change in value of the corrected value of the transverse acceleration when it ceases to be equal to said arbitrary constant.
In one preferred embodiment, the validation module comprises a first Boolean module capable of delivering a first Boolean wheel over-acceleration variable. This module comprises a first means of calculating the accelerations of the two wheels, a second means of calculating a plausible acceleration threshold for these wheels as a function of the transmission ratio engaged, first means of comparison of the accelerations of each of the two wheels with respect to said plausible acceleration threshold, second means of comparison of the difference in speed between the two wheels with respect to a difference threshold, and means of storing the Boolean wheel over-acceleration variable.
In one preceding variant embodiment, the validation module also comprises a second Boolean module receiving the value of the acceleration setpoint from the driver and capable of delivering a second in-turn Boolean pedal application variable. This validation module comprises a summing means which adds together the Boolean wheel over-acceleration variable and the in-turn Boolean pedal application variable in order to obtain the Boolean skidding variable.
Preferably, in this variant embodiment, the second Boolean module comprises a means of determining the derivative of the acceleration setpoint from the driver with respect to time, comprises means of comparison of the acceleration setpoint, of its derivative and of the previously estimated transverse acceleration, with respect to three values of setpoint threshold, of setpoint derivative threshold, of accelerated centrifugation threshold, respectively, and comprises means of storing the in-turn Boolean pedal application variable.
In another embodiment, a device for detecting a turning situation for controlling an automobile vehicle mechanism, notably for automatic transmission control, comprises one of the evaluation devices described hereinabove, together with an arbitration module capable of deciding whether the vehicle is in a turning situation. This arbitration module comprises a means of comparison of the transverse acceleration of the vehicle with respect to a first value of arbitration threshold. It can also comprise a means of comparison of the derivative of the acceleration with respect to time of this acceleration, with respect to a second value of arbitration threshold. Advantageously, the arbitration module can be configured for deciding that the vehicle is in a turning situation if the estimated transverse acceleration or its derivative is greater than their respective arbitration thresholds.
According to another aspect, a method is provided for evaluating the transverse acceleration of an automobile vehicle, in which the rotational speeds of two drive wheels of the vehicle are measured, the transverse acceleration of the vehicle is estimated from these wheel speeds, and a Boolean skidding variable is calculated as a function of operating parameters of the vehicle, notably of the rotational speeds of said drive wheels and of the transmission ratio engaged, which variable is negative if the transverse acceleration estimated by the module is relevant for detecting a turn and which is positive if the reverse is true.
In one variant embodiment of this method, the calculation of the Boolean skidding variable can also take into account the acceleration setpoint from the driver, for example the position of the accelerator pedal of the vehicle and/or the derivative with respect to time of this position of the accelerator pedal.
In one preferred embodiment of the method, if the skidding variable is positive, the corresponding transverse acceleration is then corrected by assigning it an arbitrary value.
Advantageously, the Boolean skidding variable is the sum of a first Boolean wheel over-acceleration variable and of a second Boolean in-turn pedal application variable whose calculation comprises the following steps:
using a stored data map, a first plausible wheel acceleration threshold is calculated as a function of the transmission ratio engaged; if the derivative with respect to time of one of the measured wheel rotational speeds is greater than this first plausible wheel acceleration threshold, the wheel over-acceleration variable is positive; if the two derivatives with respect to time of the measured wheel rotational speeds are less than this first plausible wheel acceleration threshold and if, simultaneously, the difference in rotational speeds of the two wheels is less than a (constant) difference threshold, the wheel over-acceleration variable is negative; in the other cases, the wheel over-acceleration variable keeps its value; the derivative with respect to time of the acceleration setpoint from the driver is calculated; the acceleration setpoint from the driver, its derivative and the estimated transverse acceleration of the vehicle are compared with respect to three values of setpoint threshold, of setpoint derivative threshold and of accelerated centrifugation threshold; if the three values are simultaneously greater than their respective thresholds, the in-turn pedal application variable is positive; if the transverse acceleration of the vehicle is less than its respective threshold, the in-turn pedal application variable is negative; in the other cases, the in-turn pedal application variable keeps its value.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages and features will become apparent upon examining the detailed description of one non-limiting embodiment and of the appended drawings, in which:
FIG. 1 is a schematic diagram of one exemplary embodiment of a device for calculating the transverse acceleration of a vehicle according to the invention,
FIG. 2 shows one exemplary embodiment of a logic block from FIG. 1 in more detail,
FIG. 3 shows one exemplary embodiment of another logic block from FIG. 1 in more detail.
DETAILED DESCRIPTION
In the following description, analogous, identical or similar elements will be denoted by the same reference numbers.
As it is illustrated in FIG. 1 , a device for evaluating the transverse acceleration of a vehicle (not shown) comprises a validation module 2 , a module for estimating the transverse acceleration D 3 and a correction module D 4 . The validation module 2 itself comprises two logic blocks D 1 and D 2 and a logic adder 3 . The logic block D 1 receives, via connections 4 , the values of the rotational angular speeds Vrr and Vrl respectively coming from a rotational speed sensor 6 of a right wheel and a rotational speed sensor 7 of a left wheel from one and the same wheel set of a vehicle. The block D 1 receives, via a connection 5 , the value “Rtransmission” of the ratio engaged in the transmission system of the vehicle. The module for estimating the transverse acceleration D 3 receives, via connections 8 , the same values of rotational speeds Vrr and Vrl coming from the sensors 6 and 7 . The module D 3 transmits an estimated value γt of transverse acceleration via a connection 9 to the logic block D 2 , and transmits the same value γt, via a connection 10 , to the correction module D 4 . The logic block D 2 also receives, via a connection 11 , a value “pedal” corresponding to the acceleration setpoint from the driver, which can for example be the angular position of an accelerator pedal. This acceleration setpoint could also correspond, amongst other things, to an accelerator throttle angle, an acceleration regulator position or an angle of the gas inlet butterfly valve. The values transiting via the connections 5 and 11 can, for example, be sent by an onboard computer and transmitted to the blocks C 1 and D 2 via the multiplexed network or any other means of communication between processors. The logic blocks D 1 and D 2 send, respectively, a Boolean value SkidD 1 via a connection 12 and a Boolean value SkidD 2 via a connection 13 to the logic adder 3 which sends a logic variable “Skidding”, via a connection 14 , to the correction module D 4 . The correction module D 4 delivers a corrected transverse acceleration {circumflex over (γ)} t which can be sent, depending on the applications, to a management system for an automatic control unit of the vehicle, to a control system for the orientation of the headlamps in a turn, or any other system using the transverse acceleration and which can handle the ranges of uncertainty in the calculation of the transverse acceleration according to the invention.
Using the rotational angular speeds of the two wheels Vrr and Vrl, the module for estimating the transverse acceleration D 3 carries out an estimation of the transverse acceleration γt that the vehicle would have if neither of the two wheels were in a slipping situation with respect to the road surface. This estimation can for example be carried out by the method described in the patent application FR 2802 646 in the name of the applicant. The value of the transverse acceleration thus estimated γt is transmitted to the block D 2 which uses it for calculating the variable SkidD 2 and is also transmitted to the correction module D 4 . Using the operating parameters of the vehicle, i.e. the rotational speeds of the two wheels equipped with the sensors 6 and 7 , the transmission ratio engaged and the acceleration setpoint from the driver, together with the transverse acceleration estimated by the block D 3 , the logic blocks D 1 and D 2 calculate the Boolean variables SkidD 1 and SkidD 2 . These two values are sent over the adder 3 which delivers, via the connection 14 , the Boolean skidding variable “Skidding”, being the logic sum of SkidD 1 and SkidD 2 , which is positive if one of the variables SkidD 1 or SkidD 2 is positive (or denoted as 1) and which is negative (or denoted as 0) if the two variables SkidD 1 and SkidD 2 are negative (equal to zero). This variable Skidding is therefore negative if the tests carried out by D 1 and D 2 do not detect the slipping of one of the two wheels; it is positive if slipping of at least one of the wheels is detected.
The correction module D 4 calculates a corrected value {circumflex over (γ)} t for the transverse acceleration as follows: If the corresponding Boolean Skidding variable at the moment at which the transverse acceleration γt is estimated is negative, the corrected value {circumflex over (γ)} t is equal to the estimated value γt; if the corresponding Boolean Skidding variable at the moment at which the transverse acceleration γt is estimated is positive, the corrected value {circumflex over (γ)} t is equal to an arbitrary value {circumflex over (γ)} o . The arbitrary value {circumflex over (γ)} o can for example be chosen equal to zero so that the management device for the rules for switching the automatic transmission interpret this result as corresponding to an absence of bend in the road. In one variant of the invention, the value {circumflex over (γ)} o could be chosen equal to an arbitrary negative constant, for example the value −1. In this way, the system or systems using the value of transverse acceleration can detect a potential skidding situation upon reading {circumflex over (γ)} t . In one variant embodiment, which may be combined with the preceding one, the correction module D 4 can impose a time delay δt onto {circumflex over (γ)} t (for example of the order of 0.01 seconds to 1 second) by each time maintaining the value {circumflex over (γ)} t at its value {circumflex over (γ)} o over a period δt after the Boolean variable Skidding has become negative. The time delay can also be directly imposed onto the variable Skidding when it goes from the positive value (1) to the negative value (0).
FIG. 2 shows a flow diagram for calculation of the wheel over-acceleration Boolean variable SkidD 1 by the logic block D 1 in FIG. 1 . At a calculation time t, the block D 1 receives, via the connection 4 , the rotational angular speed values of two wheels Vrl and Vrr from one and the same set and receives, via the connection 5 , the identifier of the transmission ratio engaged. In parallel, the block D 1 saves in a memory 20 the value of the Boolean variable SkidD 1 calculated at the preceding calculation time (calculation time t−1). The connection 4 is connected to a processing block 22 and the connection 5 is connected to a processing block 21 , capable of reading in a data map stored in memory 23 . Based on the value stored in the memory 20 and on the values calculated by the blocks 21 and 22 , three test blocks 24 , 25 , 26 allow a value to be assigned to the Boolean variable SkidD 1 at time t. The processing block 22 calculates the accelerations Grl and Grr of the two wheels by differentiating their speeds Vrl and Vrr with respect to time. The block 22 also calculates the absolute value of the difference Δ in the two speeds Vrl and Vrr, being Δ=|Vrl−Vrr|. The two values Grl and Grr are sent, via the connections 27 and 28 , to the test blocks 24 and 25 , respectively. The value Δ is sent to the test block 26 via the connection 29 . Depending on the transmission ratio engaged “Rtransmission”, the processing block 21 extracts from the data map 23 the value SGplaus representing the plausible acceleration threshold for a wheel Grl or Grr in the absence of slipping of this wheel. This mapped threshold SGplaus is chosen such that SGplaus multiplied by the radius of a wheel is close to the value of the maximum acceleration that the vehicle can reach for the transmission ratio engaged. This value SGplaus is sent to the test blocks 24 and 25 via the connections 18 and 19 , respectively. The blocks 24 and assign a positive value (or denoted as 1) to the value SkidD 1 if one of the wheel accelerations is greater than the plausible value SGplaus. The block 26 analyzes the case where the two values Grl and Grr are within the range of plausibility, in other words less than SGplaus. If the difference Δ between the two wheel speeds is reduced, in other words less than an arbitrary difference threshold ε (close to zero, for example ε equals 0.1 km/h), the case of skidding is no longer considered and SkidD 1 takes a negative value (also denoted as 0). If the two values Grl and Grr are within the range of plausibility and if the difference between the two wheel speeds is greater than the threshold ε, the block 26 assigns the value, extracted from the memory 20 via the connection 30 , that SkidD 1 had at the preceding calculation time (time t−1), to the value SkidD 1 at time t. In this way, in the block D 1 , an onset of wheel skidding is detected when one of the wheel accelerations goes above the plausibility threshold, and the Boolean variable continues to indicate the skidding state for as long as the two wheel speeds do not go through an identical value. Indeed, in practice, the onset of the skidding is characterized by an abrupt increase in the speed of the wheel on the inside of the turn, hence by a spike in acceleration of the wheel in question. The blocks 24 and 25 detect these onsets of skidding. The end of the skidding is characterized by a crossing of the curves of the speeds of the two wheels, because the speed of the wheel on the inside of the turn is lower than the speed of the wheel on the outside when they both drive without skidding. The block 26 therefore detects this end of skidding.
The logic block D 1 is able to detect most in-turn skidding phenomena thanks to the calibration of the plausible wheel accelerations stored in the data map 23 . In one variant embodiment of the invention, the logic block D 1 can, on its own, form the validation module 2 , in which case the variable Skidding is identical to the variable SkidD 1 . The thresholds SGplaus from the data map 23 are calibrated at values that are sufficiently high to limit the number of false skidding detections (result of calculation Skidding=1 whereas neither of the two wheels skids). If the vehicle is in an over-steer situation, the invention thus avoids the transverse acceleration γt being detected as invalid, which is notably necessary for correct management of the automatic transmission gear-change rules. The corollary is that, on the other hand, some cases of skidding are not then detected by the logic block D 1 .
The role of the logic block D 2 , whose operation is detailed in FIG. 2 , is to pick up some of the cases of skidding undetected by the block D 1 owing to the calibration chosen for the thresholds from the data map 23 . The logic block D 2 detects specifically the cases of skidding caused by depressing the accelerator pedal during a turn. It does not therefore detect any case of skidding corresponding to an over-steer situation, since the cases of over-steer occur when the accelerator pedal is released.
FIG. 3 shows a flow diagram for the calculation of the Boolean wheel over-acceleration variable SkidD 2 by the logic block D 2 in FIG. 1 . At a calculation time t, the block D 2 receives, via the connection 9 , the value of the transverse acceleration γt estimated by the block D 3 in FIG. 1 and receives, via the connection 11 , the acceleration setpoint from the driver, represented by the angular position “Pedal” of the accelerator pedal of the vehicle. In parallel, the block D 2 saves in a memory 31 the value of the Boolean variable SkidD 2 calculated at the preceding calculation time (calculation time t−1). The logic block D 2 comprises a processing block 32 and three test blocks 32 , 34 and 35 which, based on the value stored in the memory 31 , on the value calculated by the processing block 32 and on the values γt and Pedal, allow a value to be assigned to the Boolean variable SkidD 2 at time t. The connection 11 is connected to the processing block 32 and to the test block 34 . The processing block 32 returns a value “Pedal Variation” to the test block 35 via a connection 38 . The test block 35 can access the memory 31 via a connection 36 . The block 33 carries out a comparison between the transverse acceleration γt estimated by the block D 3 and an accelerated centrifugation threshold γt plaus . If γt is less than the threshold γt plaus , the case of skidding is no longer considered, and the block 33 assigns a negative value (also denoted as 0) to SkidD 2 at time t. The block 32 calculates the derivative with respect to time of the variable Pedal and delivers, via the connection 38 , a value Pedal Variation representing the angular speed of displacement of the accelerator pedal. In the case where γt is less than the accelerated centrifugation thresholdt γt plaus , the test blocks 34 and 35 carry out the comparisons of the value Pedal and of its derivative Pedal Variation with respect to two constant thresholds “Setpoint Threshold” and “(Setpoint) Derivative Threshold”, respectively. If the value Pedal and the value of its derivative Pedal Variation are both greater than their respective thresholds, the value SkidD 2 at time t takes the positive value (also denoted as 1). If the reverse is true, the block 35 assigns the value, extracted from the memory 31 via the connection 36 , that SkidD 2 had at the preceding calculation time (time t−1) to the value SkidD 2 at time t. The role of the block D 2 is to detect the cases of skidding occurring when the accelerator pedal is depressed by the driver in a turn, notably in the situations where the skidding situation has not been detected by the logic block D 1 . For this purpose, the accelerated centrifugation threshold γt plaus , which is a constant value, is advantageously chosen to be high within the range of the plausible accelerations of the vehicle. In practice, an acceleration close to 10 ms −2 , for example in the range between 8 and 12 ms −2 , allows a reasonable level of detection to be obtained.
One of the applications of the method is the management of the gear-change rules for the transmission as a function of the curvature of the road on which the vehicle is being driven. The application of the method of the invention is not however limited to this management of the transmission ratios: it can be applied to the management of any mechanism on the vehicle which requires an estimation of the transverse acceleration of the vehicle, and which is however capable of functioning without the availability of this information during cases of skidding of the drive wheels.
It goes without saying that the reasoning described above on the choice of the Boolean variables and the values that are assigned to them should be understood in the functional sense. The positive and negative values of the variables could be denoted by other pairs of values, Yes/No, True/False, Skidding/Gripping, etc. The Boolean variables could have the opposite definitions to that in the description and the claims and the stated logical proposals then being reformulated accordingly.
The implementation of the invention in the form of logic blocks or processing blocks can take the form of electronic components or physically independent processors configured as described above. The invention may also be implemented by programming all the logic blocks and the processing blocks described in the form of software code, the corresponding program, together with its sub-programs, being installed in one or more processors, integrated or otherwise with the electronic control unit.
The invention allows comfort functions using the value of the transverse acceleration, such as the management of the gear-change rules for an automatic gearbox or the orientation of the headlamps in a turn, to be provided at a lower cost on vehicles equipped with only two wheel speed sensors on its drive wheels (for example for front-wheel drive vehicles without ABS).
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A device for evaluating the transverse acceleration of a motor vehicle measures the rotational speeds of two wheels of the vehicle, estimates the transverse acceleration of the vehicle from these speeds, and calculates, as a function of vehicle operating parameters, particularly of the rotational speeds of the wheels and of the transmission ratio engaged, a Boolean slip variable which is negative if the transverse estimated acceleration is relevant for detecting a bend, and which is positive if the reverse is true.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application is a divisional of U.S. Ser. No. 07/582,891, filed Oct. 5, 1990, now U.S. Pat. No. 5,169,628, which was the U.S. National Phase application of PCT/US89/00814, filed Mar. 3, 1989, which was a continuation of U.S. Ser. No. 07/184,648, filed Apr. 22, 1988, abandoned.
FIELD OF THE INVENTION
This invention encompasses novel chimeric glycoproteins which are useful for preparing virus specific immune responses against human parainfluenza virus type 3, PIV3. Host cells transformed with structural genes coding for the glycoproteins, expression and replication plasmids containing the structural genes, vaccines made from the glycoproteins and methods for protecting humans by inoculation with said vaccines are also part of this invention.
BACKGROUND
Human parainfluenza virus type 3, PIV3, is an important primary cause of severe lower respiratory tract disease in infants and young children. The virus occurs worldwide and infects virtually all children under the age of four. Acute respiratory disease and secondary complications are particularly serious in infants and young children due to the immaturity of the respiratory system and may require hospitalization in severe cases. Lower respiratory infections are referable to all segments of the respiratory tract, are usually associated with fever, cough, runny nose, and fatigue, and are diagnosed clinically as bronchitis, bronchiolitis, pneumonia, croup, or viral infection. Older children and adults are also frequently reinfected although reinfection typically results in less severe upper respiratory tract illness.
Attempts to develop effective PIV3 vaccines have been largely unsuccessful. Clinical studies using live or inactivated PIV3 vaccines demonstrated an increase in virus specific serum antibodies but provided no significant protection against the disease.
INFORMATION DISCLOSURE STATEMENT
The recombinant vaccinia virus expression system is known to separately express the F and HN glycoproteins of PIV3 and to separately induce protective immune responses in challenged cotton rats, Collins, P. L., et al, Expression of the F and HN Glycoproteins of Human Parainfluenza Virus Type 3 by Recombinant Vaccinia Viruses: Contributions of the Individual Proteins to Host Immunity, Journal of Virology 61: 3416-3423 (1987). The recombinant vaccinia virus expression system is also known to induce PIV3-specific serum neutralizing antibodies and to confer resistance to PIV3 replication in the respiratory tract in primates, Collins, P. L., et al., Journal of Virology 62: 1293-1296 (1988). Immunization with a mixture of purified F and HN glycoproteins induced virus neutralizing activity and afforded complete protection from challenge infection in hamsters, Ray, R., et al., Journal of Virology 62: 783-787 (1988).
SUMMARY OF THE INVENTION
This invention encompasses a polypeptide comprising a signal sequence and at least one immunogenic fragment from both human parainfluenza virus type 3 glycoproteins F and HN. The use of this protein as a vaccine, methods to prevent PIV3-related disease and preparation of this protein using recombinant techniques are also part of this invention.
DETAILED DESCRIPTION
The following defined terms are used in this specification. The phrase "cell culture" refers to the containment of growing cells derived from either a multicellular plant or animal which allows for the cells to remain viable outside the original plant or animal. The term "downstream" identifies sequences proceeding farther in the direction of expression; for example, the coding region is downstream from the initiation codon. The term "upstream" identifies sequences proceeding in the opposite direction from expression; for example, the bacterial promoter is upstream from the transcription unit, the initiation codon is upstream from the coding region. The term "microorganism" includes both single cellular prokaryote and eukaryote organisms such as bacteria, actinomycetes and yeast. The term "operon" is a complete unit of gene expression and regulation, including structural genes, regulator genes and control elements in DNA recognized by regulator gene product. The term "plasmid" refers to an autonomous self-replicating extrachromosomal circular DNA and includes both the expression and nonexpression types. Where a recombinant microorganism or cell culture is described as hosting an expression plasmid the phrase "expression plasmid" includes both extrachromosomal circular DNA and DNA that has been incorporated into the host chromosome(s). Where a plasmid is being maintained by a host cell, the plasmid is either being stably replicated by the cells during mitosis as an autonomous structure or as an incorporated portion of the host's genome. The term "promoter" is a region of DNA involved in binding the RNA polymerase to initiate transcription. The phrase "DNA sequence" refers to a single or double stranded DNA molecule comprised of nucleotide bases, adenosine, thymidine, cytosine and guanosine. The phrase "essentially pure" refers to a composition of protein that contains no parainfluenza virus protein other than the desired recombinant chimeric glycoprotein. Although the essentially pure proteins may be contaminated with low levels of host cell constituents, the protein is devoid of contaminating structural and non-structural viral protein produced by replicating parainfluenza viruses. The phrase "suitable host" refers to a cell culture or microorganism that is compatible with a recombinant plasmid and will permit the plasmid to replicate, to be incorporated into its genome or to be expressed.
This invention involves a series of molecular genetic manipulations that can be achieved in a variety of known ways. The manipulations can be summarized as obtaining a cDNA of the protein, the cloning and replication of the cDNA in E. coli and the expression of the desired cDNA in a suitable host. The following descriptions will detail the various methods available to express the protein and are followed by specific examples of preferred methods.
Generally, the nomenclature and general laboratory procedures required in this invention can be found in Maniatis, et al., Molecular Cloning A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1982).
All E. coli strains are grown on Luria broth (LB) with glucose, Difco's Antibiotic Medium #2 and M9 medium supplemented with glucose and acid-hydrolyzed casein amino acids. Strains with resistance to antibiotics were maintained at the drug concentrations described in Maniatis. Transformations were performed according to the method described by Rowekamp and Firtel, Dev. Biol., 79:409-418 (1980).
All enzymes were used according to the manufacturer's instructions. Transformants were analyzed by colony hybridization as described in Grunstein and Wallis, Methods in Enzymology, 68:379-388.
After hybridization, the probes are removed and saved, and the filters are washed in 0.1% SDS, 0.2x SSC for a total of 3 hours with 5 changes of 400 ml each. Filters are thoroughly air dried, mounted, and autoradiographed using Kodak X-OMAT AR film and Dupont Cronex Lightening Plus intensifying screens for an appropriate time at -70° C.
For sequencing of plasmids, purified plasmid DNA is prepared according to the methods described in Maniatis. End-labeled DNA fragments are prepared and analyzed by the chemical sequencing methods of Maxam and Gilbert with modifications described by Collins and Wertz, J. Virol. 54:65-71 (1985).
Nucleotide sizes are given in either kilobases (Kb) or basepairs (bp). These are estimates derived from agarose gel electrophoresis.
The first step in obtaining expression of protein is to obtain the DNA sequence coding for the protein from cDNA clones. This sequence is then cloned into an expression plasmid which is capable of directing transcription of the gene and allowing efficient translation of the transcript. The library method for obtaining cDNA encoding proteins is described generally in Maniatis, and specifically by Elango, et al., in Human Parainfluenza Type 3 Virus Hemagglutinin-Neuraminidase Glycoprotein: Nucleotide sequence of mRNA and Limited Amino Acid Sequence of the Purified Protein, J. Virol. 57: 481-489 (1986) and by Spriggs, et al., in Fusion Glycoprotein of Human Parainfluenza Virus Type 3: Nucleotide Sequence of the Gene, Direct Identification of the Cleavage-Activation Site, and Comparison with Other Paramyxoviruses, Virology 152: 241-251 (1986).
Clones are prepared by inserting the cDNA into PstI cleaved pBR322 to which homopolymer tracts of dGTP have been enzymatically added to the 3' ends at the cleavage site. Homopolymer tracts of dCTP are enzymatically added to the 3' termini of the cDNA molecules according to the methods described by Maniatis. Ideally, 10-30 residues of dCTP or dGTP should be added to maximize cloning efficiency. The cDNA and plasmid are annealed together and transformed into E. coli. The clones containing full length cDNA are detected by probes of labeled viral cDNA or oligonucleotides complementary to portions of the gene sequences, followed by restriction enzyme analysis and DNA sequencing.
Oligonucleotides are chemically synthesized according to the solid phase phosphoramidite triester method first described by Beaucage and Caruthers, Tetrahedron Letters, 22(20):1859-1862 (1981) using an automated synthesizer, as described in Needham-VanDevanter, et al., Nucleic Acids Res., 12:6159-6168 (1984). Purification of oligonucleotides is by either native acrylamide gel electrophoresis or by anion-exchange HPLC as described in Pearson and Regnier, J. Chrom., 255:137-149 (1983).
The sequence of the synthetic oligonucleotides can be verified using the chemical degradation method of Maxam and Gilbert, Grossman and Moldave, eds., Academic Press, New York, Methods in Enzymology, 65:499-560 (1980).
To obtain high level expression of a cloned gene in a prokaryotic system, it is essential to construct expression vectors which contain, at the minimum, a strong promoter to direct mRNA transcription, a ribosome binding site for translational initiation, and a transcription terminator. Examples of regulatory regions suitable for this purpose are the promoter and operator region of the E. coli tryptophan biosynthetic pathway as described by Yanofsky, Kelley, and Horn, J. Bacterial., 158:1018-1024 (1984) and the leftward promoter of phage lambda (P L ) as described by Herskowitz and Hagen, Ann. Rev. Genet., 14:399-445 (1980).
The proteins produced in E. coli will not fold properly due to the presence of cysteine residues and to the lack of suitable post-translational modifications. During purification from E. coli, the expressed proteins must first be denatured and then renatured. This can be accomplished by solubilizing the E. coli produced proteins in guanidine HCl and reducing all the cysteine residues with β-mercaptoethanol. The protein is then renatured either by slow dialysis or by gel filtration, U.S. Pat. No. 4,511,503.
Detection of proteins is achieved by methods known in the art such as radioimmunoassays, or Western blotting techniques or immunoprecipitation. Purification from E. coli can be achieved following procedures described in U.S. Pat. No. 4,511,503.
Expression of heterologous proteins in yeast is well known and described. Methods in Yeast Genetics, Sherman, et al., Cold Spring Harbor Laboratory, (1982) is a well recognized work describing the various methods used to produce proteins in yeast.
For high level expression of a gene in yeast, it is essential to connect the gene to a strong promoter system as in the prokaryote and to also provide efficient transcription termination/polyadenylation sequences from a yeast gene. Examples of useful promoters include GAL1,10, Johnston and Davis, Mol. and Cell. Biol., 4:1440-1448, 1984), ADH2, Russell, et al., J. Biol. Chem. 258:2674-2682, 1983), PHO5, EMBOJ. 6:675-680, (1982), and MFα1. A multicopy plasmid with a selective marker such as Lue-2, URA-3, Trp-1, or His-3 is also desirable. The MFα1 promoter is preferred. The MFα1 promoter, in a host of the α mating-type is constitutive, but is off in diploids or cells with the a mating-type. It can, however, be regulated by raising or lowering temperature in hosts which have a ts mutation at one of the SIR loci. The effect of such a mutation at 35° C. on an α type cell is to turn on the normally silent gene coding for the a mating-type. The expression of the silent a mating-type gene, in turn, turns off the MFα1 promoter. Lowering the temperature of growth to 27° C. reverses the whole process, i.e., turns the a mating-type off and turns the MFα1 on, Herskowitz and Oshima, The Molecular Biology of the Yeast Saccharomyces, Strathern, Jones, and Broach, eds., Cold Spring Harbor Lab., Cold Spring Harbor, N.Y., 181-209, (1982).
The polyadenylation sequences are provided by the 3'-end sequences of any of the highly expressed genes, like ADH1, MFα1, or TPI, Alber and Kawasaki, J. of Mol. and Appl. Genet. 1:419-434, (1982).
A number of yeast expression plasmids like YEp6, YEp13, YEp24 can be used as vectors. A gene of interest can be fused to any of the promoters mentioned above, and then ligated to the plasmids for expression in various yeast hosts. These plasmids have been fully described in the literature, Botstein, et al., Gene, 8:17-24, (1979); Broach, et al., Gene, 8:121-133, (1979).
Two procedures are used in transforming yeast cells. In one case, yeast cells are first converted into protoplasts using zymolyase, lyticase or glusulase, followed by addition of DNA and polyethylene glycol (PEG). The PEG-treated protoplasts are then regenerated in a 3% agar medium under selective conditions. Details of this procedure are given in the papers by Beggs, Nature (London), 275:104-109 (1978); and Hinnen, et al., Proc. Natl. Acad. Sci. USA, 75:1929-1933 (1978). The second procedure does not involve removal of the cell wall. Instead the cells are treated with lithium-chloride or acetate and PEG and put on selective plates, Ito, et al., J. Bact., 153:163-168, (1983).
The cDNA can be ligated to various expression vectors for use in transforming host cell cultures. The vectors all contain gene sequences to initiate transcription and translation of the proteins that are compatible with the host cell to be transformed.
In addition, the vectors preferably contain a marker to provide a phenotypic trait for selection of transformed host cells such as dihydrofolate reductase or metallothionein. Additionally a replicating vector might contain a replicon.
Insect or mammalian cell cultures are useful for the production of proteins. Mammalian cell systems often will be in the form of monolayers of cells although mammalian cell suspensions may also be used. Illustrative examples of mammalian cell lines include VERO and HeLa cells, Chinese hamster ovary (CHO) cell lines, WI38, BHK, COS-7 or MDCK cell lines.
The vector which is used to transform the host cell preferably contains gene sequences to initiate the transcription and translation of the protein's gene sequence. These sequences are referred to as expression control sequences. When the host cell is of mammalian or insect origin illustrative useful expression control sequences are obtained from the SV-40 promoter, Science, 222, 524-527 (1983), the CMV I.E. promoter, Proc. Natl. Acad. Sci. 81:659-663 (1984), the metallothionein promoter, Nature, 296, 39-42, (1982) or the baculovirus polyhedrin promoter (insect cells), Virol., 131, 561-565 (1983). The plasmid for replicating or integrating DNA material containing the expression control sequences is cleaved using restriction enzymes and adjusted in size as necessary or desirable an(i ligated with cDNA coding for proteins using methods well known in the art.
When higher animal host cells are employed, polyadenylation or transcription terminator sequences from known mammalian genes need to be incorporated into the vector. An example of a terminator sequence is the polyadenylation sequence from the bovine growth hormone gene. Additionally gene sequences to control replication in the host cell may be incorporated into the vector such as those found in bovine papillomavirus type-vectors, Saveria-Campo, "Bovine papillomavirus DNA: a eukaryotic cloning vector", DNA Cloning Vol. II--A practical approach, Glover, ed., IRL Press, Arlington, Va. 213-238 (1985).
The preferred expression vector useful for expressing proteins in Chinese hamster ovary (CHO) cells is a shuttle vector pSVCOW7 which replicates in both CHO and E. coli cells utilizing ampicillin resistance and dihydrofolate reductase genes as markers in E. coli and CHO cells respectively. Plasmid pSVCOW7 also provides the polyadenylation sequence from bovine growth hormone which is necessary for expression in CHO cells. Plasmid pSVCOW7 is cleaved and a viral promoter and cDNAs inserted.
The preferred expression vector useful in forming recombinant baculovirus for expressing proteins in insect cells is pAc373, Smith, et al., Mol. Cell. Biol. 3:2156-2165 (1983). The plasmid replicates in E. coli cells utilizing ampicillin resistance, and provides the eukaryotic promoter and polyadenylation signal from the baculovirus polyhedrin gene for expression of genes. Plasmid pAc373 is cleaved and a cDNA is inserted adjacent to the promoter. This new plasmid is cotransfected with baculovirus (Autograpa californica nuclear polyhedrosis virus) DNA into insect cells by calcium phosphate precipitation. Recombinant baculovirus in which the pAc373 polyhedrin gene containing a cDNA has replaced the resident viral polyhedrin gene by homologous recombination is detected by dot blot hybridization using 32 P-labeled cDNA as a probe, Summers and Smith, A Manual of Methods for Baculovirus Vectors and Insect Cell Culture Procedures, Texas A & M University, College Station, Tex., 29-30 (1986). Insect cells infected with recombinant baculovirus may also be differentiated by their occlusion-negative morphology since the insertion of the cDNA into the polyhedrin gene prevents the synthesis of this occlusion-forming protein.
The preferred expression vector used in conjunction with bovine papilloma virus (BPV) for expressing proteins is pTFW9 (Plasmid pTWF9 was deposited in accordance with the Budapest Treaty. Plasmid pTFW9 is maintained in an E. coli host and has been deposited with the Northern Regional Research Center, Peoria, Ill., U.S.A. on Nov. 17, 1986 and assigned Accession Number NRRL B-18141.) The plasmid replicates in E. coli utilizing ampicillin resistance, and provides the mouse metallothionein promoter and SV40 polyadenylation signal for expression of genes. Plasmid pTFW9 is cleaved and a cDNA is inserted adjacent to the promoter. This new plasmid is then cleaved to allow insertion of BPV. The recombinant plasmid is transfected into animal cells by calcium phosphate precipitation and foci of transformed cells are selected.
The host cells are competent or rendered competent for transfection by various means. There are several well-known methods of introducing DNA into animal cells. These include: calcium phosphate precipitation, fusion of the recipient cells with bacterial protoplasts containing the DNA, treatment of the recipient cells with liposomes containing the DNA, and microinjection of the DNA directly into the cells. The transfected cells are cultured by means well known in the art, Biochemical Methods in Cell Culture and Virology, Kuchier, Dowden, Hutchinson and Ross, Inc., (1977). Recombinant glycoproteins expressed in one of the above eukaryotic expression systems are isolated from cell suspensions created by disruption of the host cell system by well known mechanical or enzymatic means. Proteins which are designed to be secreted from the cells are isolated from the media without disruption of the cells. For purification of glycoproteins it is helpful to first apply the cytoplasmic fraction to a lentil lectin column which will specifically bind glycoproteins. The eluted glycoproteins are then applied to an affinity column containing antibody.
A typical glycoprotein can be divided into three regions. At the amino terminal end is a hydrophobic region called the signal sequence. This sequence of amino acids signals the transport of the glycoprotein to the cell membrane. Following transport the signal sequence is removed by cleavage. Downstream from the signal sequence is the extracellular domain of the mature glycoprotein. This is the immunogenic portion of the glycoprotein since it is accessible to antibodies. At the carboxy terminal end of the glycoprotein is the hydrophobic anchor region which causes the glycoprotein to be retained in the cell membrane. The PIV3 F is a typical glycoprotein in that it contains an amino terminal signal sequence and carboxy terminal anchor sequence, Spriggs, et al., Virology 152:241-25, (1986). However, the PIV3 HN glycoprotein is unusual since its amino terminal end acts as both a signal and anchor region, Elango, et al., J. Virol. 57:481-489, (1986).
A glycoprotein may be designed to be secreted from cells into the surrounding media. This is accomplished by causing the early termination of the glycoprotein before translation of the anchor region, Lasky, et al., Biotechnology, 2:527-532 (1984). Early termination may be accomplished by inserting a universal translational terminator oligonucleotide into an appropriate site in the gene's DNA. These oligonucleotides are commercially available. Early termination may also be accomplished by altering the reading frame, thus generating a translational termination codon.
The chimeric glycoprotein described below consists of the signal and extracellular domains of PIV3 F linked to the extracellular domain of PIV3 HN, and will be referred to as FHN. When properly placed in a eukaryotic expression vector, the FHN gene described above is designed to express a chimeric glycoprotein which would be transported to the cell's surface and secreted into the media.
The majority of the cytoplasmic domain of the PIV3 HN protein is contained within the coding region spanned by the DraI (nucleotide position 452 of the protein coding region) and PstI (nucleotide position 1709 of the protein coding region) restriction enzyme sites. This sequence does not code for the signal/anchor region of the glycoprotein. The majority of the cytoplasmic domain of the PIV3 F protein is contained within the coding region prior to the XbaI (nucleotide position 1398 of the protein coding region) restriction enzyme site. This sequence codes for the signal region and the majority of the antigenic region, but not the anchor region of the F glycoprotein.
To insert the HN glycoprotein sequence into the F glycoprotein of PIV3, the HN gene is digested with PstI and the end is made blunt with T4 DNA polymerase. An XbaI linker (New England Biolabs) with the sequence ##STR1## is ligated to the end. The gene is separated from residual linker by agarose gel electrophoresis. The above linker contains an in phase translation termination signal to stop protein synthesis. The HN gene is then digested with DraI and a XbaI linker (New England Biolabs) with the sequence ##STR2## is ligated to the end. This linker does not contain an in phase translation termination signal and will allow read through of the protein from the F to the HN sequences. The HN gene fragment (1.3 Kb) containing the linkers is digested with XbaI and separated from residual linkers by agarose gel electrophoresis. The PIV3 F gene is digested with XbaI and dephosphorylated with bacterial alkaline phosphatase. The 1.3 Kb HN fragment is then ligated into the F gene at the XbaI site and transformed into E. coli HB101. A clone containing the chimeric glycoprotein gene is isolated and the junctions between the F and HN DNA sequences are verified correct by Maxam-Gilbert sequencing. The PIV3 chimeric glycoprotein gene can be placed in an appropriate expression vector.
The above restriction enzyme sites were chosen because they allow for the expression of a large proportion of the relevant regions of the F and HN glycoproteins. However, other portions of the glycoproteins could be expressed by choosing other restriction enzyme sites within the F and HN coding sequences for the fusion of these genes. For instance, the restriction enzymes HaeIII, KpnI, or NlaIV could be used to cleave at the 5' end of the HN gene. The restriction enzymes BalI, BglII, or HaeIII could be used to cleave at the 3' end of the HN gene. The enzymes could be used in any combination of two with one enzyme being from each group to give immunogenic protein fragments. For the gpF gene, the BglII, HaeIII, NsiI, or XhoII restriction enzymes could be used in place of XbaI. Linker oligonucleotides could be added to correct the reading frame in the junction regions. Two oligonucleotides which would correct the two possible frame shifts are the SalI linkers ##STR3## which are commercially available. Also when an anchor region is desired in the glycoprotein, a linker oligonucleotide is added a the second junction to allow synthesis of the gpF anchor region. Alternative strategies could be designed for the expression of a FHN chimeric protein by insertion or deletion of various sequences. The major criterion for the protein is the retention of a signal sequence and the immunologically important regions of the two glycoproteins.
Insertion of FHN gene into CHO, BPV, or baculovirus expression vectors is as already described.
The FHN chimeric glycoprotein offers advantages over expression of the individual glycoproteins. Since FHN is a single protein, it requires half the labor and reagents for purification compared to the separate F and HN glycoproteins. Also, the FHN chimeric glycoprotein is secreted into the media for ease of purification. The F glycoprotein can be engineered as a secreted glycoprotein by truncation prior to the anchor region sequences. However, the PIV3 HN glycoprotein contains a signal/anchor region at its amino terminal end. Therefore, truncation of this glycoprotein will not generate a secreted form. The signal/anchor region could be replaced with a signal region from a foreign glycoprotein, but this would introduce foreign protein sequences into the potential vaccine.
Conventions used to represent plasmids and fragments in Charts 1-6, are meant to be synonymous with conventional circular representations of plasmids and their fragments. Unlike the circular figures, the single line figures on the charts represent both circular and linear double-stranded DNA with initiation or transcription occurring from left to right (5' to 3'). Asterisks (*) represent the bridging of nucleotides to complete the circular form of the plasmids. Fragments do not have asterisk marks because they are linear pieces of double-stranded DNA. Endonuclease restriction sites are indicated above the line. Gene markers are indicated below the line. The relative spacing between markers do not indicate actual distances but are only meant to indicate their relative positions on the illustrated DNA sequence.
Example 1 Removing the G-C tails from the F glycoprotein gene--Chart 1
In order to obtain maximum expression of the F glycoprotein, the G-C nucleotides which are used to insert the cDNA into the plasmid pBR322 must be removed from the ends of the cDNA. In order to conveniently insert the FHN cDNA into the preferred expression vector for CHO cells (pSVCOW7, described below), or the preferred expression vector for baculovirus (pAc373, described below), it is necessary to supply a BamHI site upstream from the protein coding sequence. Methods for the synthesis of the cDNA clones containing the entire sequence for the F glycoprotein have been described. Spriggs, et al., Virology 152: 241-251, (1986).
The cDNA containing the intact PIV3 F gene (pGPF1) is digested with BstXI and NdeI. BstXI cleaves the F gene at position 39 relative to the gene's initiation codon, and NdeI cleaves at position 1599. Oligonucleotide I is ligated to the BstXI cleavage site and oligonucleotide 2 is ligated to the NdeI cleavage site. Oligonucleotide I contains the DNA sequences from 10 bases prior to the coding region to the BstXI cleavage site in the coding region of the F gene (-10 to +39), and has a BamHI site on the 5' end of the oligonucleotide. Oligonucleotide 2 contains the DNA sequences from the NdeI cleavage site to the termination codon of the F gene (+1599 to +1620). At the 3' end of oligonucleotide 2 is a NruI restriction enzyme site followed by a BamHI restriction enzyme site.
Following ligation of the oligonucleotides, the DNA is digested with BamHI and the F gene (fragment 1, 1.6 Kb) is gel purified. Fragment I is ligated into plasmid pBR322 (Pharmacia) which has been digested with BamHI and dephosphorylated with bacterial alkaline phosphatase. The plasmid (pGPF2) is transformed into E. coli HB101. The newly synthesized regions of pGPF2 are sequenced by the Maxam-Gilbert procedure to verify accurate synthesis and ligation. ##STR4##
Example 2 Construction of a PIV3 Chimeric FHN Gene--Chart 2
A. Preparation of the PIV3 HN glycoprotein gene. Clones containing the entire coding region of the PIV3 HN gene and methods for isolating such clones have been described. Elango, et al., J. Virol. 57:481-489, (1986). A cDNA clone containing the PIV3 HN gene (pGPHN1) is digested with PstI. This enzyme cleaves toward the 3' end of the HN gene (nucleotide +1714). The ends of the fragment are made blunt with T4 DNA polymerase and then dephosphorylated with bacterial alkaline phosphatase. An XbaI linker (New England Biolabs; linker 1) with the sequence ##STR5## is ligated to the end. The cDNA is separated from residual linker by electrophoresis in a 1.2% agarose gel. The 1.7 Kb fragment (fragment 2) containing the HN gene is excised from the gel and the DNA is purified from the agarose. The above linker contains an in phase translation termination signal to stop protein synthesis. The HN gene is then digested with DraI. This enzyme cleaves 3' to the signal/anchor encoding region of the HN gene (nucleotide +452). A XbaI linker (New England Biolabs; linker 2) with the sequence ##STR6## is ligated to the end. This linker does not contain an in phase translation termination signal. The DNA is digested with XbaI and separated from residual linkers by electrophoresis in a 1.2% agarose gel. The 1.3 Kb fragment containing the relevant region of the HN gene is excised from the gel and the DNA is purified from the agarose.
B. Insertion of the HN cDNA into the PIV3 F glycoprotein gene.
Plasmid pGPF2 is digested with XbaI and dephosphorylated with bacterial alkaline phosphatase. The 1.3 Kb fragment is ligated into the XbaI site to yield the chimeric FHN gene (pGPFHN1). The plasmid is transformed into E. coli HB101. Clones are isolated and selected from the correct orientation of the HN cDNA within the F gene by digestion with BamHI and PvuII which will generate fragments of approximately 2.5 Kb and 350 bp within the FHN gene. The incorrect orientation of the HN fragment will yield fragments of approximately 1.5 Kb and 1.3 Kb upon digestion with BamHI and PvuII. The junction regions of a properly orientated clone are sequenced by the Maxam-Gilbert technique to verify proper ligation of the HN fragment.
Example 3 Using DNA oligonucleotides to generate genes coding for chimeric FHN glycoproteins of various lengths--Chart 3
Genes coding for chimeric FHN glycoproteins containing various regions of the F and HN glycoproteins can be generated using a combination of restriction enzymes and oligonucleotides. This procedure allows the F and HN glycoproteins to be linked at any desirable point of their amino acid backbone, permitting incorporation or removal of regions likely to contain epitopes which will be recognized by the host immune system. Individual amino acids may also be changed if so desired. Oligonucleotides are synthesized corresponding to the DNA sequence from the point of desired linkage to a convenient restriction enzyme site. The glycoprotein gene is digested with that restriction enzyme and the oligonucleotide is ligated to the gene at the restriction enzyme site to generate a DNA fragment of the desired length. The oligonucleotides are synthesized with ends compatible with the restriction enzyme sites for ease of ligation.
A. Insertion of Glycoprotein HN cDNA into the F Glycoprotein Gene.
Clone pGPHN1 is digested with PstI and DraI. The 1.3 Kb fragment representing the cDNA region from nucleotide position 452 to 1714 (fragment 4) is gel purified. Oligonucleotides representing adjoining regions of the HN cDNA are then ligated to each end of fragment 4. The DNA sequences in these oligonucleotides may code for additional epitopes found on the HN glycoprotein. The individual oligonucleotides were designed to incorporate regions which may contain unique epitopes. The oligonucleotide ligated to the 5' end of the HN cDNA may consist of either oligonucleotide 3 (cDNA nucleotides 395 to 452), oligonucleotides 3-4 (cDNA nucleotides 335 to 452), oligonucleotides 3-4-5 (cDNA nucleotides 275 to 452), oligonucleotides 3-4-5-6 (cDNA nucleotides 218 to 452), or oligonucleotides 3-4-5-6-7 (cDNA nucleotides 162 to 452). Parentheses enclose nucleotides which would be included only in the terminal oligonucleotide. For instance, the enclosed nucleotides would not be included on oligonucleotide 5 if oligonucleotide 6 were to be added. These enclosed nucleotides code for a XbaI site. The enclosed nucleotides are not included when an additional oligonucleotide(s) is to be added in order to allow ligation between the compatible ends of the oligonucleotides. For instance, the 5' end of the oligonucleotide 3 is compatible with the 3' end of oligonucleotide 4 when the nucleotides enclosed by parentheses are not included in oligonucleotide 3. Oligonucleotide 8 is ligated to the 3' end of the HN gene fragment. The 5' end of this oligonucleotide is compatible with the 3' end of fragment 4. The 3' end of this oligonucleotide contains an in phase translation termination signal followed by a XbaI restriction enzyme site.
Following ligation of the oligonucleotides to the HN cDNA fragment, the DNA is digested with XbaI and the enlarged HN cDNA fragment (fragment 5) is gel purified. The new HN cDNA fragment is then ligated into XbaI digested pGPF2. The DNA is transformed into E. coil HB101 and a clone containing the HN gene in the correct orientation within the F gene is isolated (pGPFHN2). Orientation is determined by digestion with appropriate restriction enzymes. The newly synthesized regions of the chimeric gene are verified correct by Maxam-Gilbert sequencing. The clone may then be placed in various expression vectors as described below. ##STR7##
Example 4 Construction of a PIV3 chimeric FHN glycoprotein gene containing an anchor region--Chart 4
Examples 2 and 3 illustrate the synthesis of genes coding for chimeric FHN glycoproteins which do not contain anchor regions and will therefore be secreted into the medium of expressing cells. A gene coding for a chimeric FHN glycoprotein containing an anchor region can be synthesized. The anchor region would cause the retention of the chimeric glycoprotein in the cellular membranes in a manner similar to most viral glycoproteins. The anchor region may be on the carboxy-terminal end of the glycoprotein so that the immunogenic regions of the chimeric molecule from both the F and HN glycoproteins would protrude into the extracellular fluid. The gene described below will code for a chimeric glycoprotein consisting of the extracellular region of PIV3 F, the extracellular region of PIV3 HN, and the anchor region of PIV3 F in the above order from amino-terminus to carboxy-terminus.
A. Insertion of the HN cDNA fragment into the PIV3 F glycoprotein gene.
The clone pGPHN1 is digested with DraI and PstI. Oligonucleotide 9 is first ligated to the DNA fragment (oligonucleotide is compatible with DraI site). Oligonucleotide 10 is then ligated to the DNA fragment (compatible with PstI site). Both oligonucleotides contain XbaI restriction enzyme sites. ##STR8## Following ligation, the DNA is digested with XbaI and the 1.3 Kb fragment of the HN cDNA (fragment 6) is gel purified. Fragment 6 is then ligated into XbaI digested pGPF2. The DNA is transformed into E. coli HB101. Clones are isolated and selected from the correct orientation as described in Example 2. The junction regions of a properly orientated clone are then verified correct by Maxam-Gilbert sequencing. This clone (pGPFHN3) may be placed in various expression vectors as described below.
Example 5 Construction of a PIV3 chimeric HNF glycoprotein gene
A portion of the extracellular region of the PIV3 F glycoprotein may be placed at the carboxy-terminal end of the HN glycoprotein. This chimeric glycoprotein would consist of the signal/anchor region from the amino-terminus of HN, the majority of the extracellular region of HN, and a portion of the extracellular region of F in the above order from amino-terminus to carboxy-terminus.
A. Preparation of the PIV3 HN glycoprotein gene--Chart 5.
To prepare clone pGPHN1 for expression, the G-C tails used in cDNA cloning must be removed and compatible restriction enzyme sites placed on its ends. Clone pGPHN1 is digested with HhpI. HphI cleaves at position 75 on the cDNA gene coding sequence. The following oligonucleotide is then ligated to the cDNA fragment: ##STR9## Oligonucleotide 11 will ligate to the HphI site and generate a BamHI restriction enzyme site on the 5' end of the cDNA fragment. Following ligation of oligonucleotide 11, the DNA is digested with BamHI and PstI (PstI cleaves at nucleotide position 1714 in the HN gene). The DNA is electrophoresed in a 1.2% agarose gel. The 1.7 Kb HN cDNA fragment (fragment 7) is excised from the gel and the DNA is purified from the agarose. Fragment 7 is then ligated into pUC19 which has been digested with BamHI and PstI to yield pGPHN2. The plasmid is transformed into E. coli HB101 and plasmid DNA is isolated.
B. Insertion of an F cDNA fragment into the PIV3 HN glycoprotein gene--Chart 6.
The clone pGPF1 is digested with BstEII and XbaI. BstEII cleaves at position 190 and XbaI at position 1398 on the F cDNA gene sequence. The following oligonucleotides are then ligated to the cDNA fragment. ##STR10## Oligonucleotide 12 will ligate to the BstEII site and will generate a PstI restriction enzyme site on the 5' end of the cDNA fragment. Oligonucleotide 13 will ligate to the XbaI site and will generate a translational termination codon, a NruI restriction enzyme site, a BamHI restriction enzyme site, and a PstI restriction enzyme site in the indicated order (5' to 3') on the 3' end of the cDNA fragment. The DNA is then digested with PstI and the 1.2 Kb F cDNA fragment (fragment 8) is gel purified. Fragment 8 is then ligated into pGPHN2 which has been digested with PstI. The plasmid is transformed into E. coli HB101. Clones are isolated and selected from the correct orientation of the F cDNA within the HN gene by digestion with BamHI and NruI which will generate a 2.9 Kb fragment. The incorrect orientation will generate a 1.7 Kb fragment. The junction regions of a properly orientated clone are then verified correct by Maxam-Gilbert sequencing. This clone (pGPHNF1) may be placed in various expression vectors as described below.
Example 6 Expression of the Chimeric FHN Glycoprotein of PIV3 in CHO Cells
A. Construction of pSVCOW7
The starting plasmid pSV2dhfr (available from the American Type Culture Collection or prepared according to the procedure of S. Subramani, et al., "Expression of the Mouse Dihydrofolate Reductase Complementary Deoxyribonucleic Acid in Simian Virus 40", Molecular and Cellular Biology 2:854-864 (September 1981) is digested with BamHI and EcoRI to yield the 5.0 Kb fragment (fragment 9) containing the ampicillin resistance gene, the SV40 origin, and the dhfr gene. The second portion of pSVCOW7 is obtained from plasmid p GH2R2 which is digested with the same restriction endonucleases used to cleave pSV2dhfr to obtain the 2.1 Kb fragment (fragment 10) containing the 3' end of genomic bovine growth hormone gene, i.e., BGH gDNA. Plasmid p GH2R2 is publicly available from an E. coli HB101 host, deposited with the Northern Regional Research Laboratories in Peoria, Ill. (NRRL B-15154). Fragments 9 and 10 are ligated to yield pSVCOW7 (7.1 Kb).
B. Construction of pGPFHN-IE-PA
The genes constructed in Examples 2-5 may be used for expression of a chimeric glycoprotein in CHO cells. The plasmid pGPFHN-1 will be used in the following example. The other chimeric genes are treated as described for pGPFHN-1 except when otherwise indicated. The assembly of pGPFHN-IE-PA is accomplished in two steps. First the gpFHN cDNA from pGPFHN1 is inserted into pSVCOW7 yielding pGPFHN-PA and then the immediate early promoter of cytomegalovirus is inserted to initiate transcription of the PIV3-like proteins yielding pGPFHN-IEPA.
STEP 1. Plasmid pSVCOW7 is cut with EcoRI and PuvII and fragment 11 (600 bp) containing the polyadenylation sequence of bovine growth hormone extending from the PvuII site in the 3' most exon of the BGH gene, to the EcoRI site downstream from the 3' end is isolated. For a complete discussion of the BGH polyadenylation sequence see the following references: (1) European patent application 01 12012, published on 27 Jun. 1984 wherein the identification and characterization of BGH genomic DNA is disclosed; (2) Woychik, R. P. et al., "Requirement for the 3' Flanking Region of the Bovine Growth Hormone Gene for Accurate Polyadenylation", Proc. Natl. Acad. Sci. USA 81:3944-3948 (July 1984); and, D. R. Higgs, et al., Nature 306:398-400 (24 Nov. 1983) and references cited therein disclosing that the nucleotide sequence AATAAA characterizes the polyadenylation signal at a location 11 to 30 nucleotides upstream (towards the 5' end) from the 3' end of the BGH gene.
A second sample of pSVCOW7 is cut with EcoRI and BamHI to yield fragment 12 (5.8 Kb). Fragment 12 can be alternatively derived from the EcoRI/BamHI fragment from parent plasmid pSV2dhfr available from Bethesda Research Laboratories. Fragment 12 contains the origin of replication from pBR322 and an ampicillin resistance gene expressed in E. coli which allows for the selection of the plasmid in E. coli. The fragment also contains the mouse dihydrofolate reductase cDNA in a construction that allows expression in mammalian cells. Subramani, et al., Mol. Cell. Biol. 1:854-864 (1981).
Plasmid pGPFHN1 is cut with BamHI and NruI to yield fragment 13 (2.7 Kb) which is gel isolated. The BamHI site is just upstream from the cDNA coding for the 5' untranslated sequences of the FHN MRNA, and the NruI site is a few bases downstream from the translation termination codon.
Fragments 11, 12 and 13 are ligated to form pGPFHN-PA (9.1 Kb) which is a replication vector capable of shuttling between E. coli and CHO cells. Plasmid pGPFHN-PA is transformed into E. coli.
STEP 2. In step 2, pGPFHN-PA is converted into expression plasmid pGPFHN-IE-PA by inserting the immediate early gene promoter from human cytomegalovirus (CMV I.E. promoter). The CMV I.E. promoter is obtained from the PstI digestion of the CMV genome. The restriction endonuclease cleavage maps of the region of the human cytomegalovirus (CMV) genome containing the major immediate early gene (CMV I.E.) have been described in detail Stinski, et al., J. Virol. 46:1-14, 1983; Stenberg, et al., J. Virol. 49:190-199, 1984; and, Thomsen, et al., Proc. Natl. Acad. Sci. USA, 81:659-663, 1984.
The Stinski and Thomsen references describe a 2.0 kilobase PstI fragment which contains the promoter for the major immediate early gene. When this 2.0 Kb PstI fragment is isolated and digested with Sau3AI, a 760 basepair fragment is obtained among the products. This 760 base pair fragment can be distinguished from the other products by its size and the presence of a SacI cleavage site and a BalI cleavage site within the fragment. Because of its convenient identification, utilization of this Sau3AI fragment is the preferred method of use of the CMV I.E. promoter as described in the present specification.
Plasmid pGPFHN-PA is cleaved with BamHI, and a Sau3AI fragment containing the CMV immediate early promoter is ligated into the compatible BamHI site. Plasmids containing the CMV promoter fragment in an orientation such that transcription from the promoter would synthesize an MRNA for a PIV3-like protein are identified by cleavage of the plasmids with SacI. The resulting plasmid is designated pGPFHN-IE-PA having the CMV I.E. promoter at the 5'-end of the cDNA and the BGH polyadenylation signal on its 3'-end. The plasmid is maintained in E. coli until transfection into CHO cells.
C. Transfection and Culturing of CHO Cells.
Plasmid pGPFHN-IE-PA is transfected into Chinese hamster ovary (CHO) cells deficient in dihydrofolate reductase(dhfr) using the calcium phosphate method for transfection of DNA into cells which is described in detail by Graham, et al., Introduction of Macromolecules into Viable Mammalian Cells, Alan R. Liss Inc., N.Y., 1980, pp. 3-25. The cell line used is the mutant DXB-11 originally available from L. Chasin, of Columbia University and completely described in Proc. Natl. Acad. Sci. USA 77:4216-4220 (1980). The above methods for transfection relies on the fact that cells which incorporate the transfected plasmids are no longer dhfr deficient and will grow in Dulbeeco's modified Eagle's medium plus proline.
If the chimeric glycoprotein does not contain an anchor region, then supernatant from CHO cells expressing secreted chimeric FHN protein is clarified by low speed centrifugation. The supernatant is applied to a conconavalin A or lentil lectin column. The glycoprotein is eluted after extensive washing with a linear gradient of a α-D-methylglucoside (0-0.5 M) in the above buffer. The eluted glycoprotein is dialyzed against PBS containing 0.1% Triton X-100 and applied to an affinity column. The affinity column is composed of either polyclonal or monoclonal antibodies directed against PIV3 linked to Sepharose 4B beads (Pharmacia, Piscataway, N.J.) by known techniques. The column is washed in dialysis buffer and the PIV3 FHN glycoprotein is eluted with PBS containing 0.1M glycine (pH 2.5) and 0.1% Triton X-100. The glycoprotein is dialyzed against saline and checked for purity by electrophoresis on a SDS-PAGE gel.
If the chimeric glycoprotein contains an anchor region, then the CHO cells expressing the glycoprotein are washed in phosphate buffered saline (PBS) and then lysed in PBS containing 1.0% Triton X-100 and 1.0% sodium deoxycholate. After pelleting the nuclei, the cytoplasmic extract is applied to a conconavalin A column and purified as described above for secreted glycoproteins.
Example 7 The Expression of PIV3 GPFHN Using Bovine Papilloma Virus (BPV)
A. The construction of a cloning vector containing a nontranscribable expression cassette suitable for replication in E. coli
The constructions of pTFW8 and pTFW9 offer a convenient starting material for expressing PIV3 proteins using BPV. The transcription terminator of the deposited plasmid prevents the expression of PIV3 proteins and must be removed in a single step excision and ligation.
1. Construction of pTFW8
Plasmid pdBPV-MMTneo (342-12) described in Mol. and Cell Biol., Vol 3 (No. 11):2110-2115 (1983) and obtained from Peter Howley of the National Cancer Institute, Bethesda, Md., USA. Plasmid pdBPV-MMT neo (342-12) consists of three parts: a complete BPV-1 genome (100%) opened at the unique BamHI site; pML2 (a "poison-minus" derivative of pBR322); and a transcriptional cassette composed of the murine metallothionein I gene promoter, the neomycin phosphotransferase 11 gene of Tn5, and the simian virus 40 early-region transcriptional processing signals. Plasmid pdBPV-MMT neo (342-12) is first digested with BamHI to remove the BPV sequences which were isolated and stored for later insertion. The remaining fragment is religated using T4 ligase to form pMMpro.nptII (6.7 Kb). Removal of the BPV genome facilitates later genetic manipulations by creating unique restriction sites in the remaining plasmid. After the recombinations are complete, the BPV genome is replaced.
Plasmid pMMpro.nptII is digested with BglII and a synthetic DNA fragment 14 containing unique restriction sites is inserted and ligated using T4 ligase to yield pTFW8 (6.7 Kb). Plasmid pTFW8 is identical to pMMpro.nptII except for the insertion of unique restriction sites between the murine metallothionein I gene promoter and the neomycin resistance gene.
2. Construction of pTWF9
Plasmid pTWF9 contains the transcription terminator T I from phage lambda inserted between the metallothionein I gene promoter and the neomycin resistance gene. The transcription terminator can be obtained from Donald Court of the National Cancer Institute in Bethesda, Md. USA. The transcription terminator is supplied in pKG1800sib3 which is the same as pUS6 as described in Gene, 28:343-350 (1984), except that t I carries the sib3 mutation as described in Guarneros, et al., PNAS, 79:238-242 (1982). During the normal infection process of phage lambda, the t I terminator functions in the inhibition of bacteriophage int gene expression from P L and in the termination of int gene transcription originating from P I . The terminator is excised from pKG1800sib3 using AluI and PvuI as fragment 15 (1.2 Kb), which is gel isolated and XhoI linkers are placed on either end of the fragment.
The linkers are available from New England Biolabs, Beverly, Ma., U.S.A. The terminator fragment bounded by XhoI complementary ends is then inserted into pTWF8 which has been previously digested with XhoI. The fragments are then ligated using T4 DNA ligase to yield pTWF9 (7.9 Kb). Plasmid pTWF9 was deposited in accordance with the Budapest Treaty. Plasmid pTFW9 is maintained in an E. coli host and has been deposited with the Northern Regional Research Center, Peoria, Ill., U.S.A. on Nov. 17, 1986 and assigned Accession Number NRRL B-18141.
B. The construction of pTFW/GPFHN
The genes constructed in Examples 2-5 may be used for expression of a chimeric glycoprotein using BPV. The plasmid pGPFHN-1 will be used in this example. The other chimeric genes are treated as described for pGPFHN-1 except when otherwise indicated. To construct pTFW/GPFHN, pGPFHN1 is digested with BamHI. Its ends are made flush with Klenow enzyme and synthetic BglII linkers (New England Biolabs) are ligated to the ends of the clone. The DNA is digested with BglII and designated fragment 16 (2.7 Kb). Fragment 16 containing the gpFHN gene (2.7 Kb) is then isolated from a gel. The purified fragment is ligated into pTFW9 which has been digested with BglII to yield pTFW/GPFHN (10.6 Kb).
C. Conversion of pTFW/GPFHN into a eukaryote expression vector
Plasmid pTFW/GPFHN is converted into a eukaryote expression vector by reinserting the 100% complete BPV-1 genome excised with BamHI. Plasmid pTFW/GPFHN is cut with BamHI and the BPV-1 intact genome, a 7.9 Kb fragment is inserted to yield pTFW/GPFHN/BPV* (18.5 Kb) which is replicated in E. coli until production of glycoprotein FHN by eukaryotic cells is desired.
D. Expression of gpFHN in murine C127 cells
Prior to transfection into murine C127 cells, pTFW/GPFHN/BPV* is digested with XhoI to excise the T 1 terminator and religated with T4 DNA ligase. The resulting plasmid pTFW/GPFHN/BPV (17.4 Kb) will now direct the expression of high levels of gpFHN which is secreted into the culture media. The C127 cells are available from the American Type Culture Collection and grown in Dulbecco's modified minimal essential media containing 10% fetal calf serum. The levels of gpFHN proteins in the media of the C127 cells are determined by Western blot experiments with anti-PIV3 antibody and 125 I -labeled protein A.
PIV3 gpFHN is purified from the culture media or cells as described in Example 6.
Example 8 The Expression of PIV3 GPFHN Using Baculovirus Virus
The following example relates to the expression of glycoprotein FHN in insect cell cultures. All procedures are detailed in Summers, M. D. and Smith, G. E., A Manual for Baculovirus Vectors and Insect Cell Culture Procedures published by the College of Agriculture, Texas Agricultural Experiment Station, Texas Agricultural Extension Service, College Station, Tex., 1986. The starting plasmid pAc373 (7.1 Kb) is a general baculovirus expression vector having a unique BamHI site immediately downstream from the polyhedron promoter for Autographs californica nuclear polyhedrosis virus (AcNPV). The polyhedron protein is a matrix protein that is nonessential for viral infection and replication in vitro. The 5plasmid is available from Professor Max Summers of the Department of Entomology, Texas A & M University, College Station, Tex. 77843 and is fully described in Molecular and Cell. Biology, 3(12):2156-2165 (1983).
A. Construction of pAcGPFHN
The genes constructed in Examples 2-6 may be used for expression of a chimeric glycoprotein using baculovirus. The plasmid pGPFHN1 will be used in this example. The other chimeric genes are treated as described for pGPFHN1 except when otherwise indicated. Plasmid pGPFHN1 is digested with BamHI and fragment 17 (2.7 Kb) containing the gpFHN gene is isolated from a gel. The purified fragment is ligated into pAc373 which has been digested with BamHI.
B. Transfection and culturing of S. Frugiperda
The gpFHN cDNA insert of pAcGPFHN is recombined with native AcNPV DNA by cotransfection in S. frugiperda. S. Frugiperda (SF9; ATCC CRL 171 1) are cultured in Grace Media (Gibco Lab. Livonia, Mich. 48150), 10% fetal calf serum and supplemented with Difco Lactalbumin hydrolysolate and yeastolate. The cells are cotransfected with AcNPV DNA and pAcGPFHN at 1 μg/ml and 2 μg/ml respectively. Resulting virus particles are obtained by collecting the media and removing cellular material by low speed centrifugation. The virus containing-media is then used to infect S. frugiperda. Subsequent infection of S. frugiperda using these viral particles which include both native viral DNA and DNA recombined with the cDNA coding for glycoprotein FHN will result in some cells expressing the PIV3 protein instead of the polyhedron protein. Purification of recombinant virus is accomplished by a series of limited dilution platings in 96-well tissue culture plates containing S. frugiperda cells. Wells containing recombinant virus are detected by dot blot hybridization using pGPFHN1 which has been labeled with 32 p-dCTP by nick translation as a probe. Once sufficiently pure, the recombinant virus is detected by its unique occlusion-negative plaque morphology. PIV3 protein synthesized in recombinant baculovirus infected cells is detected by Western blot experiments with anti-PIV3 antibody and 125 I-labeled protein A (Amersham Corp.).
The PIV3 protein is purified from the culture media or cells as described in Example 6.
Example 9 Preparation of a Vaccine
The immunogen can be prepared in vaccine dose form by well-known procedures. The vaccine can be administered intramuscularly, subcutaneously or intranasally. For parenteral administration, such as intramuscular injection, the immunogen may be combined with a suitable carrier, for example, it may be administered in water, saline or buffered vehicles with or without various adjuvants or immunomodulating agents such as aluminum hydroxide, aluminum phosphate, aluminum potassium sulfate (alum), beryllium sulfate, silica, kaolin, carbon, water-in-oil emulsions, oil-in-water emulsions, muramyl dipeptide, bacterial endotoxin, lipid X, Corynebacterium parvum (Propionobacterium acnes), Bordetella pertussis, polyribonucleotides, sodium alginate, lanolin, lysolecithin, vitamin A, saponin, liposomes, levamisole, DEAE-dextran, blocked copolymers, ISCOMS or other synthetic adjuvants. Such adjuvants are available commercially from various sources, for example, Merck Adjuvant 65 (Merck and Company, Inc., Rahway, N.J.).
The proportion of immunogen and adjuvant can be varied over a broad range so long as both are present in effective amounts. For example, aluminum hydroxide can be present in an amount of about 0.5 % of the vaccine mixture (Al 2 O 3 basis). On a per dose basis, the concentration of the immunogen can range from about 0.015 μg to about 1.5 mg per kilogram per patient body weight. A preferable dosage range is from about 0.5 μg/kg to about 0.15 mg/kg of patient body weight. A suitable dose size in humans is about 0.1-1 ml, preferably about 0.1 ml. Accordingly, a dose for intramuscular injection, for example, would comprise 0.1 ml containing immunogen in admixture with 0.5% aluminum hydroxide.
The vaccine can be administered to pregnant women or to women of child bearing age to stimulate maternal antibodies. The female can be revaccinated as needed. Infants can be vaccinated at 2 to 3 months of age after depletion of maternal antibodies and revaccinated as necessary, preferably at 6 to 9 months of age after maturation of the immune system. Babies born to unvaccinated mothers can be vaccinated at 2 to 3 months of age. The vaccine may also be useful in other susceptible populations such as elderly or infirmed patients.
The vaccine may also be combined with other vaccines for other diseases to produce multivalent vaccines. It may also be combined with other medicaments such as antibiotics. ##STR11##
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This invention encompasses novel chimeric glycoproteins which are useful for preparing virus specific immune responses against human parainfluenza virus type 3, PIV3. Host cells transformed with structural genes coding for the glycoproteins, expression and replication plasmids containing the structural genes, vaccines made from the glycoproteins and methods for protecting humans by inoculation with said vaccines are also part of this invention.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image formation device which can carry out the normal development and the inverted development by switching between them, and to a microfilm reader-printer which includes such an image formation device.
2. Description of the Prior Art
In a prior-art microfilm reader-printer of the above kind, if the paper to be used for copying is set to be of the A4 size, then there is formed an image of A4 size on the photosensitive drum. In transferring an image formed on the photosensitive drum to a copying paper, the leading edge of the image on the photosensitive drum and the leading edge of the paper are set to be flush with each other.
Now, if a letter paper is used as the copying paper in the above, its length is not large enough to cover the end portion of the image on the drum. As a result, development and transfer will continue to be carried out even after the end of the paper passed the transfer position, and the toner on the photosensitive drum makes contact with the transfer charger, which may pollute the toner.
In so doing, the toner will be wasted. In addition, due to the toner pollution by the transfer charger, especially in a reader-printer designed for image pickup from microfilms, there was a problem that the transfer cannot be carried out properly since the microfilm has a black background in the margins. Further, in an image formation device which carries out the inverted development, an exposed portion of the photosensitive drum is developed and there exists, in general, a rise or a fall time of the exposure lamp when it is turned on or off, that is, it takes 1 or 2 seconds before the exposure lamp rises or falls completely.
For this reason, the portions that come before the leading edge and after the trailing edge of the effective image formation region are also exposed and developed. This results in a problem which brings about wastes of the toner and an increase in the burden to the cleaner of the residual toner.
Moreover, in an image formation device which can be switched between the normal development and the inverted development, in the case of carrying out an inverted development, the photosensitive drum will be developed if it is not given a sufficiently high potential. Therefore, development of the nonimaging section in the axial direction of the photosensitive drum is prevented by setting the charging width to be greater than the exposure width and the exposure width to be slightly wider than the paper width.
Further, as for the developing width, it used to be set somewhat wider than the paper width, since the development at the end portions of the paper will become unsatisfactory if the developing width approaches the paper width. Accordingly, the relationship between the various widths is given by "charging width > developing width > exposure width > paper width." However, when normal development is carried out using such an image formation device, the nonimaging portion is also developed so that it leads to a waste of the toner and to an increase in the burden to the cleaner which cleans the residual toner.
On the contrary, in an image formation device which is set for the normal development as "exposure width > developing width > charging width > paper width," areas outside of the charging region of the photosensitive drum will be developed in the inverted development, so that there is also a problem of bringing about a waste of the toner. In other words, in the existing image formation device, there was a problem that the toner is wasted when switching between the inverted development and the normal development is carried out.
Further, in an image formation device such as a microfilm reader-printer, even when the image formation operation is started under a condition in which the developing apparatus is not set, the image will never be copied on the paper. Because of this, if the system is designed such that all of the functions are to be interrupted when both of the developing apparatuses are removed, the system cannot be used as a microfilm reader, in spite of the fact that it should still be usable in principle for that purpose.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an image formation device which can prevent a wasteful consumption of the toner and a pollution of the transfer charger.
Another object of the present invention is to provide an image formation device which can expose and charge solely the region which is to be transferred to the recording medium.
Another object of the present invention is to provide a microfilm reader-printer which can be used as a microfilm reader even under a condition which forbids the operation of image formation.
Another object of the present invention is to provide a microfilm reader-printer which can prevent a wasteful use of the toner when it is switched between the normal development and the inverted development.
A feature of the present invention is that in an image formation device which includes an image bearing roll on which is formed a toner image, a charger which charges the image bearing roll, an exposure apparatus which forms an electrostatic latent image by exposing the charged image bearing roll, an apparatus for normal development which carries out the normal development of the image bearing roll on which is formed an electrostatic latent image, an apparatus for inverted development which carries out the inverted development of the image bearing roll, and a transferring apparatus which transfers the toner image which is formed on the image bearer. The present invention is further equipped with a designation switch which specifies the size of the recording paper, an exposure shutter device, and a microcomputer. The microcomputer carries out a control so as to form a toner image only in a region on the image bearer that can be transferred to the recording paper, in accordance with the size of the recording paper that is detected by a detector, in such a way as to control, in the case of the inverted development, the opening and closing of the exposure shutter device in order to regulate the exposed length in the direction perpendicular to the axial direction of the image bearing roll, and to control, in the case of the normal development, the charger in order to regulate the charged length in the direction perpendicular to the axial direction of the image bearing roll.
Another feature of the present invention is that in an image formation device which includes an image bearing roll on which is formed a toner image, a charger which charges the image bearing roll, an exposure apparatus which forms an electrostatic latent image by exposing the charged image bearing roll, an apparatus for normal development which carries out the normal development of the image bearing roll on which is formed an electrostatic latent image, an apparatus for inverted development which carries out the inverted development of the image bearing roll, and a transferring apparatus which transfers the toner image which is formed on the image bearer. The present invention is further equipped with a designation switch which specifies the size of the recording paper, a discharge light source device which is provided adjacent to the exposure light path of the exposure apparatus, and a microcomputer which controls the discharge light source device so as to have the exposed width and the charged width in the axial direction of the image bearing roll in such a way as to set the exposed width to be greater than the charged width for normal development, and the charged width to be greater than the exposed width for inverted development.
Another feature of the present invention is that in a microfilm reader-printer which projects the image of a microfilm and records the projected image on the recording paper, the present invention is equipped with (a) a film setting unit which has film pressing plates for placing the microfilm and a light source for projection, (b) a projection unit which projects with the light from the light source the microfilm image on the projection screen, (c) a scanning light guiding unit which guides the scanning light obtained by the projection unit, (d) an image formation unit which forms an image on the recording paper based on the scanning light from the scanning light guiding unit, a microfilm reader-printer comprising, an image bearing roll on which is formed a toner image, a charger which charges the image bearing roll, the scanning light exposing the charged image bearing roll in order to form an electrostatic latent image, a freely attachable and detachable developing apparatus which develops the image bearing roll on which is formed an electrostatic latent image, and a transferring apparatus which transfers a toner image formed on the image bearer to the recording paper, and (e) a microcomputer which controls the image formation unit so as to bring only the image formation operation to a standstill when the developing apparatus is not set on the image formation unit.
These and other objects, features and advantages of the present invention will be more apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an external perspective view of a microfilm reader-printer which employs the present invention;
FIG. 2 is an internal block diagram of the microfilm reader-printer;
FIG. 3 is an internal block diagram of the image formation unit of the microfilm reader-printer;
FIG. 4 is a front view of the shutter device shown in FIG. 3;
FIG. 5a, and 5b are a block diagram for the control circuit in a first embodiment;
FIG. 6 is a timing chart for controlling the switching of the development modes which form the core of the present invention;
FIG. 7 is a diagram which schematically shows the operation of image formation;
FIG. 8 is an internal block diagram of the image formation unit for a second embodiment of the microfilm reader-printer in accordance with the present invention;
FIG. 9 is a perspective block diagram for the discharge light source shown in FIG. 8;
FIG. 10 is an explanatory diagram for showing the action of the discharge light source shown in FIG. 9.
FIG. 11a, and 11b are a block diagram for the control circuit in a second embodiment;
FIG. 12 is an internal block diagram for the image formation unit of a third embodiment of the microfilm reader-printer in accordance with the present invention;
FIG. 13 is a circuit diagram for the detection unit of the developing apparatus for the third embodiment;
FIG. 14 and FIG. 15 are circuit diagrams for each of the modifications of the detection circuit for the developing apparatus;
FIG. 16 is a flow chart which shows the operation of the third embodiment; and
FIG. 17 and FIG. 18 are explanatory diagrams which shown the case in which copying is forbidden by the nonsetting of the developing apparatus in the third embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 is shown an external view of the microfilm reader-printer which embodies the present invention.
The reader-printer has on its front face side, a projection screen 1 on which is projected an enlarged microfilm, an operating panel 2 which has various kinds of operating keys and others, film pressing plates 3 for holding the microfilm in between, and so forth. In addition, a cassette 4 which feeds papers for film copying is attachable and detachable from the front face side, and a paper on which is transferred the content of a film image is arranged to be ejected from above the opening for attaching and detaching the paper feeding cassette 4.
As shown in FIG. 2, in the interior of the reader-printer, there are provided a film setting unit 6 which has film pressing plates 3 and a light source 5 for projection, a projection unit 7 which projects a film image on the projection screen 1, a scanning light guiding unit 9 which guides the scanning light obtained by a rotatable mirror 8 in the projection unit 7, and an image formation unit 10 which forms an image on a paper in the paper feeding cassette 4, based on the scanning light from the scanning light guiding unit 9.
In FIG. 3 are shown the details of the image formation unit 10. In the image formation unit 10, 11 is the body of the unit. To the lower front face side of the body 11 is fitted the paper feeding cassette 4, and a tray 12 for ejected paper is fitted above the cassette 4. At about the center of the unit body 11, there is arranged a photosensitive drum 13 which is the bearer of the image, and above the photosensitive drum 13 there is arranged a shutter device 15 which shields scanning light from the scanning light guiding unit 9. Namely, the shutter device 15 is provided above a scanning light incident slit 16a of the upper frame 16, to shield and control the incidence of the scanning light.
The shutter device 15 consists, as shown in FIG. 4, of a shutter 15a which shields the scanning light incidence slit 16a, a link mechanism 15b which closes and opens the shutter 15a, and a shutter solenoid 15c which drives the link mechanism 15b. It has a construction which opens the shutter 15a when the shutter solenoid 15c is turned off, and opens the shutter 15a when the shutter solenoid 15c is turned on.
In the surroundings of the photosensitive drum 13, there are arranged a charger 17, a developing device 18, a pre-transfer discharger 19, a transfer charger 20, a detachment (or peeling) charger 21, a cleaner 22, a discharge lamp 23 and others. In the lower part of the unit body 11, there is formed a paper transporting route 26 which leads a paper which is taken out automatically from the paper feeding cassette 4 via paper feeding roller 24 through an image formation unit 25 formed between the photosensitive drum 13 and the transfer charger 20, to the tray 12 for ejected paper. On the upstream side of the image formation unit 25 of the paper transporting route 26, there are arranged resist rollers 27, and on the downstream side, there are arranged heat rollers 28 and paper eject rollers 29 as a fixing device.
Now, when the photosensitive drum 13 is driven in the direction of the arrow a, first it is charged uniformly by the charger 17, and then scanning light from the scanning light guiding unit 9 is focused successively on the photosensitive drum 13 to form an electrostatic latent image. The electrostatic latent image thus formed is brought out explicitly by being developed by the developing device 18, and is sent in toward the transfer charger 20. The image formed beforehand on the photosensitive drum 13 is transferred by the transfer charger 20 to a paper which is supplied by the paper feeding cassette 4 and is fed by the resist rollers 27. Then, the paper with transferred image is detached from the photosensitive drum 13 by the detachment charger 21, and is led to the heat rollers 28 by way of the paper transporting route 26. After the transferred image is fixed by melting at the heat rollers 28, the paper is ejected to the tray 12 for ejected paper by the paper eject rollers 29. On the other hand, after transferring the image to the paper, the residual image on the photosensitive drum 13 is erased in preparation for the next copying operation.
The developing device 18 has a first developing roller 18a and a second developing roller 18b, and a selective driving of the developing rollers 18a and 18b is arranged to enable one to develop both of a negatively recorded microfilm and a positively recorded microfilm into positive images. Namely, the developing device 18 is subdivided into a first developing apparatus 181 that contains the first developing roller 18a and a second developing apparatus 182 that contains the second developing roller 18b. The first developing apparatus 181 carries out the positive → positive development, while the second developing apparatus 182 carries out the negative → positive development.
In the development mode which carries out the positive → positive development (referred to as the P-P development mode hereinafter), an image formed on the paper becomes brighter when the exposure to the light source lamp of the light source 5 is increased, and becomes darker when the exposure is decreased. Further, in the development mode which carries out the negative → positive development (referred to as the N-P development hereinafter), the image formed on the paper becomes brighter when the exposure to the light source lamp of the light source 5 is decreased, and becomes darker when the exposure is increased.
In FIGS. 5(a) and (b) are shown block diagrams for a control circuit of a first embodiment with the above construction. The control circuit includes a microcomputer 100 which carries out the control of the device as a whole. The microcomputer 100 is connected to a paper size detector (DIP switch) 102 and others placed on the operating panel for carrying out the A4/LETTER switching, via an input interface circuit 101 such as a data selector, and the microcomputer 100 reads the state of the DIP switch at the time of initialization after turning-on of the power supply to the main body. Further, the microcomputer 100 is connected via an output interface circuit 103 to a charging power supply 104 of the charger 17, the shutter solenoid 15c of the shutter device, and so on.
The longitudinal length of the image, namely, the length in the direction perpendicular to the axial direction of the drum, that is formed on the drum is determined, in the case of the present machine, by the timing for turning-off of the charger or by the timing for the closing of the shutter. Accordingly, when LETTER is selected by the DIP switch, the microcomputer 100 regulates the exposure length in the direction perpendicular to the axial direction of the drum, in the case of inverted development, and regulates the charging length in the direction perpendicular to the axial direction of the drum, in the case of normal development, in order to match the length of the image formed on the drum to the size of the letter paper. In other words, the microcomputer 100 sends via the interface circuit 103 a control signal to the shutter solenoid 15c when an inverted development is to be carried out, and sends a control signal to the power supply for charging 104 when a normal development is to be carried out, in order to control the above-mentioned timings.
A chart for these timings is shown in FIG. 6. In the figure, the origin of the time axis is chosen at the time of opening the exposure shutter (starting time of exposure).
As indicated in the figure, the timing for closing the shutter and the timing for turning-off the charger are sooner for the letter paper than for the A4 size paper. This difference in the timings corresponds to the difference in the times of passing the transfer point by the last portion of the A4 size paper and the letter paper. In the case of the inverted development, opening and closing of the exposure shutter is controlled, while the charging time is controlled in the case of the normal development.
Further, in order to facilitate the understanding of the time chart shown in FIG. 6, the angles at which the timings for charging, exposure, development, transfer, cleaning, and discharging take place are shown in FIG. 7.
Next, several other embodiments of the method of setting the switch for the A4/LETTER changeover will be described. (a) A protrusion for discriminating between an A4 size paper and a letter paper is provided on the paper feeding cassette, and the switch detects the protrusion in the state in which the cassette case is set on the machine. (b) There is provided in the machine a switch which can detect whether or not there is fed a paper. By counting the time during which the switch is pressed (the passing time of the paper) by means of a microcomputer, it can discriminate whether the fed paper is an A4 size paper or a letter paper.
As described in the foregoing, according to the first embodiment of the microfilm reader-printer, a wasteful consumption of the toner and the pollution of the transfer charger can be prevented effectively in forming an image on a special size paper such as a letter paper.
Referring to FIG. 8, a second embodiment of the microfilm reader-printer in accordance with the present invention is shown.
In the second embodiment, a light source device for discharge 33 is provided, in addition to the devices of the first embodiment, on the scanning light route 32 that forms an electrostatic latent image on the photosensitive drum 13. The discharge light source device 33 consists, as shown in FIG. 9, of an L-shaped frame 35 that has a slit 34 in the scanning light route 32, and a pair of discharge light sources 36. In the normal development, discharge of the photosensitive drum 13 is carried out by the lighting of the light sources 36 to regulate the charged width in the axial direction of the drum.
In this case, the discharge light sources 36 are controlled by the microcomputer 100 (FIG. 11) to have a relationship among the charging width, exposure width, discharge light source width, developing width, and paper width to be given, to reduce the waste of the toner, by "charging width > developing width > exposure width > paper width" for the inverted development, and by "exposure width > charging width > developing width > paper width," with the exposure width that includes the discharge light source width, for the normal development, as shown in FIG. 10.
It should be noted that the present invention is not limited to this embodiment alone, and the exposure width may be adjusted by providing a shutter device on both sides of the slit 34. Further, the charging width may also be adjusted by providing a plurality of chargers.
As described in the above, according to the second embodiment of the present invention, toner waste can be prevented for both cases of the normal development and the inverted development, by providing means for regulating the exposure and charging widths which adjust the exposure width and the charging width to their optimum values.
Referring to FIG. 12, a third embodiment of the microfilm reader-printer in accordance with the present invention is shown.
The image formation unit 10 of the third embodiment has a unit body 11, and in the lower part of the front face side of the unit body 11 there is set a paper feeding cassette 4, and a tray 12 for ejected paper is set above the paper feeding cassette 4. Above an image bearer drum 13 which is situated at about the center of the unit body 11, there are arranged a shutter mechanism 15 for shielding the scanning light from the scanning light guiding unit 9, and a solenoid 16 for driving the shutter mechanism 15.
In the surroundings of the photosensitive drum 13 there are arranged a charger 17, developing device 18, pre-transfer discharger 19, transfer charger 20, detachment charger 21, cleaner 22, discharge lamp 23, and others. In the lower part of the unit body 11, there is formed a paper transporting route 26 which leads a paper which is taken out automatically from the paper feeding cassette 4 via a paper feeding roller 34, through an image formation unit 25 formed between the photosensitive drum 13 and the transfer charger 20, to the tray 12 for ejected paper. On the upstream side of the image formation unit 25 of the paper transporting route 26, there are provided resist rollers 27, and on its downstream side there are provided heat rollers 28 and paper eject rollers 29 as the fixing device.
When the photosensitive drum 13 is driven in the direction of the arrow a of the figure, it is first charged uniformly by the charger 17, and the operating light from the scanning light guiding unit 9 is focused successively on the photosensitive drum 13 to form an electrostatic latent image. The electrostatic latent image thus formed is developed by the developing device 18 to be brought out explicitly, and is sent to the side of the transfer charger 20. On the other hand, a paper fed by the paper feeding cassette 4 is supplied by the resist rollers 27, and an image formed on the photosensitive drum 13 beforehand is transferred to the paper by the transfer charger 20. The paper that has the transferred image on it is peeled off from the photosensitive drum 13 by the detachment charger 21, and led to the heat rollers 28 by way of the paper transporting route 26. After the transferred image the is fixed by melting there, the paper is ejected to the tray 12 for ejected paper by the paper eject rollers 29. On the other hand, after the image is transferred to the paper, the residual image on the photosensitive drum 13 is erased in order to be ready for the next copying operation.
The developing device 18 has a first developing roller 18a and a second developing roller 18b. By a selective operation of the developing rollers 18a and 18b, it is designed to be able to develop both of a negatively recorded microfilm and a positively recorded microfilm into positive images. Namely, the developing device 18 is divided into two parts of a first developing apparatus 181 that contains the first developing roller 18a and a second developing apparatus 182 that contains the second developing roller 18b, and the first developing apparatus 181 carries out positive → positive development and the second developing apparatus 182 carries out negative → positive development.
In the development mode for carrying out the positive → positive development (referred to as the P-P development mode hereinafter), the image that is formed on the paper becomes brighter when exposure to the light source lamp of the light source 5 is increased and it becomes darker when the exposure is decreased. Further, in the development mode for carrying out negative → positive development (referred to as the N-P development mode hereinafter), the image that is formed on the paper becomes brighter when exposure to the light source lamp of the light source 5 is decreased and it becomes darker when the exposure is increased.
With the above construction, a detection circuit as shown in FIG. 13 is used for the first developing apparatus 181 and the second developing apparatus 182 in the third embodiment.
As shown in FIG. 13, the detection circuit 40 is connected to a central control circuit 300 such as a microcomputer that includes a CPU.
When the developing apparatus 18 (meaning either the first developing apparatus 181 or the second developing apparatus 182) is set on the body of the detection circuit 40, terminal a and terminal b are connected. Then, between the terminals c and d, there appears a TTL level signal which is an electrical signal of "H" level when the developing apparatus 18 is set on the body, and an electrical signal of "L" level when the developing apparatus is not set. By means of this signal, the central control circuit 300 detects the setting condition for each of the first developing apparatus 181 and the second developing apparatus 182.
Here, if the developing apparatus (either one of the first developing apparatus 181 or the second developing apparatus 182) selected by the operation on the control panel is not set, it means that the machine is unable to carry out copying. Hence, a system program is adopted in which the central control circuit ignores the copy start switch thereafter.
In the state in which all of the developing apparatuses (both of the first developing apparatus 181 and the second developing apparatus 182) are not set, all the functions related to image formation (image formation unit 10) are first brought to a standstill, and all of the LED displays on the panel in the body front that are related to image formation are put out. As for the key acceptance, regarding the display of the warning light on the front panel due to an error generated within the body 40, while the machine is being used as a reader (mainly the projection unit 6), it is designed to be carried out immediately after the occurrence of the error.
Moreover, the detection circuit may be constructed as shown in FIG. 14 or FIG. 15.
In a modification shown in FIG. 14, at the time of setting the developing apparatus 18 on the body 41, a lead switch fixed to the body 41 is brought to on-state by the magnetism of a permanent magnet that is fixed to the developing apparatus 18, so that there appears an "H" signal of TTL level between the terminals a and b. When the developing apparatus 18 are not set, an "L" signal appears between the terminals a and b.
In a modification shown in FIG. 15, at the time of setting the developing apparatus 18 on the body 42, a protrusion fixed to the developing apparatus 18 presses to turn on a microswitch that is fixed on the body 42 side, so that an "H" signal of TTL level appears between the terminals a and b. When the developing apparatus 18 are not set, an "L" signal appears between the terminals a and b.
In the case of carrying out detection of setting or nonsetting of the developing apparatus 18, by means of one of the detection circuits shown in FIG. 13, FIG. 14, or FIG. 15, the operation will be described according to a flow chart shown in FIG. 16. In FIG. 16, developing apparatus A signifies the first developing apparatus 181 and developing apparatus B signifies the second developing apparatus 182.
In the first step 701 that follows the main processing, the operation as a reader is executed. If the copy start switch is depressed (affirmative case of step 704) with the developing apparatus A mounted (affirmative case of step 702) and the developing apparatus A selected (affirmative case of step 703), the copying processing will be executed (step 705). On the other hand, while the developing apparatus A is not set (negative case of step 702), if the developing apparatus A is not selected (negative case of step 706), the developing apparatus B is set (affirmative case of step 707), the developing apparatus B is selected (affirmative case of step 708), and the copy start switch is depressed (affirmative case of step 704), then the copying processing will be executed (step 705). Moreover, in the state in which the developing apparatus A is set (affirmative case of step 702), when the developing apparatus A is not selected, if the developing apparatus B is set (affirmative case of step 708) and the developing apparatus B is selected (affirmative case of step 710), then the copying processing will be executed (step 705) by the depressing of the copy start switch (affirmative case of step 704).
However, while the developing apparatus A is not set (negative case of step 702), if the developing apparatus A is selected (affirmative case of step 706), or if the developing apparatus A is not selected, and the developing apparatus B is not set (negative case of step 707), or if the developing apparatus A is not selected, the developing apparatus B is not set, and the developing apparatus B is not selected (negative case of step 708), then the operation returns to step 701.
Furthermore, even when the developing apparatus A is set (affirmative case of step 702), if the developing apparatus A is not selected (negative case of step 703) and the developing apparatus B is not set (negative case of step 709), or if the developing apparatus A is not selected, the developing apparatus B is not set and the developing apparatus B is not selected (negative case of step 710), then the operation goes back to step 701. Moreover, if the copy start switch is not depressed (negative case of step 704), the operation goes back to step 701.
From the above considerations, it will be seen that the system may be used as a microfilm reader even under the condition which prohibits the image formation (copying) operation. Moreover, there may be formed a loop which is shown by the chained line in FIG. 16.
It should be mentioned that in a reader-printer of the above kind, a construction may be adopted by which the selection of a developing apparatus is forbidden when the developing apparatus is not set.
In that case, there may be adopted an arrangement by which the kind of developing apparatus that is set can be displayed.
Referring to FIG. 17 and FIG. 18, realization of such a construction will be described next.
In such embodiments, the central control circuit in the body detects the presence or absence of the two developing apparatuses to forbid the copying by the developing apparatus that is not set.
Furthermore, the acceptance of the key input for the selection of the developing apparatus is set to be impossible, and the display lamp for showing the selection condition is fixed to the lighting only of the developing apparatus that is being set.
In FIG. 17 is illustrated the disposition of the developing apparatus selection key 41 and the selection display lamps 42 on the front panel.
In FIG. 18 is shown a flow chart that illustrates that processing situations following the detection.
In FIG. 13, if the developing apparatus is set on the body 40, the terminals a and b are connected electrically, and so are connected the terminals c and d. Then, between the terminal e and f, there appears a TTL level signal which is an "H" signal when the developing apparatus is et, and an "L" signal when it is not set.
As explained in the above, according to the third embodiment, the system can be used as a microfilm reader even when it is under the condition in which the image formation operation is forbidden. Therefore, it will be extremely convenient for the user of the system.
Various modifications will become possible for these skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.
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A microfilm reader-printer including an image formation device having an image baring roll, a charger, an exposure apparatus, an apparatus which carries out the normal development of the image bearing roll, an apparatus which carries out the inverted development of the image bearing roll, and an apparatus which transfers the toner image which is formed on the image bearer. The reader-printer further includes a switch which specifies the size of the recording paper, an exposure shutter device, and a microcomputer. The microcomputer directs forming a toner image only in a region on the image bearer that can be transferred to the recording paper, in accordance with the size of the recording paper that is detected by a detector, in such a way as to control, in the case of the inverted development, the opening and closing of the exposure shutter device, and to control, in the case of the normal development, the charger. In addition, this microfilm reader-printer includes a freely attachable and detachable developing apparatus which develops the image bearing roll, an apparatus which transfers a toner image formed on the image bearer to the recording paper, and a microcomputer which controls the image formation unit so as to bring only the image formation operation to a standstill when the developing apparatus is not set on the image formation unit.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and arrangement for detecting a wear limit or break in a cutting edge of a tool having at least one insulated conductor path embedded in its cutting plate and connected with a voltage source so as to form part of a circuit for actuating a signal to break off the machining process.
For an electrically nonconductive ceramic cutter, a system has been proposed for the early detection of a break in the cutting edge according to which a crack in a region of a secondary cutting edge is detected. The detection of such a break interrupts a circuit by destroying a thin conductor path that has been vapor-deposited onto the free secondary face of the tool, thus interrupting the machining process.
This system, up to now, has been used only experimentally. It has not found acceptance in practice because it has considerable drawbacks. In manufacturing processes, electrically conductive workpieces as well as electrically nonconductive workpieces are processed by means of electrically conductive or electrically nonconductive cutting materials, either dry or together with electrically conductive or nonconductive cooling and lubricating agents. It is, therefore, not predictable whether and when in the prior system a current flowing through the circuit is actually interrupted due to the formation of a crack. For example, an electrically conductive bridge may be formed across the crack by particles of the material of the workpiece or the coolant or by particles of an electrically conductive cutting substance and also by contact with the workpiece itself so that, in spite of the fact that the limit of permissible wear has been reached or a break in the cutting edge has occurred, the signal for breaking off the machining process is not initiated.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the aforementioned drawback and to provide a method and an arrangement which reliably furnishes the required signal even if, for whatever reason, an interruption in the conductive path is bridged.
The above and other objects are accomplished according to the invention by the provision of a method for detecting a wear limit or break in a cutting edge of a tool used in a machining process, wherein the cutting edge is formed of material subject to wear. The method includes embedding two insulated conductor paths in the cutting material; connecting each insulated conductor path to a source of voltage so that one of the conductor paths forms part of a closed circuit and the other of the conductor paths forms part of an open circuit; producing a signal for interrupting a machining process if either the conductor path in the closed circuit is interrupted or the conductor path in the open circuit is closed.
According to a further aspect of the invention, an arrangement is provided for detecting a wear limit or break in a cutting edge of a tool used in a machining process, wherein the arrangement includes: a cutting tool having a cutting edge formed by cutting material subject to wear; first and second insulated conductor paths embedded in the cutting material; a source of voltage connected to each conductor path; first and second circuit means each for actuating a signal to interrupt the machining process, the first circuit means including the source of voltage, first switch means and the first conductor path connected to form a closed circuit with the voltage source and the first switch means, the second circuit including the voltage source, second switch means and the second conductor path connected to form an open circuit with the voltage source and the second switch means, wherein the first switch means is connected for actuating a signal to interrupt the machining process if the first conductor path in the closed circuit is interrupted, and the second switch means is connected for actuating a signal to interrupt the machining process if the second conductor path in the open circuit is closed.
In carrying out the invention, two conductor paths, which have thin cross sections and are insulated against one another and toward the exterior of the cutting plate (and if the cutting plate comprises an electrically conductive substrate, also against the substrate), are embedded in the material of the cutting edge so that the two conductor paths are parallel to one another in a side by side arrangement or one above the other. The two conductor paths are connected to a voltage source by way of contact points so that one conductor path is part of a closed circuit and the other conductor path is part of an open circuit. The signal for breaking off the machining process is produced if either the closed circuit is interrupted by wear or a break in the cutting edge, or the open circuit is closed, after removal of the insulating layer due to wear or a break, in that a conductive bridge is formed.
In machining tools, such conductor paths may be disposed at the free faces or at the cutting faces along the primary cutting edges, the secondary cutting edges, or separately for each cutting edge or pair of cutting edges at the primary and secondary cutting edges. According to the invention, a plurality of pairs of conductor paths, connected with mutually independent circuits, may be arranged along one cutting edge. The various circuits may be used to switch different drives of a machine tool, e.g. the drives for switching the feed or the main drive.
Such combinations of pairs of conductor paths may be used so that, for example, the operating parameters and thus the load on the tool is reduced by the circuits of one pair of conductors while only the pulse generated by the circuits of the other pair of conductors ultimately interrupts the machining process if machining of the workpiece is not completed when it occurs.
Reversible cutting plates made of hard substances are particularly well suited for use in combination with arrangements employing the method according to the invention. If the reversible cutting plates are made of an electrically conductive material, e.g. of a hard metal, the plate may initially be coated with a very thin electrically nonconductive ceramic layer, e.g. of aluminum oxide, aluminum oxynitride or silicon nitride. This can be accomplished, as known, by coating the plate with the aid of the so-called PVD [precipitation vapor deposition] or CVD [chemical vapor deposition] process. In the same way, the conductor paths can be produced in that a layer of a conductive material, e.g. titanium carbide, titanium carbonitride or titanium nitride is applied. This layer can be applied within limits to the locations intended for it or over the entire surface area. If the layer is applied to the entire surface area, the conductor paths are produced by subsequent working. The insulating layer toward the exterior may again be a second ceramic layer precipitated according to one of the abovementioned methods. However, electroplating processes or screen printing may also be used to apply insulating layers and conductor paths. The important factor is here that the wear resistance of the insulating layers to be applied must correspond at least to that of the cutting materials employed, better yet be superior to them. This requirement is met if a hard metal or a ceramic material is employed as the cutting substance together with nonconductive ceramic layers. However, all other known hard substances, when used in the proper association, are suitable for the production of nonconductive, i.e. insulating, layers and to produce the conductor paths of devices for implementing the method.
Various embodiments of the invention are illustrated schematically in the drawing figures described below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a schematic drawing of an embodiment according to the invention showing a reversible cutting plate having two electrical conductor paths and associated electrical circuits.
FIG. 1b is a schematic drawing showing another embodiment of the circuits of FIG. 1a.
FIG. 2 schematic drawing showing a further variation of the circuits of FIGS. 1a and 1b with four electrical conductor paths.
FIG. 3 is a schematic drawing showing an arrangement of conductor paths according to the invention in a cutting bit that can be used on four sides.
FIG. 4a is a schematic isometric drawing, partially cutaway, showing a reversible cutting plate made of a hard metal and having two juxtaposed conductor paths per cutting edge.
FIG. 4b is a schematic isometric drawing, partially cutaway, showing a reversible cutting plate made of a hard metal and having two superposed conductor paths per cutting edge.
FIGS. 5a to 5h are schematic drawings showing different arrangements of conductor paths in cutting plates made of hard metal and having electrically conductive or electrically nonconductive substrates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1a shows a reversible cutting plate 1 equipped with conductor paths 2 and 3, made, for example of titanium nitride. These conductor paths are connected with circuits 7 and 8, respectively, by way of contact points 4, 5, 6. Circuits 7 and 8 are fed by a voltage source 9. Switching elements 10 and 11 are provided in circuits 7 and 8, respectively, for actuating a machine control 13 by way of circuit 12.
FIG. 1a shows that conductor path 2 belongs to open circuit 7 and conductor path 3 belongs to closed circuit 8. FIG. 1a further shows that switching elements 10 and 11 operate to open circuit 12 to actuate machine control 13 for interrupting the machining process if open circuit 7 is closed by the establishment of a conductive connection between conductor paths 2 and 3 or if closed circuit 8 is opened due to the interruption of conductor path 3.
The switching scheme shown in FIG. 1b represents a variation of the circuit of FIG. 1a. In FIG. 1b the control signal is generated not by opening of switching elements 10 or 11, but by their closing.
FIG. 2 shows an arrangement comprising multiple pairs of conductor paths which act on separate regulating circuits 14 and 16. Reference numerals 2 and 3 as well as 2a and 3a represent conductor paths. For example, these conductor paths are embedded in layers made of an electrically nonconductive material, for example of aluminum oxide, and are applied to the basic hard metal body of a reversible cutting plate 1. Conductor paths 3 and 3a each form parts of open circuit 7, and conductor paths 2 and 2a are parts of closed circuit 8. With such an arrangement, it is possible to generate switching pulses at different intensities, which, for example, give different pulses to the machine controls 15 and 17 by way of circuits 14 or 16, respectively.
FIG. 3 shows an arrangement of the conductor paths within a reversible cutting plate having four cutting edges and the connection of the conductor paths with the required external contacts. Conductor paths 2 and 3 are brought in an insulated manner to contact points A, B, C, whose countercontacts (not shown) are disposed in, for example, a tool holder, an adaptor or an intermediate member so that they always make contact with three associated contact faces of the respective cutting edge which is in the working position in the reversible cutting plate. If the reversible cutting plate is rotated so as to bring a new cutting edge into the working position, the respective new contacts of the reversible cutting plate move into the connection position. One pair of conductor paths 2 and 3 extends, for example, over almost the entire length of the primary cutting edge and over a small region of the secondary cutting edge. The connections of conductor paths 2 and 3 with contact points A, B, C, which may be produced in the same manner as the conductor paths themselves, are shown by dashed lines in FIG. 3.
FIGS. 4a and 4b show a cutaway of the construction of a reversible cutting plate 1 made of a hard metal and incorporating the conductor paths according to the invention in its insulating and cover layers which are made of a ceramic, electrically nonconductive material. The hard metal substrate bears the reference numeral 18. With the aid of known CVD or PVD methods, a first layer 19 of aluminum oxide is applied to the substrate. Then a metallic conductor path 22 of titanium nitride is applied to layer 19 on top of which a further cover layer 20 of aluminum oxide is applied. Another metallic conductor path 21 of titanium nitride is thereafter applied to layer 20 next to conductor path 22 (i.e., in a different plane) and at the same height. Another insulating layer (not shown) of aluminum oxide is applied to cover conductor path 21. The variation shown in FIG. 4b differs from the embodiment of FIG. 2a in that conductor paths 21 and 22 are not disposed next to one another, but on top of one another in the same plane.
FIGS. 5a to 5h are simplified views of different arrangements of the conductor paths in a reversible cutting plate. Of course, in reversible cutting plates, the conductor paths shown in FIGS. 5a to 5h can also be provided at each cutting edge.
FIG. 5a shows the parallel arrangement of a pair of conductor paths at the free surface of a primary cutting edge. FIG. 5b shows a corresponding arrangement in which, however, the conductor paths also extend over to the free surface of the secondary cutting edge.
In the embodiment of FIG. 5c, the pair of conductor paths is arranged in the cutting face parallel to the primary cutting edge; in FIG. 5d parallel to the primary and secondary cutting edges.
The embodiment according to FIG. 5e shows the arrangement of a conductor path with the use of an electrically conductive substrate. Here, the open circuit may be conducted over the substrate, with the closed circuit being disposed opposite thereto and separated therefrom by a layer of insulating material.
FIG. 5f shows the arrangement of two pairs of conductor paths per cutting edge so as to produce stepped signals for the control of different working parameters.
In the embodiment of FIG. 5g, the conductor paths are arranged at an angle to the primary cutting edge; in FIG. 5h they are arranged in steps with respect to the primary cutting edge. These two embodiments have the advantage that it is possible to set different wear limits for actuation of the signal in dependence on the location of the cutting edge.
The present disclosure relates to the subject matter disclosed in German Serial No. P 35 35 474.7 of Oct. 4, 1985, the entire specification of which is incorporated herein by reference.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A method and arrangement for detecting a wear limit or break in a cutting edge of a machine tool. At least two conductor paths are embedded in the cutting material forming the cutting edge, one of the conductor paths being part of a closed circuit while the other is part of an open circuit. A signal serving to break off the machining process is produced if either the conductor path disposed in the circuit is interrupted or the open circuit is closed by the creation of a conductive connection between the two conductor paths.
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This is a division, of copending application Ser. No. 773,561, filed Mar. 2, 1977, now U.S. Pat. No. 4,098,789, issued July 4, 1978.
RELATED APPLICATION
Copending United States patent application Ser. No. 736,990, filed Oct. 29, 1976 by John Krapcho, now U.S. Pat. No. 4,064,125, issued Dec. 20, 1977, discloses and claims compounds that are related to the compounds of the instant application.
Brief Description of the Invention
Compounds having the formula ##STR2## or a pharmaceutically acceptable salt thereof, have useful antiinflammatory activity. In formula I, and throughout the specification, the symbols are as defined below.
R 1 is alkoxycarbonyl, amido, alkylamido, or dialkylamido;
R 2 is ##STR3## wherein Y is alkyl, cycloalkyl, aryl, arylalkyl, styryl or styryl wherein the phenyl group is substituted with a halogen, alkyl, alkoxy, trifluoromethyl, nitro or amino group;
R 3 is alkylamino, dialkylamino or a nitrogen containing heterocyclic group selected from 1-pyrrolidinyl, 1-piperidinyl, 4-morpholinyl, and 4-alkyl-1-piperazinyl;
A 1 is an alkylene group having 2 to 5 carbon atoms; and
N IS 1, 2 OR 3.
The terms "alkyl" and "alkoxy", as used throughout the specification, whether by themselves or as part of larger groups, refer to groups having 1 to 6 carbon atoms.
The term "aryl", as used throughout the specification, whether by itself or as part of a larger group, refers to phenyl or phenyl substituted with a halogen, alkyl, alkoxy, trifluoromethyl, nitro, or amino group.
The term "halogen", as used throughout the specification, refers to fluorine, chlorine, bromine and iodine; chlorine and bromine are preferred.
The term "cycloalkyl", as used throughout the specification, refers to cycloalkyl groups having 3 to 7 carbon atoms.
The term "alkylene", as used throughout the specification, refers to a straight or branched chain, divalent, saturated hydrocarbon group.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of this invention can be prepared using as starting materials a benzaldehyde having the formula ##STR4## wherein R' 3 is alkylbenzylamino, dialkylamino or a nitrogen containing heterocyclic group, and a primary amine having the formula
H.sub.2 N--(CH.sub.2).sub.n --R.sub.1 III
reaction of a benzaldehyde of formula II with an amine of formula III yields the corresponding Schiff base having the formula ##STR5## The reaction can be run in an organic solvent, e.g., ethanol or an aromatic hydrocarbon such as toluene, and is usually run without the addition of heat.
Reduction of a compound of formula IV, using chemical or catalytic means, yields the corresponding intermediate having the formula ##STR6## The reaction can be run using gaseous hydrogen in the presence of a catalyst such as Raney nickel or palladium. Preferably, the reaction will be run using a chemical reducing agent such as sodium borohydride.
The Schiff bases of formula IV and the compounds of formula V are novel compounds useful in the preparation of the antiinflammatory compounds of formula I; as such, they constitute a part of this invention.
The products of formula I, wherein R 3 is dialkylamino or a nitrogen containing heterocyclic group, can be prepared by reacting a compound of formula V, wherein R' 3 is dialkylamino or a nitrogen containing heterocyclic group, with an acid or sulfonyl halide, preferably an acid or sulfonyl chloride, having the formula VI
R.sub.2 --Cl VI
or, when R 2 ##STR7## an acid anhydride having the formula ##STR8## can also be used. The reaction can be run in an organic solvent, e.g., a halogenated hydrocarbon such as chloroform.
The products of formula I, wherein R 3 is alkylamino, can be prepared by first reacting a compound of formula V, wherein R' 3 is alkylbenzylamino, with a compound of formula VI or VII as described above to yield an intermediate having the formula ##STR9## Debenzylation of a compound of formula VIII using the well-known catalytic hydrogenation procedure yields the corresponding product of formula I.
Those products of formula I wherein the R 2 group contains an amino substitutent are preferably prepared by reduction of the corresponding nitro compound.
The pharmaceutically acceptable salts of the compounds of formula I are readily prepared using procedures well known in the art. Acid addition salts are specifically contemplated. Exemplary salts are the hydrohalides, sulfate, nitrate, phosphate, oxalate, tartrate, maleate, citrate, benzenesulfonate, and others.
The compounds of formula I, and the pharmaceutically acceptable salts thereof, can be used for the treatment of inflammation in mammalian species such as mice, dogs, cats, monkeys, etc. Joint tenderness and stiffness (in conditions such as rheumatoid arthritis) are relieved by the compounds of this invention. Formulation of the compounds can be carried out according to accepted pharmaceutical practice in oral dosage forms such as tablets, capsules, elixirs or powders, or in injectable form in a sterile vehicle. The compounds of this invention can be administered in amounts of about 0.1 to 2.0 grams per 70 kilograms of animal body weight per day, preferably about 0.1 to 1.0 gram per 70 kilograms of animal body weight per day.
The following examples are specific embodiments of this invention.
EXAMPLE 1
[[[2-[3-(Dimethylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl)amino]acetic acid, ethyl ester, oxamate salt (1:2)
(A) [[[2-[3-(Dimethylamino)propoxy]phenyl]methylene]amino]acetic acid, ethyl ester
A stirred solution of 15 g of 2-(3-dimethylaminopropoxy)benzaldehyde and 10.2 g of glycine, ethyl ester, hydrochloride in 300 ml of ethanol is treated with 4.8 g of 85% potassium hydroxide and stirring continued for 3 hours at room temperature. Potassium chloride is filtered off, washed with ethanol, and the solvent is removed on a rotary evaporator (water bath temperature, 30°-35° C.). The residue is dissolved in ether, filtered, and the evaporation repeated to give 20.9 g of an oil. The material is stored in the cold.
(B) [[[2-[3-(Dimethylamino)propoxy]phenyl]methyl]amino]acetic acid, ethyl ester
A stirred solution of the above Schiff base (20.8 g) in 250 ml of ethanol is cooled to 20° C. and treated portionwise with 8.3 g of sodium borohydride. After stirring at room temperature for 4 hours (temperature kept at less than 30° C.), the bulk of ethanol is removed on a rotary evaporator and the cooled residue is shaken with 50 ml of water and 100 ml of ether. The layers are separated, the aqueous phase extracted with additional ether (four 100 ml portions), the combined ether layers washed with water (30 ml), dried, and the solvent evaporated to give 17.3 g of an oily residue. Distillation yields 12.1 g of an oil; boiling point 154°-160° C./0.2-0.3 mm of Hg.
(C) [[[2-[3-(Dimethylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl)amino]acetic acid, ethyl ester
The above amine (17.2 g) and 10.0 g of cinnamoyl chloride are reacted in 240 ml of chloroform by first cooling a stirred solution of cinnamoyl chloride in chloroform to 15° C. and then treating the solution dropwise with a solution of the amine in chloroform. A cold water bath is used to maintain the temperature at 10°-15° C. After stirring for about an hour at room temperature, the solution is heated at reflux for an additional hour. The solution is cooled and the chloroform evaporated.
The semi-solid residue is converted to the oily base by treatment with potassium carbonate in water, and extraction into ether to yield 22.7 g of base. The base is chromatographed on 500 g of Woelm basic alumina (Activity III), and eluted with a total of 2 liters of chloroform to yield 15.3 g of base.
(D) [[[2-[3-(Dimethylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl)amino]acetic acid, ethyl ester, oxamate salt (1:2)
The above base (15.3 g) and 6.4 g of oxamic acid are dissolved in 100 ml of warm methanol, filtered, and diluted to cloudiness with ether. On scratching and rubbing, the crystalline salt gradually separates. More ether is added and after cooling for about 16 hours, the material is filtered, washed with ether, and dried in vacuo, yielding 19.1 g of material; melting point 103°-105° C. (sintering at 100° C.). Following crystallization from methanol-ether, the product weighs 16.5 g; melting point 105°-107° C. (sintering at 102° C.).
EXAMPLE 2
N-(2-Amino-2-oxoethyl)-N-[[2-[3-(dimethylamino)propoxy]phenyl]methyl]-3-phenyl-2-propenamide, hydrochloride (1:1)
(A) 2-[[[2-[3-(Dimethylamino)propoxy]phenyl]methylene]amino]acetamide
Fifteen grams of 2-(3-dimethylaminopropoxy)benzaldehyde and 8.1 g of glycinamide, hydrochloride are reacted in 300 ml of ethanol in the presence of 4.8 g of 85% potassium hydroxide as described in Example 1 to give 20 g of a crude semi-solid product. The crude product is triturated with 100 ml of isopropyl ether and cooled to yield 17.9 g of solid; melting point 71°-73° C. (sintering at 60° C.).
(B) 2-[[[2-[3-(Dimethylamino)propoxy]phenyl]methyl]amino]acetamide
The above Schiff base (17.3 g) is reduced with 7.6 g of sodium borohydride in 140 ml of methanol as described in Example 1 to give 15.7 g of a viscous oil. The corresponding dioxalate salt has a melting point of 167°-169° C.
(C) N-(2-Amino-2-oxoethyl)-N-[[2-[3-(dimethylamino)propoxy]phenyl]methyl]-3-phenyl-2-propenamide, hydrochloride
The above amine (7.4 g) and 5.0 g of cinnamoyl chloride are reacted in 80 ml of chloroform as described in Example 1 (addition carried out at 10°-15° C.). The colorless solid product which separates during the reflux period is cooled, filtered, washed with chloroform and with ether, and dried in vacuo to yield 5.7 g of material; melting point 190°-192° C. The chloroform-ether liquor is evaporated to give 6.8 g of sticky foamy residue which when shaken with water and ether, basified with potassium carbonate, separated, and further extracted with ether, yields 2.4 g of a viscous oil. The latter gives an additional 0.9 g of the title hydrochloride salt (melting point 190°-192° C.) when treated in 20 ml of acetonitrile with an equivalent of alcoholic hydrogen chloride. The two fractions are combined and 6.3 g of material is crystallized from 400 ml of acetonitrile. The final yield of product is 5.4 g; melting point 192°-194° C.
EXAMPLE 3
[(4-Chlorobenzoyl)[[2-[3-(dimethylamino)propoxy]phenyl]methyl]amino]acetic acid, ethyl ester, barbiturate salt (1:2)
Twenty-one grams of [[[2-[3-(dimethylamino)propoxy]phenyl]methyl]amino]acetic acid, ethyl ester (see Example 1B) and 13 g of p-chlorobenzoyl chloride are reacted in 300 ml of chloroform as described in Example 1 to give 25.5 g of a viscous oil. The latter is chromatographed on 500 g of Woelm basic alumina (Activity III). The desired base (13.9 g) is eluted with a total of 1 liter of chloroform.
The base (13.5 g) and 8.0 g of barbituric acid are dissolved in 500 ml of boiling methanol, filtered while hot, and the solvent removed on a rotary evaporator. The solid residue is rubbed under ether (the evaporation is repeated), triturated with 200 ml of boiling acetonitrile, and cooled for about 16 hours to give 16.8 g of material; melting point 186°-190° C. (sintering at 160° C.). Following recrystallization from 1.5 l of acetonitrile containing 35 ml of dimethylformamide, the solid weighs 14.5 g; melting point 190°-193° C. (sintering at 166° C.).
EXAMPLE 4
N-(2-Amino-2-oxoethyl)-4-chloro-N-[[2-[3-(dimethylamino)propoxy]phenyl]methyl]benzamide, hydrochloride (1:1)
Ten grams of 2-[[[2-[3-(Dimethylamino)propoxy]phenyl]methyl]amino]acetamide (see Example 2B) and 7.1 g of p-chlorobenzoyl chloride are reacted in 110 ml of chloroform as described in Example 1. The finely-divided, solid product separates at the end of the addition; crude yield, after standing for about 16 hours at room temperature, 10.2 g; melting point 195°-197° C. dec, sintering at 175° C. Work-up of the mother liquor does not yield any additional product. Following crystallization (of 9.7 g) from 50 ml of warm methanol -100 ml of ether, the material weighs 6.3 g; melting point 198°-200° C., dec, sintering at 175° C.
EXAMPLES 5-22
Following the procedure of Example 1 (without the final salt formation), but substituting the compound listed in column I for 2-(3-dimethylaminopropoxy)benzaldehyde, the compound listed in column II for glycine, ethyl ester, hydrochloride, and the compound listed in column III for cinnamoyl chloride, yields the compound listed in column IV.
__________________________________________________________________________ Column I Column II Column III Column__________________________________________________________________________ IV(5) 2-(2-diisopropylaminoethoxy)- glycine, methyl ester, phenylacetyl chloride [[[2-[2-(diisopropyl- benzaldehyde hydrochloride amino)ethoxy]phenyl]- methyl] (1-oxo-2-phenyl- ethyl)amino]acetic acid, methyl ester(6) 2-[4-(1-pyrrolidinyl)butoxy]- glycine, ethyl ester, propionyl chloride [[[2-[4-(1-pyrrolidinyl)- 8 benzaldehyde hydrochloride butoxy]phenyl]methyl]- (1-oxopropyl)amino]acetic 5 acid, ethyl ester(7) 3-[2-(1-piperidinyl)ethoxy]- glycine, propyl ester, benzoyl chloride [[[3-[2-(1-piperidinyl)- benzaldehyde hydrochloride ethoxy]phenyl]methyl]- (benzoyl)amino] acetic acetic acid, butyl ester(8) 2-[5-(4-morpholinyl)pentoxy]- glycine, butyl ester, 4-bromobenzoyl chloride [[[2-[5-(4-morpholinyl)- benzaldehyde hydrochloride pentoxy]phenyl]methyl]- (4-bromobenzoyl)amino]- acetic acid, butyl ester(9) 4-[2-(4-ethyl-1-piperazinyl)- glycine, pentyl ester, 3-trifluoromethyl- [[[4-[2-(4-ethyl-1-piperaz inyl) ethoxy]benzaldehyde hydrochloride benzoyl chloride ethoxy]phenyl]methyl]- (3-trifluoromethylbenzoyl) - amino]acetic acid, pentyl ester(10) 2-[3-(4-methyl-1-piperazinyl)- glycine, hexyl ester, 2-methylbenzoyl chloride [[[2-[3-(4-methyl-1-piper- propoxy]benzaldehyde hydrochloride azinyl)propoxy]phenyl]- methyl](2-methylbenzoyl)- amino]acetic acid, hexyl ester(11) 2-(2-dimethylaminoethoxy)- glycine, ethyl ester, 2-methoxybenzoyl [[[2-[2-(dimethylamino)- benzaldehyde hydrochloride chloride ethoxy]phenyl]methyl](2- methoxybenzoyl)amino]- acetic acid, ethyl ester(12) 2-(3-diisopropylamino- glycine, ethyl ester, cyclohexanoyl chloride [[[2-[3-(diisopropyl- propoxy)benzaldehyde hydrochloride amino)propoxy]phenyl]- methyl](cyclohexanoyl)- amino]acetic acid, ethyl ester(13) 2-[4-(1-pyrrolidinyl)butoxy]- glycinamide, hydro- cycloheptanoyl chloride N-(2-amino-2-oxoethyl)- benzaldehyde chloride N-[[2-[4-(1-pyrrolidinyl)- butoxy]phenyl]methyl]- cycloheptanamide(14) 3-[2-(1-piperidinyl)ethoxy]- 2-amino-N,N-diethylacetamide, phenylacetyl chloride N-[2-(diethylamino)-2- benzaldehyde hydrochloride oxoethyl]-N-[[3-]2-(1- piperidinyl)ethoxy]- phenyl]methyl]phenyl- acetamide(15) 2-[3-(4-morpholinyl)propoxy]- 2-amino-N-methylacetamide, 3-(4-chlorophenyl)-2- N-[2-(methylamino)-2- benzaldehyde hydrochloride propenoyl chloride oxoethyl]-N-[[2-[3-(4- morpholinyl)propoxy]- phenyl]methyl]-3-(4- chlorophenyl)-2-propen- amide(16) 2-[3-(4-ethyl-1-piperazinyl)- glycinamide, hydro- 3-(2-methylphenyl)-2- N-(2-amino-2-oxoethyl)- propoxy]benzaldehyde chloride propenoyl chloride N-[[2-[3-(4-ethyl-1- piperazinyl)propoxy]phenyl ]- methyl]-3-(2-methylphenyl) - 2-propenamide(17) 3-[2-(4-methyl-1-piperazinyl)- glycinamide, hydro- 3-(2-methoxyphenyl)- N-(2-amino-2-oxoethyl)- ethoxy]benzaldehyde chloride 2-propenoyl chloride N-[[3-[2-(4-methyl-1- piperazinyl)ethoxy]- phenyl]methyl]-3-(2- methoxyphenyl)-2-propen- amide(18) 3-(2-dimethylaminoethoxy)- glycinamide, hydro- 3-(3-trifluoromethyl- N-(2-amino-2-oxoethyl)- benzaldehyde chloride phenyl)-2-propenoyl N-[[3-[2-(dimethylamino)- chloride ethoxy]phenyl]methyl]- 3-(3-trifluoromethyl- phenyl)-2-propenamide(19) 4-(2-dimethylaminoethoxy)- glycinamide, hydro- propionyl chloride N-(2-amino-2-oxoethyl)- benzaldehyde chloride N-[[4-[2-(dimethylamino)- ethoxy]phenyl]methyl]- propionamide(20) 2-(2-dimethylaminoethoxy)- 4-aminobutyramide, benzenesulfonyl chloride N-(4-amino-4-oxobutyl)-N- benzaldehyde hydrochloride [[2-[2-(dimethylamino)- ethoxy]phenyl]methyl]ben- zenesulfonamide(21) 3-(2-dimethylaminoethoxy)- 3-aminopropionamide, methanesulfonyl chloride N-(3-amino-3-oxopropyl)- benzaldehyde hydrochloride N-[[3-[2-(dimethylamino)- ethoxy]phenyl]methyl]- methanesulfonamide(22) 4-(2-dimethylaminoethoxy)- 3-aminopropionic acid, propionyl chloride [[[4-[2-(dimethylamino)- benzaldehyde methyl ester, hydro- ethoxy]phenyl]methyl]- ch loride (1-oxopropyl)amino ]pro- pionic acid, methyl__________________________________________________________________________ ester
EXAMPLE 23
[[[2-[3-(Methylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl)amino]acetic acid, ethyl ester, oxamate salt (1:2)
A. [[[2-[3-(N-Benzyl-N-methylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl)amino]acetic acid, ethyl ester, oxamate salt (1:2)
Following the procedure of Example 1, but substituting 2-[3-(N-benzyl-N-methylamino)propoxy]benzaldehyde for 2-(3-dimethylaminopropoxy)benzaldehyde, yields the title compound.
B. [[[2-[3-(Methylamino)propoxy]phenyl]methyl](1-oxo-3-phenyl-2-propenyl]amino]acetic acid, ethyl ester, oxamate salt (1:2)
A suspension of 10 parts of material from part A in 100 ml of ethanol is treated with 1 part of 5% palladium on carbon and placed under 3 atmospheres of gaseous hydrogen and shaken until 1 equivalent of hydrogen is consumed. The mixture is filtered to remove the catalyst and the solvent is evaporated under reduced pressure to yield the title compound.
EXAMPLE 24
[[[2-[3-(Dimethylamino)propoxy]phenyl]methyl][1-oxo-3-(4-nitrophenyl)-2-propenyl]amino]acetic acid, ethyl ester, oxamate salt (1:2)
Following the procedure of Example 1, but substituting 3-(4-nitrophenyl)-2-propenoyl chloride for cinnamoyl chloride, yields the title compound.
EXAMPLE 25
[[[2-[3-(Dimethylamino)propoxy]phenyl]methyl][1-oxo-3-(4-aminophenyl)-2-propenyl]amino]acetic acid, ethyl ester, oxamate salt (1:2)
A suspension of 10 parts of [[[2-[3-(dimethylamino)propoxy]phenyl]methyl][1-oxo-3-(4-nitrophenyl)-2-propenyl]amino]acetic acid, ethyl ester, oxamate salt (1:2) in 100 ml of ethanol is treated with 1 part of 5% palladium on carbon and placed under 3 atmospheres of gaseous hydrogen. The mixture is shaken until one equivalent of hydrogen is consumed, filtered and the solvent evaporated under reduced pressure to give the title compound.
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Compounds having the formula ##STR1## and the pharmaceutically acceptable salts thereof, wherein R 1 is alkoxycarbonyl, amido or substituted amido; R 2 is acyl or sulfonyl; R 3 is alkylamino, dialkylamino or a nitrogen containing heterocyclic group; A 1 is an alkylene group having 2 to 5 carbon atoms; and n is 1, 2 or 3; have antiinflammatory activity.
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This application is a continuation of Ser. No. 08/747,549 filing date Nov. 12, 1996, now U.S. Pat. No. 5,775,191, which is a continuation of Ser. No. 250,797 filing date May 27, 1994, now U.S. Pat. No. 5,572,940.
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for producing finished sewn products from a roll of cloth. More particularly, the method and apparatus pertains to cutting predetermined lengths of fabric from a large roll of fabric and then performing various sewing operations on the fabric to produce articles such as lined drapes, sheets, valances, etc.
Heretofore, one of the major expenses in producing valances was cutting lengths of fabric to precise lengths and then sewing folded hems on the edge of the fabric prior to performing additional sewing operations. Such has been time consuming and labor intensive adding considerable cost to the finished products.
OBJECTS AND SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide a method and apparatus for efficiently cutting fabric into predetermined lengths and automatically performing sewing operations thereon.
Another important object of the present invention is to provide a method and apparatus for automatically cutting fabric from a large roll and then automatically folding the edges of the fabric. The folded edges are then sewn into hems, and the fabric is transported to a folding station. After the fabric has been folded at the folding station, it is then transported to another sewing station for performing sewing operations thereon.
Still another important object of the present invention is to provide an efficient and automatic system for folding and sewing sheet material.
Still another important object of the present invention is to provide an efficient method and apparatus for automatically producing sewn valances from a roll of cloth.
Still another important object of the present invention is to provide an apparatus and method for automatically producing hemmed fabric for subsequent manufacture into drapes and the like.
Still another important object of the present invention is to provide a method and apparatus for cutting fabric in predetermined lengths, folding the edges of the fabric to produce precise hems and then transporting said fabric to a receiver.
A further object of the present invention is to provide a method and apparatus for precisely folding fabric of a predetermined length into a desired folded pattern for subsequent sewing.
Still another important object of the invention is to provide a method and apparatus for automatically sewing sockets and pockets into a folded fabric to produce valances.
Additional objects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the apparatus of the present invention comprises a let off device which carries a large roll of fabric that is to be used for producing the finished product. The fabric is unwound by the let off device which is under the control of a dancer so as to maintain uniform tension in the fabric as it leaves the let off device. The open fabric then passes under a pair of spaced edge cutters which trim opposed edges of the fabric to a predetermined width.
After the fabric has been trimmed, the edges of the fabric are folded in by a hem forming and hem width control device. The folded edge of the fabric is maintained at a precise location by means of a photoelectric sensor and a hem shifting device. The photoelectric sensor includes a pair of laterally spaced photosensors which generate signals indicating when the edge of the fabric is at the precise location in between the two photodetectors. The photodetectors in turn control the hem shifting device to keep the edge of the hem properly aligned. After the hem has been folded onto the edges of the open cloth, the hem then passes through a curling device which curls the outer edge of the hem under so as to produce a double layer hem. This curl portion is then passed under a sewing head which advances the cloth and sews the hem into the edges of the fabric. The fabric is then fed into an accumulator which accumulates a predetermined length of fabric.
Following the accumulator is a length cutter which makes a transverse cut across the fabric to cut the fabric into predetermined lengths.
In order to cut the fabric into predetermined lengths, a cloth puller moves from the downstream end of the machine to adjacent the cutting head for gripping the edge of the fabric in order to pull the fabric from the accumulator when the cloth puller is moved back towards the downstream end of the machine. After the cloth puller pulls the cloth back towards the end of the machine, a predetermined length of cloth rests on a folding table and is ready for being folded into a desired pattern. In one particular embodiment, the apparatus is used for making valances. At the folding table it is desired to fold the open fabric so that it can be subsequently sewed with elongated stitching to produce the final product.
In order to fold the open length of fabric on the folding table, a pair of spaced dies are lowered down on top of the fabric. The dies are spaced a distance that corresponds to the ultimate width of the valance.
Once the dies are lowered onto the fabric carried on the folding table, the cloth puller which is still gripping the leading edge of the fabric is moved back towards the front end of the machine, folding the fabric over a first die. It then releases the leading edge of the cloth and moves back adjacent the end of the machine. The trailing edge of the cut cloth is then folded up over the second die and overlaps the edge of the cloth that was previously folded.
The cloth in this folded position is then transported to a sewing station wherein two sewing heads are provided for sewing a pair of elongated spaced stitching so as to form a socket in the folded fabric for receiving a curtain rod as well as a pocket in the fabric. This completes the construction of the valance.
The apparatus and machine can also be used for producing lined draperies. When being used to produce lined draperies, a second roll of fabric is carried on a second let off above the first let off which carries the facing layer of fabric. The fabrics are superimposed on each other under uniform tension. The superimposed liner and facing are then passed through the cutting and hem forming device as described above. The cloth puller is used for pulling the sewn liner and facing from an accumulator so that they can be cut to a desired length.
The folding operation discussed above takes place in a similar but wider spaced configuration when producing lined draperies.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the embodiments of the invention and together with the description, serve to explain the principle of the invention.
It is to be understood that the invention is made up of a plurality of various elements. It is understood of course that equivalent components could be substituted for the elements shown in the drawings and described hereto in the specification without departing from the spirit or scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view illustrating a portion of a machine constructed in accordance with the present invention.
FIG. 2 is an enlarged perspective view illustrating a cutting head used for cutting the edge of a fabric.
FIG. 3 is an enlarged perspective view illustrating an edge folding and positioning device.
FIG. 4 is an end view of the edge aligning and locating device.
FIG. 5 is an elevational view illustrating one of the sewing machines used for sewing the hem on one side of the fabric.
FIG. 6 is a sectional view illustrating the curl and double folded hem produced on the edge of the fabric.
FIG. 7 is an elevational view illustrating a sewing head positioned on the opposite side of the fabric from the sewing head of FIG. 5 .
FIG. 8 is an enlarged perspective view illustrating one of the sewing heads used for sewing the hems into the fabric.
FIG. 9 is a perspective view illustrating another embodiment of the sewing head of FIG. 8 .
FIG. 10 is a perspective view of a movable cutter which is used for cutting the cloth into predetermined lengths.
FIG. 11 is an enlarged perspective view illustrating the cutter head from part of the cutter of FIG. 10 .
FIG. 12 is a cross-sectional view of a movable gripping head carried on the cloth puller shown in more detail in FIG. 21 .
FIG. 13 is an end view partially in section illustrating a portion of the folding table and the cloth pulling mechanism.
FIG. 14 is an end view illustrating the cloth pulling mechanism in a position immediately prior to gripping the end of the cloth.
FIG. 15 is an end view partially in section of the cloth pulling mechanism gripping the cloth.
FIG. 16 is an end view of the cloth pulling mechanism after the cloth has been pulled back over the folding table.
FIG. 17 is an end view of the cloth pulling mechanism and the folding table showing the dies being placed down on the cloth.
FIG. 18 is an end view illustrating the folding table and the first fold of the fabric forming a folded valance.
FIG. 19 is an end view illustrating a folding table illustrating the trailing edge of the fabric being folded into a valance.
FIG. 20 illustrates an end view of the folding table showing the fabric in a folded condition immediately prior to being transported to a sewing mechanism.
FIG. 21 is an enlarged fragmentary perspective view illustrating a portion of the cloth pulling device.
FIG. 22 is an enlarged perspective view illustrating a pair of dies used for holding the cloth down on the folding table during the folding operation.
FIG. 23 is a cross-sectional view illustrating a gripping device for gripping and retaining the cloth prior to the cloth being cut into predetermined lengths.
FIG. 24 is an enlarged perspective view illustrating the folded cloth on the folding table prior to sewing.
FIG. 25 is a fragmentary perspective view illustrating part of the cloth processing apparatus.
FIG. 26 is a plan view illustrating a final sewing station for sewing valances.
FIG. 27 is a perspective view illustrating a valance that was sewn automatically on the apparatus of the present invention.
FIG. 28 is a perspective view with parts broken away for the purpose of clarity illustrating a sewn valance.
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in more detail to the drawings, FIG. 1 is a side elevational view of the machine which is provided for hemming and cutting predetermined lengths of material from a large roll of material 10 . The large roll of material 10 is carried on a let off A. The let off A includes a pair of idle rollers 14 and 16 which permit the roll 10 of cloth to be rotated when it is pulled by a power driven roll 18 which has a friction covering thereon. The power driven roll 18 is driven by an electric motor 20 . The motor is a variable speed driven motor which is under control of a dancer roll 22 . The dancer roll 22 is permitted to move up and down responsive to variations in tension in the cloth extending therearound. As the dancer roll 22 moves up and down, it varies the adjustment on a potentiometer that in turn varies the voltage applied to the motor drive board for varying the let off speed for the cloth. The cloth 24 is then fed from the let off A up over a guide roll 26 onto a sewing table 28 . As the cloth enters the sewing table, it first passes through an edge cutting device B. There are two edge cutters B spaced on opposite sides of the table so as to cut the cloth to a predetermined width. The cloth then moves under an edge folding and positioning station C which forms a fold of a predetermined width in the edge of the cloth. This occurs on one or both sides of the cloth.
From the edge folding and positioning station C, the cloth is then fed to a hem folding mechanism D which folds the hem into a double fold. From the hem folder D, the cloth is then fed under to a hem sewing head and cloth advancer E for sewing the hem into the edge of the cloth.
The cloth is fed from the hem sewing head and cloth advancer E into an accumulator F which accumulates a cloth reserve. The cloth passes around an adjustable tension roll 30 provided in the accumulator and from the roll 30 proceeds up onto a cutting table.
Provided on the cutting table is a length cutter G which cuts the cloth from one side to the other.
The particular length of cloth that is cut at this point is controlled by a cloth puller H. To explain the operation to this point we will take up from the point where the cloth was previously cut. As a result, there is a leading edge of cloth 24 directly under where the transverse cutter blade severed the cloth.
The cloth puller H is brought up from the end of the machine into engagement with the leading edge of the cloth 24 directly under the path of the cutting blade. The cloth puller H then grips the edge of the cloth and pulls it back towards the end of the machine over a folding table 8 . The cloth puller H pulls the cloth a predetermined length. Once the cloth 24 reaches that predetermined length, the cloth puller H is stopped by a proximity switch. The length cutter G then cuts the cloth extending over the table to a predetermined length.
While the cloth is on the folding table, folding dies I are lowered down on top of the cloth. Die lifters J are used for lowering the dies I down onto the cloth and retracting. Later they cycle to raise them up off of the cloth. Once the dies I are put in position on top of the cloth, the cloth puller H is moved back towards the cut edge to fold the leading edge of the cloth over the first folding die. It releases the cloth and retracts back to the end of the machine.
A trailing end folder K is then used for folding the trailing end of the cloth over the other die and other edge of the cloth. Once the cloth is folded, and in this particular instance for making a valance, a cloth hold down bar L is lowered on top of the free edges of the cloth pressing them in contact with a cloth shifter M. The cloth shifter M includes a plurality of drive belts which are supported on the folding table 8 directly beneath the bottom surface of the folded cloth and are in engagement therewith. In particular, the two dies and the cloth hold down bar L press the cloth down into engagement with the cloth shifting belts M.
The folded pattern is then shifted laterally off of the folding table.
As the folded pattern is shifted laterally off of the folding table, the leading edge comes in contact with an edge separating device N (see FIG. 26) which separates the upper edge from the lower edge and feeds it into a hem edge curler O which curls the upper edge inward to form a hem. The curled upper edge then is shifted by the cloth shifter M into engagement with the sewing head of a first sewing machine P. The first sewing machine sews the hem into the folded pattern to produce a pocket in the folded fabric. A second sewing head Q follows the first sewing head P and puts a continuous stitch in the fabric which is laterally spaced from the stitch placed by the first sewing head P so as to sew an elongated socket in the valance which is capable of receiving a curtain rod.
A photocell R is carried by the first sewing head P to sense the leading edge of the folded pattern as it is shifted by the cloth shifter M. At this point in the operation, both of the sewing heads P and Q are operating at the same speed so as to place the same number of stitches per inch in the fabric. However, upon the photosensor R sensing the leading edge of the folded pattern, it causes a signal to be generated that in turn slows down the rate that the cloth shifter is moving the cloth over the table and also slows down the stitching speed of the second sewing machine Q. As a result, the first sewing machine P goes into a tack mode to place more stitches per inch at the leading edge of the folded fabric. The tack mode continues for approximately one inch and then a controller associated with the operation of the sewing station returns the cloth edge shifter M to its original traveling speed and returns the speed of the second sewing head Q to its original speed. At this point in time, the folded fabric continues to be moved under both of the sewing heads P and Q to place a less dense stitch in the main body of the valance. Upon reaching the trailing edge of the folded pattern, the tack mode is again entered into to place more stitches per inch adjacent the trailing edge of the valance. All of this is under control of a controller that is activated by the photocell R. Any suitable controller can be used for synchronizing the operation of the feed of the fabric with the speed of the cloth shifter M and the sewing machine Q.
Before describing in detail the operation of the cloth cutting and sewing apparatus, one's attention is directed to a valance such as shown in FIGS. 27 and 28 that can be produced automatically on the apparatus. As can be seen, the valance 50 is produced from a predetermined length of fabric that is folded over and has a hem 52 sewed along its length. Another seam 54 is sewn longitudinally the length of the valance. As a result, a socket 56 is produced in the valance for receiving the conventional curtain rod holder and a pocket 58 is provided in the valance which can be stuffed with any suitable material to bulk up the valance if desired.
As shown in FIG. 27, when the valance is mounted over a window it has a header portion 60 located directly above the socket 56 through which the curtain rod extends. The valance can be gathered together to any degree to make the final position and design of the valance aesthetically pleasing.
Referring now to FIG. 1, the let off A may be any suitable conventional let off that allows the cloth to be unrolled from a large roll of cloth such as 10 and supplied under a uniform tension to a working table.
One particular cutter B that can be used for cutting an edge 70 off of the cloth is shown in FIG. 2 . It includes a motor 74 which can be energized by any suitable source of power that is in direct engagement with a shaft 76 which carries a rotating cutting disc 78 . As the cloth 24 moves under the disc 78 , it severs the cloth. In order to make the cut produced by the rotating disc cleaner, a carbide block can be placed closely adjacent the lower edge of the blade so that the cloth is severed by the outer edge of the blade pressing against the carbide block. An edge sharpener 80 can be carried adjacent to the cutting edge of the blade for being brought into engagement when desired to sharpen the blade 78 . The blade assembly and motor 74 is mounted on a carriage 80 which can be shifted laterally on a cross-support bar 82 that is in turn supported on the frame 84 of the table. As a result, the width of the cloth can be adjusted by moving the cutting head B laterally onto the cross bar 82 .
As the edge of the cloth 24 is severed by the cutting blade 78 , it then passes between a channel shaped member 86 which maintains the edge of the cloth straight during the severing operation by the blade.
After the cloth passes through the channel shaped member 86 , it is fed to the edge folding and positioning station C. The edge folding and positioning station C is shown in greater detail in FIGS. 3 and 4. The purpose of the edge folding and positioning station C is to properly and uniformly fold both edges of the fabric so that a straight and uniform width hem can be subsequently sewed into the edges of the cloth. The location of the inner edge 90 of the cloth is sensed by a pair of photoelectric sensors 92 and 94 . As long as the edge of the folded cloth is positioned in between the sensors 92 and 94 , no signal is generated to rotate an adjusting wheel 96 . As a result, a uniform width fold is produced in the edge of the cloth for subsequently hemming.
If the width of the fold is too great, then both of the photosensors 92 and 94 will be activated. When such occurs, a signal is generated and fed to an electric motor or any other suitable type motor 98 through conventional control circuitry. When the motor 98 is in turn activated, it rotates the wheel 96 clockwise. This clockwise motion of the wheel 96 causes the edge 90 of the cloth 24 to move outwardly. After a short delay, photosensors 92 and 94 are again activated for sensing the edge 90 of the cloth 24 . If the cloth is not properly aligned at this point, the wheel 96 is rotated further. If inner edge 90 is properly aligned between sensors 92 and 94 , no further adjustments are needed, and wheel 96 assumes a straight path.
If on the other hand the folded edge 90 is not wide enough and does not come between under each of the photosensors 92 and 94 , then the wheel 96 is rotated in the counterclockwise direction similar to as described above to guide the edge 90 of the fabric back between the photosensor cells.
The photosensor cells 92 and 94 include a light source positioned under the fabric and a sensor positioned on a space member. The fabric moves between the light source and the two sensor heads and operates in the conventional manner.
The position of the wheel 96 can be physically adjusted by loosening a screw 100 that is carried within an elongated slot 102 provided in a bracket 104 . The screw extends into a horizontal supporting plate 106 which is in turn carried on top of support block 108 . As can be seen in FIG. 4, the support block 108 is in turn hinged adjacent its lower end through a hinge 110 to a fold forming plate 112 .
The fold forming plate 112 has a vertically extending flange 114 that is in turn fixed to a vertical shaft 116 as shown in FIG. 3 that is in turn carried on a slidable tubular member 118 . The slidable tubular member 118 is carried on a square horizontally extending tubular member 120 . As a result, the horizontal or lateral position of the entire edge folding and positioning station C can be adjusted.
A spring loaded screw 122 extends between the support block 108 and the vertical flange member 114 for applying a predetermined pressure through the wheel to the cloth during its guiding operation. As can be seen in FIG. 4, the entire wheel assembly including the wheel 96 and the motor 98 can be pivoted slightly about the hinge 110 for controlling the pressure asserted on the cloth during the guiding operation.
After the cloth passes under the edge folding and positioning station C, it then moves through a conventional hem edge curler D such as shown in cross-section in FIG. 6 . The hem edge curler D includes a spherically twisted piece of sheet metal 130 that curls the cloth 24 into a double fold adjacent its leading edge 90 such as best shown in FIG. 6 . Such is a conventional hem forming mechanism. Once the fold is placed in the edge of the cloth 24 , it then passes under a hem sewing head and cloth advancer E as shown in FIGS. 5, 7 , 8 , and 9 . At this point on the table, the cloth has been advanced or moved forward by the cloth advancer E.
The hem sewing head 142 is a conventional sewing head that sews the hem into the edge of the cloth once it is folded by the folder D.
Coupled to the shaft 140 of the sewing head 142 is an eccentrically mounted linkage 144 . This linkage in turn is connected off center to a shorter linkage 146 that is in turn carried on a shaft 148 .
During the sewing operation, the upper shaft 140 of the sewing machine runs continuously. As a result of the linkage 144 being eccentrically attached to the shaft, a reciprocating motion is imparted to the linkage member 144 . Such is shown by the arrow 150 in FIG. 8 . This reciprocating motion is in turn imparted to the shaft 148 which has a sprague clutch mounted therein which permits rotation to take place in one direction. The output of the sprague clutch is connected to an advancing roll 152 that engages the surface of the cloth 24 for pulling the cloth through the sewing head and across the table described previously.
The purpose of intermittently pulling the cloth through the sewing head is for not pulling the cloth when the needle is in the cloth. In other words, the material is only pulled when the needle comes out of the cloth. Thus, the feed roll 152 advances the cloth a predetermined distance in synchronicity with the sewing machine. A second roller 154 is positioned in tandem with the drive roller 152 and is in pressure engagement therewith so that when the drive roll 152 is rotated it causes the cloth 24 to be advanced therebetween.
As shown in FIG. 8, the sewing head E is carried on laterally extending guide rails 156 and 158 so that its position can be adjusted for accommodating and sewing cloth of various widths.
As a result of using a sprague clutch to the output of shaft 148 instead of a ratchet, the clutch will give infinitesimal adjustable intermittent forward movement through the cloth as compared to a ratchet which would be controlled by the spacing between the individual teeth. The principle of moving in one direction is analogous to a ratchet operation but by operating through a sprague clutch one can adjust the forward stroke.
In FIGS. 8 and 9, two embodiments of a sewing head and cloth advancer E are shown. In particular, in FIG. 8 the drive roller 152 is located above second roller 154 . In FIG. 9, on the other hand, drive roller 152 is located below the second roller 154 . Either embodiment can be used in the apparatus of the present invention. However, for most conventional sewing heads such as 142 , preferably the drive roller is located below the static roller for smoother operations. Of course, depending upon the equipment used or the particular circumstances, drive roller 152 can be placed in either position.
After the cloth 24 passes under the hem sewing head and cloth advancer E it is then fed into the accumulator F as shown in FIG. 1 . The weight of the roll 30 pulls the cloth down into the accumulator to accumulate a reserve of cloth.
The cloth extends around the bottom surface of the roll 30 and up on top of the length cutting table where a length cutter G has previously severed the cloth. At the cutting table, the cloth is being held in place by means of a brush like member 170 . The brush like member 170 extends entirely all the way across the frame. The angles of its bristles 172 point in the forward direction, in the direction of the cloth, so that the cloth can pass easily thereunder. However, brush member 170 prevents the cloth from being pulled backwards into the accumulator once the edge of the cloth has been severed by the length cutter G.
The length cutter G is shown in greater detail in FIGS. 10 and 11. It includes a cutting head 174 that is propelled back and forth across the cutting table by a gear tooth belt 176 that is driven by a driven pulley 178 . The pulley 178 is driven by a conventional electric motor 180 through a gear box 182 which is shown in broken lines in FIG. 10 so as not to obscure the remaining parts of the drawing. The cutting head is carried on a channel shaped bracket 184 that is in turn attached to the gear tooth belt 176 by means of bolts 186 which extend through a plate 188 . The channel member 184 is in turn attached to a supporting block 190 that has a pair of spaced guide channels 192 and 194 attached thereto. The pair of spaced guide channels are in turn supported on a rail 196 . The guide channels 192 and 194 are made of a self-lubricating material such as high molecular weight polyethylene so that the cutting head can be readily reciprocated back and forth across the machine during the cutting operation.
The timing belt 176 extends around a roller 198 which guides the belt around a geared roller 200 for driving the gear roller 200 . The belt then extends up around another idle roller 202 . As a result, as the belt is driven by the drive roller 178 , the cutting head moves back and forth across the cutting table. As it moves back and forth across the cutting table, the gear roller 200 is rotated. The gear roller 200 is fixed to a shaft 204 . The other end of the shaft 204 has a circular cutting blade 206 secured thereto.
A leaf spring 208 is carried adjacent to the lower end of the cutting head and the blade 206 so that it passes under the cloth during the cutting operation and guides the cloth into engagement with the rotating edge of the blade 206 . A carbide cutting block 210 is positioned adjacent to the bottom edge of the cutting blade 206 so as to make a clean severance of the cloth as the cutting head traverses back and forth across the machine.
The cutting head has a sharpening device 212 mounted thereon so that when a sharpening head 214 is brought into engagement with the rotating blade, it sharpens the edge of the blade at a proper angle.
The guide rail 196 upon which the length cutter G is carried extends entirely across the cutting table and is supported by its ends by any suitable standards.
As shown in FIG. 1, the cloth puller and leading edge folder device H is provided for pulling a predetermined length of cloth from the accumulator across a folding table 8 so that the length of the cloth can be cut by the length cutter G. The cloth puller has a gripping jaw that can be closed over the edge of the cloth that was cut by the length cutter. Once the cloth puller H engages the edge of the cloth, it can be retracted for pulling a predetermined length of cloth from the accumulator F.
The cloth puller H as shown in FIGS. 12 and 21 includes a pivoting gripping jaw 220 that has an upper movable flange member 222 that is hinged at hinge joint 224 that can be pivoted downwardly to a closed position to grip the leading edge of the cloth 24 with a cooperating jaw 226 located therebelow. The gripping jaw has a vertically extending flange 228 connected thereto so that when the flange is pushed forward by a plunger 230 to a vertical position, the gripping jaw 220 will be pushed down to grip the cloth. The plunger 230 is carried on the output of a pneumatically operated cylinder 232 that has a piston 234 extending therefrom. The hinge member 224 is supported on a base plate 236 that is in turn secured to a tubular member 238 . The tubular member 238 is in turn supported on spaced slide blocks 240 constructed of lubricated high molecular weight polyethylene material. Angle members 242 secure the tubular member 238 to the side block 240 . Side blocks 240 are carried on opposite sides of the frame as only one side of the cloth puller H is shown in FIG. 21 . The slide blocks 240 are in turn carried on a tubular rail 244 that is suitably supported on side frame members 246 . The guide blocks 240 have a metal support plate 248 attached to the bottom thereof which are in turn attached to a timing belt 250 . The timing belt 250 extends around spaced driven pulleys 252 . One of the pulleys 252 is supported on a rotatable shaft 254 . The upper end of rotatable shaft 254 has a gear 256 provided thereon. The gear 256 is in turn coupled by a chain 258 to a grip driven gear 260 . The driven gear 260 is coupled to the output of a gear box 262 which has its input connected to a motor 264 . By turning the motor 264 on and off, the gripping jaw 220 can be moved along the guide rail 244 to a position closely adjacent the previously cut end of the cloth for gripping the cloth. Once the gripping jaw 220 is engaged to grip the cloth, it can be retracted to pull a predetermined length of cloth from the accumulator.
A spring 266 extends from a vertically extending portion 228 of the jaw and the slide block 240 to hold the jaws in a normally open position. In order to close the jaw 220 , air is supplied to the pneumatic cylinder 232 to move the piston to the right, as shown in FIG. 12 . When the piston 234 is moved to the right, the plunger 230 engages the vertically extending portion of the upper jaw to pivot it about the hinge 224 to cause the horizontal gripping jaw 222 to move to the closed position where it would engage the cloth.
Before describing the sequence of operation of the pulling head and the folding of the cloth on the folding table, the dies for facilitating the folding of the cloth will be described. The dies include two elongated metal plates 270 and 272 such as best shown in FIGS. 22 and 24. The dies are placed on top of the cloth 24 after the cloth 24 has been pulled onto the folding table 8 . The dies are raised and lowered by lifting devices J. The lifting devices J as shown in FIG. 13 include an electrical magnet 274 carried on the end of a piston rod 276 extending out the lower end of a pneumatically operated cylinder 278 . The die plates are raised and lowered from the lifting table by manipulating the pneumatically operated cylinders 278 . In order to lower the die onto the cloth carried on the table, air is supplied to an upper port of the pneumatic cylinder 278 forcing the piston rod 276 out the lower end of the cylinder. The electromagnet 274 is energized at this time and has the metal die 272 secured thereto. When the die is positioned on top of the cloth, the electromagnet is deenergized releasing the die 272 , and the pneumatic cylinder 278 has air supplied to its lower port for raising the piston with the electromagnet upwardly so as not to interfere with the folding operation.
There are three electromagnets positioned above each of the dies for engaging metal plates 280 carried on the dies.
In order to ensure that the dies are properly positioned on the folding table, a T-shaped attachment 282 is carried on one of the ends of each of the dies. The T-shaped attachment is positioned between three abutments 284 , 286 , and 288 , which properly align the end of the die on the folding table 8 . Aligning members 290 are provided adjacent to the other end of the dies and include a triangular shaped end portion 292 that is rotated into engagement with a V-shaped recess 294 provided on the end of the dies opposite the end where the T-shaped member 282 is carried. The positioning member 290 is carried on the end of an output shaft of a motor 291 that when energized rotates the engaged member 290 from a retracted position such as shown in FIG. 22 to a positioning position wherein the triangular shaped end portion 292 engages the V-shaped slot 294 to properly align the dies. The T-shaped attachments 282 and aligning members 290 maintain the dies 270 and 272 in their proper position during the folding operation as will be described hereinafter.
The entire pulling and folding operation of the fabric will be described below, but it is felt that it is best to describe some of the elements that are to be used in the operation before going through the sequences. Another functional device is the cloth hold down device L. The cloth hold down device L as shown in FIGS. 13 and 25 includes an elongated wooden block 300 that extends across the entire folding table 8 . Positioned adjacent the bottom of the elongated wooden block 300 is a foam pad 302 that has secured to the bottom surface thereof a strip of high molecular weight polyethylene 304 . The elongated block 300 is secured to the lower end of a plurality of pistons 306 that are in turn manipulated by pneumatically operated cylinders 308 . The purpose of the cloth hold down bar L is to hold the cloth flush against the folding table when it is desired to transport the folded cloth pattern laterally to a subsequent sewing station. As a result of the foam pad 302 , the low friction surface 304 is allowed to ride over seams and hems while imparting a substantially uniform pressure all the way across the cloth. The low friction surface 304 permits the cloth to slide under the hold down device when it is being shifted laterally to a subsequent sewing operation.
This sequence of the pulling and cutting of the predetermined lengths of fabric will now be described. First, reference is directed to FIG. 13 which shows on the right, the edge of the cloth 24 located directly under the cutter blade 206 . At this point in time, the cloth puller H is retracted to the end of the machine such as shown in FIG. 13, and the gripping jaw 220 is in an open position. The controller for the machine energizes the drive motor 264 which causes the timing belt 250 to be driven to move the gripping head 220 to the right, to the position shown in FIG. 14 . As the gripping head 220 approaches-the position shown in FIG. 14, a metal member 320 which is carried by the timing belt 250 and which projects laterally beyond the frame of the machine first passes proximity switch 322 as shown in FIG. 25 . At this point in time a signal is generated to slow the motor 264 down. The gripping head 220 continues, however, moving forward until the member 320 is positioned adjacent the proximity switch 324 which generates a signal that is fed back to stop the motor 264 in the position shown in FIG. 14 . Note in FIG. 14 that the dies I are engaged with the electromagnets and are in a raised position so as to permit the gripping head to pass thereunder.
FIG. 15 shows the gripping head 220 lowered to a closed position gripping the leading edge of the fabric 24 .
In FIG. 16, the controller associated with the machine again energizes the motor 264 to retract the puller H with the gripping head in the closed position pulling the cloth 24 out of the accumulator F. As the activating member 320 carried by the gripping head comes adjacent a proximity switch 326 as shown in FIG. 25, the motor slows down and keeps going backwards until it comes adjacent the proximity switch 328 which stops the motor 264 . In this position, the cloth 24 is extended its full length such as shown in FIG. 16 . The proximity switches are adjustable for extending the cloth 24 a predetermined distance.
The next step in the sequence is activating the pneumatic cylinders forming part of die lifters J to lower the dies I down on top of the folding table 8 as shown in FIG. 17 . At this point in time, the electromagnets carried on the end of the pistons associated with the lifting device are deenergized and leave the dies 270 and 272 on top of the extended cloth 24 such as shown in FIG. 22 . The cloth puller and leading edge folder H is again moved back to the right as shown in FIG. 18, and while it is moving to the right, it has the leading edge of the cloth engagement between the gripping jaws. When it reaches the position such as shown in FIG. 18, the jaws of the gripping device 220 are open to release the cloth. As can be seen in FIG. 18, a single fold has been made in the cloth at this time.
A trailing end folder K has an L-shaped angled member 340 carried on the upper end thereof which in turn has the trailing end of the fabric 24 resting on top. By pivoting the trailing end folder in the forward direction, the angle member 340 pushes the trailing edge of the fabric over the die 272 to produce the folded pattern such as shown in FIG. 19 . This folded pattern is now in position for being transported to a sewing station which will sew a hem in the edge of the upper fold and produce two elongated stitch lines along across the width of the entire valance to define a pocket and a socket in the valance.
The next step in the sequence is to lower the cloth hold down bar L onto the folded cloth pattern directly above the ends of the cloth as shown in FIG. 20 . The cloth shifter M, which is in the form of three driven belts 350 , 352 , and 354 , is used for shifting the folded pattern of cloth laterally from the folding table to an adjacent sewing station. The T-shaped attachments 282 carried on the end of the dies 270 and 272 prevent the dies from being moved laterally as the cloth is pulled by the moving belts 350 , 352 , and 354 , off of the folding table into the next sewing station.
As can be seen in FIG. 26, the folded pattern of cloth 24 is carried on the movable belts 350 , 352 , and 354 . The pattern 24 is held down flush against the belts 352 and 354 by spring loaded plates not shown. The upper edge of the cloth 24 engages a first driven belt 360 . Prior to engaging the belt 360 , the folded pattern 24 moves into engagement with an edge separating device N which includes a thin upwardly projecting finger that protrudes between the adjacent folds in the pattern of cloth 24 and feeds the edge of the upper fold into a conventional hem edge curler O which curls the edge under to form a hem.
The hem is then fed towards a first sewing machine P which has a single needle.
The purpose of the first sewing head P is to put a length of stitch across the entire folded pattern and to tack stitches adjacent to the leading edge of the valance and the trailing edge of the valance. A second sewing machine Q follows the first sewing machine, and its purpose is to place a stitch continuously across the entire valance. The second sewing head is offset from the first sewing head so that you have offset stitch lines to define a socket for receiving a curtain rod and a pocket for receiving filler material.
A controller is used for controlling the drive of the sewing machines P and Q as well as the drive for the moving belts 350 , 352 and 354 and the upper belts 360 and 362 .
A photocell R is carried by the first sewing machine P, and it generates a signal indicating that the leading edge of the folded pattern 24 has reached the sewing head. This causes a signal to be sent to the controller which slows down the conveying belts 350 , 352 and 354 and the trailing sewing machine Q. The first sewing machine P continues to sew at its normal rate but since the movement of the fabric under the head has been slowed, more stitches per inch are placed in the leading edge of the folded fabric. This occurs for approximately one inch, depending on the preference of the customer.
The same tacking operation takes place at the trailing edge of the folded fabric. The controller can be set for activating the tacking operation according to the lengths of valances being produced.
After the two elongated stitches have been placed across the valances by the sewing heads P and Q, the thread extending between adjacent valances is cut by a thread cutter 364 , and the valances are moved off the end of the sewing station onto a rotating folder which folds the valances into a rectangular package.
Proper spacing is maintained between the valances being transferred from the folding table 8 to the final sewing station by means of a photocell 370 that is positioned adjacent to the side of the folding table as shown in FIG. 25 . This photocell senses the trailing and leading edges of the folded valances, and activates the controller which starts and stops the conveying and sequencing operation of the machine. Any suitable conventional controller can be used for synchronizing the various conveying and sewing operations taking place.
The apparatus of the present invention can also be adapted to feed two rolls of material simultaneously through the system as can be shown in FIG. 25 . The second or top roll of material is placed on the apparatus when it is desirable to have a liner included with the finished product. As shown in FIG. 25, a roll of fabric 400 is carried on a second let off A′. The let off A′ includes a power driven roll 402 which has a friction covering thereon. Similar to as described above, power driven roll 402 is driven by an electric motor. The motor is a variable speed driven motor. The speed of the motor can be placed under the control of a dancer roll 404 . The dancer roll 404 is permitted to move up and down responsive to variations in tension in the cloth extending therearound. As the dancer roll 404 moves up and down, the voltage applied to the motor drive board is varied for varying the let off speed of the cloth.
However, unlike roll let off A, roll let off A′ further includes a second power driven roll 406 . Preferably, roll 406 is driven by a slip clutch for varying the torque. Power driven roll 406 is added to let off A′ in order to have differential tension on the face fabric in comparison to the liner.
In one embodiment, dancer roll 22 can be set at a particular weight and thus at a constant tension. Dancer roll 404 is then also set at a particular weight. However, by including the second powered roll 406 the tension exerted on the liner 410 can be varied by adjusting the slip clutch engaged with the motor. This adjustment can be made in response to the tension being exerted on the cloth by the sewing heads and cloth advancers E. Once a proper adjustment in the tension of liner 410 is made, the liner 410 and cloth 24 should feed simultaneously and uniformly.
In this arrangement, power roller 406 always applies a continuous torque to liner 410 for placing in equilibrium the rate at which the liner and the cloth are fed to the sewing heads. One type of clutch that can be used in conjunction with the motor used to drive roll 406 is a hysteresis clutch which is well-known in the art. Using a hysteresis clutch, by increasing the voltage, a magnetic field is increased which can be used to vary the torque placed upon roller 406 . Of course, other similar types of clutches can be used in the present invention.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to be limitative of the invention so further described in such appended claims.
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An apparatus and method are provided for converting a roll of material into various products such as curtains, draperies, valances, or the like. Specifically, the apparatus includes a roll let off for supporting and feeding a roll of material or cloth. After the let off, the edges of the cloth are cut if desired and are engaged by a pair of edge folding and positioning stations for forming vertically folded edges. The folded edges are then converted into hems and sewn into the material by a pair of corresponding hem sewing heads and cloth advancers. Once vertical hems are formed in the cloth, the cloth is cut to predetermined lengths and if desired, folded in a predetermined pattern. The folded pattern can then be transported to a sewing station for further sewing the material into a desired product.
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This is a divisional of application Ser. No. 08/041,041, filed Mar. 31, 1993 pending.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to- sheet-like polyethylene terephthalate materials having slight surface roughness, a process for their preparation by exposure of the surfaces to UV radiation produced by the decomposition of excimers and the use of polyethylene terephthalate films treated in this manner as substrate material for ferromagnetic thin metal layers.
The embodiment of sheet-like polyethylene terephthalate material having a defined surface roughness is required for many uses of this material. The roughness generally results in an improvement in the adhesion, for example in adhesive bonds, and in the printability or the wettability. A roughened surface is also advantageous in the stacking of this material or in the winding of corresponding film webs. Polyethylene terephthalate (PET) films having a defined roughness are of considerable importance in particular for the production of magnetic recording media which consist of a polymeric substrate, a coherent, ferromagnetic thin metal layer applied to the surface of the substrate by a PVD (physical vapor deposition) method and, if required, a protective layer formed on the metal layer. The surface roughness of the films ensures little wear of the magnetic layer in the case of tribological stress due to the head. The roughening of the polymer surface also results in an improvement in the adhesion between the polymer and the magnetic layer. In addition, the mechanical and chemical stability of the metal layer set particular requirements for the procedure. However, these problem areas cannot be viewed in isolation, since any optimization of the mechanical properties of the magnetic recording media under discussion must never be achieved at the expense of the magnetic properties, i.e. of the properties relating to information storage.
A reduction in the wear of the magnetic layer due to the tribological stress of the head is achieved, inter alia, by virtue of the fact that direct contact between the head and the metal layer is avoided over its entire, macroscopic contact surface by means of the surface roughness. In order for this effect to be achieved, it is important for the average distance between the protuberances on the surface to be small compared with the dimensions of the macroscopic contact surface of the head. The height of the surface roughness is limited by the fact that, when the roughness has an excessively great height, the magnetic recording and playback properties of the applied layers are poor owing to the attenuation due to distance.
2. Description of the Related Art
Films in which a defined surface roughness is produced by incorporation or application of very small particles of an inert material are being used to date in order to obtain the desired properties of the polymer films for use as substrate material for magnetic thin-layer media (e.g. European Patent 0,153,853). Although these films are suitable, the production of such films requires particular and expensive production techniques.
The other conventional processes for the surface treatment of polymer surfaces in plasma, or by glow discharge, corona discharge, flaming, chemical etching or ion irradiation prior to metallization are never completely satisfactory. Essential aspects here were in particular the inadequate controllability of the energy effect and/or residual gas control and the resulting contamination by decomposition products.
The processes described to date and involving UV irradiation of polymer surfaces with continuous UV lamps, for example mercury vapor lamps, for improving the coat-ability, for improving the printability of polyolefins (U.S. Pat. No. 4,933,123) and for increasing the adhesive strength of adhesives on polyethylene terephthalate films (JP-A 313 850/1989), on the other hand, also results in only an insufficient increase in adhesion in the case of magnetic recording media having coherent metal layers. Owing to the long exposure time to continuous UV lamps, of the order of a few minutes, the process is very time-consuming and does not permit high processing speeds.
Furthermore, it is known that a periodic nub-like or cylindrical structure can be produced on the surface of oriented PET films by exposure to a UV excimer laser (E. Ahrenholz et al., Appl. Phys. A 53 (1991), 330). These structures occur in an energy range in which the laser radiation leads to removal of material (laser ablation). The structures have a typical distance of a few μm and are completely formed only after irradiation of the films with their plurality of pulses (at least 3 or 4). The spacing of the structure as well as the height of the structures increase with increasing energy and number of pulses. The height of these structures may be several μm. Both the height of these structures and the spacing of the structure are generally too large to permit the films treated in this manner to be used as substrates for magnetic thin-layer media.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide sheet-like polyethylene terephthalate materials having a defined but very slight surface roughness and a process which does not have the stated disadvantages and by means of which such surface roughnesses can be produced in a simple manner and without removal of material and which ensure uniformity of the properties even over large areas at high processing speed.
We have found that this object is achieved by sheet-like polyethylene terephthalate materials if the surface roughness consists of dendritic, plateau-like structures having a fissured, fractal edge.
The present invention furthermore relates to a process for the preparation of these sheet-like polyethylene terephthalate materials having the surface roughnesses defined as stated above by exposure of the polyethylene terephthalate material to UV light produced by the decomposition of excimers, in a wavelength range of from 150 to 400 nm. In this procedure, it has proven advantageous to carry out the exposure of polyethylene terephthalate material under reduced pressure and at less than 100° C., preferably less than 60°. The process can also be effected in an atmosphere containing oxygen, nitrogen or argon, provided that the partial pressure is less than 200 mbar in the case of oxygen and nitrogen and less than 1 bar in the case of argon. Up to these partial pressures and at the state temperatures, it is therefore possible to obtain the dendritic, plateau-like structure even in the presence of oxygen, nitrogen or argon. Heating of the material carried out after the production of the dendrite structure has no effect on the resulting structure provided that the polyethylene terephthalate material itself remains stable, and there is no decline in the dendrite structure.
The PET materials defined according to the invention by the surface possessing fine roughness have a homogenous surface density of isolated and discrete projections having the characteristic dendritic structures. These structures possessing a fractal edge are from 2 to 50 nm, preferably from 2 to 30 nm, high and the ratio of circumference to height is greater than 500. The average distance between the branched structures is less than 10 μm, if necessary less than 1 μm, depending on the energy input for their production and on the duration of action. These structures defining the novel materials thus differ considerably, both in their appearance and in their size, from the conventional nub-like or cylindrical structures obtained either by surface treatment of the materials or by UV exposure of the surface by a prior art method.
The present invention has made it possible for PET materials to have the advantages of a roughened surface but not the disadvantages due to global and drastic roughening of the surface according to the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages, details and features of the novel material and of the novel process are evident from the following description, certain embodiments and the Figures.
FIG. 1 shows a novel PET surface having the dendritic, plateau-like structures exhibiting a fissured edge,
FIG. 2 shows the untreated PET surface and
FIG. 3 shows a PET surface altered according to the prior art by exposure to UV light.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The surface shown in FIG. 1 is produced by exposing the PET film to an excimer laser of wavelength 248 nm with a pulse at an energy density of 39 mJ/cm 2 under greatly reduced pressure, while an identical PET film in the same apparatus, as is customary in the prior art, having many pulses at an energy density of 90 mJ/cm 2 leads to a surface having nubs, as shown in FIG. 3.
The radiation used for the novel process and based on the decomposition of excimers, for example of the excimer laser or of the incoherent excimer lamp, is known. The suitable wavelengths are from 150 to 400 mm, the KrF laser having a wavelength of 248 nm and the XeCl laser having a wavelength of 308 nm being particularly preferred. Depending on the chemical composition and on the incident wavelength, the surface of the PET material is exposed to 1-25, preferably 1-3, pulses/area at an energy density of from 1 to 1,000, preferably from 20 to 90, in particular, for example in the case of the KrF laser, from 30 to 70, mJ/cm 2 . When they are used for the novel process, the repetition rate of the lasers is from 1 to 1,000 Hz and suitable pulse lengths are from 10 to 100 ns.
The PET materials defined according to the invention and the surfaces having fine roughness and obtained by the novel process are used in connection with the conditioning of PET films. They furthermore have a standard surface possessing uniform properties.
PET films of this type are very useful in particular as substrate material for the production of magnetic recording media which have a coherent ferromagnetic thin metal layer as the magnetic layer. These metal layers are applied to the substrate material with the aid of PVD methods, the form of the surface of the substrate material being a substantial, quality-determining factor for the adhesion of the layer to the substrate and for the wear of the layer under tribological stress due to the head.
Regarding the use of the novel PET materials, the production of these magnetic thin-layer media will be described by way of example. PET substrates used as film webs are exposed to an appropriate excimer laser by the novel process of UV exposure. The coherent ferromagnetic thin metal layer is then applied by a known procedure to a substrate pretreated in this manner. Suitable metal layers are in general cobalt-containing ones, for example Co-Ni-Cr, Co-Pt, Co-Ni-O and Co-Cr. Cobalt-chromium layers containing from 15 to 35 atom % of Cr, cobalt-nickel layers containing more than 10 atom % of nickel or cobalt-nickel-oxygen layers containing more than 10 atom % of nickel and from 3 to 45 atom % of oxygen are preferred. However, corresponding thin metal layers based on iron are also known and used. These layers are produced with the aid of a PVD method, for example by vaporization, electron beam vaporization, sputtering, ion plating or application of layers for metal components by the arc method. Vapor deposition and sputtering are preferred. The ferromagnetic metal layers produced in this manner are from 20 to 500 nm thick. In the case of lower layers, layer thicknesses of from 2 to 300 nm are preferred. The thickness of protective layers for improving the abrasion resistance and corrosion resistance is from 1 to 100 nm. The application of the carbon layer, the surface oxidation of the metal layer, coating with liquid oligomers generally based on fluorine-containing polyethers, the formation of oxides, nitrides or carbides of silicon, of zirconium, of hafnium and of titanium or combinations of these measures are known here.
The magnetic recording media obtained using the novel PET materials or the novel process exhibit high adhesion of the metal layer to the polymer film and a reduction in friction as well as an improvement in the still picture behavior. This is illustrated by the Examples which follows.
In general, in the novel process for the production of the specific surface having fine roughness on the PET material, the toughening by the UV exposure is carried out in a single process step, and only the surface of the film is altered while the remainder of the film is not damaged. Treatment of the structured PET material, in particular after heating, with, for example, alcohols or acetone has no effect on the surface structure. On the other hand, the dendrite structures can be removed by means of chloroform with the formation of a grainy surface, the surface of the PET material exhibiting indentations whose shape corresponds to the appearance of the dendrites. Owing to the use of smaller amounts of energy and an excimer laser having a small number of pulses, it is possible to expose large areas uniformly with a higher throughput.
Where the novel process is used for the production of magnetic thin-layer media, it is also advantageous that the production of the surface roughness of the PET films can be carried out directly before a further processing step, for example the application of a ferromagnetic thin metal layer, in one and the same process chamber. Such an in situ pretreatment ensures that aging or soiling of the roughened surface does not occur and, since the radiation source is mounted outside the process chamber, easy controllability and monitoring of the substrate pretreatment process are ensured.
EXAMPLE 1
Improvement of the adhesion
In a commercial vapor deposition unit, 200 nm thick Co 80 Ni 20 layers are applied under greatly reduced pressure to 50 μm thick PET films (Mylar film from DuPont) using an electron beam evaporator. The PET films were either subjected to no pretreatment prior to vapor deposition or were exposed, in the vapor deposition unit, through a quartz window, to an excimer laser at a wavelength of 248 nm with energy densities of from 30 to 50 mJ/cm 2 and from 1 to 3 pulses.
For each of the samples obtained, the peel force was determined in a peel test (inverse 180° EAA peel test; Y. De Puydt, P. Bertrand, P. Lutgen, Surf. Interface Anal. 12 (1988), 486; P. Phuku, P. Bertrand, Y. De Puydt, Thin Solid Films, 200 (1991), 263). It was found that an unexposed sample had an adhesion of 0.9 N/cm whereas the exposed samples had a peel force of at least 3.5 N/cm.
EXAMPLE 2
Reduction of friction
Superquasistatic friction (SQF):
200 nm thick (Co 80 Ni 20 ) 80 O 20 layers were applied by vapor deposition to Mylar PET films (50 μm) which had been pretreated in situ beforehand in a vacuum chamber by UV exposure under reduced pressure to a KrF excimer laser (248 nm) with from 1 to 3 pulses at energy densities of from 29 to 40 mJ/cm 2 . In the measurement of the SQF coefficient (after a grinding-in phase in which the test specimen was drawn over 50mm of the layer at 550 μm/sec, followed by the actual measuring phase in which the test specimen was moved over the following 5 mm of the layer only at the very low advance speed of 13 μm/sec), the fluence showed a clear trend, i.e. the SQF coefficient μ' decreased with increasing fluence. FIG. 4 shows the results of the measurements for the untreated film A in comparison with the films B and C exposed to 28.9 mJ/cm 2 and 39.3 mJ/cm 2 , respectively.
Sliding friction:
The conventional coefficient μ of sliding friction was measured for the same abovementioned layers (WC sphere, diameter d=6 mm, advance speed 1 cm/min). In all cases, a significant reduction in the coefficient of sliding friction is found in comparison with the unexposed parts of the same sample (FIG. 5).
EXAMPLE 3
Improvement of the wear behavior
To evaluate the effect of UV pretreatments on the tribological properties, still picture measurements were carried out for Co-Ni-O layers on pretreated Mylar films. First a signal (10 kfci) was recorded on the medium and then the decrease in output level with time was monitored on a drum tester in which the fixed head was in contact with the clamped circular medium rotating beneath it. A read signal decreasing monotonically with time was recorded until the magnetic layer had been rubbed away completely down to the film and a read signal was no longer detectable. Mylar 200D PET films (inner surface) were pretreated at 248 nm by means of an excimer laser and then coated with a 200 nm Co-Ni-O layer by vapor deposition. The laser fluences chosen were 30, 40 and 59 mJ/cm 2 , and exposure was carried out in each case from 1 to 3 pulses. The Co-Ni-O layers had the following structure: first a 180 nm thick layer containing about 15% of oxygen and then a 20 nm thick layer containing about 40% of oxygen. The layers were lubricated with Fomblin Z-DOL and were subjected to the still picture test. Compared with unexposed reference samples, the lives in stop motion were longer and the drop in output level considerably smaller. Considerably more revolutions are possible on exposed surfaces than on the unexposed surfaces of the same sample until the layer has been completely rubbed through.
While lives in stop motion of only a few minutes or less were often observed until complete disappearance of the output, lives in stop motion of several hours could be achieved on exposed surfaces. The read signal on the exposed surfaces was greater than on the non-pretreated surfaces in all cases. Optical micrographs showed flaking of the magnetic layer on unexposed surfaces along the head track. Extensive delamination of the layer frequently occurred, particularly at the edge of the track, where particularly high shear forces act and the layers are subjected to high stresses. This destruction made the medium completely useless, and the output level dropped abruptly to zero. On exposed surfaces, abrasion was substantially less and no signs of mechanical damage or destruction of the layer along the head track were found under the optical microscope.
Owing to the improved adhesion of the layer, the medium withstood far greater shear forces at the interface, and the lower friction reduced the stress field and led to less force being applied during the tribiological stress due to the head.
This shows that the fine roughness in the form of dendritic structures, produced on the surface of PET by UV exposure, leads to improved still picture behavior, whereas the untreated smooth films tend to stick owing to the large contact area with the head, with the result that the layer is rapidly destroyed and they therefore have completely inadequate wear properties.
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Sheet-like polyethylene terephthalate materials having slight surface roughness consisting of dendritic, plateau-like structures having a fissured, fractal edge, a process for their preparation by exposing the surfaces to UV radiation produced by the decomposition of excimers, and the use of polyethylene terephthalate films treated in this manner as a substrate for ferromagnetic thin metal layers.
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BACKGROUND OF THE INVENTION
[0001] (a) Field of the Invention
[0002] This invention relates a new therapy for the treatment of neurodegenerative diseases, this new therapy delaying the onset of the disease and increasing the survival time of the subject.
[0003] (b) Description of Prior Art
[0004] Amyotrophic lateral sclerosis (ALS) is a late onset neurodegenerative disease characterized by progressive muscle weakness, muscle atrophy and eventual paralysis, leading to death within 2-5 years (Julien, J.-P. (2001) Cell 104, 581-591; Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699). The disease occurs in both sporadic and familial forms with highly similar clinical courses. Familial forms of ALS (FALS), being inherited in an autosomal dominant pattern, make up ˜10% of all ALS cases. In 20% of FALS, missense mutations have identified in the gene coding for superoxide dismutase 1 (SOD1). Transgenic mice overexpressing SOD1 mutants linked to FALS develop progressive motor neuron disease with many pathological features observed in both familial and sporadic ALS cases (Julien, J.-P. (2001) Cell 104, 581-591; Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699; Wong, P. C., et al. (1995) Neuron 14, 1105-1116). Yet, the mechanism of SOD1-mediated, as well as the sporadic form of disease is not fully understood. The current view is that the motor neuron death in ALS is complex and may involve multiple pathways including formation of protein aggregates, proteosome dysfunction, axonal transport defects, oxidative damage, mitochondrial defects, alterations in calcium homeostasis, caspase activation, and changes in levels of Bcl-2 members. In addition, excitotoxicity due to astrocyte dysfunction, impaired glutamate transport or altered glutamate receptor function, and inflammatory processes from microglia activation are other factors likely to be involved in the propagation of the neurodegenerative process (Rothstein, J. D., et al. (1995) Ann. Neurol. 38, 73-84; Almer, G., et al. (1999) J. Neurochem. 72, 2415-2425).
[0005] At the present, there is no effective pharmacological treatment for ALS. The only currently approved therapy, the antiglutaminergic agent riluzole, has been shown to have only a marginal survival benefit (Julien, J.-P. (2001) Cell 104, 581-591; Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699). In two clinical trials, riluzole prolonged survival by three to six months (Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699). When tested in transgenic animals with mutant SOD1, riluzole extended survival by 13-15 days with no significant effects on the onset of disease (Gurney, M. E., et al. (1996) Ann. Neurol. 39, 147-157).
[0006] Recently, several reports showed that minocycline, a second-generation tetracycline, can exhibit biological effects completely distinct from its antimicrobial action (Yrjänheikki, J., et al. (1998) Proc. Natl. Acad. Sci. USA 95, 15769-15774; Yrjänheikki, J., et al. (1999) Proc. Natl. Acad. Sci. USA 96, 13496-13500; Chen, M., et al. (2000) Nat. Med. 6, 797-801). Thus, in experimental model of cerebral ischemia, minocycline inhibited microglial activation, reduced inflammation and decreased the size of infarct (Yrjänheikki, J., et al. (1998) Proc. Natl. Acad. Sci. USA 95, 15769-15774). It also inhibits caspase-1 and inducible nitric oxide synthase (iNOS) upregulation (Yrjänheikki, J., et al. (1998) Proc. Natl. Acad. Sci. USA 95, 15769-15774; Yrjänheikki, J., et al. (1999) Proc. Natl. Acad. Sci. USA 96, 13496-13500; Chen, M., et al. (2000) Nat. Med. 6, 797-801). Moreover, minocycline was able to delay mortality and to inhibit caspase-1 and -3 upregulation in a mouse model of Huntington disease (Chen, M., et al. (2000) Nat. Med. 6, 797-801). In addition, results of our recent study demonstrated that minocyline inhibits microglial activation and delays mortality in SOD1 mutant mice.
[0007] Numerous studies have suggested that increased intracellular calcium is associated with motor neuron injury. Motor neurons from ALS patients may contain elevated calcium levels due to increased mitochondrial volume. Moreover, many ALS patients have anti-calcium channel antibodies capable to provoke apoptotic cell death in vitro through influx of voltage gated calcium channels (Julien, J.-P. (2001) Cell 104, 581-591; Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699). Thus, blockers of voltage gated calcium might confer benefits. Nimodipine is voltage gated calcium channels blocker that preferentially affects central nervous system (Langley, M. S. & Sorkin, E. M. (1989) Drugs 37, 669-699). Its principal physiological action is to inhibit the influx of extracellular calcium through the voltage-dependent and receptor-operated slow calcium channels in the membranes of myocardial, vascular smooth muscle and neuronal cells.
[0008] It would be highly desirable to be provided with a new therapy delaying the onset of the disease and increasing survival time of a subject suffering from a neurodegenerative disease.
SUMMARY OF THE INVENTION
[0009] There is currently no effective pharmacological treatment for amyotrophic lateral sclerosis (ALS). Since there is growing evidence that multiple molecular pathways underlie ALS pathogenesis, it was tested in a mouse model of ALS a combination therapy composed of three generic drugs for distinct targets in the complex pathway to neuronal death. The ALS mice used for drug testing are derived from a well established mouse line, the SODI G37R line 29 with an average life span of above 48 weeks. The cocktail administered in the mouse diet at late stage of disease consisted of minocycline—an antimicrobial agent that inhibits microglial activation, riluzole—a glutamate antagonist, and nimodipine—a voltage gated calcium channel blocker. This combination therapy, called miripine, delayed the onset of disease and increased the average life span of ALS mice by 6 weeks. Remarkably, even when applied after the onset of disease, the miripine therapy increased the longevity of ALS mice by 4 weeks. These results indicate that the miripine three-therapy, which is clinically well tolerated, may represent a novel and effective treatment for ALS having a synergistic effect over the previously discussed three therapy administered alone.
[0010] In accordance with the present invention there is provided a method for reducing symptoms related to a neurodegenerative disease and/or treating this neurodegenerative disease, the therapy comprising the administration of a therapeutically effective amount of at least two compounds selected from the group of an inhibitor of microglial activation, an antiglutominergic agent and a voltage gated calcium channer blocker to a patient suffering from the neurodegenerative disease.
[0011] The method in accordance with a preferred embodiment of the present invention, wherein the inhibitor of microglial activation is minocycline.
[0012] The method in accordance with a preferred embodiment of the present invention, wherein the antiglutaminergic agent is Riluzole.
[0013] The method in accordance with a preferred embodiment of the present invention, wherein the voltage gated calcium channel blocker is Nimodipine.
[0014] The method in accordance with a preferred embodiment of the present invention, wherein the neurodegenerative disease is selected from the group consisting of: Amyotrophic Lateral Sclerosis (ALS), Alzheimer's disease, Parkinson's disease, Pick's disease, Huntington's chorea, multiple sclerosis, stroke and spinal cord injury.
[0015] In accordance with the present invention, there is provided a composition for reducing symptoms related to a neurodegenerative disease and/or treating this neurodegenerative disease, comprising a therapeutically effective amount of at least two compounds selected from the group of an inhibitor of microglial activation, an antiglutaminergic agent and a voltage gated calcium channel blocker in association with a pharmaceutically acceptable carrier.
[0016] In accordance with the present invention, there is provided a composition for reducing symptoms related to a neurodegenerative disease and/or treating this neurodegenerative disease, comprising a therapeutically effective amount of at least two compounds selected from the group of an inhibitor of microglial activation, an antiglutaminergic agent and a voltage gated calcium channel blocker, wherein the inhibitor of microglial activation, the antiglutaminergic agent and the voltage gated calcium channel blocker being administered to a subject simultaneously or consecutively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1A illustrates Miripine three-therapy increases life span of SOD1 G37R mice.
[0018] [0018]FIG. 1B illustrates Distribution of the mortality of miripine-treated vs control SOD1G37R mice according to their age in weeks;
[0019] [0019]FIG. 2 illustrates Miripine three-therapy improves muscle strength and delays disease onset; and
[0020] FIGS. 3 A- 3 B are histograms showing the total number of axons in L4 and L5 ventral roots of normal mice (WT), drug-treated (tr) and control SOD1 G37R mice at the age of 10 months (A) and of 11 months (B);
[0021] FIGS. 4 A- 4 ) are micrographs showing the immunoreactivities of Cdk5, Cdk4 and activated capsase-3 in the spinal cord of WT mice (A, B, c), of drug-treated SOD1 G37R mice (D, E, F) and of control SOD1 G37R littermates (G, H, I) at 10 month-old as well as of drug-treated SOD1 G37R mice (J, K, L) and of control SOD1 G37R littermates (M, N, O) at 11 month-old;
[0022] FIGS. 5 A- 5 C are micrographs illustrating the attenuation of microglial activation and astrogliosis in the spinal cord of SOD1 G37R mice.
DETAILED DESCRIPTION OF THE INVENTION
[0023] In accordance with the present invention, there is provided a new therapy useful for delaying the onset and increasing the survival time of a subject suffering from a neurodegenerative disease.
[0024] Material and Methods
[0025] Generation of SOD1 G37R Mice
[0026] Transgenic mice overexpressing SOD1G37R by ˜5-fold (line 29) (3) were enriched in C57BL/6 background. Only mice heterozygous for the SOD1G37R transgene were used for our study. All mice were genotyped by Southern blotting. The use of animals and all surgical procedures were carried out according to The Guide of Care and Use of Experimental Animals of the Canadian Council of Animal Care.
[0027] Three-Therapy Treatment Protocol
[0028] The SOD1G37R mice were housed at the standard temperature (21° C.) and in light controlled environment with ad libitum access to the food and water. The study was carried out using transgenic littermates. The mouse littermates were fed a regular rodent food (Harlan, Teklad) and were randomly divided into Three Therapy-treated and control groups, including wild type littermates. At the age of 8-9 months, SOD1G37R mice from the experimental groups were administered triple medicated diet TD 01146 (Harlan, Teklad), containing 1000 mg/kg of minocycline, 500 mg/kg of riluzole and 500 mg/kg of nimodipine. All three compounds were purchased from (Sigma, Oakville,Canada). For the control groups the regular diet was continued until the mice reached end-stage disease. When progression of muscle weakness became marked, mice were fed at the bottom of their cages together with specially designed containers allowing them permanent access to water. Onset of the clinical disease was determined by measurement of motor strength, as described bellow and by the hind limb contraction when mice are suspended by their tail. At the end-stage disease, mice were monitored daily. They were killed when they started to lie on the side in their cages and when they start to express difficulties in grooming. To confirm the effects of combined three-therapy, two independent experiments were carried out on the different sets of trangenic SOD1G37R mice littermates. The therapy was applied at the late presymptomatic stage (7 and 8 months old mice) of disease.
[0029] Muscle Strength Test
[0030] The mice were allowed to grab vertically oriented wire (˜2 mm in diameter) with the loop at the lower end. The wire was designed in such a way that it allowed the mice to use both fore- and hind limbs. For more consistent measurements, the wire was maintained in the vertically oriented circular motion (circle radius ˜15 cm at 35 r.p.m.). Three tests (three consecutive days) were first used as a learning period trial in which all the mice learned to use both fore and hind limbs in order to stay longer on the circulating wire. Therefore, both skeletal muscle groups contribute in this strength assay. The maximum performance time was cut to 3 min. After the learning period, the test was performed once a week.
[0031] Immunohistochemistry
[0032] Mice were sacrified by intraperitoneal (I.p.) injection of chlorale hydrate, perfused with 16 g/l sodium cacodylate buffer (pH 7.4) followed by fixative (3% glutoraldehyde in sodium cacodylate buffer). Immunohistochemical studies were performed as previously described. Incubation with the primary antibodies anti-Cdk5 (C-8, 1:1000, Santa Cruz Biotechnology, Santa Cruz, Calif.), anti-glial fibrillary acidic protein monoclonal antibody (anti-GFAP, Sigma, Oakville, Canada, 1:200 dilution), anti-mouse-Mac2 rat monoclonal antibody (TIB-166) distributed by ATCC (Manassas, Va., 1:500 dilution), and anti p-p38, and anti cleaved caspase-3 rabbit polyclonal antibody (New England Biolab, Mississauga, Canada, 1:500 dilution) was performed overnight at room temperature in PBS/BSA. The labeling was developed using a vector ABC kit (Vector Laboratories, Burlington, Canada) and Sigma-fast tablets (Sigma, Oakville, Canada). Tissue section for the axonal counting were prepared for embedding in Epon as described previously.
[0033] Western Blots
[0034] The mice were sacrificed by overdose of chloralhydrate (i.p.). Immediately after, total protein extracts were obtained from L4-L5 spinal cord sections by homogenization in SDS-urea (0.5% SDS, 8M urea in 7.4 phosphate buffer) with a cocktail of protease inhibitors (PMSF 2 mM, Leupeptine 2 mg/ml, Pepstatin 1 mg/ml and Aprotinin). The protein was measured using a DC-protein assay™ (BioRad, Hercules, Calif.). The proteins were separated on 10% SDS-PAGE, transferred to nitrocellulose membranes and detected using monoclonal primary antibodies against anti-glial fibrillary acidic protein monoclonal antibody (anti-GFAP, Sigma, Oakville, Canada, 1:2000) anti-actin (C-4; 1:5000 Boehringer, Manheim) and anti p-p38, rabbit polyclonal antibody (anti p-p38, Thr 180/Tyr 182, New England Biolab, Mississauga, Canada 1:500 dilution). The Western blots were revealed using the Renaissance chemiluminescence kit (NEN Life Science, Boston, Mass.).
[0035] Data Analysis
[0036] Data are expressed as a mean±standard error. Statistical significance was assessed by two-tailed student t test (p<0.05).
[0037] Results
[0038] Miripine Three-Therapy increases the life span of SOD1 G37R mice
[0039] Mouse littermates heterozygous for the SOD1G37R transgene (line 29) were fed a regular rodent food (Harlan, Teklad). At late presymptomatic stage (8 and 9 months), the mice littermates were randomly divided into three-therapy treated and control groups. The three drugs (miripine) were delivered as a dietary supplement in the Special Custom Made Rodent Diet. FIG. 1A shows the survival curves of the miripine-treated (group A) and control SOD1G37R transgenic mice fed on regular diet. In FIG. 1A, the survival probability of transgenic mice is plotted as a function of their age in weeks. It shows that treatment with miripine starting at late presymptomatic stage of disease increased the average life span of SOD 1G37R mice by ˜6 weeks. When applied at the late presymtomatic stage, the miripine three-therapy increased longevity of SOD 1G37R mice by 7 weeks. As compared to the non-treated littermates, the average life span of miripine-treated SOD1 G37R mice was increased by 6 weeks (54.1±0.9; n=10 vs 48.0±0.6; n=10) (Table 1). Remarkably, even when applied after the onset of paralysis, in one group of the animals, the miripine three-therapy slowed down the progression of disease and delayed mortality by 4 weeks.
TABLE 1 Three-therapy delays the onset of disease and increase longevity of SOD1 G37R mice Muscle Onset of End Stage SOD1 G37R Weakness Paralysis Paralysis mice (weeks) (weeks) (weeks) Three-Therapy 47.8 ± 0.95* 49.6 ± 1.06* 54.1 ± 0.98* Control 43.0 ± 0.92 45.4 ± 0.59 48.0 ± 0.62
[0040] As shown in the FIG. 1B, the distribution of mortality rate for the tested mice revealed almost no overlapping between the two tested groups. For non-treated SOD 1G37R mice the peak of mortality was at 47-48 weeks, while the morality rate for the treated mice showed more equally spread distribution between 52 and 58 weeks. The difference in life span for some of the miripine-treated vs non-treated animals was more than 10 weeks (FIG. 1B).
[0041] Miripine Three-therapy Delays the Onset of Disease and Muscle Strength Decline in SOD1 G37R Mice
[0042] To determine the effects of miripine three-therapy on disease onset and progression in SOD1 G37R mice, a muscle strength assay was conducted (see Material and Methods). This assay is based on the time that single mouse was able to grip a vertical circulating wire. The results of the test revealed several different aspects of muscle strength changes associated with different stages of the disease progression. Unlike normal mice, the treated and control SOD1 G37R mice showed an age-dependent decline in hanging time (FIG. 2). In FIG. 2, unlike normal mouse littermates, measurement of muscle strength revealed an age-dependent decline in motor performance of SOD1 G37R mice. Treatment with miripine three-therapy prevented the decline in muscle strength and significantly improved motor performance of SOD1 G37R littermates until end-stage of disease. Muscle strength was indirectly measured as time that mice were able to send hanging on the circulating wire. Each point represents mean±SEM, * significant difference in comparison of miripine-treated vs non-treated SOD1 G37R mice, (p≦0.05 by two-tailed t test). The number of animals in each groups were for wild type, n=6; miripine-treated SOD1 G37R mice, n=8; control SOD1 G37R mice, n=8. The onset of disease in SOD1 G37R mice was characterized by a rapid decline in muscle strength (at the age of 43 to 44 weeks), followed by a slower declining stage of muscle strength (46 to 47 weeks of age) progressing to a stage of complete hind limb paralysis. Treatment with miripine three-therapy significantly delayed the first appearance of muscle weakness and significantly improved the motor performance of the treated SOD1 G37R mice throughout the tested period (FIG. 2). Applied three-therapy also significantly delayed the onset and slowed down the progression of the disease (FIG. 2 and Table 1).
[0043] Effective Protection Against the Loss of Motor Aaxons in SOD1 G37R Mice
[0044] To assess whether the three-drug therapy delayed degeneration of motor neurons, the total number of motor axons in L4 and L5 ventral roots from treated SOD1 G37R mice (n=3 or 4) and control SOD1 G37R littermates (n=4) at early symptomatic stage of disease (44 weeks) and at late stage of disease (48 weeks) was counted as shown in FIGS. 3A and 3B. At early stage of disease, motor axons from treated SOD1G37R mice were mostly spared unlike axons from control SOD1 G37R littermates (FIG. 3A). For instance, at 44 week-old, the L5 ventral roots from control SOD1 G37R mice had 390±23 remaining axons whereas those from drug-treated mice had 823±41 axons, which is not significantly different from control values (911±36). A similar pattern was observed at the level of L4 ventral roots (713±20 for drug-treated vs. 352±20 for control SOD1 G37R mice). At 48 week-old, the number of remaining axons in the L4 and L5 ventral roots from drug-treated SOD1 G37R mice were of 637±112 and 685±115, respectively. Thus, while some axonal loss was evident at 48 weeks, the majority of motor axons were still present in the drug-treated SOD1 G37R mice.
[0045] Reduced Cdk5 Mislocalization and Capsasa-3 Activation
[0046] Recent studies demonstrated the involvement of caspase-3 activation in ALS pathogenesis. Activation of caspase-3 occurs late in the course of disease and it is associated with the loss of large motor neurons. Two other pathological hallmarks of degenerating neurons in SOD1 G37R mice are the mislocalization of Cdk5 30 and the nuclear localization of Cdk4 31 . Cdk5 is normally targeted to the cell membrane by its activator p35. However, in SOD1 G37R mice, Cdk5 is mostly detected in the cytoplasm of motor neurons. To examine whether the three-drug therapy attenuated the signals for markets of neurodegeneration in the spinal cord sections of SOD1 G37R mice, immunohistochemistry with anti-Cdk5, anti-Cdk4 and anti-caspase-3 antibodies were carried out.
[0047] Whereas the spinal motor neurons of control SOD1 G37R mice exhibited robust immunoreactivities for Cdk5 and Cdk4 at 10 month-old (FIGS. 4C and 4H), very low immunoreactivities were detected for Cdk5 and Cdk4 in spinal cord sections of 10 month-old SOD1 G37R mice under drug treatment (FIGS. 4D and 4E). At the age of 11 months, immunoreactivities for Cdk5 and Cdk4 were detected in spinal motor neurons of drug-treated SOD1 G37R mice but at reduced levels as compared to control SOD1 G37R mice (FIGS. 4J, 4K, 4 M and 4 N).
[0048] Antibodies against activated form of caspase-3 yielded a weak cytoplasmic immunostaining in several spinal motor neurons of drug-treated SOD1 G37R mice at 10 month-old (FIG. 4F), indicating that caspase-3 activation preceded axonal degeneration. Again, much stronger caspase-3 immunoreactivity was detected in moto neurons of 10 month-old control SOD1 G37R littermates. This shows that the beneficial effects of the three-drug treatment are associated with reduced signals for markers of neurodegeneration.
[0049] Three-drug Therapy Attenuates Astrocytosis and Microglial Activation
[0050] Astrocytosis and microgliosis are non-neuronal events that are likely to contribute to the neurodegenerative processes in ALS. Recently, it was shown that minocycline alone attenuates microglial activation but not astrocytosis in SOD1 G37R mice. To determine whether inclusion of nimodipine and riluzole together with minocycline exerted additional effects on glial cell activation in SOD1 G37R , immunohistochemistry and western blotting expression of Mac-2 and phosphorylated form p38 MAPK (p-p38) which are markers of microglial activation, and GFAP as a marker of astrogliosis were examined. At early symptomatic stage (44 weeks), the spinal cord sections of age-matched normal mice and drug-related SOD1 G37R mice were almost completely devoid of Mac-2 immunoreactivity (FIG. 5). In contrast, the spinal cord of control SOD1 G37R mice showed a robust Mac-2 immunoreactivity. The Mac-2 immunoreactive cells revealed morphology typical of activated microglia/macrophages (irregular shape, short processes) (FIG. 5A, panel C). A similar pattern of immunoreactivity was observed with antibodies against p-p38. Control SOD1 G37R mice yielded a strong p-p38 immunoreactivity in the white and gray matter (predominantly ventral horns) of the spinal cord (FIG. 5A, panel F). The p-p38 signal was considerably attenuated by the three-drug treatment. At the age of 44 weeks, the p-p38 immunoreactivity in the spinal cord of drug-treated SOD1 G37R mice was a low as in normal mice (FIG. 5 a , panels D and E). this was further confirmed by western blotting. At age of 10 months weeks, spinal cord extracts from normal mice or from drug-treated SOD1 G37R mice (FIG. 5B). During disease progression, the levels of p-p38 in spinal cord extracts gradually increased in drug-treated SOD1G37R mice.
[0051] Unlike minocycline alone, the presence of riluzole and nimodipine in the three-drug therapy of the present invention markedly attenuated GFAP immunoreactivity in spinal cord sections of SOD1 G37R mice at 44 week-old (FIG. 5A, panels G and H). This was further confirmed by the weak GFAP immunostaining on western blot of spinal cord extracts from drug-treated SOD1 G37R mice as compared to control SOD1 G37R littermates (FIG. 5C).
[0052] Discussion
[0053] It is reported here for the first time a three-therapy pharmacological approach (combination of minocycline, riluzole and nimodipine) which is effective in delaying the onset of disease and mortality in a mouse model of ALS. Starting at the late presymptomatic stage (8 or 9 months of age) administration of miripine three-therapy in the diet significantly delayed the onset of motor neuron degeneration, attenuated astrogliosis and microglial activation, slowed down the disease progression and increased the motor performance of SOD1 G37R mice. This three-therapy approach delayed the onset of disease and increased the average longevity of ALS mice by 6 weeks. Moreover, for some mice the increase in life span exceeded 10 weeks.
[0054] Minocycline is a semisynthetic tetracycline derivative that effectively crosses blood-brain barrier and it is extensively used in human with relatively little side effects. It has been suggested that minocycline exerts neuroprotective effects by preventing microglial activation and reducing the induction of caspase-1, thereby decreasing the level of mature proinflammatory cytokine IL-1β (Yrjänheikki, J., et al. (1998) Proc. Natl. Acad. Sci. USA 95, 15769-15774; Yrjänheikki, J., et al. (1999) Proc. Natl. Acad. Sci. USA 96, 13496-13500; Chen, M., et al. (2000) Nat. Med. 6, 797-801). In addition, it has been shown that minocycline, doxycycline and their non-antibiotic derivatives (chemically modified tetracyclines) inhibit matrix metalloproteases, nitric oxide synthases, protein tyrosin nitration, cyclooxygenase-2 and prostaglandine E2 production. Recent studies performed with primary neurons and purified microglial cultures demonstrated that minocycline may also confer neuroprotection through inhibition of excitotoxin-induced microglial activation. Minocycline inhibits glutamate- and kainate-induced activation of p38 MAPK, exclusively activated in microglia.
[0055] A protection mechanism based on attenuation of microglial activation is compatible with an inflammation involvement in the pathology of neurodegenerative disorders. In human ALS, reactive microglia and reactive astrocytes are abundant in affected areas. Such gliosis as a phenomenon occurs also in the SOD1 G37R mouse model described here. It is known that minocycline, as a single therapy, slowed down progression of disease in SOD1 G37R mice but without affecting the onset. This shows that activated microglia, through the release of pro-inflammatory molecules, are more likely to play an active role in later stages of disease, contributing more to spreading of the neurodegenerative process (Julien, J.-P. (2001) Cell 104, 581-591).
[0056] Riluzole, a glutamate antagonist, is the only drug currently approved for therapy of ALS with only marginal effects on survival (Rowland, L. P. & Shneider, N. A. (2001) N. Eng. J. Med. 344, 1688-1699). In two controlled clinical trials it increased survival of ALS patients by 3-6 months. Although the precise mechanism of action of riluzole has not been fully elucidated, it appears to involve interference with excitatory amino acid (EAA) in the CNS, possibly through inhibition of glutamic acid release, blockade or inactivation of sodium channels and/or activation of G-protein coupled transduction pathways. When tested as a single therapy in SOD1 mutant mice it increased survival for 13-15 days without affecting the onset of disease (Gurney, M. E., et al. (1996) Ann. Neurol. 39, 147-157).
[0057] At the present, there is enough substantial evidence supporting hypothesis that Ca2+ influx through L-type voltage gated channels may contribute to neuronal death. Recent study by demonstrated that Ca2+ entry through L-type calcium channels induces mitochondrial disruption and cell death. In addition, antibodies against voltage gated calcium channels have been isolated from cerebrospinal liquor of some ALS patients, and when tested in in vitro and in vivo condition they induced selective increase of intracellular calcium in motor neurons associated with cell injury and death. Calcium channel blocking agents antagonize EAA receptor and decrease calcium entry into damaged neurons that may slow down or reverse neurodegenerative processes in ALS.
[0058] Nimodipine is the L-type voltage gated calcium channel blocker with preferential effects on CNS (Langley, M. S. & Sorkin, E. M. (1989) Drugs 37, 669-699). It exerts anxiolytic and antiamnestic effect in animals, it facilitates learning in old animals, exhibits certain neuroprotective effects in ischemia/hypoxia induced nerve damage, posses some anticonvulsant properties. Recently, it has been shown that nimodipine promotes regeneration and functional recovery after intracranial facial nerve crush. However, tested as a mono-therapy in one controlled clinical trial nimodipine was not effective in slowing down the disease progression in ALS patients.
[0059] Previous studies indicated that nimodipine and riluzole when applied in human ALS or mouse model as a single therapy exert very modest or no effects on ALS. In contrast, minocycline was quite effective in slowing down the disease progression in mouse model of ALS. However, combination of minocyline, riluzole and nimodipine, applied as a three-therapy increased average life span of SOD1G37R mice by 6 weeks (FIG. 1, Table 1), which represents 100% increase in efficacy as compared to minocycline therapy. Remarkably, for some of the animals difference in the life span was more than 10 weeks (see FIG. 2). As shown in the FIG. 3 and Table 1, treatment with three-therapy also significantly delayed decline of the muscle strength and disease onset of SOD1G37R mice.
[0060] To date, aside from miripine three-therapy, no pharmacological treatment was able to delay both, the onset and the progression of disease in a mouse model of ALS. Comparing the effectiveness of our three-therapy approach to a pharmacological efficacy of every single compound contained in our drug cocktail, it is evident that they acted in synergy. Multiple factors and pathological pathways, that are not mutually exclusive, are involved in the pathogenesis of ALS and the disease progression. Our results clearly demonstrated that strategic and simultaneous pharmacological intervention on three different pathological pathways, riluzole as antiglutaminergic agent prevents excitotoxic effects of glutamate; nimodipine as voltage gated calcium channel blocker prevents excessive calcium influx into depolarized damaged neurons and minocycline, as a inhibitor of microglial activation, prevents toxic effects of activated microglia, resulted in remarkably effective treatment.
[0061] The miripine three-therapy is also suitable to be used for the reduction of symptoms and/or treatment of other related neurodegenerative diseases like Alzheimer's disease, Pick's disease, Parkinson's disease, multiple sclerosis and Huntington's chorea. It may also be useful for the treatment of spinal cord injuries and stroke.
[0062] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
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The present invention relates to a method for reducing symptoms related to a neurodegenerative disease and/or treating a neurodegenerative disease, this therapy comprising the administration of a therapeutically effective amount of at least two compounds selected from the group of an inhibitor of microglial activation, an antiglutominergic agent and a voltage gated calcium channer blocker to a patient suffering from a neurodegenerative disease. The present invention also relates to a composition for reducing symptoms related to a neurodegenerative disease and/or treating a neurodegenerative disease, comprising a therapeutically effective amount of at least two compounds selected from the group of an inhibitor of microglial activation, an antiglutaminergic agent and a voltage gated calcium channel blocker in association with a pharmaceutically acceptable carrier.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a device for use in a manhole or catch basin structure and more particularly to a device for restricting the flow of debris into the manhole or catch bash structure. The device is adaptable to be disposed above a base of the manhole or catch bash and may be used both during the construction of roadways and after the final grade has been completed. The device further includes an interlocking frame and lid to thereby deter access into the underground conduits that link manholes or catch basins together. The frame and lid are lightweight, corrosion resistant, durable, and able to withstand a weight bearing load.
2. Discussion of the Related Art
During the construction of roadways, residential developments and streets, sanitary manhole structures are used to provide access to underground conduits. Likewise, storm manhole structures and catch bash structures are used to direct surface water drainage into underground drainage conduits. A manhole structure generally includes a monolithic or precast base, a cone or top slab positioned on top of the base, a support frame positioned above the base or cone, and a cover or grate which rests on the support frame. Extension rings may be positioned between the base or cone and support frame to thereby raise the top of the support frame to the desired elevation. Similarly, a catch bash structure generally comprises a base, a cone or top slab positioned on top of the base, a support frame having a rectangular or a round opening positioned above the base or cone, and a grate which rests on the support frame.
Oftentimes during construction, the underground conduits, base, and cone or top slab are first positioned in the desired location. Next, the grade is raised to the height of the cone or top slab. Then it may be several weeks or months before the support frame is positioned above the cone and the final grade completed. In these instances, a board or metal plate may be placed over the opening in the cone or top slab and gravel or other substrate fill placed over the board or plate. During rainfalls or other water runoff and drainage events, water tends to drain and collect near the partially constructed manholes or catch basins. It is common for loose gavel, sand, silt and other sediment to flow under the board or plate and into the manhole or catch basin structure. The sediment should eventually be removed from the structure requiring additional labor and expense. Hence, there is a need for a device that catches debris and other sediment before it reaches the base of the manhole or catch basin structure.
Both during and after construction it may be desirable to deter access to the manhole opening. Although steel locks and chains have been provided to lock the manhole cover to the support frame, over time these locking devices may become inoperative from exposure to the elements requiring an increased expense to remove the entire cover and support frame. Hence, there is a need for a means to deter access to the manhole opening that will not corrode and become inoperative over time.
Various types of structures have been devised for plugging the top open end of the manhole and catch basin structures until final grade and asphalt work has been completed. For example, U.S. Pat. No. 3,621,623 issued to Downes (hereinafter referred to as "the '623 patent"), discloses an apparatus for temporarily closing an opening formed at the top of a manhole or catch basin. The '623 patent describes a protective membrane that is fixed between the top of the base or cone and the support frame in a position to close the wall opening and having a displaceable central portion for gaining access to the wall opening. However, it does not appear that the '623 protective membrane would support a substantial weight bearing load. Further, although the membrane traps debris and sediment from entering into the manhole, water is also trapped by the membrane. In cold climates, the water may freeze causing damage to the manhole structure and potentially requiring expensive repair. If the water freezes, access into the manhole structure may be limited until the ice thaws and removal of the water or ice from above the membrane can prove costly. Also, the '623 does not provide a means for deterring access through the manhole opening.
U.S. Pat. No. 4,957,389 issued to Neathery (hereinafter referred to as "the '389 patent"), describes a method and apparatus for sealing the open top end of a manhole. A pan is sealed within the opening of the manhole and includes a drain plug in the bottom of the pan. The plug can be pulled to drain the pan. As water drains from the pan, sediment may be carried with the water into the manhole structure. In cold climates the water may freeze in the pan making the plug inoperative. Further, the '389 apparatus for sealing the open top end of the manhole significantly reduces the size of the access opening, thereby limiting the physical size of the operator entering the access opening or requiring additional materials and possible increased expense to increase the opening of the manhole base. The present invention addresses these and other needs.
SUMMARY OF THE INVENTION
The purpose of the present invention is to provide a device that deters access to underground conduits linking manholes or catch basins, wherein the device is positionable above a base of the manhole or catch basin and restricts the flow of debris into the manhole or catch basin structure. In a broad aspect of the present invention, the device generally includes an annular ring, a partially domed cap, and a plurality of locking members.
The annular ring comprises inner and outer concentric sidewalls and is shaped to fit within an opening of the base or cone of the manhole or catch basin. A flange extends outwardly from an upper edge of the annular ring and a ledge extending inwardly from a lower edge of the annular ring towards a center axis of the annular ring. The ledge defines a surface on which the cap rests. Without any limitation intended, a butyl rubber, closed cell sponge rubber saturated with polyurethane, or other sealant of known construction may be applied to the upper surface of the ledge to thereby hermetically seal the cap to the annular ring. An inner edge of the ledge may include indentations which create shoulder clearance and thereby increase the diameter of the access proximate the shoulder clearance indentations. The diameter of the ledge may be increased such that the diameter of the ledge, proximate the shoulder clearance, is approximately equal to the inner diameter of the manhole opening.
The side of the cap is cylindrical in shape having inner and outer concentric sides, wherein the outer side of the cap conforms to the shape of the annular ring. Extending upward from the outer side is a partially domed top surface. The bottom surface of the cap is partially concave, extending upward from the inner side of the cap, thereby partially mirroring the shape of the outer surface of the cap. The bottom surface of the cap includes support ribs extending from the inner side and bottom surface of the cap. When the cap is positioned on the ledge of the annular ring, debris, sediment and water fall along the slope of the partially domed cap, thereby falling towards the lower outer sides of the cap. The debris and sediment may be shoveled away before the cap is removed. A bore may extend through a thickness dimension of the cap, proximate the center of the cap, thereby providing an overflow outlet for water to drain into the manhole system. The ribs reinforce the cap, thereby allowing a weight bearing load to be applied on the cap. A flat planar surface is formed proximate the apex of the top surface of the cap, whereby indicia may be included on the planar surface. Without any limitation intended the indicia may be alpha/numeric to identify the type of manhole or catch basin.
A plurality of corrosion resistant locking members extend from the inner side of the annular ring. The locking members may be formed integral with the annular ring or may be affixed to the annular ring. The locking members protrude inward and include a downward sloping surface. When the cap is aligned and engaged with the ledge, the cap snaps in place underneath the locking members, thereby securing the cap against the ledge of the annular ring. To remove the cap, the cap is pried around the locking members.
Those skilled in the art will appreciate that the locking members may alternately comprise one half of a ball and socket arrangement, a tab and slot arrangement or other similar locking arrangement of known construction. Without any limitation intended, the ball and socket arrangement may comprise partial spheres extending from the sidewalls of the annular ring that interlock with concave indentations formed in the sidewall of the cap. Of course, the spheres may alternatively extend from the cap sidewall and the indentations may be formed in the sidewall of the annular ring. The tab and slot arrangement may comprise tabs extending from the sidewall of the cap that snap into slots formed in the sidewall of the annular ring when the cap is engaged to the ledge of the annular ring.
In use, the outward protruding flange of the annular ring rests on the upper annular surface of the base or cone. Extension rings and the support frame may be stacked on top of the flange, thereby sandwiching the flange of the annular ring between the base and support frame of the manhole. The outer sidewall of the annular ring is dimensioned to fit within the opening of the base or cone. The height of the annular ring sidewalls may be dependent upon the number of extensions ring used and the height of the support frame. During removal of the manhole cover, it is common to allow half of the cover to rotate down into the opening of the support frame. The height of the annular ring should be such that, when the cover rotates down into the opening of the support frame, the outer edge of the cover does not contact the upper surface of the cap.
Once the annular ring is positioned on the top surface of the base or cone, the cap is aligned and engaged to the annular ring. The cap serves to catch debris and sediment flowing into the manhole structure while allowing excess water drainage to overflow into the manhole structure. In warmer climates, it may be desirable to plug the overflow bore, thereby preventing water from draining into the manhole structure. In colder climates, several wedges may be positioned between the ledge and the cap to allow drainage water to drain past the sidewalls of the cap and annular ring. In this manner, water will not be blocked by the cap and access into the manhole structure should not be inhibited by freezing temperatures and resulting ice.
In an alternate embodiment, a rectangular or round cap may include a plurality of perforations formed through a thickness dimension of the cap. Without any limitation intended, the perforated cap may be used in manhole inlet structures. This cap may serve as a grating to block a predetermined size of debris, while allowing water drainage to enter freely into the manhole structure. The perforated cap may also serve as a secondary deterrent from access into the underground conduits linking the manholes and catch basins.
In another alternate embodiment, the upper surface of the cap may be partially conical in shape, wherein, when the cap is aligned and engaged to the annular ring, at least a portion of the partially conical top surface of the cap extends upward and outward above the support frame. The cap has a plurality of perforations formed through a thickness dimension of the cap and further includes an enlarged perforation or overflow outlet formed through a thickness dimension of the cap near the apex of the conical cap. In use, during the construction of the manhole, the annular ring and conical cap may be positioned on top of the cone of a manhole. A filtering fabric or other filtering medium of known construction could be positioned around the conical upper surface of the cap. During heavy rains or other drainage events, the water level may raise above the top of the cone of the manhole and may even submerge the conical cap. The filtering fabric would prevent debris and other sediment from entering the manhole structure while allowing water to drain into the manhole inlet structure. The overflow outlet controls the maximum height that the water level may reach before allowing rapid drainage into the manhole inlet structure.
In yet other embodiments, the annular ring and cap are rectangular in shape. The annular ring is positioned within the base or cone of a catch basin. The rectangular cap is then snapped into place, engaging the ledge of the annular ring. The upper surface of the cap may be partially domed or conical as described above and may include perforations to thereby form a secondary grate for the catch basin.
OBJECTS
It is accordingly a principal object of the present invention to provide a device a lightweight, corrosion resistant, durable device for restricting the flow of debris into the manhole or catch basin structure.
Another object of the present invention is to a device for restricting the flow of debris into the manhole or catch basin structure that is adaptable to be disposed above a base of the manhole or catch basin and may be used both during the construction of roadways and after the final grade has been completed.
A further object of the present invention is to provide a device for restricting the flow of debris into a manhole or catch basin structure that includes a means of deterring access into the underground conduits that link manholes or catch basins together.
Still another object of the present invention is to provide an overflow drainage that deters access into the base of the manhole or catch basin.
Yet another object of the present invention is to provide a device that is positionable below the manhole or catch basin cover or grating that includes indicia that identifies the type of access opening.
These and other objects and advantages of the present invention will become readily apparent to those skilled in the art from a review of the following detailed description of the preferred embodiment especially when considered in conjunction with the claims and accompanying drawings in which like numerals in the several views refer to corresponding parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cylindrical annular ring and a cylindrical partially domed cap of the present invention, wherein the cap is elevated above the ring;
FIG. 2 is a perspective view of a rectangular annular ring and a rectangular partially domed cap of the present invention, wherein the cap is elevated above the ring;
FIG. 3 is an enlarged sectional view of the annular ring and cap of the type shown in FIG. 1, positioned within a manhole structure;
FIG. 4 is a top plan view of the cap of the type shown in FIG. 1;
FIG. 5 is a bottom plan view of the cap of the type shown in FIG. 1;
FIG. 6 is a top plan view of the annular ring of the type shown in FIG. 1;
FIG. 7 is a bottom plan view of the cap of the type shown in FIG. 2;
FIG. 8 is a perspective view of an alternate embodiment of the cylindrical annular ring and partially domed cap, wherein the cap is elevated above the ring;
FIG. 9 is a perspective view of an alternate embodiment of the cylindrical annular ring and partially conical cap, wherein the cap is elevated above the ring;
FIG. 10 is a bottom plan view of the cap of the type shown in FIG. 9;
FIG. 11 is a perspective view of an alternate embodiment of the cylindrical annular ring and partially conical cap, wherein the cap is elevated above the ring; and
FIG. 12 is a perspective view of an alternate embodiment of the rectangular annular ring and partially conical rectangular cap, wherein the cap is elevated above the ring.
DETAILED DESCRIPTION
Referring first to FIG. 1, there is shown generally the debris catcher 10. The debris catcher 10 generally includes an annular ring 12 and cap 14. The annular ring 12 comprises inner and outer sidewalls 16 and 18 respectively, a flange 20 extending perpendicularly outward from an upper edge 22 of the annular ring 12 and a ledge 24 extending perpendicularly inward from a lower edge 26 of the annular ring 12. Locking members 28 extend inward from the inner sidewall 16 of the annular ring 12 towards the center of the annular ring 12. A lower engaging edge of each locking member 28 is aligned and positioned above the ledge 24 at a height slightly greater than the height of the cap sidewalls (see FIG. 3), whereby the cap 14 is pressed down past each locking member 28 snapping into place against the ledge 24.
The cap 14 includes inner and outer sidewalls 30 and 32 respectively (see also FIGS. 3 and 5), wherein the outer sidewall 32 is shaped to conform to the inner sidewall 16 of the annular ring 12. A partially domed top surface 34 extends from the outer sidewall 32. A flat planar surface 36 is formed proximate the apex of the top surface 34 of the cap 14. As shown in FIG. 4, indicia 38 may be included on the flat planar surface 36. As indicated above, the indicia 38 may be alpha, numeric, or a combination thereof to identify the type of manhole or catch basin in which the debris catcher 10 is positioned. A bore 40 may extend through a thickness dimension (between the inner and outer sidewalls 30 and 32) of the cap 14, proximate the center of the cap 14. When the debris catcher 10 is positioned within the manhole or catch basin, the bore acts as an overflow outlet for water draining into the manhole system. Although the bore 40 is shown as a generally circular aperture, it is to be understood that the bore may be formed in any number of different shapes without departing from the scope of the present invention. The bore 40 may be plugged to thereby prevent water from draining past the debris catcher 10 and into the manhole base.
FIG. 2 shows an alternate embodiment of the annular ring 12 and cap 14. The annular ring 12 and cap 14 are rectangular in shape, wherein in the outer sidewall 18 of the annular ring is sized to fit within the opening of a base or cone of a catch basin. The inner sidewall 16 of the annular ring 12 and both the inner and outer sidewalls 30 and 32 of the cap 12 are also rectangular in shape (see also FIG. 7). When the cap 14 is positioned on the ledge 24, debris and sediment carded by water drain into the catch basin and fall along the slope of the partially domed cap 12. The debris falls towards the lower outer sidewall 32 of the cap 14, while the water drains into the catch basin system through the bore 40.
As seen in FIGS. 3, 5 and 7, a bottom surface 42 of the cap 14 is partially concave and extends upward from the inner sidewall 30 of the cap 14. Support ribs protrude from the bottom surface 42 and extend between the inner sidewall 30 and the bore's 40 sidewall. The ribs reinforce the cap, thereby allowing a weight bearing load to be applied on the cap 14, without the center of the cap 14 collapsing from the load.
Referring again to FIG. 3, the annular ring 12 and cap 14 are shown positioned within a manhole structure. The flange 20 of the annular ring 12 is positioned between the top annular surface of the manhole base or cone 46 and extension rings 48. The support frame 50 rests on top of the extension rings 48. The support frame 50 includes a lip 52 on which a manhole cover or grating may rest. The distance between the flat planar surface 36 of the cap 14 and the lip 52 of the support frame 50 should be greater than one half the diameter of the manhole cover or grating so that during removal of the cover, the cover may rotate down into the opening of the support frame without contacting the cap 14. The height of the annular ring 12 may vary, to thereby increase or decrease the distance between the flat planar surface 36 of the cap 14 and the lip 52 of the support frame 50.
FIG. 6 is a top view of the annular ring 12 removed from the manhole structure. The ledge 24 has two cut away portions or shoulder indentations 54 aligned diametrically opposite each other, thereby creating shoulder clearance. Although the ledge 24 further restricts the size of the access opening into the manhole structure, the shoulder clearance indentations 54 increases the diameter of the ledge 24 proximate the shoulder clearance to be approximately equal to the inner diameter of the inner sidewall 16 of the annular ring 12.
FIGS. 8-12 show several alternate embodiments of the present invention. It is to be understood that the size and shape of the cap 14 may be modified without exceeding the scope of the present invention. FIG. 8 shows an annular ring 12 and cap 14, similar to that described above, wherein the cap 14 includes a plurality of perforations 56 formed within the cap 14 extending between the domed surface 34 and bottom surface 42. Those skilled in the art will appreciate that the size, shape, and number of the perforations 56 may vary depending upon the desired size of debris to be filtered by the cap 14.
FIGS. 9 and 10 shows another embodiment of the cap 14 having an outer sidewall 58, a conical upper surface 60 and a flat top 62. A bore extends through the flat top 62 of the cap 14. A plurality of perforations or apertures extend through the conical upper surface 60 of the cap 14. An enlarged perforation 68 also extends through the conical upper surface 60 of the cap 14. The enlarged perforation 68 serves as an overflow outlet. Those skilled in the art will appreciate that the top surface of the cap 14 may be formed into an enlarged opening to create a large overflow opening. Support ribs 70 are formed on the lower surface 72 of the cap 14 to provide support to the cap when the cap 14 is submerged in water. FIG. 12 is an embodiment similar to that shown in FIG. 9, wherein the shape of the annular ring 12 and cap 14 are rectangular in shape, so as to conform to the opening of a base or cone of a rectangular catch basin.
FIG. 11 shows cap 14 of the type shown in FIG. 9, further including a handle 74 extending from the flat top surface 62 of the cap 14. An upper annular lip 76 extends perpendicularly outward from an upper edge of the outer sidewall 58. When the cap 14 is aligned and engaged with the annular ring 12, the lip 76 rest on top of the flange 20. A lower annular lip 78 extending perpendicularly outward from a lower edge of the outer sidewall 58 snaps under the locking members 28 and engages the ledge 24 of the annular ring 12. As the cap 14 is aligned and engaged with the annular ring 12, the locking member slides along groove 80 formed in the sidewall 58 of the cap 14. Once the lower annular lip 78 is engaged with the ledge 24, the cap 14 is rotated. As the cap rotates the locking members follow the curve of the groove 80. Following rotation, the cap 14 is held in place against the ledge 24 and can not be pulled away from the ledge, without first rotating the cap 14. Alternatively, the lip 76 may be aligned and engaged to the base or cone, wherein the upper annular lip 76 rests directly on the top annular surface of the base or cone.
Having described the constructional features of the present invention the mode of use will now be presented in further detail. The debris catcher 10 may be used by an operator both during the construction of manhole and catch basin structures and after completing the final grade surrounding the manhole or catch basin structure. Once the manhole base and/or cone have been constructed, the operator positions the outward protruding flange 20 of the annular ring 12 on top of the uppermost annular surface of the base or cone. The intended use of the debris catcher is then determined in order to select an embodiment of the cap 14 most suited for the intended use. Without any limitation intended, the cap 14 may be used as a secondary manhole cover, a secondary catch basin grate, or a secondary manhole inlet grate. The selected cap 14 is then snapped into place against the ledge 24 of the annular ring 12. Extension rings 48 and the support frame 50 may be stacked on top of the flange 20, and the grade may be brought up level with the top of the support frame 50.
A filtering fabric or other filtering medium of known construction may be positioned around the upper surface 34 or 60 of the cap 14 to further prevent debris and other sediment from entering the base of the manhole. During heavy rains or other drainage events, the water level may raise above the support frame 50 and may even submerge the cap 14. The filtering fabric would prevent debris and other sediment from entering the manhole structure while allowing water to quickly drain into the manhole inlet structure through the enlarged overflow bore 40 or perforation 66. The overflow outlet 68 controls the maximum height that the water level may reach before allowing rapid drainage into the manhole inlet structure.
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different devices, and that various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself.
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An annular ring and cap that are positionable within a manhole or catch basin structure above the base of the manhole or catch basin to reduce the amount of debris entering into the manhole or catch basin. The annular ring may be positioned within the manhole or catch basin such that a flange of the annular ring is sandwiched between the base and support frame. When a final grade surrounding the manhole or catch basin is complete and the cover or grating is positioned above the support frame, the cap then serves as a secondary restriction thereby deterring access to underground conduits that are linked to the manhole or catch basin. A plurality of corrosion resistant locking members secure the cap against a ledge of the annular ring. The annular ring further has an inner edge of the ledge that includes first and second shoulder clearance indentations aligned opposite each other.
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BACKGROUND OF THE INVENTION
This invention relates generally to environmentally sealed switch case configurations. Prior U.S. Pat. Nos. 4,242,551, 4,268,734, and 4,340,791 disclose electric switch configurations wherein the chamber or cavity for the switching components or contacts is sealed to some extent. However, the switch stands well above the panel and a recess must be provided in the mounting bracket portion of the switch case with drain openings for allowing fluids to escape.
SUMMARY OF THE INVENTION
In accordance with the present invention a switch housing or case is provided in two parts, one a base having a bottom wall in which openings are provided for terminals that define fixed contacts within the case cavity. The case also has laterally spaced front and rear walls as well as opposed end walls all integrally connected to the bottom wall and to each other. At least one movable contact is provided in the switch cavity. The switch case or housing also includes a mounting bracket having a top wall and laterally spaced front and rear walls adapted to mate with the front and rear walls of the base. The bracket also has opposed end walls integrally connected to the front and rear walls thereof to define a downwardly open cavity that communicates with the cavity in the base to define the enclosed switch chamber or cavity. The mounting bracket top wall defines a raised center rib portion which in turn defines laterally spaced sockets inside the switch cavity to receive upper shoulder portions of an actuator. The actuator has at least one downwardly biased plunger slidably received in a plunger cavity of the actuator and the lower end of the plunger engages the movable contact to pivot the movable contact in response to actuator movement on a laterally extending axis defined by these actuator shoulders and associated sockets. A manually movable means preferably in the form of a rocker is provided above the mounting bracket top wall and transfers pivoting movement to the actuator by means of a rod extending into a central hole in the top of the mounting bracket generally between the shoulder receiving sockets in the rib.
In an illuminated version of the switch one or two lamps is supported in one or two openings in the mounting bracket top wall. The laterally spaced front and rear walls of the mounting bracket define downwardly open slots for receiving lamp leads, which leads would be connected to fixed terminals located on ides of the switch case opposite from the lamp, and which leads are electrically connected to said terminals by coil compression springs compressed between the terminals and lamp leads within cavities defined in part by the end walls of the switch case base and mounting bracket.
The rocker or manual means for operating the switch has a depending post provided centrally of the rocker and received in an upwardly open recess provided for said post in the actuator. Laterally spaced pivot posts are provided at opposite ends of the central rib of the mounting bracket and are received in openings provided for them in depending walls of the rocker or similar operating means, spaced inwardly of the side walls or skirts of the rocker itself. Finally, still other depending walls of the rocker are adapted to engage the upstanding rib portion of the mounting bracket to further define and strengthen the pivot for the rocker so that the rocker and actuator move on the same pivot axis in the switch case. The rocker is so designed to snap easily and securely onto the switch bracket while allowing easy removal with a simple removal tool. The easy rocker installation and removal allows later customer replacement or exchange of rockers without impairing the integrity of the switch sealing.
A snap-on connector plug to house terminal connectors may be provided. A depending orientation pin is provided on the switch base and is adapted to be received in a corresponding opening provided for this purpose in the plug. The plug also has a resiliently deformable upstanding leg with a latching ledge that is received in a notch in the switch base whereby the ledge locks behind an edge of the bracket which is secured to the switch base. The connector plug is adapted to house a variety of conventional female connectors, each of which is crimped to a wire conductor and is then nested within the connector plug so as to receive a terminal projecting from the switch base.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical section taken through a switch constructed in accordance with the present invention, the rocker and actuator and movable contact being shown in one position.
FIG. 2 is a vertical section taken generally on line A--A of FIG. 1, but with the actuator shown in a position intermediate of its two extreme end positions, that is with the plungers aligned with the center fixed contacts of which two different versions are shown.
FIGS. 2A and 2B are sectional views through the composite rocker.
FIG. 3 is a top plan view of the bracket.
FIG. 4 is a vertical section of the bracket taken generally on the line B--B of FIG. 3.
FIG. 5 is a top plan view of the bracket with a cutaway sectioning of the bracket top surface to reveal details of the bracket struts and mounting wings.
FIG. 6 is a vertical section of the bracket taken generally on the line C--C of FIG. 3.
FIG. 7 is a vertical section though an alternative switch illustrating a connector plug attached to the bottom of the switch base.
FIG. 8 is an end view of the switch illustrating the attachment of the connector plug to the switch base.
FIG. 9 is a top plan view of the connector plug.
FIG. 10 is a vertical section through the connector generally on the line D--D of FIG. 9.
FIG. 11 is a diagonal view of the rocker removal tool.
DETAILED DESCRIPTION
Turning now to the drawings in greater detail, FIG. 1 shows an electric switch case constructed in accordance with the present invention, and the invention will be described with reference to the orientation of the switch as depicted in these drawings with the understanding that the terms upwardly and downwardly are relative when interpreting the scope of the claims as presented hereinafter.
The switch shown is equipped with a lamp 10, which lamp has associated conductors 10a and 10b adapted to be electrically connected respectively to fixed terminals 39 and 36 of the switch. The lamp 10 may be in the form of a neon incandescent, or light-emitting diode (LED). With the use of an LED or neon lamp a resistor 16 may be provided in the lamp circuit. Coil compression springs such as indicated at 18 and 20 would be provided between the lamp leads 10a and 10b and the terminals 39 and 36 in order to make contact between the lamp and terminals and allow the option of installing a resistor 16 in the lamp circuit.
The electric switch case or housing comprises an upwardly open base 22 having a bottom wall 22b in which openings are provided for various fixed terminals such as 36, 37, 38 and 39. The switch base 22 also includes laterally spaced front and rear walls 22c and 22d, FIG. 2, and opposed end walls 22e and 22f, FIG. 1, all of which upstanding walls are integrally connected to one another and to the bottom wall 22b so as to define an upwardly open cavity that cooperates with a downwardly open cavity, defined by the mounting bracket 24, to provide an enclosed cavity for the switch components. The mounting bracket 24 includes front and rear walls 24c and 24d which are adapted to mate with the front and rear walls 22c and 22d, respectively, of the base 22 as indicated generally at 23c and 23d in FIG. 2. The mounting bracket 24 also includes end walls 24e and 24f which mate with the end walls 22e and 22f, respectively, as indicated generally at 23e and 23f in FIG. 1. This geometry effectively seals the interior of the switch case cavity from external environmental hazards.
Still with reference to the mounting bracket 24 its top wall 24b defines a peripherally extending flange 24a, which flange is adapted to engage the outer face of a panel that defines an opening of suitable rectangular shape for receiving the switch case. As best shown in FIG. 3 this top wall surface 24b of the mounting bracket 24 has a central laterally extending rib portion 24g, illustrated at least in part in FIG. 2 and also shown in FIG. 4. An upstanding boss 24h is defined centrally of the top wall 24b, and forms the center portion of the rib 24g. The ribs 24g define inner sockets 24j, FIG. 4, that receive shoulder portions 28a, FIG. 2, of an actuator 28 provided inside the switch case and adapted to move pivotally between the limit stops 24k illustrated in FIG. 1. With reference to FIG. 2, laterally opposed outwardly projecting axle defining posts 24i serve to lock into openings created in resilient wall portions 26a of the rocker 26.
The rocker is of two part construction 26/27, whereby the first part 26 is molded with resilient wings 26a. Slots 26s, FIG. 2, in the first part 26 receive depending skirts 27a defined by the second part material. These skirts 27a extend to the edge 26b of the resilient wings 26a which engage the bracket posts 24i. The first part 26 of the rocker is of a hard plastic and provides the structural form and strength of the rocker, thereby allowing the second overlay material, 27, to be molded of either a soft pliable material or a hard material, as desired. The second overlay material, 27, is molded over the top and side surface of the rocker with the underside of the rocker defined by the first part 26, except for the skirts 27a that fills the slots 26a through the top surface of the first part, 26, and extend down to the edge 26b of the resilient wings 26a. This skirt material 27a flexes outward with the resilient wings 26a as the rocker is forced onto the bracket posts 24i, and the wings 26a snap back to engage the posts 24i with the edges 26b. The skirt material 27a remains flexed outward. The rocker also includes inner walls 26c with an inverted U-shaped bottom edge which provides a stop limit when the rocker is snapped onto bracket posts 24i, and which provides a recess to pivot upon the external U-shaped top surface 24v, FIGS. 2 and 4, of the ribs 24g. These walls 26c also prevent damaging downward or twisting pressure exerted upon the rocker from being transmitted to locking posts 24i.
The rocker may be easily removed from the bracket with the use of a tool with two tapered probes 33, FIG. 11, which would be inserted from either end of the switch, between the rocker 26 and the flange 24a, FIG. 1, whereby the pointed ends of the probes would enter the gaps 26x between the resilient wings 26a and the bracket rib ends 24x. As the probes are pushed further into the gaps, the expanding width of the probes causes the wings 26a to flex outward, ultimately forcing the surfaces 26b to unlatch from the posts 24i and the rocker to move upward off the bracket. Due to the angled inner surfaces of the wings 26a, the wings 26a will be forced upward by the probe as well as outward.
The first part of the rocker may be of translucent or transparent material and the second overly material 27 may be opaque and molded so as to leave a portion of the translucent material uncovered to provide illumination by a lamp located beneath the uncovered area 26d, FIG. 1. The actuator 28, FIG. 2, defines a central opening 28b which serves to receive a depending post 26c of complementary shape provided for it centrally of the rocker 26. As so constructed and arranged the rocker and actuator move together about a laterally extending axis defined by the axle defining posts 24i of the mounting bracket top wall rib portion. To further define this axis, the upper edge of the shoulders 28a of the actuator cooperate with the sockets 24j defined by the mounting bracket so that the actuator always moves on the same axis as that defined for the rocker.
Still with reference to the actuator 28, at least one spring biased plunger 30 is provided in a downwardly open plunger recess or cavity, and the lower end of the plunger engages a movable contact element which is pivotally received in the upper end of the central fixed contact 13 referred to previously. As can best be seen with reference to FIG. 1 movement of the actuator and rocker between the two limit positions defined by the stops 24k will normally result in movement of the contact lever 32 to an opposite mirror-image position. If for any reason the contacts 32a and 38a fail to open as the plunger 30 moves past the intermediate position where it is aligned with the center fixed contact 37, further movement of the actuator and rocker will cause the top of plunger 30 to engage the abutments 28c of the actuator, and as a result impede further movement of the actuator. Additional pressure on the rocker can only achieve further movement of the actuator by forcing the contacts to break apart. In normal operation of the switch, these contacts would open without such action. When the switch is actuated the abutment 28c and the top of plunger 30 limit the travel of the plunger and thereby would force the contacts open if the contacts have welded in a closed condition due to electrical arcing.
As so constructed and arranged the switch case comprises two half sections, one the lower base which supports the terminals and fixed and movable contacts inside the switch cavity, and the other part comprising a mounting bracket which mates with the base and defines the top wall of the switch case cavity. The geometric fit of the base to the bracket effectively seals the sides of the switch case cavity from external environmental hazards. The central boss 24h of the mounting bracket is so configured as to receive means connecting or coupling the rocker to the actuator. Such means preferably comprises a raised center portion of the actuator that in turn defines a central opening 28b for receiving the depending post 26c on the rocker. An O-ring 29 is preferably provided in the gap between the boss on the center portion of the mounting bracket top wall and the raised portion of the actuator as best shown in FIGS. 1 and 2. The post 26c on the rocker is of a lesser diameter that the opening 28b in the actuator to allow an amount of non-binding movement of the post into and out of the opening 28b. This clearance allows pivoting movement to be transferred from the rocker to the actuator, yet prevents the transfer of pressure which may force the actuator into the switch housing and compromise the seal provided by the spring biased plunger 30 exerting pressure through the raised center portion of the actuator and compressing the O-ring 29 against the bracket boss 24h. The upper edge of the shoulders 28a of the actuator cooperate with the angled sockets 24j of the mounting bracket so that the space provided for the O-ring seal is maintained constant during actuation, thereby allowing consistent compression of the O-ring, maximizing the sealing effectiveness and minimizing wear of the O-ring. The actuator shoulders 28a engagement with the angled sockets 24j provide stability to the actuator when only one spring biased plunger 30 is employed.
Still with reference to the mounting bracket 24, FIG. 5, each end wall 24e and 24f defines a central strut 24n, which strut has laterally outwardly projecting wings 24m that have stepped ridges for cooperating with the underside of the mounting panel opening edge to secure the switch case in the mounting panel. These struts 24n are designed to permit assembly of the mounting bracket to the switch case in only one orientation. This result is achieved by providing ribs 24p and 24r of different size on these struts 24n. The ribs 24p and 24, respectively, are adapted to be received only in appropriately sized slots of corresponding geometry in the end walls 22e and 22f of the switch case base 22.
Again with reference to the mounting bracket 24, and as best shown in FIGS. 1, 2, and 6, the front and rear walls 24c and 24d respectively have inner surfaces which include inwardly projecting portions 24k which serve as stops for pivotal movement of the actuator, and which also serve to cooperate with the walls 24c and 24d to define downwardly open slots 24t that are adapted to receive a lead line 10a of the lamp 10 and to prevent the lead line 10a from interfering with the motion of the actuator 28 in the switch case as described above.
The lamp 10 is conveniently mounted in the mounting bracket 24 as referred to previously, and two circumaxially spaced feet 24y, FIGS. 1 and 3, support the lamp 10 in a position where light from the lamp can emanate through a transparent window portion 26d defined for this purpose in the rocker 26/27. The external configuration of the rocker 26/27 is preferably such that its ends 27y are adapted to extend over the flange 24a of the mounting bracket. As shown in FIG. 2, the rocker has outer skirts 27x that are not used to pivotally support the rocker and therefor do not have the usual openings provided in prior art rockers for this purpose. The rocker as so designed provides a low profile, clean design above a mounting panel while shielding the O-ring actuator seal and, if employed, the O-ring lamp seal(s) from top surface environmental elements.
The area between the lamp and the bracket would be preferably sealed with an O-ring 11, FIG. 1. The O-ring would be inserted from above the lamp and compress into the area between the lamp and bracket with a stop provided by the ledge 24s. The switch may be provided with two lamps as allowed for in the bracket in FIG. 3, or with one lamp as shown in FIG. 1 with the second lamp area molded closed, or with no lamp in which case both lamp areas would be molded closed.
The lamp mounting arrangement is designed to receive either neon, incandescent, or LED type lamps. The diametrically opposed depending leg portions 24y, FIGS. 3, 4, and of the bracket are adapted to flex outwardly to maintain pressure against and hold in place a neon or incandescent bulb. The legs 24y, FIG. 6, have notches 24w configured to snap over the bottom circumferential ridge of a light-emitting-diode, LED, and lock such a diode securely in place when used as a lamp. The feet have angled edges 24z at top and bottom to allow insertion of a lamp from either direction.
Turning next to a detailed discussion of the connector plug 150, FIGS. 7, 8, 9, and 10, this component of the assembly is held i place by means of an upwardly extending resilient arm 150a having a free end portion defining a latching edge 150b that is adapted to be received in a suitable notch 22s defined for this purpose in the switch case base 22. The latching edge 150b snaps over an edge 24q of the bracket extending from the struts 24h. The extension edges 24q from the struts 24n also provide a surface which latches against protrusions 22q of the base 22, thereby securing the bracket in the base.
The connector plug 150 also defines an upwardly open bore 150p, FIGS. 7 and 9, for receiving a locating pin 22p defined for this purpose in the bottom wall of the switch case 22. The plug 150 serves to electrically connect any depending terminals such as 46, 47, and 49, FIG. 7, to conductive female terminals (not shown) provided in the plug itself.
As best shown in FIGS. 9 and 10, the plug 150 has relatively large openings or receptacles 150d-150g. These openings are designed to receive a variety of conventional spring type female connectors which lock within the connector plug after being secured to the end of a conductive wire. These female connectors are adapted to be received in the cavities 150d, 150e, 150f, 150g, 150h, 150i, 150k, FIG. 9, in such a way to accept terminals extending from the switch base, such as terminals 46, 47, and 49. Once the female connectors have been inserted into the receptacles provided for them in the plug 150, they become locked securely in place as a result of the shape of these receptacles and a barb commonly furnished on this type of female connector.
FIG. 9 shows the plug 150 in top plan view with the switch's optional spade terminals 46 through 49, and 36 through 39 being illustrated in broken lines. The female connectors or terminal ends are not shown in the views FIGS. 9 and 10 because they are of conventional configuration and of standard size for a particular size spade terminal of the type illustrated as 37 and 47, on the switch case base of FIG. 2.
It will be apparent that the movable contact shown in FIG. 7 is different from that illustrated in FIG. 1. As indicated previously with reference to the description of FIG. 2, these differently configured movable contacts are adapted to be supported on differently configured center fixed contacts. It will be apparent that a typical double pole switch may include identical movable contacts and center fixed contacts of either of the two varieties illustrated in the drawings.
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A split switch case has a base and a mounting bracket fitted thereto. The top wall of the latter has a lateral rib defining sockets for receiving shoulder portions of the actuator. Plungers in the actuator can bottom out to break free the switch contacts should they fuse together. The rocker has a unique shape and is coupled to the actuator for positive pivotal movement on a lateral axis defined by surfaces in the rocker and in the mounting bracket's top wall rib. In the illuminated switch shown, the lamp circuit has at least one lead provided in a slot defined inside the mounting bracket. The lamp can be mounted in the mounting bracket either from above or from below, two depending legs will accommodate a conventional LED from either direction.
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BACKGROUND OF THE INVENTION
The present invention deals with a ventricular assist device. More particularly, the present invention deals with cardiomyoplasty using a ferro fluid or other similar fluid.
A number of different types of coronary disease can require ventricular assist. Present ventricular assist devices (VADs) employ mechanical pumps to circulate blood through the vasculature. These pumps are typically plumbed between the apex of the left ventricle and the aortic arch (for LVADs), and provide mechanical assistance to a weak heart. These devices must be compatible with the blood, and inhibit thrombus formation, due to the intimate contact between the pump components and the blood.
Cardiomyoplasty is a form of ventricular assist which includes squeezing the heart from the epicardial surface to assist the ejection of blood from the ventricles during systole. This form of ventricular assist does not require contact with blood or surgical entry into the cardiovascular system. It has been expressed in several embodiments over the years. The first involves an approach which is drastically different from the mechanical pump approach discussed above. The approach uses a muscle in the patient's back. The muscle is detached and wrapped around the epicardium of the heart. The muscle is then trained to contract in synchrony with the ECG pulse, or other pulse (which may be generated by a pacemaker). Since the back muscle does not contact blood, many of the issues faced by conventional LVADs are avoided. However, this approach also suffers from disadvantages, because operation of the muscle tissues is poorly understood and largely uncontrolled.
A number of other methods are also taught by prior references. Some such references disclose balloons or bellows which squeeze on the exterior surface of the heart in synchrony with the ECG signal. U.S. Pat. No. 3,455,298 to Anstadt discloses an air pressure source which is used to inflate a balloon about a portion of the external surface of the heart, in order to provide a squeezing pressure on the heart.
Other references disclose similar items which are inflated using fluid inflation devices. Still other references disclose mechanical means which apply pressure radially inwardly on the epicardial surface of the heart. For instance, U.S. Pat. No. 4,621,617 to Sharma discloses an electromechanical mechanism for applying external pressure to the heart.
The air and fluid inflation devices exhibit certain advantages in that they use conformable fluids to provide an atraumatic squeezing force on the surface of the heart, as opposed to mechanical and electromechanical devices which use rigid surfaces, which contact the heart, in order to exert the squeezing force. However, one disadvantage of the fluid devices is the need for a pump which delivers fluid from a reservoir. The pump and the associated electronics is generally bulky, and can be too large and cumbersome to be implanted within the patient. Thus, such devices often require the patient to remain in bed while the device is in use.
Further, while the human muscle wrap approach does address some of these problems, it requires radical surgery plus the training of the muscle, which may not always be accomplished successfully.
SUMMARY OF THE INVENTION
The present invention is directed to a cardiac assist device for assisting the function of a heart. The assist device includes a compressor positioned against the epicardial wall of the heart and a field generator for driving a fluid coupled to the compressor to exert pressure on the heart. The pressure exerted against the heart improves heart function.
The field generator may be a magnetic field generator and the fluid coupled to the compressor may be a ferrofluid. The magnetic field generator may include an electromagnet having a core and an energizeable coil disposed thereabout. The ferrofluid may be disposed proximate a gap in the electromagnet such that the compressor exerts a force against the heart wall by generation of a magnetic field in the gap.
The compressor may include two containment regions containing ferrofluid on opposite sides of the heart, and a pair of compression portions coupled to the containment regions. The electromagnet may include two electromagnets having corresponding core portions and corresponding coils. The electromagnets may be disposed with their north and south poles in alignment and separated by a gap to allow relative movement. The electromagnets may be external or internal to the body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a partial sectional view of a human heart and its associated proximate vascular system.
FIG. 2 is a diagrammatic illustration, in partial schematic form, of an assist device in accordance with one aspect of the present invention.
FIG. 3 is a top view of the device shown in FIG. 2 .
FIGS. 4A-4C illustrate an assist device in accordance with another aspect of the present invention.
FIGS. 5A-5C illustrate an assist device in accordance with another aspect of the present invention.
FIGS. 6A-6C illustrate an assist device in accordance with another aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a partially sectioned view of a human heart 20 , and its associated vasculature. The heart 20 is subdivided by muscular septum 22 into two lateral halves, which are named respectively right 23 and left 24 . A transverse constriction subdivides each half of the heart into two cavities, or chambers. The upper chambers consist of the left and right atria 26 , 28 which collect blood. The lower chambers consist of the left and right ventricles 30 , 32 which pump blood. The arrows 34 indicate the direction of blood flow through the heart. The chambers are defined by the epicardial wall of the heart.
The right atrium 28 communicates with the right ventricle 32 by the tricuspid valve 36 . The left atrium 26 communicates with the left ventricle 30 by the mitral valve 38 . The right ventricle 32 empties into the pulmonary artery 40 by way of the pulmonary valve 42 . The left ventricle 30 empties into the aorta 44 by way of the aortic valve 46 .
The circulation of the heart 20 consists of two components. First is the functional circulation of the heart 20 , i.e., the blood flow through the heart 20 from which blood is pumped to the lungs and the body in general. Second is the coronary circulation, i.e., the blood supply to the structures and muscles of the heart 20 itself.
The functional circulation of the heart 20 pumps blood to the body in general, i.e., the systematic circulation, and to the lungs for oxygenation, i.e., the pulmonic and pulmonary circulation. The left side of the heart 24 supplies the systemic circulation. The right side 23 of the heart supplies the lungs with blood for oxygenation. Deoxygenated blood from the systematic circulation is returned to the heart 20 and is supplied to the right atrium 28 by the superior and inferior venae cavae 48 , 50 . The heart 20 pumps the deoxygenated blood into the lungs for oxygenation by way of the main pulmonary artery 40 . The main pulmonary artery 40 separates into the right and left pulmonary arteries, 52 , 54 which circulate to the right and left lungs, respectively. Oxygenated blood returns to the heart 20 at the left atrium 26 via four pulmonary veins 56 (of which two are shown). The blood then flows to the left ventricle 30 where it is pumped into the aorta 44 , which supplies the body with oxygenated blood.
The functional circulation, however, does not supply blood to the heart muscle or structures. Therefore, functional circulation does not supply oxygen or nutrients to the heart 20 itself. The actual blood supply to the heart structure, i.e., the oxygen and nutrient supply, is provided by the coronary circulation of the heart, consisting of coronary arteries, indicated generally at 58 , and cardiac veins. Coronary artery 58 resides closely proximate the endocardial wall of heart 24 . The coronary artery 58 includes a proximal arterial bed 76 and a distal arterial bed 78 downstream from the proximal bed 76 .
In order to assist the heart, the present invention provides a fluid either partially surrounding the heart, or completely surrounding the heart, wherein the fluid can be influenced by electric or magnetic fields. The fluid is located closely proximate the epicardial surface of the heart and is influenced by the application of an electric or magnetic field in order to assist the heart.
FIG. 2 is a diagram, in partial schematic form, illustrating cardiomyoplasty system 100 which is used, in accordance with one aspect of the present invention, in order to assist the heart 20 . In system 100 , heart 20 is illustrated surrounded by a bag 102 which is substantially, or partially, filled with a ferrofluid (shown in FIG. 3 ). System 100 also includes electromagnet sections 104 and 106 which are coupled, through switches 108 and 110 , to a power supply 112 . Switches 108 and 110 are controlled by controller 114 which, in one preferred embodiment, receives an ECG input signal from heart rate sensor or monitor 116 .
In one preferred embodiment, bag 102 is formed of a non-compliant balloon material which is preferably attached to portions of the heart by sutures, indicated generally at 118 . Bag 102 is filled with a ferrofluid which, in one preferred embodiment, is paramagnetic in that it becomes magnetic in the presence of an applied magnetic field. Such fluids are commercially available from Ferrof luidics Corporation, 40 Simon Street, Nashua, N.H. 03061, and Lord Corporation, 405 Gregson Drive, Cary, N.C. 27511. The fluid is preferably biocompatible and includes suspensions of small, ferromagnetic particles. In zero applied field, the fluid is non-magnetic. However, the fluid becomes magnetized when an external magnetic field is applied. The maximum magnetization which can occur in the fluid is referred to as the saturation induction, and is typically achieved in applied fields of about 1000 Oersteds, and has typical values of about 1000 Gauss. Applied fields in this range, and higher, can be achieved with electromagnets using conventional core materials and fairly modest electrical power.
The ferrofluids surrounding the heart are energized by magnetic fields which can originate from electric currents or permanent magnets situated either within or outside the body. For example, the magnetic fields in FIG. 2 are generated by electromagnets 104 and 106 located outside the body. Electromagnets 104 and 106 each include a coil 120 and 122 , respectively which is formed, illustratively, of insulated copper wire. Coils 120 and 122 are wound around thin sheets of magnetic material 124 and 126 , respectively. The material 124 and 126 , in one preferred embodiment, is commercially available under the commercial designation Hiperco, from Carpenter Metals, of Reading, Pa. In the embodiment illustrated in FIG. 2, electromagnets 104 and 106 are generally semi-circular in shape, and are each configured as half torroids set up in a repulsion configuration.
Coils 120 and 122 are coupled to power supply 112 (which in one preferred embodiment is a battery) through switches 108 and 110 , which are controlled by controller 114 . A bipolar ECG lead 130 is attached at a point on the patient's chest and provides a signal to heart rate sensor 116 which, in turn, provides a signal to controller 114 indicative of the activity of heart 20 . Controller 114 controls switches 108 and 110 to selectively energize coils 120 and 122 during systole.
When current is passed through coils 120 and 122 , in the direction indicated, a magnetic field is directed through the chest of the patient from the north poles (indicated by the letter N in FIG. 2) to the south poles (indicated by the letter S in FIG. 2) of coils 120 and 122 . This field magnetizes the ferrofluid within bag 102 and forces it to a center line (designated by dashed line 132 ) between electromagnets 104 and 106 , in the direction indicated by arrows 134 and 136 . Energization of electromagnets 104 and 106 also forces the ferrofluid in bag 102 toward the north and south poles in the direction generally indicated by arrows 138 and 140 . Bag 102 reacts in this way because a force develops which pulls the ferrofluid to the point of the strongest field concentration within system 100 .
As the field is applied, bag 102 , under the force of the ferrofluid driven by the magnetic field, is squeezed inwardly and flattened. The force is proportional to the area of the ferrofluid. Only a few pounds per square inch (psi) are required to pump the blood from within heart 20 . This can be achieved when only a few Watts of power are delivered to coils 120 and 122 . The amplitude of the coil current controls the pressure exerted by the bag 102 of ferrofluid. Of course, the magnitude of the current can be adjusted until the patient's blood pressure is within a normal range.
In one illustrative embodiment, electromagnets 104 and 106 are contained within a vest worn about the chest of the patient. Also, magnetic shields 142 are provided to cover the region of the gap between the semi-circular magnets, both on the North Pole and South Pole ends, and reside on the outside surface, away from the patient. Magnetic shield 142 confines the high magnetic field to a region within the patient's chest.
FIG. 3 is a top view of a portion of system 100 shown in FIG. 2 . In FIG. 3, bag 102 is shown as having a pair of generally oppositely disposed pouches 146 and 148 which are connected by bands 150 and 152 which extend about, and are sutured to heart 20 . Pouches 146 and 148 contain the ferrofluid material. Thus, when the magnetic field is applied, pouches 146 and 148 are pulled in generally opposite directions toward the north and south poles, respectively. This tends to flatten bag 102 about heart 20 . Since pouches 146 and 148 generally reside closer to the north and south poles, this provides more efficient magnetic coupling between those poles and the ferrofluid residing in pouches 146 and 148 .
Of course, a wide variety of other bag configurations can be used as well. For example, instead of having two discrete pouches, bag 102 can be formed having a single pocket which extends about the entire periphery of heart 20 , bag 102 can be formed having a number of separately divided pockets which extend about the periphery of heart 20 . Further, bag 102 may preferably be formed with seams 119 which are disposed about regions having larger coronary vessels 121 in order to avoid compressing those vessels during energization of the coil. Other, different bag configurations can be used as well.
FIGS. 4A-4C illustrate a cardiac assist system 200 in accordance with another aspect of the present invention. A number of other items in system 200 are similar to those in system 100 illustrated in FIGS. 2 and 3, and are similarly numbered. However, system 200 is substantially entirely implantable. System 200 includes a plurality of electromagnets 202 , 204 , and 206 . Each electromagnet includes a core 208 surrounded by a coil 210 . Each of the coils 210 is coupled to a corresponding switch 212 , 214 , or 216 , which is controlled by controller 114 based on an ECG or other suitable signal, and selectively couples coils 210 to battery 112 . As with system 100 , the cores 208 of the electromagnets are preferably a Hiperco or other suitable core material surrounded by coils 210 , which is preferably formed of insulated silver or gold wire. All circuitry is preferably implantable, and battery 112 is preferably inductively recharged from outside the body.
The plurality of electromagnets 202 , 204 and 206 are separated by gaps 220 . Thus, the electromagnets form torroids which substantially surround the heart, but which are split into a plurality of sections which define magnetic gaps 220 . Each of the gaps contains two bags 222 and 224 , which are separated by a septum 226 . In one preferred embodiment, bags 222 are disposed in a direction radially toward the epicardial wall of heart 20 , while bags 224 are disposed in an opposite direction.
Bags 222 are filled with non-magnetic fluid, while bags 224 are filled with ferrofluid. When current is applied to the torroidal coils during systole, each ferrofluid bag 224 is drawn into a corresponding gap 220 , thus exerting an inwardly directed force on bags 222 and thus on the epicardial wall of heart 20 . This force displaces the non-magnetic fluid against the heart wall. During diastole, the coils are de-energized and expansion of heart 20 advances bag 222 back into gaps 220 and thus displaces the ferrofluid in bag 224 , out of gap 220 . Bags 222 and 224 thus mimic the action of fingers performing heart massage.
In accordance with one aspect of the present invention, gaps 220 are narrower at the apex of heart 20 and wider toward the top of the heart 20 . Since the gaps are narrower at the apex, the magnetic field in the narrower gap region is stronger than at the top of heart 20 . This causes pressure to build, once the coils are energized, from the apex upward in a natural progression to assist displacement of blood from left ventricle 30 . In addition, as illustrated in FIG. 4A, bags 222 and 224 are formed in gaps 220 substantially about the left ventricle 30 of heart 20 , while no gaps are preferably defined by the electromagnets about right ventricle 32 . This preferentially exerts pressure to assist in displacement of blood from left ventricle 30 .
FIGS. 4B and 4C illustrate the action of one set of bags 222 and 224 under the influence of the magnetic field exerted by the electromagnets 204 and 206 . It will be appreciated that similar action will take place in each of the gaps 220 . FIG. 4B illustrates that the coils on electromagnets 204 and 206 are energized during systole to create a magnetic field in gap 220 . The magnetic field draws the ferrofluid in bag 224 into the gap, thus displacing the non-magnetic fluid in bag 222 inwardly toward heart 20 . By contrast, when the magnets are de-energized during diastole, the heart chambers fill thus exerting a pressure on bag 222 which displaces the ferrofluid in bag 224 from gap 220 , radially outwardly, to allow expansion of the heart 20 .
FIGS. 5A-5C illustrate a portion of another assist system 300 in accordance with another aspect of the present invention. As with systems 100 and 200 , a heart rate monitor 116 , a controller 114 , a plurality of switches, and implantable battery 112 are preferably provided in system 300 , although they are not illustrated for the sake of clarity. In system 300 , a torroidal electromagnet 302 includes a core member 304 , which is preferably formed of Hiperco material, and winding 306 , which is preferably formed of insulated silver or gold wire. To improve flexibility of the electromagnet, the core may consist of a flat bag of ferrofluid. Core member 304 is disposed about the epicardial layer of heart 20 and defines a gap 308 between ends thereof. Core member 304 is also preferably sutured to heart 300 in two or more locations generally indicated by numeral 310 . The areas at which core 304 is sutured to the epicardial wall of heart 20 are preferably proximate left ventricle 30 .
System 300 also preferably includes a bag 312 of ferrofluid material. Bag 312 includes a plurality of separate pouches 314 , each of which form an elongate finger containing ferrofluid material. Bag 312 is preferably sutured to the epicardial layer of heart 20 in gap 308 . The current in coil 306 is preferably driven by an implanted battery, and is switched on during the heart's systolic phase. The beginning of systole can be sensed in several different ways, including by using the QRS complex on an ECG electrode planted on the heart, by using the heart sound produced when the aortic valve opens and sensed by an implanted microphone, or by using a preset pressure threshold as measured on or in the left ventricle. The current through coil 306 is switched off when the T-wave of the ECG signal is identified, when the aortic valve is heard closing, or when the pressure drops below a valve closing threshold.
When coil 306 is energized, the end portions of core 304 tend to move toward one another in the directions generally indicated by arrows 316 and 318 , in order to close gap 308 . This causes a squeezing on heart 20 in the direction indicated by arrows 316 and 318 .
In addition, pouches 314 , containing ferrofluid, are preferably centered longitudinally in gap 308 , but are radially displaced on the left ventricle 30 outward from the plane of gap 308 when not under the influence of a magnetic field. The ferrofluid in pouches 314 is positioned to partially close the magnetic circuit in gap 308 . Thus, when coil 306 is energized, the ferrofluid is drawn radially inward, in the direction indicated by arrows 320 , as gap 308 is closing generally tangentially. Thus, left ventricle 30 is receiving a squeezing force in two directions, which enhances the efficiency of the cardiac assist.
It should also be noted that sutures 310 are preferably formed in a region of left ventricle 30 , or approximately on a line dividing left ventricle 30 from right ventricle 32 . Thus, only left ventricle 30 is squeezed. The sutures maintain a gap between electromagnet 302 and the epicardial wall of heart 20 in the area of right ventricle 32 . Thus, right ventricle 32 does not receive any of the squeezing force. Of course, without sutures 310 , both left ventricle 30 and right ventricle 32 could be squeezed.
FIGS. 5B and 5C are top views of system 300 illustrating the operation thereof. In FIG. 5B, coil 306 is de-energized, such that gap 308 is larger and pouches 314 are radially displaced, somewhat, from gap 308 . However, upon energization of coil 306 , gap 308 tends to close in the direction indicated by arrows 316 and 318 , and pouches 314 tend to move radially inwardly, into gap 308 , in the direction indicated by arrows 320 . FIG. 5C illustrates system 300 after coil 306 is energized. Note that gap 308 has closed somewhat, and pouches 314 are now more closely drawn within gap 308 , thus squeezing left ventricle 30 .
It should be noted that, in FIGS. 5A-5C, and in accordance with one aspect of the present invention, core 304 is made from a plane of individual Hiperco wires overwound with AWG #25 copper wire. This entire structure is only approximately 0.048 inches thick, and is quite flexible, especially when held together by a flexible adhesive, such as urethane. The structure is wrapped around heart 20 , and sutured. The ends defining gap 308 are softened with a urethane coating. Flexibility can also be achieved by making the magnetic core from a flat bag of ferrofluid. Alternatively, the torroid is made of a more rigid structure which is shaped to fit snugly about heart 20 , without sutures. In such an embodiment, only the magnetically permeable material in bag 312 moves under the influence of the magnetic force, while the ends of the torroid do not close.
Also, in the embodiment shown in FIGS. 5A-5C, the coil resistance of the torroidal coil is approximately 6.5 ohms with a maximum current rating of 1 amp. The average heat dissipation required to generate desirable compressive force is approximately 3.3 watts, with an efficiency of 55% (i.e., 4 watts of pumping power).
FIGS. 6A-6C illustrate another system 400 in accordance with another aspect of the present invention. System 400 includes a rigid structure or frame 402 , which has a bag 404 partially filled with ferrofluid material, supported thereby. In one embodiment, bag 404 is adhered to structural frame 402 . The structural frame 402 is formed of non-magnetic material, such as structural plastic, and structure 402 and bag 404 are overwound with a copper coil 406 .
The density of the windings is greater in a region proximate left ventricle 30 than in the region proximate right ventricle 32 . In one preferred embodiment, the density in the region of left ventricle 30 is double that in the region of right ventricle 32 . For example, in a region of structure 402 proximate right ventricle 32 , coil 406 includes N windings per unit length. However, in a region of structure 402 proximate left ventricle 30 , coil 406 includes more windings, such as 2N windings. It should also be noted that bag 404 is disposed on the outside of rigid structure 402 in the area proximate right ventricle 32 , but is disposed on the inside surface of structure 402 in the area proximate left ventricle 30 . In accordance with one aspect of the present invention, structure 402 includes a transition section 408 which forms a gap between two longitudinally separated rails 410 and 412 . The bag passes from the outer surface of structure 402 to the inner surface thereof through gap 408 .
The conductive windings, in one embodiment, are physically attached to the surface of bag 404 , and the wires are quite flexible. In another embodiment, where the wires are more rigid, the wires are not attached to the surface of balloon 404 , but are instead simply draped over the surface of bag 404 . Further, in addition, the windings of coil 406 are physically attached to the outside of structure 402 in the area proximate left ventricle 30 , and are physically attached to the inside of structure 402 in the area proximate right ventricle 32 .
As with previous embodiments, one or more switches are provided to alternately couple coil 406 to a power supply 112 under the control of a controller 114 . In addition, a heart rate sensor 116 can also be provided to provide an input to the control circuitry such that the coil can be energized in synchronicity with the heart action.
Initially, balloon 404 is evacuated and partially re-filled with ferrofluid. When coil 406 is energized, the ferrofluid is forcibly moved within balloon 404 to the region around left ventricle 30 , because the greater density of windings in coil 406 in that region produces a stronger magnetic field. This preferentially fills balloon 404 proximate left ventricle 30 and thereby exerts a compression force on the epicardial surface of heart 20 in the region of left ventricle 30 . However, even when the coil is energized, there is still enough ferrofluid in the remainder of balloon 404 in the region around right ventricle 32 to complete the torroidal magnetic circuit throughout the entire circumference of heart 20 .
During diastole, the left ventricle 30 expands, and coil 406 is de-energized. The ferrofluid within balloon 404 is thus displaced from the left ventricle side of balloon 404 to the right ventricle side of balloon 404 where it occupies space outside of the volume of heart 20 . When the right ventricle side of balloon 404 is fully inflated, there is still enough ferrofluid left on the left ventricle side of balloon 404 to make a complete magnetic circuit, once coil 406 is re-energized.
FIGS. 6B and 6C are top views of system 400 shown in FIG. 6 A. In FIG. 6B, system 400 is shown with coil 406 energized during systole. It can be seen that balloon 404 preferentially fills on the side of heart 20 proximate left ventricle 30 , to exert compressive force in the direction generally indicated by arrow 420 on the epicardial surface of heart 20 . However, during diastole, and as shown in FIG. 6C, left ventricle 30 fills thus displacing ferrofluid from the left ventricle side of bag 404 , causing it to be displaced to a position outside structure 402 to the right ventricle side of balloon 404 .
It should also be noted that, system 400 shown in FIGS. 6A-6C can be sutured to the epicardial surface of heart 20 at any desirable location. For example, structure 402 can be sutured to a region of epicardial surface of heart 20 proximate the division between left ventricle 30 and right ventricle 32 . In this way, as balloon 404 fills, it exerts a backpressure on the rigid structure causing balloon 404 to expand inwardly and thus compress left ventricle 30 , without exerting any pressure on right ventricle 32 . In addition, during diastole, the ferrofluid falls under the force of gravity to the region of balloon 404 proximate the apex of the heart, and to the lower, posterior side of the heart, which is tilted back in the chest cavity. When current is applied to coil 406 , the apex region of the heart will be squeezed first, forcing the blood up and out of the heart in a natural contractile motion.
Thus, it can be seen that the present invention provides significant advantages over prior systems. The present invention need not be as compatible and deal with thrombus formation issues as required by systems which are deployed within the heart. Similarly, the present invention does not require external fluid sources for selectively filling a bag or pouch with fluid in order to exert compression on the heart. In addition, the present invention does not deal with natural muscle fibers wrapped around the heart, and thus does not encounter the difficulties associated with such techniques. Also, the present invention exerts a pressure on the heart with a pliable fluid filled surface which yields an atraumatic compressive force on the heart, as opposed to a traumatic compressive force encountered during compression with a rigid mechanical structure.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A cardiac assist device and method of use for assisting the function of a heart. The assist device includes a compressor positioned against the epicardial wall of the heart and a field generator for driving a fluid coupled to the compressor to exert pressure on the heart. The field generator may be a magnetic field generator and the fluid coupled to the compressor may be a ferrofluid. The compressor may include two containment regions containing ferrofluid on opposite sides of the heart, and a pair of compression portions coupled to the containment regions. The filled generator may be electromagnetic which includes two electromagnets having corresponding core portions and corresponding coils. The electromagnets may be disposed with their north and south poles in alignment and separated by a gap to allow relative movement. The electromagnets may be external or internal to the body.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Phase under 35 U.S.C. §371 of International Application No. PCT/GB2007/050112, filed Mar. 8, 2007, which claims priority to United Kingdom Application No. 0604647.8, Filed Mar. 8, 2006. The disclosures of the above-referenced applications are hereby expressly incorporated by reference in their entireties.
FIELD OF THE INVENTION
The present invention related to isotopically modified compounds and their use as food supplements.
BACKGROUND OF THE INVENTION
A currently accepted theory of ageing blames the irreversible changes in cell machinery and reduced efficiency of metabolic processes on the detrimental effects of free radicals and other reactive oxygen species (ROS) or reactive nitrogen species (RNS) which are normally present in the cell as part of the respiratory process. ROS and RNS oxidize/nitrate DNA, proteins, lipids and other cell components. Of these, protein oxidation, which converts arginine, lysine, threonine, thryptophan and proline into corresponding carbonyl compounds, cannot be repaired by proteases after a certain threshold number of amino acid residues have been oxidized.
The damaged protein loses its catalytic or structural activity, but proteases are unable to disintegrate heavily carbonylised strands, so that the damaged species accumulate and aggregate, clogging up cellular passages. This rust-like process gradually wears down all cellular mechanisms, slowing everything down and ultimately causing cellular death.
Apart from ageing, many diseases such as Alzheimer's, Parkinson's, dementia, cataract, arthritis, chronic renal failure, acute repiratory syndrome, cystic fibrosis, diabetes, psoriasis and sepsis, to give a few examples, are associated with increased protein carbonylation. Typically, physiological levels of protein carbonyls are at around 1 nmol/mg protein, whereas pathological levels go to 8 nmol/mg and above.
For the two molecules involved in the process of oxidative damage of proteins, i.e. an oxidizer and its substrate, the oxidizer has been the subject of many studies aiming at neutralizing or removing it by means of increasing the number of antioxidants (vitamins, glutathione, peptides or enzymes). The substrate, e.g. amino acid (AA) residues which are converted into carbonyls, has received less attention.
One common feature of all the AA residues (except praline) vulnerable to carbonylation is that they belong to the group of essential AAs, which cannot be synthesized by vertebrata and should be ingested, e.g. consumed with food. The group includes phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, arginine, lysine and leucine (arginine is essential for children of up to 5 years of age).
Oxidation of both Arg and Lys by ROS yields aminoadipic semialdehyde and proceeds through sequential replacement of ω-hydrogens with hydroxyls. Oxidation of Lys, Arg, Trp, Thr, Phe and His is shown in FIG. 1 . Side-chains undergo the same transformations if these AAs are part of polypeptides/proteins. Other essential AAs undergoing ROS-driven oxidation include Leu (to 5-hydroxyleucine), Val (3-hydroxyvaline) and Ile (several products).
Other types of oxidative damages affecting essential AAs involve reactive nitrogen species (RNS). Examples are shown in FIG. 2 .
Yet another process detrimental to proteins is a ROS-driven peptide bond cleavage, which is preceded by oxygen free radical-mediated protein oxidation. A hydrogen atom is abstracted from a C α , atom of the polypeptide chain, which then leads to formation of an alkoxyl radical. This can lead either to hydroxyl protein derivative, or to peptide bond cleavage by (1) diamide or (2) α-amidation pathway. This is illustrated in FIG. 3 .
Nucleic acids are not normally considered as essential components of the diet, but are also damaged by ROS. An example particularly important for the mitochondrial functioning is the formation of 8-oxy-G, as illustrated in FIG. 4 . This leads to mutations in the mitochondrial genome, which is not maintained and repaired as efficiently as the nuclear genome, with detrimental consequences to the efficiency of respiratory processes in the cell. Another cause of degradation is radiation.
The kinetic isotope effect is widely used when elucidating mechanisms and rate-determining stages of chemical and biochemical reactions. The rate of reaction involving C— 1 H bond cleavage is typically 5 to 10 times faster than the corresponding C— 2 H ( 2 H=D=deuterium) bond cleavage, due to the two-fold difference in the masses of H and D isotopes. The difference in reaction rates is even higher for tritium ( 3 H or T) as it is 3 times heavier than hydrogen, but that isotope is unstable. The second component of the C—H bond, the carbon atom, can also be substituted for a heavier 13 C isotope, but the bond cleavage rate decrease will be much smaller, since 13 C is only a fraction heavier than 12 C. See Park et al., JACS (2006) 128: 1868-72.
Oxidation reactions are a good example of the isotope effect, as the hydrogen subtraction by an oxidizer is usually a rate-limiting step of the process. Damgaard, Biochemistry (1981) 20: 5662-69, illustrates this: the kinetic isotope effect upon V/K for (1-R)[1- 2 H 2 ]— and (1-R)[1- 3 H 2 ]— ethanol oxidation by liver alcohol dehydrogenase (ADH) to acetaldehyde, measured at pH 6, was 3 (D(V/K)) and 6.5 (T(V/K)), decreasing to 1.5 and 2.5 respectively at pH 9. Lower than expected rates confirm the discrete role of the non-ADH systems as alternative pathways. In vivo experiments in perfused rat liver, as reported in Lundquist et al, Pharm. & Tox. (1989) 65: 55-62, gave the mean value of D(V/K) of 2.89. Therefore, in all cases the oxidation of deuterated ethanol was substantially slowed down.
Isotopically labelled material has been administered to animals, and also to humans, for diagnostic purposes. Gregg et al, Life Sciences (1973) 13: 755-82, discloses the administration to weanling mice of a diet in which the digestible carbon fraction contained 80 atom % 13 C. The additive was 13 C-labelled acetic acid. Tissue examination revealed no abnormalities clearly attributable to the high isotopic enrichment.
SUMMARY OF THE INVENTION
The present invention is based on the realisation that isotopic substitution can be used to synthesize a class of compounds that, when ingested, result in the formation of bodily constituents (e.g. proteins, nucleic acids, fats, carbohydrates, etc) that are functionally equivalent to normal bodily constituents but which have a greater resistance to degradative/detrimental processes, e.g. those mediated by ROS and RNS or radiation. Therefore, according to this invention, a nutrient composition comprises a nutrient composition comprising an essential nutrient in which at least one exchangeable H atom is 2 H and/or at least one C atom is 13 C.
Compounds for use in the invention are identical to normal nutrients or constituents of food except that they contain stable isotopes which, when incorporated into bodily constituents make such bodily constituents more resistant to degradative processes than they would be otherwise. They provide a method for protecting the preferred functionality of natural biomolecules; the method comprises supply of a compound in such a way that it becomes incorporated into biomolecules and in so doing confers properties on the biomolecule that protect against damaging or unwanted chemical changes.
Compounds for use in the invention may be chemically synthesized and, when ingested by an organism, are metabolized in a way that results in the incorporation of the compound into a functional biomolecule; the incorporation of the compound resulting in the biomolecule having a higher degree of resistance to damaging molecular changes than would be the case for the equivalent biomolecule that did not comprise the compound. Such compounds may act as mimics of naturally occurring precursor elements of biomolecules. They may mimic an essential amino acid. The organism is typically a plant, microbe, animal or human.
A compound for use in the invention is typically not degraded by enzymes of the P450 pathway. It can therefore accumulate in a subject for which it is essential.
DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 4 each show reactions that degrade essential nutrients.
DESCRIPTION OF THE INVENTION
The present invention relates to the fact that essential supplements may undergo irreversible chemical transformations such as oxidation, nitration, etc, leading to the onset of senescence or diseases. Essential food components cannot be synthesised de novo by an organism, e.g. mammal, primate or human, and therefore need to be supplied with the diet. For the purposes of this specification, a nucleic acid is essential, although it may be more properly be described as conditionally essential. Conditionally essential nutrients need to be supplied with the diet under certain circumstances.
For humans, 10 amino acids are essential, i.e. Phe, Val, Trp, Thr, Ile, Met, His, Leu, Lys and Arg (up to the age of five). Purine and pyrimidine nucleosides are conditionally essential. Essential fatty acids are ω-3 and ω-6, while monounsaturated oleic acid is generally non-essential.
According to this invention, the proposed undesired effects such as ageing/diseases can be slowed down. The compounds consumed should be modified to slow down the undesired reactions, while still retaining their chemical identity. This can be achieved in one embodiment by substituting hydrogen atoms subjected to abstraction during oxidation/oxidative substitution at the most reactive carbon sites, or the sites known to undergo the ROS/RNS inflicted damage as illustrated on FIGS. 1-4 , with deuteriums, which due to the isotope effect slow down the rate of reactions. Substituting carbons instead of or in addition to H atom substitution may require a greater degree of substitution since one does not add so much to the reaction rate decrease (D is twice the weight of H, and 13 C is less than 10% heavier than 12 C).
Depending in part of the method of preparation, a compound for use in the invention may comprise partial or total isotopic substitution. For example, deuterium substitution may be only at the one or two hydrogen atoms that are considered chemically exchangable, e.g. at OH or CH 2 adjacent to a functional group. Total rather than partial 13 C substitution may often be achieved more effectively.
In a preferred embodiment of the invention, the (or only the) oxidation-sensitive hydrogens should be substituted with deuteriums, to minimize the risk of other metabolic processes slowing down when fragments of these AAs are used to build up other structures. In special cases, to further increase the resistance to oxidation, both 1 H and 12 C of a H—C bond can be substituted by 2 H and 13 C. To minimize any possible negative effect of isotopes, such as unwanted slowing down of biochemical reactions that utilise fragments of AAs protected with isotopes, preferably only the most sensitive parts of the AAs should be derivatised, for example, ω-atoms of Lys and Arg. Preferred compounds of this type are
If the oxidative stress is so severe that benefits from protecting the vulnerable sites overweigh potential damaging effects from slowing down other metabolic pathways (as is the case with some diseases), then AAs more heavily protected with isotopes can be employed, as shown in the following, illustrative formulae
Such derivatives confer protection from the detrimental effects illustrated in FIGS. 1-4 .
As all vertebrate have lost the ability to synthesise the essential AAs and require the outside supply of essential AAs or fatty acids, non-painful ways of delivering the deuterated/deuterated and 13 C-modified AAs into human food sources are possible. For AAs, one example of process is to create essential AAs-deficient yeast/algae/bacteria/etc, growing them on appropriate isotopically ‘protected’ media/substrates and then feeding the obtained biomass to fish or livestock. The fish or livestock can then be introduced into the food chain in the normal manner. Another example is by a direct pill/supplement-based delivery.
Non-essential components of food are the compounds that can be produced by an organism, such as nucleic acid bases. But when these are consumed as food, some of the non-essential components are digested/used as precursors for other compounds, but a certain fraction is utilized directly in metabolic processes, e.g. nucleic acid (NA) bases, incorporated into DNA. Therefore, as an example, some of the NA bases supplied with food may be isotopically protected, as shown in the following, illustrative formulae
Such species are less vulnerable to oxidation upon incorporation into DNA. In other words, the oxidation rate of DNA, including mitochondrial DNA, can be reduced.
Both essential and non-essential components may be administered through a digestive system to achieve a desired effect of slowing down detrimental changes associated with ageing process and various diseases. Nevertheless, ways other than through the digestive tract, for instance intravenous delivery, can be envisaged. The important aspect of any delivery system is to get the isotopically engineered compounds incorporated into bodily/biochemical constituents.
A composition of the invention can be provided like any food supplement. It typically comprises one or more nutrients in addition to the isotopically labelled essential component. It may comprise plant material, microbial material or animal material. The composition may be a normal foodstuff, a tablet or other solid medicament, or an injectable or other liquid.
The composition may comprise unmodified compounds in addition to those that have been labelled. The labelled compound is typically present in a larger amount, and certainly greater than that which may be present naturally.
Compounds for use in the invention may be prepared by procedures that are known or that can be modified as appropriate by one of ordinary skill in the art. For example, the deuterated analogue of Lys, 2,6-diaminohexanoic acid-6,6-D 2 , may be synthesized from a precursor nitrile by hydrogenolysis in D 2 according to standard procedures.
The deuterated analogue of Arg, 2-amino-5-guanidinopentanoic acid-5,5-D 2 , may be synthesized from a corresponding nitrile.
Ornithine-D 2 , obtained by hydrogenolysis in a way similar to that described above for Lys, was dissolved in water and mixed with an equal volume of 0.5M O-methylisourea, pH 10.5, adjusted with NaOH. After 4-5 h, 1% TFA was added to stop the reaction. The compound was purified by a RP HPLC (Buffers were A: 0.1% TFA/H 2 O; B: 0.1% TFA/(80% MeCN/20% H 2 O)), 0-65% B over 40 min. See Kimmel, Methods Enzymol. (1967), 11: 584-589, and Bonetto et al, Anal. Chem. (1997), 69: 1315-1319.
Cyano-aminoacids are precursors to amino acids. Synthesis of cyano-aminoacids can be carried out by several routes, starting from a variety of precursors. Alcohols (Davis & Untch, J. Org. Chem. (1981); 46: 2985-2987), amines (Mihailovic et al, Tet. Lett. (1965) 461-464), amides (Yamato & Sugasawa, Tet. Lett. (1970) 4383-4384) and glycine (Belokon et al, JACS (1985)107: 4252-4259) can all serve as starting materials in such syntheses. Some methods can yield both 13 C and 2 H-substituted compounds, while others are only compatible with deuteration.
Deuteration can be carried out using deuterium gas (for example, as described in White et al, JACS (1994) 116: 1831-1838) or different deuterides, for example NaBD 4 (Satoh et al, Tet. Let. (1969) 4555-4558); the choice between these methods should be made based on the availability and price of the corresponding deuterium derivatives. Some of the strategies tested are described in detail below.
The sites to be protected within essential fatty acids for the purpose of the present invention are the methylene groups of the 1,4-diene systems (‘bis-allyl’ positions). They are the most reactive, and can easily be derivatised using a variety of methods. Bromination of this position followed by reduction with 2 H 2 results in the substitution of one hydrogen at a time. To substitute both, the procedure should be repeated twice. A more attractive method may be a direct one-step substitution in heavy water. An example of such exchange is given below (Example 6) for 8-deuteration of deoxyguanosine.
An alternative approach to the synthesis of deuterated unsaturated fatty acids is based on strong base treatment of 1,4-dienes followed by quenching with heavy water. This is illustrated in Example 7.
There are literature examples for substitutions at any position for all major nucleotide bases, with all major types of isotopes ( 2 H 2 , 3 H 2 , 13 C, 14 C, 15 N, 18 O etc). Described below are just two procedures, based on the previously published work, for selective deuteration of purines (Esaki et al, Heterocycles (2005) 66: 361-369, and Chiriac et al, Labelled Compd. Radiopharm. (1999) 42: 377-385). Numerous other protocols are suitable as well. It is often possible to exchange hydrogens for deuteriums on an existing nucleic acid base/nucleoside, while to incorporate 13 C, the bases should be assembled (for example, see Folesi, et al, Nucleosides Nucleotides Nucleic Acids (2000).
Syntheses of some isotopically ‘reinforced’ essential dietary components suitable for use in the present invention are known; see for instance, 6,6- 2 H 2 ,1,1- 13 C 2 -L-Lys: Lichtenstein et al, J. Lipid Res. (1990) 31: 1693-1701 and 8-deutero-deoxy-guanosine: Toyama et al, J. Raman Spectrosc. (2002) 33: 699-708).
The invention is not limited by the synthetic organic chemistry methods described above, as there exists a large arsenal of different methods that can also be used to prepare the above mentioned and other isotopically protected components suitable for use in the present invention. For instance, in addition to the methods disclosed in the Examples, other methods suitable for convertion of a primary amino group function into a CN function (with the aim of subsequent deuteration of the alpha-(relative to N) carbon atom) can be employed, such as:
a direct oxidation by oxygen catalysed by cuprous chloride-dioxygen-pyridine system (Nicoiaou et al, Synthesis (1986) 453-461; Capdevielle et al, Tet. Lett. (1990) 31: 3305-3308) a direct conversion using bromosuccinimide (Gottardi, Monatsh. Chem. (1973) 104: 1690-1695) a direct iodosobenzene oxidation (Moriarty et al, Tet. Lett. (1988) 29: 6913-6916) a two-step conversion via a di-tosyl derivative and an iodo derivative (DeChristopher et al, JACS (1969) 91: 2384-2385).
The following Examples 1 to 9 illustrate the preparation of materials suitable for use in the invention.
(MA)LDI-TOF mass spectra were obtained using a Voyager Elite Biospectrometry Research Station (PerSeptive Biosystems, Vestec Mass Spectrometry Products) in a positive ion mode; FAB spectra were acquired using a Varian instrument. Analytical thin-layer chromatography was performed on the Kieselgel 60 F 254 precoated aluminium plates (Merck) or aluminium oxide 60 F 254 precoated aluminium plates (Merck), spots were visualized under UV or as specified. Column chromatography was performed on silica gel (Merck Kieselgel 60 0.040-0.063 mm) or aluminium oxide (Aldrich aluminium oxide, activated, neutral, Brockmann I, 150 mesh, 58 Å).
Reagents for biological experiments, unless otherwise specified, were from Sigma-Aldrich. 13 C-glucose was from Sigma and Reakhim (Russia).
Reagents obtained from commercial suppliers were used as received. All solvents were from Aldrich; trifluoroacetic acid was from Pierce; HPLC grade solvents were from Chimmed (Russia), and were used without further purification. (S)-2-Amino-5-cyanopentanoic acid was from Genolex (Russia). Deuterium gas was generated by electrolysis by a GC Hydrogen Supply Module (output 6 atm; Himelectronika, Moscow, Russia), using heavy water as a source. Heavy water ( 2 H 2 O, D 2 O), NaBD 4 and Na 13 CN were from Reakhim (Russia) and Gas-Oil ISC (Russia). DMF was freshly distilled under reduced pressure and stored over 4 Å molecular sieves under nitrogen. DCM was always used freshly distilled over CaH 2 . THF was distilled over LiAlH 4 .
Example 1
(S)-2-Amino-4-cyano( 13 C)-butyric acid (a Precursor for 13 C-Arg and 13 C, 2 H 2 -Arg)
2.19 g (10 mmol) of N-Boc-homo-Serine (Bachem; desiccated overnight over P 2 O 5 ) was dissolved in 10 ml of a mixture of acetonitrile/dimethylformamide (1:1). Dry Na 13 CN (Gas-Oil JSC, Russia; 1 g, 2 eqv) and NaI (10 mg, cat) were added, and the mixture was degassed. Me 3 SiCl (2.55 ml, 2 eqv) was then added with a syringe at RT under argon. The reaction mixture was stirred under argon at 60° C. for 6 h, with monitoring by TLC (chloroform/methanol 2:1, visualization in iodine vapor). Upon completion, the reaction mixture was cooled to RT, diluted with water (100 ml) and extracted with diethyl ether (2×50 ml). The organic phase was washed with water (4×50 ml) and brine (50 ml), dried (Na 2 SO 4 ), decanted and concentrated in vacuo to yield (2.07 g, 91%) of colorless oil. The structure of the Boc-nitrile was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 229.115 (MI), 230.114 (MI+H + ), 252.104 (MI+Na + ). No peaks related to the starting material were detected.
The removal of the Boc protecting group and the work-up were carried out using a standard peptide synthesis protocol (50% TFA in DCM, 30 min, RT). The structure of the nitrile was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 129.062 (MI), 130.070 (MI+H + ). No signal related to the starting material was detected.
Example 2
(S)-2-Amino-4-cyano-butyric acid (a Precursor for 2 H 2 -Arg)
4.93 g (20 mmol) of N-Boc-L-Glutamine (Sigma) was dissolved in 30 ml of anhydrous THF and added with stirring to a mixture of triphenylphosphine (10.49 g, 40 mmol, Aldrich) and 40 ml of anhydrous tetrachloromethane. The reaction mixture was stirred with gentle heating for 3 h (control by TLC, chloroform/methanol 2:1, visualization in iodine vapour), cooled and the precipitate of triphenylphosphine oxide filtered off. The oil obtained upon evaporation and re-evaporation with an additional 15 ml of THF was diluted with 30 ml of water. The aqueous fraction was saturated with brine, washed with diethyl ether (2×20 ml), and acidified to pH 3.5 with sulphuric acid. The product was extracted with ethyl acetate (2×20 ml). Combined organic fractions were dried (brine, Na 2 SO 4 ) decanted and evaporated to give 3.46 g (76%) of colorless oil. The structure of the Boc-nitrile was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 228.114 (MI), 229.114 (MI+H), 251.103 (MI+Na). No peaks related to the starting material were detected.
The removal of the Boc protecting group and the work-up were carried out using a standard peptide synthesis protocol (50% TFA in DCM, 30 min, RT). The structure of the nitrile was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 128.069 (MI), 129.075 (MI+H + ). No signal related to the starting material was detected.
Example 3
Lys- 2 H 2
(S)-2-amino-5-cyanopentanoic acid (Genolex, Russia; 14.21 g, 100 mmol) was dissolved in 100 ml of methanol. To this, Raney nickel, prepared from 4 g of alloy (30% Ni) according to (Adkins H. et al, Org. Syntheses. Coll. Vol. III, 1955, p. 180) was added, and the reaction mixture was shaken under deuterium (100 atm) at 90° C. for 24 h. (TLC: n-butanol-pyridine-acetic acid-water: 15-10-3-12; visualization by iodine vapor and fluorescamine). The reaction mixture was filtered and evaporated in vacuo. The product was redisolved in water-ethanol (3:1; 20 ml) followed by evaporation in vacuo (×4) and then crystallized from ethylacetate to give 11.55 g (78%) of the deuterated product. The structure of deuterated lysine was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 148.088 (MI), 149.089 (MI+H + ).
Example 4
(5- 13 C, 5,5- 2 H 2 ) Arginine
The (S)-2-Amino-4-cyano( 13 C)-butyric acid (182 mg, 1.41 mmol) and CoCl 2 ×6H 2 O (Aldrich, 670 mg, 2.82 mmol) were dissolved in water (6 ml) and NaBD 4 (Reakhim, Russia; 540 mg, 14.1 mmol) was added in two portions over 20 min. The nitrile was reduced in 30 min (control by TLC: n-butanol-pyridine-aeetic acid-water: 15-10-3-12; fluorescamine/UV detection for Boc-protected amino acids, iodine vapor visualisation for unprotected amino acids).
The reaction mixture was quenched by acidification (1M HCl) followed by acetone, and purified by ion exchange (Amberlite IR120P (H + ), Aldrich). The column was washed with water till neutral pH. The product was then recovered by washing the column with NH 4 OH (0.3 M) followed by evaporation. The resulting ornitine- 13 C, 2 H 2 (yield: 158 mg, 83%; MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA matrix. Found: 135.071 (MI), 136.068 (MI+H + ) was dissolved in water and mixed with an equal volume of 0.5M O-methylisourea (Kimmel, supra), pH 10.5, adjusted with NaOH. After 4-5 h 1% TFA was added to stop the reaction (Bonetto et al, supra). The compound was purified by a RP HPLC (Buffers were A: 0.1% TFA/H 2 O; B: 0.1% TFA/(80% MeCN 20% H 2 O)), 0-65% B over 40 min to give 140 mg (68%); MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA matrix. found: 177.402 (MI), 178.655 (MI+H + ).
Example 5
(5,5- 2 H 2 )-Arginine
The title compound was synthesized using the above protocol, starting from (S)-2-amino-4-cyano-butyric acid (Technohim, Russia). MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA matrix. found: 176.377 (MI), 177.453 (MI+H + ).
Example 6
11,11-di-deutero-linoleic acid (18:2)
Linoleic acid (7 g, 25 mmol, Aldrich) was dissolved in 25 ml of carbon tetrachloride dried over P 2 O 5 . N-bromosuccinimide (4.425 g, 25 mmol, desiccated overnight over P 2 O 5 ) and 0.05 g AIBN were added, and the reaction mixture in a flask with a reversed condenser was stirred with gentle heating till the reaction was initiated as manifested by an intense boiling (if the reflux is too intense the heating should be decreased). When succinimide stopped accumulating on the surface, the heating was continued for another 15 min (about 1 h in total). The reaction mixture was cooled to RT and the precipitate filtered off and washed with CCl 4 (2×5 ml). The combined organic fractions were evaporated and the 11-Bromolinoteic acid obtained was gradually added to a solution of NaBD 4 (390 mg, 10 wool) in 30 ml of isopropanol. After an overnight stirring, a diluted solution of HCl was slowly added till there was no more deuterium gas produced. Upon a standard workup, the mono-deuterated acid was brominated and reduced again to yield a target di-deutero derivative (bp 230-231° C./15 mm, 4.4 g, 63%). MALDI-TOF MS: mono-bromo derivative. found: 358.202, 360.191 (doublet, approx 1:1, MI); di-deutero derivative. found: 282.251 (MI).
Example 7
11,11-D 2 -Linoleic acid (18:2) was synthesized by treating linoleic acid with an eqv of a BuLi-tBuK (Sigma-Aldrich) mix in hexane followed by quenching with D 2 O. To improve yields this procedure needs to be repeated 3-4 times. It was found that this procedure also generates a detectable amount of alpha-deuterated product (FAB MS, Xe ions, thioglycerine. found: 283.34 (72; MI+1) + , 284.33 (11; alpha-monodeuteroderivative, MI+1) + , 285.34 (10; alpha-dideuteroderivative, MI+1) + ; the nature of ‘284’ and ‘285’ peaks was established using MS/MS. The substitution at alpha-position can be prevented by utilizing transient ortho-ester protection (Corey & Raju Tetrahedron Lett. (1983) 24: 5571), but this step makes the preparation more expensive.
Example 8
8-D-Deoxyguanosine from Deoxyguanosine
Deoxyguanosine (268 mg, 1 mmol, Aldrich) was dissolved in 4 ml of D 2 O. 10% Pd/C (27 mg, 10 wt % of the substrate, Aldrich) was added, and the mixture was stirred at 160° C. in a sealed tube under H 2 atmosphere for 24 h. After cooling to RT, the reaction mixture was filtered using a membrane filter (Millipore Millex®-LG). The filtered catalyst was washed with boiling water (150 ml), and the combined aqueous fractions were evaporated in vacuo to give deoxyguanoside-d as a white solid (246 mg, 92%). The structure of the nucleoside was confirmed by MALDI-TOF (Voyager Elite, PerSeptive Biosystems), with HPA as a matrix. Found: 268.112 (MI).
Example 9
8-D-deoxyguanosine from 8-bromodeoxyguanosine
7% Pd/C catalyst, prepared from PdCl 2 as described in Chiriac et al (1999) 42: 377-385, was added to a solution of 8-bromodeoxyguanosine (Sigma) and NaOH in water. The mixture was stirred in D 2 (2 atm) at 30° C. The catalyst was filtered off and the reaction mixture was neutralized with 2N HCl. The procedure provides approx. 85-90% yield of the product. Other reducing agents can be employed, such as NaBD 4 (see the synthesis of D,D-linoleic acid).
The following Examples 10 to 12 illustrate the utility of the invention. In order to establish a range of a potential heavy isotope substitutions for the invention (from 100% light isotope to 100% heavy isotope, as well as the localized site protection such as that shown in FIGS. 1-4 , using compounds as shown above), and to test for a possible toxicity of large amounts of heavy isotopes on an organism, the influence of heavy carbon ( 13 C) and specifically ‘protected’ building blocks of biopolymers (nucleic acid components (nucleosides), lipids and amino acids) on the life span was tested on a nematode Caenorhabditis elegans.
Previous studies of the model organism C. elegans have almost exclusively employed cultivation on a bacterial diet. Such cultivation introduces bacterial metabolism as a secondary concern in drug and environmental toxicology studies (specific metabolite-deficient bacterial strains can be employed to evaluate the influence of particular essential nutrients on the nematode longevity). Axenic cultivation of C. elegans can avoid these problems, yet some earlier work suggests that axenic growth is unhealthy for C. elegans . (Szewczyk et al, Journal of Experimental Biology 209, 4129-4139 (2006)). For the present invention, both NGM and axenic diets were employed in combination with isotopically enriched nutraceutical components.
Example 10
13 C 6 -glucose (99% enrichment; Sigma) was used as a carbon food source for culturing of Escherichia coli ; the control was identical except for the 12 C 6 -glucose. C. elegans (N2, wild type) were grown on a standard (peptone, salts and cholesterol) media seeded with Escherichia coli prepared as described above. The only carbon-containing component apart from E. coli was 12 C-cholesterol (Sigma; a hormone precursor that is essential for C. elegans ), since the corresponding 13 C-derivative was unavailable. Nematodes were thus grown on a ‘heavy’ and ‘light’ (control) diet in the temperature range of 15-25° C., in pools of 50-100 worms each. The animals on both diets developed normally with all major characteristics being very similar.
The longevity data was analyzed using Prism software package (GraphPad software, USA), according to published procedures (Larsen et al, Genetics 139: 1567 (1995)). It was found that animals on the ‘heavy’ diet have an increase of a lifespan of around 10% (in a typical experiment, 14 days for 12 C animals versus about 15.5 days for the 13 C-fed worms, for 25° C.).
Example 11
Basic composition of the axenic media used is adapted from (Lu & Goetsch Nematologica (1993) 39: 303-311). Water-soluble and TEA-soluble components (vitamins and growth factors), salts, non-essential amino acids, nucleic acid substituents, other growth factors and the energy source are prepared as described (0.5 L of 2×). To this, a mix of essential amino acids is added, containing (for 0.5 L as 2×): 0.98 f L-(D 2 )-Arg (see above); 0.283 g L-HYS; 1.05 g L-(D 2 )-Lys (see below); 0.184 g L-Trp; 0.389 g L-Met; 0.717 g L-Thr; 1.439 g L-Leu; 0.861 g L-Ile; 1.02 g L-Val, and 0.623 g L-Phe. Prior to adding to the remaining components, this mixture was is stirred at 55° C. for 4 hours until a clear solution was is formed, and then cooled to room temperature.
C. elegans (N2, wild type) are cultivated on this medium. For the control experiment, nematodes were are grown on a medium prepared as above but containing standard L-Arg and L-Lys instead of the deuterated analogues, in the temperature range of 15-25° C., in pools of 50-100 worms each. The longevity data was is analyzed using Prism software, as described in Example 10.
Example 12
A 12 C-NGM diet is enriched with 5,5-di-deutero-arginine and 6,6-di-deutero-lysine, 11,11-di-deutero-linoleic acid (18:2), and 8-D-deoxyguanosine. C. elegans are grown on a standard (peptone, salts and cholesterol) medium seeded with Escherichia coli prepared as described above, to which deuterium-‘reinforced’ derivatives (see above) are added, to a total concentration of 1 g/L of each deuterated compound. Nematodes are thus grown on a ‘heavy’ and ‘light’ (control—whereby non-deuterated L-Arginine, L-Lysine, linoleic acid (18:2), and deoxyguanosine were are used instead of deuterated analogues in 1 g/L concentrations) diet in the temperature range of 15-25° C., in pools of 50-100 worms each. The longevity data was is analyzed using Prism software package, as described in Example 10.
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A nutrient composition comprises an essential nutrient in which at least one exchangeable H atom is 2 H and/or at least one C atom is 13 C. The nutrient is thus protected from, inter alia, reactive oxygen species.
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BACKGROUND OF THE INVENTION
[0001] This application is a non-provisional application based on provisional application Serial No. 60/268,958, filed Feb. 16, 2001.
[0002] This invention relates to a method for accurate magnetization of tubular wellbore members such as casing segments or drill string segments. Such magnetization produces a remanent magnetic flux that extends at a distance or distances from the wellbore member, about that member, to facilitate detection of such a tubular member in a borehole when drilling another borehole, for example in an attempt to intercept the borehole containing the magnetized wellbore member.
[0003] The prior art discloses methods to determine the location and attitude of a source of magnetic interference such as a magnetized wellbore tubular having a remanent magnetic field. In this regard, U.S. Pat. No. 3,725,777 which describes a method to determine the earth's field from a magnetic compass and total field measurements, and then calculate the deviations, due to the external source of magnetic interference. The magnetic field of a long cylinder is then fitted to the magnetic deviations in a least-squares sense. That ′777 patent, and the paper “Magnetostatic Methods for Estimating Distance and Direction from a Relief Well to a Cased Wellbore”, describe the source of the remanent magnetic field. The ′377 patent states, at column 1, lines 33 to 41 that “To have a remanent magnetization in the casing is not difficult since most well casing is electromagnetically inspected before it is installed. The electromagnetic inspection leaves a remanent magnetization in the casing. Since casing is normally installed in individual sections that are joined together, the remanent magnetization of unperturbed casing is normally periodic.”
[0004] U.S. Pat. No. 4,072,200 and related U.S. Pat. No. 5,230,387 disclosed a method whereby the magnetic field gradient is measured along a wellbore for the purpose of locating a nearby magnetic object. The gradient is calculated by measuring the difference in magnetic field between two closely spaced measurements; and because the earth field is constant over a short distance, the effect of the earth field is removed from the gradient measurement. The location and attitude of the source external to the drill string can then be determined by comparison with theoretical models of the magnetic field gradient produced by the external source.
[0005] U.S. Pat. No. 4,458,767 describes a method by which the position of a nearby well is determined from the magnetic field produced by magnetized sections of casing. U.S. Pat. No. 4,465,140 describes a method for magnetization of well casing. In this method, a magnetic coil structure is traversed through the interior of the casing, which is already installed in the borehole. While traversing the casing, the coil is energized with a direct current which is periodically reversed to induce a desired pattern of magnetization.
[0006] European Pat. No. Application GB9409550 discloses a graphical method for locating the axis of a cylindrical magnetic source from borehole magnetic field measurements acquired at intervals along a straight wellbore.
[0007] U.S. Pat. No. 5,512,830 describes a method whereby the position of a nearby magnetic well casing is determined by approximating the static magnetic field of the casing by a series of mathematical functions distributed sinusoidally along the casing. In an earlier paper “Improved Detectability of Blowing Wells”, John I. DeLange and Toby J. Darling, “SPE Drilling Engineering”, Society of Petroleum Engineers, Mar. 1990, pp. 34-38, a method was described whereby the static magnetic field of a casing was approximated by an exponential function.
[0008] European Pat. No. Specification 0 031 671 B1 describes a specific method for magnetizing wellbore tubulars by traversing the tubular section in an axial direction through the central opening of an electric coil prior to the installation of the tubular section into a wellbore. Production of opposed magnetic poles having a pole strength of more than 3000 microweber is disclosed.
[0009] The above referenced paper “Improved Detectability of Blowing Wells”, expresses the need for as high a magnetization as possible in the target tubulars, and states, “Because most magnetometers in use in survey/MWD have a sensitivity of +/−0.2 microTesla, a value of 0.4 microTesla is considered to be a reasonable threshold value.” Note that 0.2 microTesla is equivalent to 200 nanoTesla, and that in the patent and the paper, a lower limit to the tubular magnetization, namely 3000 microweber, is described or claimed.
SUMMARY OF THE INVENTION
[0010] It is one objective of the present invention to take advantage of improvements in the state of the art of magnetometer measurements to provide a method of magnetization of wellbore tubulars for use in drilling intercept wells that does not require such a high level of magnetization as 3000 microWeber.
[0011] The value of 0.4 microTesla cited in the above referenced paper for good detectability of small magnetic field changes was representative of the state of the art in magnetometer measurements at the time of publication of that paper in 1990. The present invention employs a magnetometer sensor and electronics apparatus for borehole use having a 16-bit analog-to-digital converter enabling much higher accuracy and resolution characteristics. This leads to a quantization of about 2nT (nanoTesla) per bit that in turn leads to a root-mean-square quantization error of about 0.58nt RMS. Other electrical noise in the system as well as basic magnetometer noise limits the detectability of small changes in magnetic field to about 2nT with short-term averaging of the measurements. This value, 2nT, is thus 200 times less than the 400nT cited in the referenced paper as a “reasonable threshold.” Thus, either the range of detection of a magnetic target can be greatly increased for a given magnetization of the target tubular, or the magnetization of the tubular can be substantially reduced from previous values required by prior art.
[0012] Reduced required magnetization of the tubular results in reduced size and weight for the magnetizing apparatus, reduced electrical power for the magnetizing apparatus, reduced sideways-directed forces between the magnetizing apparatus and the tubular during magnetizing and reduced magnetic forces between the individual tubular element and other magnetic materials during handling, prior to insertion into the borehole.
[0013] The reduced electrical power for the magnetizing apparatus makes it possible, in some embodiments, to measure the magnetic pole strength of the induced magnetization and if desired control the electrical power to achieve a controlled and known level of magnetization. Such a known level of pole strength of the magnetization can lead to improvements in the estimation of range to the target casing in the intercept process.
[0014] Accordingly, the method of the invention includes, in some desirable embodiments, either or both:
[0015] 1. Measuring the induced pole strength of the induced magnetization in the tubular element;
[0016] 2. Measuring the induced pole strength of the induced magnetization in the tubular and using such measured pole strength, in feedback relation with the electrical power of the magnetizing apparatus, to control the magnetization to a desired level, in the tubular element.
[0017] It has been well known since 1971, the filing date for U.S. Pat. No. 3,725,777, that a useful remanent magnetic field in wellbore tubulars can be obtained as a by-product of magnetic inspection of the tubular prior to installing the tubular in a borehole, such inspection involving applying a magnetic field to the tubular element. This invention expands on that knowledge by describing how specific requirements on magnetic field values during the inspection process can produce the desired levels of magnetic pole strength for the tubular, without requiring a separate specific apparatus or procedure following magnetic inspection.
[0018] Major objects of the invention include providing for well tubular member magnetization, by carrying out the following steps:
[0019] a) providing a magnetizing structure comprising an electrical coil defining an axis,
[0020] b) relatively displacing said tubular member and said structure, with said coil positioned and guided in close, proximity to said member, and while supplying electric current to flow in the coil, thereby creating magnetic flux passage through said tubular member and core to magnetize that member, or a part of that member,
[0021] c) and displacing said tubular member in a wellbore.
[0022] In that method, the coil may remain positioned either externally or internally of the member during such relative displacing of the member and structure. Further, a spacer element or elements, as for example a roller or rollers, may be provided for spacing the coil from the tubular member during such relative displacing of the member and structure.
[0023] Additional objects including providing flux passing pole pieces at opposite ends of the coil; measuring the magnetic pole strength of the magnetic field produced proximate the end or ends of said member, by said flux passage; and controlling a parameter of the flux as a function of such measuring; and magnetizing the tubular member to a pole strength less than about 2,500 microWeber.
[0024] Further, the method includes and facilitates magnetically detecting the presence of the member in the wellbore, from a location outside the bore and spaced therefrom by underground formation. Also, the method may include providing a magnetic measurement device, and displacing that device within said member in the wellbore while operating the device to enhance magnetization of the member, in the well.
[0025] The tubular member may comprise any of the following:
[0026] i) a well casing section
[0027] ii) well tubing
[0028] iii) drill pipe.
[0029] These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
DRAWING DESCRIPTION
[0030] [0030]FIG. 1 shows a cross-section of a wellbore in the earth having a casing and a magnetized section of casing;
[0031] [0031]FIG. 2 shows a desired pattern of magnetization for one or more sections of magnetized casing;
[0032] [0032]FIG. 3 shows an apparatus for magnetization of a wellbore tubular that has an external magnetizing coil;
[0033] [0033]FIG. 4 shows an apparatus for magnetization of a wellbore tubular that has an internal magnetizing coil;
[0034] [0034]FIG. 5 shows an improvement to the magnetizing apparatus to provide for pole-strength measurement and feedback control of the achieved magnetization;
[0035] [0035]FIG. 6 a shows magnetized tubular members connected in a string;
[0036] [0036]FIG. 6 b is a diagram showing magnetic measurements with a magnetized tubular member; and
[0037] [0037]FIG. 7 is a section showing a method of use.
DETAILED DESCRIPTION
[0038] [0038]FIG. 1 shows a target borehole 11 having in it a casing string 12 which contains a casing section 13 which has been magnetized axially to provide a suitable target region in the target borehole. As shown, the casing section 13 is installed above a non-magnetic, or non-magnetized, section 15 and below other sections above that are also not magnetized. Another borehole 16 is adjacent to the target borehole 11 and it is necessary to determine the location of the magnetic survey tool 17 , carried by wire line 18 , with respect to the magnetized casing section. The magnetized section 13 has a center marked X and North and South magnetic poles marked N and S. Magnetic field lines F are marked and show the magnetic flux extending into the region or formation outside of borehole 10 that is to be detected. Methods to determine the direction and the distance D from the survey tool 17 to the center of the magnetized section are well known to those skilled in the art of magnetic interception.
[0039] [0039]FIG. 2 shows an expanded region of a magnetized casing section 13 having a radius r shown from the center line. In this figure, three adjacent sections of magnetization are shown. Note that the upper and lower regions 20 and 22 are of the same magnetic polarity (flux line direction) and that the intermediate section 21 is of the opposite polarity. Any number of sections in a casing string may be magnetized, and such sections may be combined in any desired manner to provide a unique magnetic signature for the casing string. Also, as shown in FIG. 1, non-magnetized sections 50 may be included. The distance D between the North “N” and South “S” poles is generally some multiple of the length of the individual casing sections. Such casing sections are typically on the order of 30 feet long, so that multiple sections on the order of 30, 60, 90 120 or 150 feet are feasible or reasonable. The range of detection of a section of length L depends both on the strength of the magnetic field and the length of the net magnetic dipole created by the magnetization of section. Typical magnetization results in the type of magnetic field structure shown in FIG. 2.
[0040] [0040]FIG. 3 shows one form or method of magnetization, using an external coil structure 30 extending about the casing section 13 . The coil structure 30 comprises an electric solenoid coil 33 with windings extending about section 13 to provide the magnetomotive force for the magnetization when supplied with electric current. Pole pieces 32 at each end of the coil can be size adapted for a variety of diameters of the casing section 13 . The axial spacing between the pole pieces 32 exceeds the casing section diameter. The magnetic flux created by the coil 33 flows through the pole pieces 32 , through the air gaps 32 a between the pole pieces and the casing section 13 and then returns longitudinally to the other end of the coil through the casing section. The magnetic flux in the air gaps is generally radial. This radial flux creates a force between the pole piece and the casing section. Spacers such as rollers wheels 34 which may be carried by or near pole pieces 32 , provide for spacing and/or reduced friction between the pole pieces and the casing. A magnetic flux measuring device 35 is placed to be near one end of the passing casing 13 so that the achieved level of magnetization may be determined. The flux measuring device 35 is connected to a flux indication instrument 37 by wire 36 b.
[0041] A power supply 38 provides a direct electrical current to the coil 33 by means of wire 36 a. A manual adjustment 39 such as a variable resistance provides a means to select the current level to be applied to the coil. Coil windings extend between pole pieces 32 , and are located radially outwardly of elongated air gap 32 a.
[0042] The apparatus shown in FIG. 3 may be used in a number of ways to magnetize the casing section. The casing section 13 can be held immobile with respect to the earth as the coil structure 30 is traversed along the casing section in an axial direction. Alternatively, the coil structure may be held immobile with respect to the earth as the casing section is traversed through the coil structure. If desired, the coil structure may be mounted axially vertically directly above the borehole. In this situation, the casing section can be magnetized as it is being lowered into the borehole.
[0043] [0043]FIG. 4 shows an alternative form of magnetizing coil. This configuration is for use internal to the casing section rather than external to the casing as shown in FIG. 3. Inside the casing segment 13 is an internal coil structure 40 . This coil structure comprises a flux passing metallic core 41 , shown as axially elongated, two end annular pole pieces 42 , and an electric solenoid coil 43 that provides the magnetomotive force for the magnetization when supplied with electric current. The annular pole pieces 42 at each end of the core 41 can be adapted for a variety of diameters of the casing section 13 . As in FIG. 3, the magnetic flux created by the coil 43 flows through the core 41 , the pole pieces 42 , through the air gaps 42 a between the pole pieces and the casing section, and then returns longitudinally to the other end of the core through the casing section. The magnetic flux in the air gaps is generally radial, and creates a force between the pole piece and the casing segment. Roller wheels 44 , carried on or near to 42 , provide spacing and/or reduced friction between the pole pieces and the casing section. If the rollers are carried by the pole pieces, changes in the pole piece diameters also change the roller positions to accommodate to different size casing, well tubing or drill pipe. The other elements of FIG. 4, items 35 through 39 , are the same as shown and discussed in relation to FIG. 3 above.
[0044] [0044]FIG. 5 shows an alternative power supply 51 that may be used with either of the coil structures of FIG. 3 of FIG. 4. Elements 30 through 37 are the same as shown and discussed in relation to FIG. 3 above. The power supply 51 includes a direct current source 52 , an alternating current source 53 , a selector switch 54 , having positions 55 and 56 , another selection switch 59 having positions 57 and 58 . In some situations, it may be desirable to demagnetize casing segments that are to be adjacent to magnetized sections. This may be accomplished by selecting with switch 54 the direct current position 55 or an alternating current position 57 . Use of alternating current transmitted to the coil effects demagnetization as the casing passes through the coil. Further, it may desirable to control the magnetization achieved in the casing section to a known and selected value. Switch 54 can select position 55 to engage a manual control of the direct current source 52 using control knob 159 . In this case, the operator can read the indicated magnetic flux on the flux indicating meter 37 and manually adjust the direct current source 52 to supply direct current to a level such that the desired flux value is reached. This manual feedback control may be made automatic by selecting position 56 to directly connect the signal from the flux measuring device 35 to the direct current source 52 . In this feedback mode of operation, the knob 159 can be used to set the desired flux value which is then automatically obtained.
[0045] In all of the above discussion, casing segments have been discussed as elements to be magnetized. All of the above applies equally well to the magnetization of drill pipe or any other wellbore tubular member that may be magnetized.
[0046] As stated above, it has been recognized that a useful magnetic field for intercept purposes was often available from some previous magnetic inspection of the casing or drill pipe sections. Apparatus described above is generally applicable in conjunction with magnetic inspection. Thus it is possible to specify certain values and limits to a casing-inspector, or contractor, and to achieve the desired casing magnetization described above as a byproduct of the casing inspection process.
[0047] As shown in FIG. 7, after the magnetized pipe or casing 70 a, magnetized by any of the methods of this invention, is placed in a completed casing or pipe string 70 in the borehole, a magnetic measuring device 74 such as a set of three magnetometers, may be used to traverse the borehole regions of the magnetized sections as shown in FIG. 7. The measured magnetic field F 1 inside the completed casing has a direct and knowable relation to the field F 2 existing outside the casing in adjacent regions, as indicated by the expression F 2 =f (F 1 ). A magnetic field measuring device 74 is shown on a wire line 75 , traversing the interior of magnetized section 70 a. Thus a knowledge of the magnitude of the external field is obtained from such an internal measurement. Knowing the magnitude of the external magnetic field permits estimation of the range between an external magnetic field sensing apparatus and the casing. See circuitry 76 at the surface, connected with 74 , and operable to provide such a range estimate, at readout 79 . This is a direct estimate based solely on the magnitude information. Circuitry employed in conjunction with operation of 74 and 76 may include a magnetometer and a 16-bit A/D signal converter, for enhancing sensing of pipe section magnetization for improved accuracy and resolution at the readout 79 , as referred to above. Device 74 is traveled in the bore near the polar end or ends 70 aa and 70 aa′ of the magnetized pipe section, to detect same.
[0048] Referring now to FIG. 6 a, casing string 160 is shown as installed in a well bore 161 . The string includes casing sections 160 a connected end to end, as at joint locations 160 b. The sections are magnetized as described above, with positive + and negative poles − formed at the casing ends, as shown. Accordingly, the casing includes casing sections connected at joints, there being first and second sections having end portions of negative polarity connected at one joint, the second section connected with a third section, and having end portions of positive polarity connected at the next joint.
[0049] See in this regard casing end portions 163 and 164 of negative polarity, and the casing end portions 165 and 166 of positive polarity.
[0050] Referring now to FIG. 6 b, it shows a series of magnetic measurements taken along a casing length, extending at an angle to vertical, in a well bore. There are four charts 6 b- 1 , 6 b- 2 , 6 b- 3 , and 6 b- 4 . Chart 6 b- 1 shows magnetic values in nanoTesla along the abcissa, and positions along the casing length, in feet, along the ordinate. Two runs are shown, one run shown in a solid line 170 and the other run shows in a broken line 171 .
[0051] Chart 6 b- 1 is for magnetic measurements along the high side of the angled casing; chart 6 b- 2 is for magnetic measurements taken along the high side right dimension; chart 6 b- 3 is for magnetic measurements taken down hole; and chart 6 b- 4 is for a computed total of the first three chart measurements, at corresponding depth locations along the casing.
[0052] In this regard, the earth's field has been mathematically removed from the measured data.
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In the method of providing for well tubular member magnetization, the steps include providing a magnetizing structure comprising an electrical coil defining an axis, relatively displacing the member and the structure, with the coil positioned and guided in close, centered proximity to the member, while supplying electric current to flow in the coil, thereby creating magnetic flux passage through the member and core to magnetize the member, or a part of the member, and displacing the member in a wellbore.
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BACKGROUND OF THE INVENTION
The invention relates to gas turbine engines, particularly the internal cooling of turbine blades, and to improved method and apparatus for delivery of cooling air to the blades.
In essence, a gas turbine engine comprises a compression stage in which air is pressurized. Pressurized air is sent to a combustion chamber where it is mixed with fuel and the mixture is ignited. The combustion gases produced by the ignition of the air/fuel mixture is a hot, rapidly expanding gaseous volume which is directed from the combustion chamber to a turbine wheel to drive the latter.
In order to achieve efficiency available with higher temperature gas turbine engine operation, the turbine rotor blades are effectively and efficiently cooled. The prior art has provided rotor blades with internal passages. Cooling fluid is injected into these internal cooling passages or channels, flows through the interior of the blade and exits therefrom to provide additional surface cooling of the blades. This arrangement is disclosed in greater detail in U.S. Pat. No. 4,270,883, assigned to the same assignee herein, issued Jan. 2, 1981; made a part hereof by reference.
When considering the addition of apparatus to cool the rotor blades of a turbine engine, the operational speed at which parts of the engine move must be given due consideration. For example, the rotor blades move in a circular path as the rotor rotates. Within as little as one second, the tip of each rotor blade may travel 2,000 feet or more. Under such dynamic conditions it is of utmost importance that the structural integrity of the rotor/rotor blade assembly be maintained.
In general, the coolant fluid employed in a gas turbine engine will be air derived from the compression stage. The more air that is drawn off for cooling purposes, the less air available for use in the combustion chamber. The most efficient cooling system will draw the least amount of air from the compressor. Once air has been drawn from the compressor for use as a coolant, it is an important function of the cooling system that losses, both fluid and mechanical, be minimized.
Cooling fluid flow losses are generally attributable to insertion losses and pumping losses. Pumping losses result from the energy taken from the rotor as it works to move coolant fluid from the radius at which it is injected on or into the rotor outward to the radius of the rotor blades, at the periphery of the rotor.
Insertion losses are made up of seal losses, frictional losses, and swirl losses. In directing coolant fluid from one place to another, the fluid may move from regions having stationary elements to those having rapidly rotating elements. Because of the high speed of rotation of these latter elements, the seals employed between stationary and moving parts generally comprise labyrinth structures which impede the flow of coolant fluid through them by providing a high impedance, tortuous fluid-flow-path. However, the structure is basically a leaky one and becomes more so as the pressure of the fluid impinging on the seal increases.
Seal losses are minimized by minimizing the static pressure of the fluid impinging on the seals. Reduction of seal losses, in turn, reduces the amount of air that must be supplied by the compressor stage. For a given compressor stage, there is more air available for combustion purposes when seal losses are minimized.
Frictional losses result from the interaction of the rotational elements of the engine with the coolant fluid. Frictional losses reduce the efficiency of cooling by raising the temperature of both the coolant and the moving parts, and by decreasing the coolant's pressure. Thus, when frictional losses are significant, a higher initial coolant pressure is required. This higher pressure increases the burden on the seals and an increased seal loss derives.
Swirl losses are caused when the rotor, rotor blades, or other rotating parts of the turbine engine have to impart energy to the coolant to accelerate the coolant fluid such that the coolant itself acquires a rotational velocity or swirl equal to that of the rotor or other rotating part. This places a load on the rotating parts, raises the temperature of the coolant fluid and reduces the shaft energy available from the turbine engine.
An optimum cooling system will minimize insertion losses (seal, frictional and swirl) and pumping losses by minimizing the work done in moving coolant fluid into the rotor blades, all the while maintaining structural integrity of the rotor. The art in this area has concentrated for the most part on a single approach to more efficiently supply cooling air to turbine blades, namely, by imparting some degree of swirl to the cooling air before it is supplied to the turbine rotor, thereby minimizing some portion of the insertion losses. This technique will reduce swirl loss, for, if it is performed effectively, the cooling air is brought to a tangential velocity equaling the tangential velocity of the turbine rotor at the point at which the cooling air is supplied to the turbine rotor.
An early reference utilized this approach is U.S. Pat. No. 2,910,268 to Davies et al., which is an apparatus for tapping air from a compressor section of a turbine engine and providing it to the interior portion of the shaft of a turbine rotor. Succeeding references have further improved the techniques of preswirling the cooling air so as to reduce some components of insertion losses including swirl loss. Such references include U.S. Pat. Nos. 2,988,325; 3,602,605; and 3,936,215. By preswirling the cooling air, insertion losses are reduced somewhat. Additionally, the preswirling effectively presents nozzles through which the cooling flow expands to reach rotor speed at a lower pressure and temperature.
These devices all possess significant problems in delivering the cooling air to the turbine blades in that they require a primary design choice to be made. If cooling air is supplied at high pressure to the turbine rotor, there is a substantial leakage problem resulting in the loss of a significant percentage of the cooling air and resulting in reduced efficiency in the cooling operation. The other alternative involves supplying cooling air at a somewhat lower pressure and utilizing a pumping vane to move the air from the interior of the turbine rotor outward to the turbine blade. This technique necessarily involves performing a substantial amount of work on the cooling air, decreasing the efficiency of the cooling operation and causing drag on the turbine wheel as well as increasing the temperature of the cooling air supplied to the turbine blades. An example of such a pumping blade is shown in U.S. Pat. No. 3,602,605 to Lee et al.
Very high speed rotating turbomachinery has yet further trade-offs in structural design considerations for delivering cooling flow to rotating, internally cooled turbine blading. Specifically, the optimal radius for injecting cooling flow into the turbine rotor oftentimes lies between the central bore of the rotor and its outer periphery where the turbine blading is located. Because of the high rotational speed of the rotor, however, in smaller gas turbine machinery the necessarily rotating support structure for defining an entry for the cooling flow at the optimal radius must be quite heavy and bulky in order to withstand the high centrifugal loads thereon. This results in added weight and dramatically increased mechanical complexity for the smaller gas turbine engine.
Additionally, it has been found that such rotating support structure must be axially offset somewhat from the rotating turbine in order to provide the required strength to these rotating elements. As a result, the cooling flow is then necessarily injected into a relatively large, open cavity wherein various aerodynamic losses occur to the cooling flow before it can find its way to the passages ultimately leading to the internal turbine blade cooling passages.
SUMMARY OF THE INVENTION
Accordingly, an important object of the present invention is to provide improved method and apparatus for delivering cooling flow, particularly for high speed rotating gas turbine machinery, wherein the cooling flow is ported directly into a radially extending sideface of the hub of the turbine rotor, and then proceeds internally within the hub to the outer periphery thereof to reach the internal passages within the turbine blading.
More particularly, the present invention contemplates a turbine hub structure made of a plurality of separate elements, or otherwise constructed to present a unitary rotating hub section having internal cavities therewithin. Additionally, an annular channel or groove on one sideface of the hub is in fluid communication with the internal cavity. A stationary, annular nozzle fits within the annular channel on the sideface of the hub for directing cooling flow thereinto in a most efficient and economical manner, thereby eliminating the heavy, rotating support structure normally associated with high speed, smaller gas turbine machinery.
These and other objects and advantages of the present invention are specifically set forth in or will become apparent from the following detailed description of a preferred arrangement of the invention, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial longitudinal cross-section of a portion of a gas turbine engine as contemplated by the present invention, with the peripheral turbine blading shown in full section;
FIG. 2 is a partial front plan view of the turbine rotor construction illustrated in FIG. 1, with the peripheral internally cooled turbine blading exploded slightly therefrom for clarity of illustration;
FIG. 3 is a partial perspective view of the annular stationary nozzle for delivering cooling flow to the turbine wheel of FIG. 1; and
FIG. 4 is a partial longitudinal cross-sectional view, similar to FIG. 1, but showing an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIGS. 1-3, a portion of a high speed rotating gas turbine engine 10 is illustrated, having a drive shaft 12 extending through the central bore 14 of a turbine rotor stage 16. Rotor 16 includes along its outer periphery 18 a plurality of internally cooled turbine blades 20 which are disposed circumferentially about the periphery of wheel 16. As conventional, the blades 20 have a dove-tail or fir-tree like base 22 which fits within corresponding fir-tree or dove-tail configured openings 24 along the outer periphery 18 of the turbine wheel 16. Internal cooling passages 26 within the blade portion per se of blades 20 extend downwardly through the dove-tail base section 22 to the outer periphery 18 of the turbine wheel. Cooling flow delivered to internal passages 26 ultimately exits the blades 20 through openings such as those illustrated at 30 in FIG. 1.
Wheel 16, along with the peripheral blades 20 is mounted in torque transmitting relationship to the shaft 12 near the central bore 14 of the wheel. Illustrated in FIG. 1 is certain surrounding stationary structure of the gas turbine engine including vanes stator 32 and 34 respectively upstream and downstream of the turbine wheel 16, along with the adjacent mounting structure 36 for defining the primary path for high temperature hot gas flow across the turbine blades 20. Additionally, the stationary support structure 36 defines a space 38 within the engine wherein a cooling flow of pressurized fluid is introduced from a source from the engine illustrated diagrammatically by element 40. Conventional sealing arrangements as at 42 are also illustrated in FIG. 1.
Turbine rotor 16 includes a hub section 44 which may be made of wrought super alloy material to withstand the high centrifugal loading imposed thereupon. As contemplated by the present invention, the hub section 44 is comprised of a plurality of separate elements. In the FIG. 1 arrangement, the three elements comprising hub 44 include elements 46, 48 and 50. Element 46 presents the primary structure of the hub, while elements 48 and 50 are both of annular configuration which are separately, permanently intersecured to element 46 such as by diffusion bonding. More particularly, element 48 which is disposed radially outwardly and concentrically to element 50, is illustrated with a plurality of axially extending support structures 52, the opposite end of which are diffusion bonded to element 46 such that elements 46 and 48 are permanently intersecured. Similarly, element 50 may include a plurality of support elements 54 extending axially to be diffusion bonded to element 46.
Importantly, the three elements 46, 48 and 50 are so relatively configured and arranged so as to define an internal cavity means 56 within the hub section 46 that extends generally radially outwardly to the outer periphery 18 of the hub section 46. From the outer periphery the internal cooling cavity 56 communicates with the internal cooling passages 26 of the turbine blades 20.
Importantly, the elements 48 and 50 each have axially extending, upstanding walls 58 and 60 which extend annularly around the hub section 46 so as to define a continuous, annular channel 62 therebetween. Channel 62 extends directly inwardly to open into internal cooling cavity 56. Walls 58 and 60 are radially located so as to define the annular channel 62 at a preselected optimal radius R as described in greater detail below.
Stationary support structure 36 provides stationary support for an annularly configured, ring-like nozzle assembly 64 disposed adjacent channel 62. More particularly, nozzle assembly 64 (illustrated in greater detail in FIG. 3) is a continuous annular circular ring defining nozzle passages 66 between radial inner and outer walls 68 and 70. Preferably, a plurality of preswirl vanes 72 extend radially across nozzle space 66. Nozzle assembly 64 is securely mounted to stationary structure such as elements 74 and 76 in FIG. 1 so as to receive the cooling fluid flow from space 38 and direct the latter into cooling channel 62 of hub section 46.
Thus, the structure of the present invention provides an inlet nozzle that is stationary, but which fits within the rotating annular channel 62 so as to deliver cooling flow directly into the interior of the hub section 44 of the turbine wheel. In this manner the present invention eliminates the axially offset coverplate which is normally associated with the turbine stage of a high speed gas turbine engine to provide the necessary support structure for delivery of cooling air flow to the cooled turbine blades 20.
In the preferred arrangement, the blades 72 act as preswirl vanes for imparting a rotary swirl to the incoming cooling air flow such that its tangential velocity approximates the tangential velocity of the rotor hub at the channel 62 in order to minimize insertion fluid losses. Similarly, in a preferred arrangement the support structure 52 may present a plurality of pumping vanes aerodynamically configured in order to provide pumping assistance in driving the cooling air flow efficiently radially outwardly to the outer periphery of the hub section 46. This further minimizes aerodynamic losses to the cooling flow while providing cooling flow at a sufficient pressure to adequately cool the turbine blades 20.
Also, preferably, the support structure 54 may be aerodynamically configured such that a certain amount of cooling air flow in cavity 56 passing radially inwardly across structure 54 imparts torque to assist in rotatively driving wheel 16. In this manner the flow across structure 54 tends to reintroduce into the turbine wheel 16 a certain amount of the rotating energy which is lost in structure 52 in pumping the cooling flow radially outwardly. In the arrangement illustrated in FIG. 1, the portion of cooling flow in cavity 56 which passes radially inwardly across structure 54 may be discharged into central bore 14 for passage therealong for secondary cooling in the zone 76 behind wheel 16.
Preferably, the walls 68 and 70 of the nozzle assembly 64 fit relatively closely to the adjoining walls 58 and 60 of elements 48 and 50. However, in a preferred arrangement, sealing means are not required between these adjacent walls. The channel 62 is relatively slightly overpressurized in comparison to the spaces 78 and 80 such that any leakage of cooling flow out of channel 62 acts as a secondary cooling flow source for the spaces 78 and 80 within the engine.
In operation of the FIG. 1 embodiment, hot combustion gas from the engine is directed across stationary vanes 32 to flow across blades 20 and rotate the turbine wheel 16. Cooling fluid flow from the source 40 is pressurized and directed into space 38 for subsequent discharge through the nozzle assembly 64 and across the preswirl vanes 72 to enter the rotating annular channel 62 of the hub section at the optimal radius R in a highly efficient manner. The cooling flow in channel 62 passes through the internal cavity 56 within hub section 46 for subsequent delivery to the internal cooling passages 26 within the blade for efficient cooling thereof. As noted, a portion of this cooling flow may pass radially inwardly to the central bore 14 for secondary cooling purposes.
Referring now to FIG. 4, an alternate arrangement for the hub section is illustrated. More particularly, turbine wheel 116 has an outer periphery 118 configured as wheel 16 of FIG. 1, for receiving the blades 20 for receiving the cooled blades 20. Adjacent one radial face of wheels 116 is like support structure 36, 74 and 76 as illustrated in FIG. 1 for supporting and positioning the same nozzle assembly 64 as previously described.
In contrast to the FIG. 1 arrangement, the hub section 144 of the turbine wheel 116 is comprised of only two sections 146,148 rather than the three sections of the hub section of the wheel FIG. 1. The two elements 146,148 are diffusion bonded together along a radial joining plane 150, and are so configured so as to define an internal cooling cavity 152 within the interior of hub section 144. Element 148 has defined on the external face thereof a pair of walls 158,160 for defining a continuous annular channel 162 therebetween. Accordingly, it will be seen that the continuous annular channel 162 may receive preswirled cooling air flow from the stationary nozzle assembly 64 as was described previously with respect to the FIG. 1 embodiment.
The continuous annular channel 162 communicates with the internal cavity 152 through a plurality of drilled holes or ducts 164. In this manner it will be seen that cooling air flow from space 38 is delivered ultimately to the internal cooling cavity 152 for radially outward flow to the cooling passages 26 of the cooled turbine blades as described with respect to FIG. 1. Preferably, the other element 146 may include a plurality of pumping vanes 154 extending axially across the internal cavity 152 in order to impart additional energy for efficiently delivering the cooling air flow to the outer periphery 118 of the hub section 144. As desired, the internal cooling cavity 152 may be so configured so as to extend radially inwardly from channel 162 in order to reduce the mass of the rotating turbine wheel 116.
In both FIGS. 1 and 4 radius R refers to the radius at which the injector nozzle 64 and the inductor channel 62,162 is located with respect to the longitudinal rotary axis of the turbine engine. As those skilled in the art will readily understand, the selection of the radius R will affect the static pressure, the dynamic pressure, and the temperature of the coolant injected into the interior cooling channels 26 of rotor blades 20. These various interactions must be borne in mind by those skilled in the art when selecting the radius R.
Those skilled in the art will recognize that, as the coolant enters cooling channels 26 in the interior of blades 21, a designated static pressure will be required to move the air into and through the cooling channels 26. The smaller the radius R, the greater the velocity component or dynamic pressure required to cause the coolant to arrive at the entry point of channels 26 at the base of rotor blades 20. The static pressure at the output of injector nozzle 64 should be reasonably low so as not to overstress any labyrinth seals in the system. The volume of air flow per unit time, sometimes referred to as dynamic pressure, must not be so great as to cause a back pressure to build up within channel 62,162.
The coolant channel volumetric capacity decreases as the radius R approaches closer to the longitudinal axis. Thus, locating channel 62,162 closer to the longitudinal axis has the effect of decreasing the volume flow capacity of coolant through inductor nozzle 64 since the channels 62,162 are of reduced volumetric capacity closer to the axis.
Coolant flowing through injector nozzle 64 and around swirl vanes 72 experiences a decrease in temperature as the velocity component, the dynamic pressure, of the coolant increases. Thus, the velocity component of the coolant, which is in turn affected by the initial injection pressure of the coolant into injector nozzle 64, should be selected to yield the lowest available temperature for the conditions of operation.
These conditions of operation include the available total pressure and volume of coolant flow available at the input to injector nozzle 64. All of these factors, then, must be considered by one practicing the invention in order to achieve the desired, swirled condition of the coolant flow. Those skilled in the art will recognize that the entire process is an iterative one.
What has been disclosed is a rotationally swirled axially directed cooling fluid flow system for use in a gas turbine engine. Coolant is directed in an axial direction while swirled tangentially to the direction of rotor motion. A continuous annular inductor or channel 62,162 inducts coolant into internal cavity 56,152 on the rotor of the engine so as to cause the coolant to be ducted to interior cooling passages 26 within the rotor vanes. A continuous annular injector or nozzle 64 located in juxtaposition to the continuous annular inductor provides an efficient means for injecting the coolant into the continuous inductor in such a manner that the coolant travels in a rotary path while the coolant maintains an axially directed impetus to move the swirling coolant toward the rotor.
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Method and apparatus for delivering cooling fluid flow to the internal blade cooling passages in a gas turbine engine, wherein cooling flow is injected into a radial side face of the hub of the turbine wheel and is ported therefrom through internal passages in the hub to the blade internal cooling passages.
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BACKGROUND OF THE INVENTION
The present invention relates to a flower holder.
DESCRIPTION OF THE RELATED ART
A holder of this kind is known from NL-A-8802054. It should be understood that where reference is made in this description to bottom opening or other parts with bottom or top, a state of the holder in which the flowers of a bouquet are situated at the top side and the stalks are situated at the inderside is intended. A bunch of flowers can, of course, also be positioned inversely.
Such a holder is used to receive a bunch of flowers. On the underside an opening remains free in order to be able to place the stalks of the flowers in a bucket or the like in order to provide supply of water.
Although packaging of this kind is quite adequate it has the disadvantage that the position of the bunch of flowers with regard to the holder is not fixed so that it is quite possible that the flowers will leave the holder in an uncontrolled way.
SUMMARY OF THE INVENTION
The invention aims to remove this drawback. This object is achieved in the case of a holder as described above by means of the characterizing features of claim 1.
As a result, the arrangement of a bouquet is preserved and damage to the plants is prevented. Moreover, due to the presence of a tying cord, the bouquet can easily be secured.
The above-described circumferentical reinforcement may be present not only on the underside but also on the top side. Moreover, further circumferential reinforcements may be present.
Although the sleeve may have all forms known in the prior art, it is preferably designed as a truncated cone.
The sleeve may be made from all materials known in the prior art. In a preferred embodiment, the structure comprises strip parts which extend perpendicularly to the above-described circumferential reinforcement.
These strip parts, as well as the rest of the sleeve, can be made from reed-like material.
It is, however, also quite possible to construct the sleeve in a different manner. Thus it can consist of a lattice, such as gauze. With a construction of this kind, at least part of what is situated inside the sleeve remains visible, which can be attractive for certain applications.
The above-described holder can also be used in combination with pot plants. If the underside of the pots is, provided with openings, it is often undesirable for moisture to escape to the outside through these openings. In such a case, it is proposed to arrange a sheet of plastic material or other liquid-tight material in the vicinity of the opening of the holder, and such a sheet provides a liquid-tight seal at the bottom when the pot plant is placed through the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be illustrated in more detail below with reference to an exemplary embodiment depicted in the drawing, in which:
FIG. 1 shows a perspective and cut-away view of the holder according to the invention;
FIG. 2 shows the holder according to the invention with a number of flowers arranged therein; and
FIG. 3 shows the holder according to the invention in combination with a pot plant.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The sleeve according to the invention is indicated in its entirety by 1 in FIGS. 1 and 2. This sleeve consists of a number of reinforcement ribs 6-8 which extend along the circumference of the sleeve 1. In this case, reinforcement rib 6 is situated in the vicinity of the bottom opening 4, reinforcement rib 7 in the vicinity of the top opening and reinforcement rib 8 between them. These reinforcement ribs are supported by strip parts 9. Tying cords 2 are fastened to the bottom reinforcement ribs 6.
All the said components can be made from a reed-like material. Conventional joining techniques, such as sewing, can be used to hold the various parts together.
Instead of the relatively fine structure shown here, it is also possible to use a coarse structure.
In FIG. 2, the use of the sleeve according to the invention in combination with a bunch of flowers 5 is shown. It can be seen from this that stalks of the bunch project through the bottom, smaller opening 4, which stalks are held together by the tying threads 2. For protection, a further sleeve 10 may optionally be placed over the stalks, or a piece of aluminium foil may be used.
With the structure chosen here, the bouquet which is present in the sleeve will not easily be changed to a different arrangement. Moreover, the reinforcement ribs 6-8 provide protection against external forces. The bouquet according to the present invention will also not be flattened during transportation and optimum presentation is obtained.
In FIG. 3, a further embodiment of the holder according to the invention in combination with a pot plant is shown.
Parts which correspond to FIGS. 1 and 2 are provided with the same reference numerals. The tying threads 2 are used here to secure the pot plant to the sleeve 1.
The pot of the pot plant is indicated by 12 and is provided with an opening 13.
In order to prevent moisture from leaking through this opening 13, it is proposed to arrange a sheet of material 14 in the holder according to the invention. When the opening 4 arranged on the underside of the sleeve 1 is spread open, the sheet 14 will provide a lower boundary for the structure. This sheet 14 remains invisible to the user due to the presence of the reed-like material.
Although the invention is described above with reference to a preferred embodiment, it should be understood that numerous modifications may be made thereto without departing from the scope of the present application. Thus it is possible to produce the structure from gauze material, which may or may not be provided with a curing resin. The opening in the holder may also be present in a prepared state, that is to say due to the absence of threads extending around the top of the cone. It is also possible to use a different polygonal shape instead of a truncated cone shape. This and similar variants are all considered to be obvious and to lie within the scope of the claims.
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A holder for a bunch of flowers includes a sleeve surrounding the bunch, which is designed as a truncated cone having circumferential reinforcements at the free openings to form a relatively rigid form and a trying cord fastened to the sleeve lower free opening.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to display devices, and in particular to a display panel capable of reducing number of data signal driving IC.
2. Description of the Related Art
FIG. 1 is a diagram showing a conventional display driving circuit 10 . It includes two data drivers 121 and 122 , a scan driver 11 , a pixel matrix comprising display cells 13 , and switches 161 and 162 comprising transistors. Each display cell 13 in the odd columns of the pixel matrix receives a data signal through a data line 151 from the data driver 121 or 122 . Each display cell 13 in the even columns of the pixel matrix receives a data signal through a data line 152 from the data driver 121 or 122 . The display cells 13 also receive scan signals through scan lines 14 from the scan driver 11 . To reduce number of the data drivers, data lines 151 and 152 are respectively coupled to the display cells 13 in the odd and even column of the pixel matrix share the same data terminal as the data driver through the switches 161 and 162 controlled by signals SW 1 and SW 2 . When one of the scan signals is applied, the odd and even display cells 13 in the scanned row of the matrix receive the data signal output from the same terminal of the data driver 121 or 122 by turns. In FIG. 1 , for example, the number of the data drivers is half that when not using the switches to share the data terminals since each data terminal provides the data signals to two columns of display cells of the pixel matrix.
However, in the conventional display driving circuit, the switching frequency of the switches 161 and 162 is n times the frame rate, wherein n is the number of the columns in the pixel matrix. For example, the switching frequency of the switches in a display having 768 pixel columns and a frame rate of 60 Hz is 46080 Hz. Such a switching frequency is much higher than that of the thin-film transistors (TFTs) used in the display cells 13 . Besides, the high duty ratio and high current stress also degrades the reliability of the circuit.
BRIEF SUMMARY OF THE INVENTION
A detailed description is given in the following embodiments with reference to the accompanying drawings.
Embodiments of display panels are provided, in which a data driver outputs first, second, third and fourth data signals in sequence through a data line, a scan driver outputs first and second scan signals in sequence through first and second scan lines and an auxiliary driver generates first and second auxiliary signals in sequence. First and second display cells receive the first scan signal through the first scan line simultaneously and receive the first and the second data signals through the data line respectively, and a first switch is coupled to the data line and the second display cell, turning on and off in sequence according to the first auxiliary signal when the first scan signal is applied thereto such that the second display cell receives the first data signal and the first display cell receives the second data signal in sequence.
The invention also provides embodiments of a display panel, in which a data driver outputs first, second, third and fourth data signals in sequence through a data line, and first and second scan drivers output first and second scan signals in sequence through first and second scan lines. First and second display cells receive the first scan signal through the first scan line and the second scan line respectively and receive the first and the second data signal respectively through the data line simultaneously.
The invention also provides embodiments of electronic device, in which the disclosed display system is applied and a power supply powers the display system to display images.
The invention also provides embodiments of a driving method, in which a first auxiliary signal is applied to turn on a first switch such that a first data signal from a data line is transferred to first and second display cells and a first scan signal is applied to enable the first and the second display cells to receive the first data signal, during a first period. The first auxiliary signal is de-asserted to turn off the first switch such that the first display cell is electrically separated from the data line and the second display cell receives a second data signal from the data line according to the first scan signal, during a second period, in which the first switch is turned off until the first scan signal and the first auxiliary signal are applied at the same time again. A second auxiliary signal is applied to turn on a second switch such that a third data signal from the data line is transferred to third and fourth display cells and a second scan signal is applied to enable the third and the fourth display cells to receive the third data signal, during a third period. The second auxiliary signal is de-asserted to turn off the second switch such that the third display cell is electrically separated from the data line and the fourth display cell receives a fourth data signal from the data line according to the second scan signal, during a fourth period, in which the second switch is turned off until the second scan signal and the second auxiliary signal are applied at the same time again.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 shows a conventional display driving circuit;
FIG. 2A shows an embodiment of a display panel of the invention;
FIG. 2B is a timing chart of the display panel shown in FIG. 2A ;
FIG. 3A shows another embodiment of display panel of the invention;
FIG. 3B is a timing chart of the display panel shown in FIG. 3A ; and
FIG. 4 is a schematic view showing an electronic device using display panels shown in FIGS. 2A and 3A .
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
FIG. 2A is a diagram showing a display panel 200 A according to a first embodiment of the invention. It includes a data driver 21 , a scan driver 22 , an auxiliary driver 23 , a timing controller 24 , and a pixel matrix composed of six (for example) display cells P 1 ˜P 6 , and three switches ST 1 , ST 2 and ST 3 . For example, the display panel 200 A can be a liquid crystal display panel, a plasma display panel or an organic light emitting display panel, but is not limited thereto.
The data driver 21 outputs the desired data signals (not shown) for the six display cells P 1 ˜P 6 through the data line DL. For example, the data driver 21 can be a data driving integrated circuit (IC) formed by single-crystal Si transistors, but is not limited thereto. The scan driver 22 outputs scan signals S 1 ˜S 3 in sequence through the scan lines SL 1 ˜SL 3 . For example, the scan driver 22 can also be a scan driving integrated circuit (IC) formed by single-crystal Si transistors. The auxiliary driver 23 outputs auxiliary signals SW 1 ˜SW 3 through auxiliary signal lines AL 1 ˜AL 3 . In the embodiment, the auxiliary driver 23 is a driving integrated circuit (IC) formed by a-Si transistors on the display panel rather than single-crystal Si transistors, and the data driver 21 , the scan driver 22 and the auxiliary driver 23 are controlled by the timing controller 24 .
The display cells P 1 and P 2 receive the scan signal S 1 through the scan line SL 1 simultaneously, the display cells P 3 and P 4 receive the scan signal S 2 through the scan line SL 2 simultaneously, and the display cells P 5 and P 6 receive the scan signal S 3 through the scan line SL 3 simultaneously. The display cells P 1 , P 3 and P 5 receive corresponding data signals respectively through the data line DL simultaneously, the display cells P 2 , P 4 and P 6 coupled to the switches ST 1 , ST 2 and ST 3 respectively, receiving corresponding data signals respectively through the data line DL simultaneously. The switches ST 1 , ST 2 and ST 3 are coupled between the data line DL and the display cell P 2 , between the data line DL and the display cell P 4 and between the data line DL and the display cell P 6 respectively.
As shown, the display cell P 1 comprises a transistor M 1 and a capacitor Cs 1 , the display cell P 2 comprises a transistor M 2 and a capacitor Cs 2 , and the display cells P 3 ˜P 6 are similar to the display cells P 1 and P 2 . Gates of the transistor M 1 , M 3 and M 5 are coupled to the scan lines SL 1 , SL 2 and SL 3 respectively, drains of which are coupled to the data line DL, and sources of which are coupled to capacitors Cs 1 , Cs 3 and Cs 5 respectively. Gates of the transistors M 2 , M 4 and M 6 are coupled to the scan lines SL 1 , SL 2 and SL 3 respectively, drains of which are coupled to the data line DL, and sources of which are coupled to capacitors Cs 2 , Cs 4 and Cs 6 respectively.
The switches ST 1 ˜ST 3 are formed by transistors M 7 ˜M 9 , gates of the transistors M 7 ˜M 9 are coupled to the auxiliary signals SW 1 ˜SW 3 respectively, drains of which are coupled to the data line DL, sources of which are coupled to the display cells P 2 , P 4 and P 6 respectively. In the embodiment, the transistors M 1 ˜M 9 are a-Si transistors, but are not limited thereto.
FIG. 2B is a timing chart of the display panel shown in FIG. 2A . The scan period when the scan signal S 1 is applied (the scan signal S 1 is asserted and has a logic high level) is divided into two sub-periods T 1 and T 2 . The auxiliary signal SW 1 turns on the transistor M 7 (closes the switch ST 1 ) and turns off the transistor M 7 (the switch ST 1 is opened) in sequence during the sub-periods T 1 and T 2 respectively, when the scan signal S 1 is applied.
During the sub-period T 1 , during which the transistor M 7 is turned on, the display cell P 2 in the even column of the pixel matrix receives the data signal from the data driver 21 through the data line DL, and the display cell P 1 in the odd column of the pixel matrix receives the data signal from the data driver 21 through the data line DL during the sub-period T 2 , during which the transistor M 7 is turned off. For example, the data signal from the data driver 21 during the sub-period T 1 can be a data signal with a positive polarity, and the data signal from the data driver 21 during the sub-period T 2 can be a data signal with negative polarity, but are not limited thereto.
It should be noted that the display cell P 1 can also receive the data signal for the display cell P 2 during sub-period T 1 , but the data signal received by the display cell P 1 is updated by the data signal on the data line DL during the sub-period T 2 . Further, during the period (T 1 and T 2 ), during which the scan signal S 1 is applied, the switch ST 1 only turns on and off once according to the auxiliary signal SW 1 until the scan signal S 1 is applied thereto again. Namely, the transistor M 7 is turned off during the sub-period T 2 and on again when the auxiliary signal SW 1 is applied thereto again.
Next, when the scan signal S 1 is de-asserted and the scan signal S 2 is applied (has a logic high level), the transistors M 1 , M 2 and M 7 are turned off. The scan period when the scan signal S 2 is applied and divided into two sub-periods T 3 and T 4 . The auxiliary signal SW 2 turns on the transistor M 8 (closes the switch ST 2 ) and turns off the transistor M 8 (the switch ST 2 is opened) in sequence during the sub-periods T 3 and T 4 respectively, when the scan signal S 2 is applied.
During the sub-period T 3 , during which the transistor M 8 is turned on, the display cell P 4 in the even column of the pixel matrix receives the data signal from the data driver 21 through the data line DL, and the display cell P 3 in the odd column of the pixel matrix receives the data signal from the data driver 21 through the data line DL during the sub-period T 4 , during which the transistor M 8 is turned off. For example, the data signal from the data driver 21 during the sub-period T 3 can be a data signal with a positive polarity, and the data signal from the data driver 21 during the sub-period T 4 can be a data signal with negative polarity, but are not limited thereto.
It should be noted that the display cell P 3 can also receive the data signal for the display cell P 4 during sub-period T 3 , but the data signal received by the display cell P 3 is updated by the data signal on the data line DL during the sub-period T 4 . Further, during the period (T 3 and T 4 ), during which the scan signal S 2 is applied, the switch ST 2 only turns on and off once according to the auxiliary signal SW 2 until the scan signal S 2 is applied thereto again. Namely, the transistor M 8 is turned off during the sub-period T 4 and on again when the auxiliary signal SW 2 is applied thereto again.
Similarly, when the scan signal S 2 is de-asserted and the scan signal S 3 is applied (has a logic high level), the transistors M 3 , M 4 and M 8 are turned off. The scan period when the scan signal S 3 is applied is divided into two sub-periods T 5 and T 6 . The auxiliary signal SW 3 turns on the transistor M 9 (closes the switch ST 3 ) and turns off the transistor M 9 (the switch ST 3 is opened) in sequence during the sub-periods T 5 and T 6 respectively, when the scan signal S 3 is applied.
During the sub-period T 5 , during which the transistor M 9 is turned on, the display cell P 6 in the even column of the pixel matrix receives the data signal from the data driver 21 through the data line DL, and the display cell P 5 in the odd column of the pixel matrix receives the data signal from the data driver 21 through the data line DL during the sub-period T 6 , during which the transistor M 9 is turned off. For example, the data signal from the data driver 21 during the sub-period T 5 can be a data signal with a positive polarity, and the data signal from the data driver 21 during the sub-period T 6 can be a data signal with negative polarity, but are not limited thereto.
It should be noted that the display cell P 5 can also receive the data signal for the display cell P 6 during sub-period T 5 , but the data signal received by the display cell P 5 is updated by the data signal on the data line DL during the sub-period T 6 . Further, during the period (T 5 and T 6 ), during which the scan signal S 3 is applied, the switch ST 3 only turns on and off once according to the auxiliary signal SW 3 until the scan signal S 3 is applied thereto again. Namely, the transistor M 9 is turned off during the sub-period T 6 and would be turned on again when the auxiliary signal SW 3 is applied thereto again.
Namely, during a frame period, during which all the scan lines are scanned in sequence once, the auxiliary signals SW 1 ˜SW 3 are only applied in sequence once such that switches ST 1 ˜ST 3 are each switched once. Thus, the switching frequency of the switches ST 1 ˜ST 3 is lowered to the frame rate, which eliminates the reliability issue in the conventional display panel.
The invention also provides a driving method for the display panel shown in FIG. 2A .
During a period T 1 , an auxiliary signal SW 1 is applied to turn on a switch ST 1 such that a data signal from a data line DL is transferred to display cells P 1 and P 2 and a scan signal S 1 is applied to enable the display cells P 1 and P 2 to receive the data signal on the data line DL.
During a period T 2 , the auxiliary signal SW 1 is de-asserted to turn off the switch ST 1 such that the display cell P 2 is electrically separated from the data line DL and the display cell P 1 receives a data signal from the data line DL according to the scan signal S 1 , in which the witch ST 1 is turned off until the scan signal S 1 and the auxiliary signal SW 1 are applied thereto again.
During a period T 3 , an auxiliary signal SW 2 is applied to turn on a switch ST 2 such that a data signal from the data line DL is transferred to display cells P 3 and P 4 and a scan signal S 2 is applied to enable the display cells P 3 and P 4 to receive the data signal on the data line DL.
During a period T 4 , the auxiliary signal SW 2 is de-asserted to turn off the switch ST 2 such that the display cell P 4 is electrically separated from the data line DL and the display cell P 3 receives a data signal from the data line DL according to the scan signal S 2 , in which the switch ST 2 is turned off until the scan signal S 2 and the auxiliary signal SW 2 are applied thereto again.
During a period T 5 , an auxiliary signal SW 3 is applied to turn on a switch ST 3 such that a data signal from the data line DL is transferred to display cells P 5 and P 6 and a scan signal S 3 is applied to enable the display cells P 5 and P 6 to receive the data signal on the data line DL.
During a period T 6 , the auxiliary signal SW 3 is de-asserted to turn off the switch ST 3 such that the display cell P 6 is electrically separated from the data line DL and the display cell P 5 receives a data signal from the data line DL according to the scan signal S 3 , in which the switch ST 3 is turned off until the scan signal S 3 and the auxiliary signal SW 3 are applied thereto again.
Namely, during a frame period, during which all the scan lines are scanned in sequence once, the auxiliary signals SW 1 ˜SW 3 are only applied in sequence once such that the switches are ST 1 ˜ST 3 each switched once. Thus, the switching frequency of the switches ST 1 ˜ST 3 is lowered to the frame rate, which eliminates the reliability issue in the conventional display panel.
FIG. 3A shows another embodiment of a display panel 200 B of the invention. It comprises a data driver 41 , two scan driver 42 A and 42 B, a timing controller 43 , and a pixel matrix composed of eight (for example) display cells P 21 ˜P 28 . For example, the display panel 200 B can be a liquid crystal display panel, a plasma display panel or an organic light emitting display panel, but it is not limited thereto.
The data driver 41 outputs the desired data signals (not shown) for the eight display cells P 21 ˜P 28 through data lines DL 1 and DL 2 . For example, the data driver 41 can be a data driving integrated circuit (IC) formed by single-crystal Si transistors, but it is not limited thereto.
The data driver 41 , the two scan drivers 42 A and 42 B are controlled by the timing controller 43 . For example, the timing controller 43 provides a first set of control signals such as clock signals CK 1 and /CK 1 and enabling signal DS 1 (as shown in FIG. 3B ) /CK 2 to the scan driver 42 A and a second set of controls signals such as clock signals CK 2 and and enabling signal DS 2 (as shown in FIG. 3B ) to the scan driver 42 B.
The scan drivers 42 A and 42 B generate scan signals S 1 ˜S 4 in sequence according to the first and second sets of control signals, and the scan driver 42 A outputs the scan signals S 1 and S 3 through the scan lines SL 1 and SL 3 respectively and the scan driver 42 B outputs the scan signals S 2 and S 4 through the scan lines SL 2 and SL 4 respectively. Namely, the scan signals S 2 and S 4 are not generated according to the scan signals S 1 and S 3 , but generated by different scan drivers. In the embodiment, the scan driver 42 A and 42 B can also be a driving integrated circuit (IC) formed by a-Si transistors on the display panel rather than single-crystal Si transistors.
The display cells P 21 and P 22 receive the scan signal S 1 through the scan line SL 1 simultaneously, the display cells P 23 and P 24 receive the scan signal S 2 through the scan line SL 2 simultaneously, the display cells P 25 and P 26 receive the scan signal S 3 through the scan line SL 3 simultaneously, and the display cells P 27 and P 28 receive the scan signal S 4 through the scan line SL 4 simultaneously. The display cells P 21 , P 23 , P 25 and P 27 receive corresponding data signals respectively through the data line DL 1 simultaneously, the display cells P 22 , P 24 , P 26 and P 28 receive corresponding data signals respectively through the data line DL 2 simultaneously.
As shown, each display cell P 21 ˜P 28 comprises a transistor, a storage capacitor and a liquid element, and the transistors in the display cells P 21 ˜P 28 can be a-Si transistors, but are not limited thereto.
FIG. 3B is a timing chart of the display panel shown in FIG. 3A . During a period T 21 , a scan signal S 1 is applied (the scan signal is asserted and has a logic high level), and the display cells P 21 and P 22 in the odd column of the pixel matrix receives the data signals from the data driver 41 through the data lines DL 1 and DL 2 .
During a period T 22 , a scan signal S 2 is applied, and the display cells P 23 and P 24 in the even column of the pixel matrix receives the data signals from the data driver 41 through the data lines DL 1 and DL 2 .
During a period T 23 , a scan signal S 3 is applied, and the display cells P 25 and P 26 in the odd column of the pixel matrix receive the data signals from the data driver 41 through the data lines DL 1 and DL 2 .
During a period T 24 , a scan signal S 4 is applied, and the display cells P 27 and P 28 in the even column of the pixel matrix receive the data signals from the data driver 41 through the data lines DL 1 and DL 2 . For example, the data signals output from the data driver 41 during the periods T 21 and T 23 can be data signals with a positive polarity and that output from the data driver 41 during the period T 22 and T 24 can be data signals with a negative polarity, but are not limited thereto.
Namely, all scan lines of the display panel 200 B are scanned in sequence by the scan drivers 42 A and 42 B, and display cells in two columns share one data line to receive data signals from the data driver. As the switching frequency of the switches ST 1 ˜ST 3 is lowered to the frame rate, the reliability issue in the conventional display panel can be eliminated.
FIG. 4 is a schematic view showing an electronic device using display systems shown in FIGS. 2A and 3A . As shown, the electronic device 300 comprises a housing 210 , the display panel 200 A/ 200 B, and power supply 220 . The power supply 220 is operationally coupled to the display panels 200 A/ 200 B to powers the display panel 200 A/ 200 B to display images. For example, the display panel 200 A/ 200 B can be a liquid crystal display panel, a plasma display panel or an organic light emitting display panel, and the electronic device 300 can be a PDA, a display monitor, a notebook computer, a table computer or a cellular phone.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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Display panels capable of eliminating reliability issues due to high switching frequency. The display panel comprises a data driver outputting first, second, third and fourth data signals in sequence through a data line, a scan driver outputting first and second scan signals in sequence through first and second scan lines and an auxiliary driver generates first and second auxiliary signals in sequence, and first and second display cells commonly receives the first scan signal through the first scan line and receives the first and the second data signal through the data line, and a first switch is coupled to the data line and the second display cell, turning on and off in sequence according to the first auxiliary signal when the first scan signal is applied thereto such that the second and the first display cells receive the first and the second data signals in sequence.
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SCOPE OF THE INVENTION
[0001] The present invention relates to a sensor-based control of vibrations in slender continua, in particular a sensor-based control of torsional vibrations in deep-hole drill strings to prevent torsional vibrations.
BACKGROUND OF THE INVENTION
[0002] Vibrations that can be described by the Wave Equation which is often applicable in slender continua. Examples of this include the vibrations of a string, axial vibrations of a rod or torsional vibrations. Long slender continua are especially susceptible to torsional vibrations because of the small ratio of diameter to length, in particular when torques are transferred via the continuum. This occurs in many types of technical equipment, for example, with long drive shafts. A particularly extreme case occurs with deep-hole drill strings used for drilling for gas or oil but also for geothermal projects. The total string reaches lengths of several kilometers so the ratio of diameter to length is often smaller than that of a human hair due to the fact that the outside diameter is only a few centimeters. FIG. 1 shows schematically the structure of a deep-hole drill string. The drill string is driven by a top drive actuator placed on the upper end of the string, for example. The so-called drill bit is located at the lower end of the string, i.e., an industrial diamond-tipped drill bit, which crushes the rock. Strong torsional vibrations, so-called stick-slip vibrations may occur in the string due to torques acting externally along the string, but in particular because of the nonlinear friction characteristic occurring between the rock and the drill bit. These effects are manifested in the drill bit coming to a standstill while the drive continues to rotate at a constant speed. This causes severe twisting of the string until the force on the bit becomes so big that the bit breaks loose again. The speed of the bit after breaking loose often reaches twice the amount of the drive speed and the string is being rotated in the other direction beyond its equilibrium position. As a result the drill bit again comes to a standstill. These vibrations are undesirable because they slow down the drilling operation and result in additional heavy loads on the drill rods.
[0003] Controlling these torsional vibrations has long been a topic of research in the field of mechanics. All the approaches so far in an attempt to control torsional vibrations have always been characterized by at least one of the following disadvantages.
[0004] On the one hand, measurements along the entire drill string must be available. On the basis of these measurements, the active modes of the drill string dynamics may be determined. Using the resulting modal representation, there are then various approaches for damping the torsional vibrations. Examples from the literature include E. Kreuzer and O. Kust, Analysis of long torsional strings by proper orthogonal decomposition , Archive of Applied Mechanics 67 (1996), no. 1, 68-80, and E. Kreuzer and M. Steidl, A Wave - Based Approach to Adaptively Control Self - Excited Vibrations in Drill - Strings , published in Proceedings of Applied Mathematics and Mechanics, 2010. In Kreuzer, Steidl, which constitutes the state of the art so far at the Institute of Mechanics and Ocean Engineering, the momentary active modes are converted into traveling waves to compensate the traveling waves at the top drive. To do so, first of all measurements along the entire drill string are necessary, secondly, continuous control is impossible and instead only a feedforward control to stabilize the string is possible. This method is not suitable if the drill string is unstable in the range around the desired target speed.
[0005] On the other hand, the dynamics of the drill string is not completely known. Therefore, the control cannot be tailored for the momentary system performance, and accordingly, the methods function better or worse, depending on the actual dynamics. The literature in this regard includes J. D. Jansen and L. Van den Steen, Active damping of self - excited torsional vibrations in oil well drillstrings , Journal of Sound and Vibration 179 (1995), 647-668, and R. W. Tucker and C. Wang, On the effective control of torsional vibrations in drilling systems , Journal of Sound and Vibration 224 (1999), 101-122. Various sources mention that the so-called “impedance control system” or “soft torque system” presented by Jansen and Van den Steen, which uses measurements of the motor current and motor voltage to implement the characteristic of a passively attenuated vibration absorber with the help of the actuator, is currently in use. The approach presented by Tucker and Wang uses measurements of the “contact torque” between the drill string and the top drive. Some frequencies are absorbed better with this method than others.
[0006] Singular disturbances, for example, a wave front caused by breaking loose, could not be controlled with such systems known from the state of the art.
SUMMARY OF THE INVENTION
[0007] A major objective of the present invention may be regarded as minimizing vibrations, in particular torsional vibrations, in deep-hole drill strings.
[0008] The present invention relates to a sensor-based control of vibrations, a respective method, a computer program and computer-readable memory medium according to the independent claims, and exemplary embodiments are embodied in the dependent claims.
[0009] According to an exemplary embodiment of the invention, a control device for sensor-based control of torsional vibrations in a slender continuum is provided, wherein the control device comprises a first input interface for receiving first angular state data, in particular angular velocity data of a first sensor to be connected, a second input interface for receiving second angular state data, in particular angular velocity data of a second sensor to be connected, an output interface for output of a control value to a drive to be connected for a continuum and a control circuit, which is designed to output, based on the Wave Equation and a model for torsional vibrations in a rod, a control value to the output interface based on the first angular state data, in particular angular velocity data and the second angular state data, in particular angular velocity data, as well as the distance between the first sensor to be connected and the second sensor to be connected.
[0010] The actuator that can be used for this control may be a top drive motor, which is located at the upper end of the drill string. The cause of the vibrations may lie at the bit or along the string. Thus, for example, the drill bit may be jammed or a location along the drill string may be jammed. Angular state data, in particular angular velocity data is understood to be data allowing a determination of the angular velocity of the drill string at the corresponding sensor location. The data may comprise pulses, for example, resulting from an optical sensor, from which it is possible to deduce the angular velocity, with a given number of pulse generators along the extent of the drill string. In particular a transducer, whose output value allows determination of an angular velocity by integration, may be provided. The angular velocity data may of course also indicate the angular velocity directly, either through a proportional value or a measured value, which has already been evaluated explicitly.
[0011] According to an exemplary embodiment of the invention, a control device is made available, such that the control device comprises a first sensor for supplying first measured data and a second sensor for supplying second measured data, the first sensor being connected to the first input interface and the second sensor being connected to the second input interface.
[0012] According to an exemplary embodiment of the invention, a drilling tool is made available, having an actuator, the drill drive, a drill string and an inventive control device of the above type for sensor-based control of torsional vibrations in a slender continuum, such that the drill drive is connected to one side of the drill rod for its drive, and the first sensor and the second sensor are arranged on the drill rod at a distance d, such that the drill drive is connected to the output interface of the control device.
[0013] Thus only two sensors, both of which are situated close to the actuator, i.e., the drive, are sufficient to detect the relevant dynamics and to stabilize the entire system. Torsional vibrations, in particular stick-slip vibrations, can be controlled more effectively than has been possible in the past. In addition, this method is very inexpensive because only two sensors are necessary and no measurements along the string are required. As a result of this control scheme, the drill string is under fewer load and the drilling can be performed more rapidly. The control concept can be used with any deep-hole drilling systems without requiring a detailed knowledge of the system used.
[0014] According to an exemplary embodiment of the invention, a drilling tool is provided, wherein the first sensor and the second sensor are arranged in an area of the drill string which is above the level of the ground.
[0015] The sensors remain accessible in this way and the entire measurement and control arrangement can be arranged so that it is readily accessible without having to accept the need for long signal paths. Furthermore, parasitic effects which may occur due to interference between the sensors and the drive can be minimized.
[0016] According to an exemplary embodiment of the invention, a drilling tool is made available, wherein the first sensor is arranged at a distance from the drill drive which corresponds essentially to the product of the propagation rate of a torsional vibration wave on the drill string and a control delay of the drill drive, and the second sensor is arranged at a distance d downstream from the first sensor on the string.
[0017] A control delay of the actuator can be compensated in this way. The distance may also take into account other delay factors, if necessary. In other words, a control value, for example, has already been output to the actuator control by a real-time control with respect to the upwards-traveling wave when the upwards-traveling wave is still propagating on the section of drill string between the first sensor and the actuator, so that the control intervention affecting the actuator can take place at a point in time very close to the arrival of the wave at the actuator.
[0018] According to an exemplary embodiment of the invention, a drilling tool is provided, wherein the drill string is axially movable with respect to the first sensor and the second sensor.
[0019] The drill string can be advanced in this way, while the sensors may remain in a stationary fixed position on the derrick with respect to the axial movement of the drill string in relation to the derrick. This is appropriate in particular when the drive, in particular a rotational drive, also remains in a stationary position on the derrick to maintain a constant distance from the sensors, and the drill string is displaced continuously during the rotational drive, for example, due to a following claw arrangement.
[0020] According to an exemplary embodiment of the invention, a drilling tool is provided, wherein the drilling tool is a deep-hole drilling tool.
[0021] Even in deep drilling, in particular offshore or geothermal drilling, an inventive control may also be implemented in this way.
[0022] According to exemplary embodiment of the invention, a method for sensor-based control of torsional vibrations in a slender continuum is made available, comprising the steps of receiving first angular state data, in particular angular velocity data of a first sensor to be connected, receiving second angular state data, in particular angular velocity data of a second sensor to be connected, and output of a control value to a drive to be connected for a continuum on the basis of the first angular state data, in particular angular velocity data and the second angular state data, in particular angular velocity data as well as the distance of the first sensor to be connected from the second sensor to be connected with the help of the wave equation and a model for torsional vibrations in a string.
[0023] Although theoretically possible, for cost reasons a measurement along the string is not usually performed and very little data can be transmitted from the output of the string. The external influences causing the torsional vibrations are thus not usually measurable, as well as the current vibrational state along the string is also unknown. The inventive method can absorb all the relevant frequencies and in addition, only a measurement of the angular state data is necessary, in particular the angular velocity data.
[0024] According to an exemplary embodiment of the invention, a computer program is provided which, when executed by a processor, is designed to implement the method according to the invention.
[0025] According to an exemplary embodiment of the invention, a computer-readable medium is provided on which the computer program according to the invention is stored.
[0026] An important idea of the invention is that the dynamics of the continuum in question are divided into two superimposed waves, such that the wave traveling in the direction of the actuator and/or drive is compensated by the actuator. In this way, reflection of the energy on the actuator is prevented and the system behaves as if it were extended to infinity beyond the actuator. By using two sensors, the wave traveling toward the actuator and the wave traveling away from the actuator can be calculated separately so that both the parameters of the approaching wave and the parameters of the departing wave can be determined in order to be able to control the drive of the drill-string on this basis.
[0027] It should be pointed out that the embodiments of the invention described below can equally be applied to the device, the method, the computer program and the computer-readable memory medium.
[0028] The individual features may of course be combined with one another so that advantageous effects which go beyond the sum of the individual effects can also be achieved in some cases.
[0029] These and other aspects of the present invention are explained and illustrated by the reference to the exemplary embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Exemplary embodiments are described below with reference to the accompanying drawings.
[0031] FIG. 1 illustrates a basic design of a drilling device consisting of a drill string, sensors and a drive.
[0032] FIG. 2 illustrates a control circuit of a dynamic system for calculating traveling vibrational waves.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0033] FIG. 1 illustrates a general design of a drilling device consisting of a drill string, sensors and a drive. The device for drilling 1 shown in FIG. 1 has a derrick 2 on which an actuator, the drill drive 10 is provided, with which a drill string 20 can be driven to turn a drill head 50 , also known as a bit, attached to the other end of the drill string 20 , which is situated in the drill hole 3 . The upper region is shown again in enlarged form in FIG. 1 . The drill drive 10 , for example, an electric motor, drives the drill string 20 on which sensors are arranged, namely two sensors 30 , 40 here. These sensors 30 , 40 serve to determine measured variables which allow a determination of the angular state data, in particular the angular velocity of the drill string 20 at the corresponding sensor position. The sensors are arranged at a distance d from one another with a drill string region 21 in between. The sensors deliver their corresponding measurement signals over corresponding signal lines 130 , 140 to a control 100 . In the control 100 the measurement signals are evaluated to deliver a control signal via a control signal line 110 to the drill drive 10 on the basis of these signals.
[0034] FIG. 2 illustrates a control circuit 100 of a dynamic system for calculation of traveling vibration waves. The control device 100 illustrated in FIG. 2 comprises a first input interface 131 for receiving first angular state data, in particular angular velocity data of a first sensor which is to be connected, a second input interface 141 for receiving second angular state data, in particular angular velocity data of a second sensor which is to be connected and an output interface 111 for output of a control value to a drive for a continuum and/or a drill string which is to be connected. The interfaces are linked to a control circuit 150 , which is designed to output a control value to the output interface 111 on the basis of the first angular state data, in particular angular velocity data, and a second angular state data, in particular angular velocity data, as well as the distance of the first sensor 30 from the second sensor 40 with the help of the wave equation and a model for torsional vibrations in a rod. Then the motor and/or actuator 10 can be controlled using this control value, for example, an angular velocity.
[0035] The drilling tool 1 having a drill drive 10 , a drill string 20 and the control device for sensor-based control of torsional vibrations in a drill string and/or a slender continuum has the first sensor 30 and the second sensor 40 on the drill string 20 with a distance d, such that the drill drive 10 is linked to the output interface 111 of the control device 100 . The first sensor 30 and the second sensor 40 are arranged in an area of the drill string 20 which is situated above ground level 4 , so that these are accessible. The distance d should be at least as great as the quotient of the wave velocity of the vibrational wave on the drill string and the sampling rate. At a sampling rate of 1000 Hz and a wave velocity of 2000 m/s, the distance should thus be at least 2 meters. The higher the sampling rate, the smaller may be the spacing of the sensors. If the first sensor is arranged at a distance from the drill drive 10 , which corresponds essentially to the product of the propagation rate of a torsional vibration wave c on the drill string 20 and a control delay of the drill drive 10 , and the second sensor 40 is arranged at a distance d downstream from the first sensor, then the transit time delay of the accelerating wave until reaching the drive may just compensate its control delay. In designing the distance of the first sensor from the drive, other delay variables may of course also be included. The drill string may be movable axially with respect to the first sensor 30 and the second sensor 40 , for example, by applying pulse generators running axially or other position markers to the drill string, extending axially.
[0036] The evaluation will be explained later, in particular with reference to FIG. 2 where the same reference numerals denote the same or similar elements.
[0037] On the basis of FIGS. 1 and 2 , the theoretical principles for the inventive control device and the respective method are described below, showing how the dynamics of a slender continuum described by the wave equation (e.g., a drill string), in particular unwanted vibration, can be decomposed into waves traveling in two opposite directions on the basis of two sensors. With this decomposition, it is possible to design a control method which compensates for the wave traveling in the direction of the actuator situated at the end of the system. In this way a reflection of the wave into the system is prevented, and a large portion of the energy is withdrawn from the unwanted vibrations. At the same time it is irrelevant here how the vibrations in the system are caused and whether one or more modes of the system are excited. In addition, the sensors may be mounted very close to the actuator although the control method stabilizes the entire system. With the control method described here, both of the problems mentioned above can be solved. Measurements along the string are no longer needed, but at the same time the dynamics relevant for the control method can be calculated accurately from the two sensors mounted very close to the drive. Accordingly, the control method fits the current system behaviour exactly. In the case of the drill string, the loads that occur along the string are usually unknown and are highly variable in the course of the drilling operation, so it is of crucial importance that the controller adapts to the momentary system behaviour. For the case of a drill string, two sensors are needed to measure the torsion angle and/or the angular velocity of the string directly on the drive as well as a small distance below the drive (e.g., 2 meters) (cf. detail in FIG. 1 ). The two measurement points are located above the ground area and are therefore readily accessible.
[0038] The idea of the control method is based on the fact that the rate of propagation of torsional waves is infinite. In addition, the rate of propagation is independent of the frequency of the wave in question. The torsional vibrations in a rod are described by the wave equation:
[0000] (δ̂2φ( x,t ))/(δ t )̂2= ĉ 2(δ̂2φ( x,t ))/(δ x )̂2. (1)
[0000] The general solution of the wave equation is
[0000] φ( x,t )= f ( x−ct )+ g ( x+ct ), (2)
[0000] where φ(x, t) is the torsion angle as a function of the length coordinate x, parameter c is the wave propagation velocity in the material. It holds that ĉ2=G/p, where G is the shear modulus and p is the density of the material.
[0039] Let the length of the structure in question be le, and the short section 0<x<1 of the structure shall be considered below and in addition: le>1. It is assumed that there are no externally acting torques within the section in question. In addition, the measurement of the rotational rate Ω(x=0)=Ω0 should be at the point x=0, and the measurement of the rotational speed Ω(x=1)=Ω1 should be at the point x=1. The sensor spacing d is selected here to be 1. However, through appropriate scaling, all other spacings d are also possible. The measurements are assumed to be available continuously and free of noise. These measurements may be interpreted as time-dependent boundary conditions of the section in question. In addition, the parameter τ is defined, such that
[0000] cτ= 1 and/or τ=1 /c (3)
[0000] i.e., τ corresponds to the propagation time of the wave between the two measurement points. Starting from the general solution and by definition of velocity waves
[0000]
α
:=
-
∂
∂
t
(
x
-
ct
)
and
β
:=
∂
∂
t
[0000] (kann das auch im deutschen Text noch berücksichtigt werden?)(x+ct) (inserting the general solution into the time-dependent boundary conditions):
[0000] Ω0( t )=α(− ct )+β(+ ct ), (4)
[0000] Ω1( t )=α(1− ct )+β(1+ ct ). (5)
[0040] Based on the known propagation rate, the following relationships hold with equation (3):
[0000] α(1− ct )+α(− c ( t−τ )), (6)
[0000] β( c ( t−τ ))=β(1+ c ( t− 2τ)). (7)
[0000] Equation (4) with equation (7) yields:
[0000] Ω0( t−τ )=α(− c ( t−τ ))+β(1+ c ( t− 2τ)). (8)
[0000] This in turn yields
[0000] α(− c ( t−τ ))=Ω0( t−τ )−β(1+ c ( t− 2τ)). (9)
[0041] If one now considers the equation for Ω1(t), this yields with equation (6)
[0000] Ω1( t )=α(1− ct )+β(1+ ct )=α( −c ( t−τ ))+β(1+ ct ). (10)
[0000] By inserting equation (9) in (10), this finally yields
[0000] Ω1( t )=Ω0( t−τ )−β(1+ c ( t− 2τ))+β(1+ ct ). (11)
[0000] This shows that β(1+ct) can be calculated as a function of the two measured values Ω0 and Ω1 as well as its state in the past by 2τ:
[0000] β(1+ ct )=Ω1( t )−Ω0( t −τ)+β(1+ c ( t− 2τ)). (12)
[0000] If the initial values are known, e.g., because the system is started from a resting position, φ(x, 0)=0 and Ω(x, 0)=0, this yields
[0000] α( x= 0 ,t= 0)=0, (13)
[0000] α( x= 1 ,t= 0)=0, (14)
[0000] β( x= 0, t =0)=0, (15)
[0000] β( x= 1 ,t= 0)=0. (16)
[0042] Accordingly, α(x=0, t), α(x=1, t), β(x=0, t) and β(x=1, t) can be determined using the measurements Ω0 and Ω1.
[0043] In order to calculate the variables being sought, the dynamic system illustrated in FIG. 2 is obtained from the above equations. The two transfer terms shown in the drawing are delay elements here with the delay T. For simplification the following hold:
[0000] α( x= 0 ,t )=α0,
[0000] α( x= 1 ,t )=α1,
[0000] β( x= 0 ,t )=β0,
[0000] β( x= 1 ,t )=β1.
[0044] This system is simulated with the two measured angular velocities Ω0 and Ω1 as input in a real time computer. Real time is understood here to refer to boundary conditions in which a loop run-through of a control and/or regulating method is shorter than two successive sampling values of a sampling rate. The accelerating wave β0=Ωctrl is then used to control the target velocity of the actuator and is thereby compensated in the actuator and thus energy is withdrawn from the vibrations.
[0045] In the case of the drill string, the system is regulated not with respect to the speed zero but instead with respect to a fixed rotational speed, which is to be adapted by the operator of the plant to the prevailing situation. Accordingly, the unwanted torsional vibrations do not occur around the speed zero but instead around the desired rotational speed. The signal generated by the system described above is therefore filtered with the help of a high pass filter having a very low cutoff frequency so that the control system can be used for various rotational speeds and/or may also be used for switching between two rotational speeds. In addition, the system described in the theory part for continuously available sensor signals is necessarily discretized in implementation in the real system, i.e., the sensor data is available only at discrete instants in time. This may lead to very high frequency noise in the dynamic system described here, but this can easily be filtered out by using a suitable low-pass filter with a very high cutoff frequency. The frequency range relevant for the dynamics of the drill string remains unaffected by the filters and completely preserved.
[0046] A functional embodiment may have a drill string, for example, which may be embodied by a drill string model having a length of 10 meters, for example. Angle sensors having an interpolated resolution of 25 bits and/or a physical resolution of 12 bits may be used as the sensors. The control may be implemented in software on a PC using a Quad-Core processor and Lab View RealTime.
[0047] It should be pointed out that the present invention may also be used with other drive geometries in which torsional vibrations are to be expected in addition to being used in deep-hole drilling technology.
[0048] It should be pointed out that the term “comprise” does not rule out additional elements or method steps, nor does the term “a” or “an” rule out the use of multiple elements and steps.
[0049] The reference numerals used here serve only to increase comprehension and should by no means be considered to be restrictive, such that the scope of protection of the invention is reflected by the claims.
LIST OF REFERENCE NUMERALS
[0000]
1 Drilling device
2 Derrick
3 Drill hole
4 Ground level
10 Drill drive
20 Drill string
21 Drill string range
30 First sensor
40 Second sensor
50 Drill head, bit
100 Control
110 Trigger signal line
111 Output interface
130 First measurement signal line
131 First input interface
140 Second measurement signal line
141 Second input interface
150 Control circuit
d Distance d
|
Control device ( 100 ) controlling a drilling operation and methods by which the dynamics of the continuum in question can be divided into superimposed waves, of which the wave traveling in the direction of the actuator and/or drive ( 10 ) is compensated by the actuator. This prevents reflection of the energy on the actuator. By using two sensors ( 30, 40 ) the wave traveling towards the actuator ( 10 ) and the wave traveling away from the actuator ( 10 ) can be calculated separately from one another, so that both the parameters of the wave traveling toward the actuator and the parameters of the wave traveling away from the actuator can be determined in order to be able to perform a control of the driving device of the drill string ( 20 ) on this basis.
| 4
|
BACKGROUND OF THE INVENTION
In a conventional sprinkler system for fire protection, thermally operated sprinkler nozzles are spaced along a pressurized water main located at an elevated position within the area to be protected. The main and associated sprinkler nozzles are fixed and a sufficient number of mains and nozzles are uniformly spaced above the area to be protected to cover the desired floor space.
In warehouses and other storage areas, it is now known to utilize movable storage cabinets, racks and similar storage members wherein the storage members are mounted upon wheels or tracks as to be horizontally movable with respect to each other eliminating the need for aisle space between adjacent storage members. The use of such movable storage members substantially increases the storage capacity of a given area as compared to conventional systems requiring aisles between adjacent racks.
Under conditions wherein inflammable and dangerous materials are stored upon storage racks, local fire safety codes often require that fire protection sprinkler systems be directly associated with the racks, and be located at each storage level therein. With a fixed storage rack, this fire protection requirement is easily met by plumbing sprinkler nozzles into the racks through fixed distribution conduits communicating with the sprinkler main. However, wherein movable storage racks are employed, difficulty has been experienced in meeting fire protection requirements.
With a movable storage member having a built-in sprinkler system, a flexible conduit system must be employed to permit the member to be moved. If flexible hose is employed to interconnect the sprinkler main with the storage rack distribution conduit, the handling of the hose becomes a problem. Movable storage racks may move twelve or fifteen feet between "closed" and "open" positions, and when the racks are "closed" the excess flexible hose must be accommodated. Further, as flexible hose is not fire resistant to the extent of rigid metal conduits, it does not meet the codes of many localities for sprinkler systems.
It is an object of the invention to provide a flexible conduit system formed of rigid conduits wherein the system may be utilized with movable storage members and permit the members to be freely moved between "closed" and "open" positions without imposing any adverse effects upon the storage member.
A further object of the invention is to provide a flexible rigid conduit system for supplying water to a movable storage member wherein the conduits are interconnected by rotary joints, and the rotary joints are of the self-aligning type and accommodate misalignments and tolerance variations.
Yet another object of the invention is to provide a flexible rigid conduit system utilizing self-aligning rotary joints wherein the portion of the conduit system remote from fixed portions thereof is movably supported by a track and carriage member which does not interfere with the flexing of the system.
In the practice of the invention, a plurality of movable storage racks are displaceable with respect to each other and each includes a built-in sprinkler nozzle system receiving pressurized water from a fixed sprinkler main through a flexible conduit assembly. The flexible conduit assembly includes rotary joints mounted adjacent the sprinkler main and the storage rack distribution conduit, and these rotary joints each communicate with generally horizontally disposed conduits interconnected at a location spaced from the main by a third rotary joint.
The conduits form a flexible elbow joined at a location remote from the fixed portions of the conduit system, and as the rotary joints are preferably of the self-aligning type, an overhead movable support is associated with the third rotary joint to support the same and maintain the conduits in a relatively horizontal orientation. The support consists of a track having a carriage movable therein, and the track does not distract from the free operation and adjustability of the conduit system.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:
FIG. 1 is a plan view of a storage rack system utilizing the flexible rigid conduit system of the invention, two storage racks being illustrated in the "closed" condition in full lines, and one of the racks being shown in an "open" position in dotted lines,
FIG. 2 is a side elevational view of the conduit and storage rack system,
FIG. 3 is an elevational, partially sectioned, view of a self-aligning rotary joint as used with the invention,
FIG. 4 is a detail, enlarged, elevational, sectional view, of the track and carriage as taken along Section IV--IV of FIG. 5, and
FIG. 5 is a detail, enlarged, elevational, sectional view of the track and carriage as taken along Section V--V of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As apparent in FIGS. 1 and 2, a plurality of movable storage members, such as storage racks, are shown at 10a and 10b, and usually several such racks are located together. In FIG. 1, the storage racks are shown in their contiguous "close" relationship in full lines, and the racks are mounted upon tracks and wheels, not shown, as to be movable to the left as viewed in FIG. 1. The displaced "open" position of storage rack 10a is illustrated in dotted lines in FIG. 1 as at 10b'. When the storage rack is in the 10a' position, 10a and 10b have been sufficiently separated to permit access to the left end of rack 10b.
The space in which the storage racks are located is provided with a fire protection system consisting of a plurality of sprinkler mains 12 extending over the area. As flammable materials are stored within the storage racks 10a and 10b, some codes require that each shelf area of a storage rack contain a sprinkler nozzle, and with the racks disclosed the individual rack sprinkling system includes a distribution conduit 14. A plurality of thermally operated sprinkler nozzles 16 are plumbed to the conduit 14, a nozzle being located within each rack compartment defined by shelves 18.
The flexible rigid conduit system of the invention is generally indicated at 20 and this system includes a plurality of identical rotary joints 22, 24 and 26. The specific construction of the rotary joint is described below.
The rotary joint 22 communicates with the sprinkler main 12 by means of a short conduit 28, and the rotary joint 26 communicates with the distribution conduit 14 through conduit 30 and conventional elbow 32. A relatively long conduit 34 also communicates with the rotary joint 22, and the relatively long conduit 36 communicates with the joint 26. The outer ends of the conduits 34 and 36 communicate with the rotary joint 24, and it will be appreciated that the conduit system 20 establishes fluid communication between the sprinkler main 12 and the storage rack distribution conduit 14.
With reference to FIG. 3, the rotary joints 22, 24 and 26 are identical and each include an upper elbow 38 which is formed with an annular skirt portion 40. The elbow 38 also includes a threaded opening 42 which receives a conduit, and the upper elbow is provided with threads 44 at its lower region. A chamber 46 is defined within the elbow 38 and an annular seal 48 is located within a recess in the skirt 40, this seal ring being formed of Teflon, a trademark of the DuPont Company.
The upper elbow 38 assembly also includes a nut 50 having an opening 52 defined therein and threads 54 formed on the nut cooperate with the threads 44 to attach the nut to the upper elbow 38.
The rotary joints also include a lower elbow 56 which has a threaded opening 58 for receiving a threaded conduit such as at 28 or 36, and the lower elbow 56 includes a spherical sealing surface 60 engaged by the seal ring 48. Thus, it will be appreciated that the components may be assembled as apparent in FIG. 3, and the nut 50 is locked to the upper elbow 38 by means of a boss 62 defined upon the nut receiving set screw 64 which engages and locks against the elbow 38.
A compression spring 65 is interposed between the upper elbow 38 and lower elbow 56 biasing these elbows away from each other which maintains a sealed engagement relationship between the seal ring 48 and the spherical surface 60.
The rotary joints 22, 24 and 26 are self-aligning due to the presence of the spherical surface 60 and the engagement thereof by the seal 48. Thus, the axes of the openings 42 and 58 need not be parallel, as a non-parallel relationship merely causes the seal ring 48 to engage a different portion of the surface 60 without adversely affecting the sealed relationship between elbows 38 and 56. This type of rotary joint has been available from the assignee for a number of years, and rotary joints of a known self-aligning type, other than that illustrated, may be utilized in the concepts of the invention.
As the rotary joints are preferably of the self-aligning type, it is desirable to support the "outer" region of the conduit system 20 at the joint 24 against the effect of gravitational force. For instance, without a support associated with the outer regions of the conduits 34 and 36, the self-aligning features of the joints 22 and 26 would permit the conduits 34 and 36 to "sag" from the preferred substantially horizontal position as illustrated in FIG. 2.
The outboard support of the conduit system may take several forms, and a preferred form is that illustrated wherein an arcuate track 66 is mounted upon the ceiling or a support bracket. The track 66 includes a base 68 from which depend parallel legs 70 terminating in inwardly deformed flanges 72. Lengthwise, the track 66 is of an arcuate form, as shown in dotted lines in FIG. 1, the arc thereof corresponding to the radius having a center at the vertical axis of rotary joint 22.
A carriage 74 is supported within the track 66 by four wheels 76, and in this manner, the carriage 74 freely moves within the track 66. A link 78 affixed to the carriage 74 is attached to the outboard rotary joint 24, FIG. 2, and in this manner sagging of the conduit system 20 is prevented, yet the adjustment and displacement of the conduit system during movement of the storage rack is unimpeded.
In FIG. 1, the "open" positions of the storage racks and associated conduit systems is illustrated in dotted lines. When the storage racks are shifted to an open position, the elbow defined by conduit 34, rotary joint 24 and conduit 36 will define an acute angle, and in the practice of the invention pressurized water will be supplied to the storage racks regardless of their position upon their supporting track. As the conduits 34 and 36 are maintained in a substantially horizontal orientation by the track 66, the conduits cause no storage or handling problems regardless of the position of the associated storage rack, and the system is relatively maintenance free for long periods of time.
It is to be appreciated that the concept of the invention could be utilized in a system wherein the rotary joints and the conduits 34 and 36 are oriented such that the conduits 34 and 36 are substantially vertical, rather than horizontal, and in such an arragement the supporting track 66 would not be required. Such a "vertical" orientation of the conduit system would limit access to one side of the storage rack due to the presence of the conduits 34 and 36, but as in the aforedescribed embodiment, the self-alignment characteristics of the rotary joints will accommodate conduit misalignment and manufacturing tolerances, and it is appreciated that other modifications to the inventive concepts within the scope of one skilled in the art may be apparent.
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A flexible rigid conduit system particularly suitable for fire protection sprinkler installations usable with movable storage racks wherein a plurality of rigid conduits are interconnected by self-aligning rotary joints permitting pressurized water to be supplied to the storage rack regardless of its location. The conduit system is supported remotely of its fixed portions by a track and carriage arrangement providing support for the conduits and permitting unhindered movement thereof.
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This is a continuation of application Ser. No. 08/701,349 filed Aug. 20, 1996.
BACKGROUND OF THE INVENTION
The present invention relates to a transfer device for transferring objects between two sequential moving-surfaces, and more particularly to a conveyor for pedestrians fitted with such a transfer device.
There are known conveyors comprising a continuous conveyor belt made from a deformable material or from a series of elements with substantially flat transport surfaces, permitting the transportation of pedestrians at a higher speed than a normal walking pace. Such conveyors require an accelerator element between the conveyor belt and the stationary entry floor to gradually accelerate pedestrians from a walking pace to the higher speed of the conveyor belt, and a decelerator element to gradually decelerate pedestrians back to a normal walking pace between the exit of the conveyor belt and the stationary exit floor.
The reference EP-A-0 509 861 discloses a conveyor of the kind defined above. As mentioned in this reference, in order to cross the transition zones between the exit of the accelerator element and the entry of the conveyor belt, and between the exit of the conveyor belt and the entry of the decelerator element, pedestrians must drop from one level to a subsequent transportation element located on a lower level. This drop may cause pedestrians to lose their balance, particularly challenging disabled persons and persons of reduced mobility.
SUMMARY OF THE INVENTION
The present invention overcomes the above-stated inconvenience of known conveyors and provides both a transfer device disposed between two transport elements, and a conveyor fitted with such a device.
The transfer device of the invention transports pedestrians between a first transport element and a second transport element arranged sequentially, each element comprising a substantially flat transport surface for transporting pedestrians. The transfer device comprises a platform for a first pedestrian bearing-surface located substantially in a plane common to the transport surfaces of both transport elements. The first pedestrian bearing-surface comprises rollers permitting the low-friction displacement of the pedestrians from one transport element to the next.
The transfer device also comprises a plate with teeth forming a comb that engages longitudinal grooves in a transport element. This plate is fastened to the transfer device's platform and comprises a second pedestrian bearing-surface also located on substantially the same plane as the platform and also having rollers.
According to a preferred embodiment, the rollers in both the platform and comb-shaped plate comprise balls rotatably accommodated within blind holes. The rollers project beyond the surfaces of the platform and the comb-shaped plate so as to define the aforesaid bearing surfaces for pedestrians. The balls in the platform are held within their corresponding blind holes by a plate fastened to the platform and comprising bores through which the balls extend. The bores have a diameter smaller than the diameter of the balls. The balls in the comb-shaped plate are kept within their corresponding blind holes by flat washers with frusto-conical central holes.
According to another embodiment, the rollers are cylindrical and are mounted for rotation about an axis transverse to the direction of displacement of the pedestrians. The rollers are disposed within semi-cylindrical recesses in the platform and in the comb-shaped plate. The rollers project beyond the surfaces of the platform and comb-shaped plate so as to define the aforesaid bearing surfaces for pedestrians.
In a further embodiment, the platform of the transfer device is pivotally supported on a support frame by supporting feet and loosely fastened to the support frame by two tie-bolts. These tie-bolts are located on either side of the platform beyond its bearing surface and allow the inclination of the platform to be adjusted so that the bearing surfaces are located in a plane substantially in common with the transport surfaces of both transport elements.
The supporting feet are accommodated within inclined supporting grooves in supporting parts fastened to the support frame. These supporting grooves extend transversely to the direction of displacement of the pedestrians, permitting a slight displacement of the platform, on the order of a few millimeters, when the longitudinal grooves of the transport element hits the teeth of the comb-shaped plate.
Each tie-bolt has a threaded end anchored in a tapped hole of a first transverse pin carried by a clevis on the platform. Each tie-bolt's other threaded end extends, with a clearance, through a bore in a second transverse pin that is carried by a clevis fastened to a supporting part that is itself fastened to the support frame. Two nuts on each tie-bolt located on either side of the second transverse pin provide limited axial play to permit the platform to pivot upwards about the supporting feet when an object becomes jammed between the longitudinal grooves of one of the transport elements and the teeth of the comb-like plate.
The invention also provides a conveyor for pedestrians that comprises a conveyor belt and an acceleration or deceleration element at each end of the conveyor belt for loading and unloading pedestrians. Transfer devices as previously defined are arranged between the acceleration element and the conveyor belt and between the conveyor belt and the deceleration element.
The features and advantages of the invention will be further understood from the following non-limiting description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of a belt-type conveyor according to the invention.
FIG. 2 is a detailed half top-view of the conveyor of FIG. 1 as seen in the direction of the arrow II.
FIG. 3 is a cross-sectional view from the line III--III of FIG. 2.
FIG. 4 is a cross-sectional view from the line IV--IV of FIG. 2.
FIG. 5 is an enlarged view of the upper portion of the transfer device shown in FIG.3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the invention will be described as applied to the transportation of pedestrians, but it should be well understood that the invention is also applicable to the conveyance of other objects such as goods, luggage, and the like.
The conveyor shown in FIG. 1 disposed between two stationary floors 1 and 2 has a substantially flat belt 3 for carrying pedestrians in the direction shown by the arrow F, referred to as the longitudinal direction of the belt. The belt 3 is driven by one of two end-drums 4. The drums' 4 axes are arranged transversely to the direction of displacement of the pedestrians.
The conveyor belt 3 moves at a higher seed than a normal pedestrian's walking pace. To bring the pedestrians from their normal walking pace to the relatively high speed of the belt 3, and to bring the pedestrians from the speed of the belt 3 back to their normal walking pace, the conveyor comprises an acceleration element 5 disposed between the stationary entry floor 1 and the entry of the conveyor belt 3, and a deceleration element 6 disposed between the exit of the conveyor belt 3 and the stationary exit floor 2.
The acceleration and deceleration elements 5 and 6 are known as disclosed in the reference EP-A-0 509 861. More specifically, the acceleration element 5 and the deceleration element 6 comprise a series of parallel rolls, imbricated into each other to forming continuous transport surface for pedestrians. The rolls are driven at speeds that gradually increase from an entry roll of the acceleration element 5 to an exit roll of this element. The rolls' speed gradually decrease from an entry roll of the deceleration element 6 to an exit roll of this element. FIG. 3 shows the acceleration element 5 comprising rolls 7 imbricated into each other and defining the transport surface S1 for pedestrians.
A transfer device 8 is disposed in the transition zones between the acceleration element 5 and the conveyor belt 3, and between the conveyor belt 3 and the deceleration element 6, to allow pedestrians to cross these transition zones without any loss of equilibrium. As shown in FIGS. 2 and 3, each transfer device 8 comprises a platform 9 having a pedestrian bearing-surface S2 located substantially in a plane common to the transport surface of the conveyor belt 3 and to the transport surface S1 of the acceleration element 5 or of the deceleration element 6. The transfer device comprises rollers 10 permitting low friction displacement of pedestrians between the acceleration element 5 to the conveyor belt 3 and from the conveyor belt 3 to the deceleration element 6.
The transfer device 8 comprises a comb-shaped plate 11 having teeth 12 that engage longitudinal grooves of the conveyor belt 3 defined between conveyor belt ribs 14. The comb-shaped plate 11 is fastened to the platform 9, for example by fastening screws 15. The pedestrian bearing-surface S3 of the comb-shaped plate 11 is in substantially the same plane as the bearing surface S2 of the platform 9. Bearing surface S3 is defined by rollers 16 that permit the low-friction displacement of the pedestrians from the comb-like plate 11 to the conveyor belt 3 or vice versa.
Preferably, the rollers of the platform 9 and of the comb-shaped plate 11 comprise balls 10 and 16. As shown more clearly in FIG. 5, balls 10 and 16 are disposed within blind holes 17 in the platform 9. Balls 16 are housed within blind holes 18 of the comb-like plate 11.
The balls 10 and 16 are kept within their respective holes 17 and 18 while protruding from the platform 9 and the comb-shaped plate 11 so as to define the bearing surfaces S2 and S3. These balls 10 and 16 revolve freely about themselves in these recesses 17 and 18 as pedestrians pass over them.
More specifically, blind holes 17 are formed in a plate 9a fastened to the platform 9 by screws 9b. A plate 19 is fastened to the plate 9a, for example by fastening screws 20. The plate 19 comprises bores 21 aligned with balls 10 but having a smaller diameter than that of balls 10.
The balls 16 are retained in therein corresponding blind holes 18 in the comb-like plate 11 by flat washers 22. Each washer is accommodated in a counter-bore 23 machined into the plate 11. Each washer 22 has a central frusto-conical opening 22a for retaining a ball 16 within its hole 18.
According to an alternative embodiment not shown, the rollers 10 and 16 are cylinders mounted transversely of the longitudinal direction of the conveyor belt 3 within corresponding semi-cylindrical recesses in the platform 9 and of the comb-shaped plate 11. These cylindrical rollers protrude from platform 9 and plate 11 so to define bearing surfaces S2 and S3 for pedestrians.
Furthermore, the platform 9 of the transfer device 8 is pivotally supported on a support frame 24 by supporting feet 25 arranged symmetrically about the longitudinal axis XX' of the belt 3. The free ends 25a of supporting feet 25 are accommodated within inclined grooves 26 in supporting parts 27 and 28 that are secured to frame 24, the grooves 26 being aligned perpendicularly to the longitudinal axis XX' of the conveyor belt 3. Two supporting parts 27 are disposed symmetrically opposite each other about the longitudinal axis XX' of the belt 3 and are fastened to a flange of an inverted L-shaped cross member 29 by fastening screws 30. Cross member 29 is fixed to the frame 24, preferably by welding.
The platform 9 is bilaterally fastened to the support frame 24 by two tie-bolts 31 arranged symmetrically about the axis XX' and on either side of the bearing surface S2 of the platform 9. These tie-bolts allow the slope of platform 9 to be set to a position in which the bearing surface S2 lies in a plane substantially common to the transport surfaces of the conveyor belt 3 and the acceleration element 5 or the deceleration element 6.
Each tie-bolt 31 is oriented substantially in parallel with the axis XX' and has a threaded end portion 31a anchored in a first corresponding tapped hole 32a that extends through a transverse pin 32 carried by a clevis 33 that is itself fastened to an end portion 9c of the platform 9. Portion 9c also comprises a supporting foot 25 that is inserted into the groove 26 of supporting part 28. Supporting part 28 is fastened to the cross member 29 by fastening screws (not shown). The other threaded end portion 31b of the tie-bolt 31 extends loosely through a bore 34a formed through a second transverse pin 34 carried by a clevis 35 fixed to the supporting part 28. Two nuts 36 and 37 are screwed onto the threaded portion 31b of the tie-bolt 31 on either side of the transverse pin 34. However, the nut 37 is not fully tightened against the second transverse pin 34, leaving a clearance j of about 2 millimeters so as to permit a slight pivoting motion of the transfer device 8 about the free ends of the supporting feet 25 in a direction tending to space the comb-like plate 11 upwards from the conveyor belt 3, as seen in FIG. 3. This pivoting motion occurs when an object becomes jammed between the longitudinal grooves 13 of the conveyor belt 3 and the teeth 12 of the comb-shaped plate 11. This motion of the transfer device 8 preferably actuates a circuit that stops the powered end-drum 4 and thus stops the conveyor belt 3. Normally, however, the transfer device 8 is kept in a stationary position by the tie-bolts 31. A central nut 31c permits the accurate adjustment of the position of the bearing surfaces S2 and S3 of the transfer device 8 in relation to the transport surfaces of the conveyor belt 3 and the acceleration element 5 or the deceleration element 6. As shown in FIG. 3, bearing surfaces S2 and S3 of transfer element 8 may be offset below the transport surface of the conveyor belt 3 by up to about 5 millimeters without causing any loss of equilibrium in pedestrians who cross the very small transition zone between the end of the comb-like plate 11 and the conveyor belt 3.
The transverse grooves 26 in the supporting parts 27 and 28 permit a transverse displacement of the transfer device 8 as the free ends 25a of the supporting feet 25 slide along these grooves 26 by an amount on the order of a few millimeters. This sliding may occur when the longitudinal ribs 14 of the conveyor belt 3 hit the teeth 12 of the comb-like plate 11. The sliding permits the transfer device 8 to compensate for a side drift or deflection beyond the offset value d shown in FIG. 2, of the conveyor belt 3 with respect to roll 4. To permit such a transverse displacement, each transverse pin 34 is mounted into two oblong holes (not shown) of the clevis 35 extending in parallel to the axis XX' of the conveyor belt 3.
The transfer device according to the invention has an extremely simple structure, provides a bearing surface in the same plane as the adjoining elements, and permits a reversal in the conveyor belt's direction of operation. The transfer device according to the invention may also be used in conveyors called "travelators" wherein the conveyor belt consists of elements linked to each other. The device may further be installed between two sequential conveyor belts, either aligned end to end or at an angle. In embodiments disposed between two conveyors, the device will comprise two comb-shaped end plates whose teeth are inserted into the longitudinal grooves of both conveyor belts.
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A transfer device for transferring objects, including pedestrians, between sequential moving-surfaces disposed in a common plane. The device comprises first rollers housed in a platform and defining a first object bearing-surface disposed substantially in the common plane. In one embodiment, the rollers comprise balls; in another, they comprise cylinders. A plate mounted on the platform defines a comb that slidably meshes with ribs of a conveyer belt that defines one of the moving surfaces. Second rollers are housed in the plate, providing a second object bearing-surface. The platform pivots within a limited and adjustable angle towards and away from one of the moving surfaces, when an object becomes jammed between the platform and the moving surface, and slides perpendicularly to said angle, by a small amount, when the ribs force the comb laterally.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for the cooling of guide vanes in a gas turbine plant which has a compressor, at least one combustion chamber and at least one turbine. The invention relates, furthermore, to a device for carrying out the method and to a use of the method.
2. Discussion of Background
Ever-higher temperatures are employed in order to achieve an even-greater power output, and, under these circumstances, structural parts where there is a particular requirement for efficient cooling become more and more important, so that even a reduction in the cooling effect due to the clogging of part of the cooling ducts constitutes a serious risk to such a structural part. The importance of lowering the temperature in the turbine guide assembly, and here particularly at the guide vanes of the first stage, has been known for a long time. If the aim nowadays is to achieve a lowering of temperature of, for example, 400° C. in the case of this structural part, efficient cooling, as well as a long service life, must be guaranteed.
When a gas turbine with steam cooling is started up, another cooling medium (for example air) is initially required, since there is still no steam available. When the steam circuit is then opened, the components to be cooled are already at operating temperature. The problem here is that the steam entrains suspended matter (rust, welding beads, condensation water droplets and other solids) deposited in the line network after a shutdown of the steam circuit and consequently may completely or partially clog the cooling ducts (film bores) which are at operating temperature. Moreover, entrained condensation water droplets may result in damage to structural parts to be cooled, since stress peaks may occur locally as a result of the thermal shock effect. Furthermore, entrained suspended matter may be deposited on the structural parts to be cooled, for example on bends of the ducts, and cause overheating there due to its insulating effect. It is apparent from the foregoing that, if possible, only pure gas should flow in the compressor outlet space (combustion chamber plenum). In order to achieve this, various measures have already been proposed, but these are very complicated.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel, improved method for this purpose. The method according to the invention is defined in that part of the crude gas flowing through the compressor is supplied to at least one dust separator, in which suspended matter is separated from the crude gas by centrifugal force, and in that the pure gas is then guided into the interior of the guide vanes of at least the first guide wheel. It is advantageous, at the same time, if the dust separator is designed as an axial cyclone.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows a diagrammatic part longitudinal section through a gas turbine plant,
FIG. 2 shows, in longitudinal section, a dust separator designed as an axial cyclone, and
FIG. 3 shows a detail of the gas turbine plant in FIG. 1, with various ways of using the axial cyclone.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, the gas turbine plant according to FIG. 1 has a compressor 1 , a combustion chamber 2 and a turbine 3 . The combustion chamber 2 is surrounded by combustion chamber cover 4 which is located in a compressor outlet space designed as a combustion chamber plenum 5 . Located within the combustion chamber cover 4 is a burner plenum 6 (burner inlet space). The combustion chamber 2 is surrounded by a cooling-air space 7 . The combustion chamber plenum 5 , the burner plenum 6 , the combustion chamber cover 4 , the combustion chamber 2 and the cooling-air space 7 are bodies of revolution about the gas turbine longitudinal axis 8 . A multiplicity of individual burners 9 are arranged so as to be distributed over the circumference of the combustion chamber 2 . A casing 10 is also shown diagrammatically. The impure gas (air) flowing through the compressor 1 flows partly in the direction of the arrows 11 in the combustion chamber plenum 5 and partly in the direction of the arrows 12 in the cooling-air space 7 .
The guide assembly of the turbine 3 has guide vanes 13 and 14 . A guide vane 15 of the first stage is also shown, which is exposed to particularly high temperatures and in which the desired cooling must therefore take effect particularly reliably. In the guide vane 15 , some film bores 16 are shown (FIG. 3 ), out of which the cooling medium (air) therefore flows from inside the guide vane 15 radially (with respect to the longitudinal extent of the guide vane 15 ) and acts as film cooling along the guide vane wall. The aforesaid design of the gas turbine plant is already known.
In the method according to the invention, it is now proposed to use at least one dust separator which is advantageously designed as an axial cyclone 24 . Such an axial cyclone (centrifugal deduster without gas stream reversal) is known per se. See, in this respect, “Leuger” Lexikon der Technik, Band 6 , Energietechnik und Kraftmaschinen (Lexicon of Technology, volume 6, Power Engineering and Power Engines), Stuttgart 1965, page 81. An exemplary embodiment of such an axial cyclone 24 is shown in FIG. 2 . It has an impure gas inlet 17 , a swirl assembly 18 (guide vane ring), a central body 19 and at least two outlet ducts, three outlet ducts 20 , 21 and 22 being present in the example.
A turbulent flow (potential vortex, solid-state vortex or a combination of the two) is imparted by the guide vane ring 18 to the gas flowing in in the direction of the arrows 11 . In this centrifugal field, suspended matter having a relatively high mass or relatively high specific gravity is carried outward. A flow field is generated, in which suspended matter is sorted according to mass over the radius. The suspended matter, separated according to mass, is led away via the outlet ducts 21 and 22 . A vortex core is avoided by means of the central body 19 , so as to avoid unclear flow conditions (very high velocities in the case of the potential vortex or very low velocities in the case of the solid-state vortex) . The diameter and length of the guide vane ring 18 , central body 19 , tube 23 and outlet ducts 20 - 22 are critical for the functioning of the axial cyclone 24 . These dimensions determine the separation accuracy and the size of the separated suspended matter. A pure gas 30 is thus formed in the axial cyclone 24 and is led away via the central outlet duct 20 . A gas stream 31 laden with suspended matter of lower mass is led away via the outlet duct 21 and a gas stream 32 laden with suspended matter of higher mass is led away via the outlet duct 22 . Valves or flaps, not illustrated, may be present in the three outlet ducts 20 , 21 and 22 , so that the throughput quantities can be regulated.
Since there is space available in the combustion chamber plenum 5 (FIG. 1 ), in one exemplary embodiment twenty to fifty such axial cyclones 24 could be arranged, distributed over the circumference, on a circular path, in each case one axial cyclone 24 supplying pure gas 30 to one or more guide vanes 15 . In another exemplary embodiment, as indicated in FIG. 1, an axial cyclone 24 ′ could also be located outside the casing 10 . In such a case, the axial cyclone 24 could also be designed so as to be very much larger than the multiplicity of small axial cyclones 24 .
At all events, the outlet duct 20 of the axial cyclone 24 , said outlet duct receiving the pure gas 30 , leads, for cooling purposes, to the interior of a guide vane 15 in the way initially mentioned. If an axial cyclone 24 ′ located outside the casing 10 is used, the pure gas is delivered via the line 25 shown by dashes and dots, the pure gas being supplied from a tapping point 26 on the compressor 1 . An outlet duct 20 ′ receiving the pure gas 30 leads, in turn, into the interior of the guide vane 15 , whereas, for example, a gas stream 31 laden with suspended matter of lower mass is led via an outlet duct 21 ′ for the purpose of cooling the guide vane 13 .
The advantages of using a larger number of small cyclone separators 24 are that the degree of separation rises with a decreasing cyclone diameter and that complicated distribution lines can be avoided.
The gas streams 32 , 31 led away via the outlet ducts 22 and 21 and laden to a greater or lesser extent with suspended matter can be used in various ways. In the example according to FIG. 1, the outlet duct 21 leads into the cooling-air space 7 . FIG. 3 shows three other examples of the use of the gas streams 31 , 32 laden with suspended matter. Thus, for example, a gas stream 32 laden with suspended matter of higher mass may be guided directly into the combustion chamber 2 via the outlet duct 22 . In another example, a gas stream 31 laden with suspended matter of lower mass is used, via the outlet duct 21 between the guide vanes 15 and a heat shield 27 , for cooling the moving blades 28 of the first rotor of the turbine 3 . In the third example, the gas stream 31 laden with suspended matter of lower mass is led, via the outlet duct 21 and via a further outlet duct 29 , to the guide vanes 13 of the second stage, in order, here, to achieve vane cooling insensitive to dust.
In the example according to FIGS. 1 and 3, the first guide wheel having the guide vanes 15 is followed by the first rotor of the turbine 3 having the moving blades 28 . In another example which is not illustrated, the combustion chamber 2 could be followed by a second combustion chamber, so that, in such an example, the turbine therefore consists only of the first guide wheel having the guide vanes 15 and of a downstream rotor which is followed by the second combustion chamber.
The method according to the invention can be used, for example, in stationary gas turbine plants, in which the film bores in the guide vanes of the first guide wheel have a diameter of about 0.8 mm. The method according to the invention may, however, also be used in a gas turbine plant in an aircraft, in which the film bores in the guide vanes of the first guide wheel then have a diameter of about 0.3 mm to 0.5 mm.
The axial cyclone has only a few structural parts of simple design. It possesses no moving structural parts and can have small dimensions. It can therefore also be exposed to high temperatures and be placed in large numbers in the combustion chamber plenum 5 , very near to the guide vane heads. Short flow paths of the pure gas 30 are thereby achieved.
Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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The temperature can nowadays be reduced by about 400° C. as a result of the cooling of the guide vane ( 15 ) of the first guide wheel. The many film bores leading outward from the guide vane ( 15 ) must therefore remain free of blockages or deposits caused by suspended matter in the cooling medium. Only pure gas must therefore be used as the cooling medium for the first guide wheel. This purpose is served by a dust separator which is designed advantageously as an axial cyclone ( 24, 24 ′). The latter has no moving structural parts, has a simple design, is therefore insusceptible to faults and can be exposed to high temperatures. The axial cyclone is a centrifugal deduster without gas stream reversal.
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The invention relates to a method for the grit-free withdrawal of water from a well and also to a device suitable for this purpose.
BACKGROUND OF THE INVENTION
A known method for the withdrawal of water uses a vertical double tube, uniformly provided with openings, via which water is drawn off by means of a subaqueous pump (or other withdrawal device). However, this method only provides a rather low withdrawal capacity if it is required that the water withdrawn shall be grit-free, i.e. if sand particles above a critical grain size are not also to be drawn off from the surrounding water-bearing stratum.
This method with the device, the so-called suction current collection (SCC), is known from German Offenlegungsschrift 2,401,327. According to the latter, the so-called collection element of the SCC consists of two coaxially disposed tubes of different diameter with uniform transverse slots over the variable length, the hollow cylindrical gap between the two tubes being filled with a fine-grain granulate. This construction is intended to achieve the result that the horizontal approach velocity at the critical point R K (FIG. 1) is approximately constant over the entire effective vertical length of the collection element, the so-called drainage length L E . As measurements have shown, a uniform horizontal approach velocity over the entire drainage length cannot be achieved with the collection element known from German Offenlegungsschrift No. 2,401,327. For a uniform approach velocity at the critical point R K (FIG. 2) over the drainage length of the collection element this has the result that for a certain delivery rate a certain quantity of fine-grain sand particles is still entrained and consequently drawn off.
It is therefore the object of the invention to provide, for a certain delivery rate, a method for the grit-free withdrawal of water from a well and also an associated device, and in doing this at the same time to reduce further the energy consumption compared to conventional water delivery without SCC as a result of a still lower groundwater depression in the well area.
SUMMARY OF THE INVENTION
The measures provided according to the invention result in the particular advantage that a uniform flow profile over the drainage length is produced for a certain delivery rate at the point R K (FIG. 2) and consequently no sand particles above the critical grain size are drawn off. in addition, the drive power required for the pump used is lower than for the conventional SCC according to German Offenlegungsschrift No. 2,401,327 since the mean approach velocity in the water-bearing stratum is lower and the collection element consists only of a transversely slotted, thin-wall single tube with as large a diameter as possible, which tube therefore produces no appreciable loss in pressure in the radial direction across the wall.
According to an advantageous embodiment of the invention, a uniform flow profile at the point R K is achieved by keeping the product of the length element Δx, the flow velocity V ssc (x) into the slots in the wall of the collection element (slot velocity) and the relative, i.e. referred to the area of the length element Δx of the SCC, water passage area (x) (relative slot area Δ slot factor) constant over the entire drainage length of the SCC. That is to say that the same partial water quantity ΔV flows radially into the SCC through each element of length Δx of the drainage length L E . In flow science terms this can be explained by the fact that the radial pressure drop across the SCC wall decreases in a specified manner from top to bottom, and consequently the flow velocity in the water passage areas which is proportional to this pressure drop also becomes correspondingly less from top to bottom. In order, therefore, to achieve delivery rate ΔV=constant, the relative water passage area has therefore to become increasingly larger from top to bottom (FIG. 3).
An absolutely uniform flow profile at the point R K (FIG. 2) would theoretically result if the relative water passage area were to increase in specified manner in infinitesimally small steps from top to bottom. The only possibility of achieving this continuous slot area increase from top to bottom would theoretically be by a continuous longitudinal slot or a slot tangentially displaced in sections which increases in width in a specified manner continuously from top to bottom. Both the latter, and also a transverse slotting performed in infinitesimally small steps are virtually not achievable at justifiable expense for manufacturing reasons. However, it emerged in practical field trials that a uniform flow profile at the point R K over the drainage length can be achieved with a relative water passage area which increases in finite small steps. It is conceivable that the length Δ x of the individual steps can be chosen as small as desired and is only limited by manufacturing expense. At any event the step length Δx represents a very small value in proportion to the overall drainage length L E .
Particularly advantageous is the fact that, with the measures provided according to the invention for a certain delivery rate V at the point R K (transition from water-bearing stratum to the filter-gravel layer), a flow velocity v K can be achieved which is smaller than the so-called entrainment velocity for critical sand particles (entrainment velocity: the critical flow velocity at which a sand grain of specified grain size is just set in motion). If, however, the flow velocity at this point is already lower than the entrainment velocity for critical sand particles, it is considerably still further below the entrainment velocity inside the water-bearing stratum as follows from the continuity theorem for line decline. Sand particles of critical grain size can therefore no longer be set in motion by the flow and be drawn off by the pump.
A further substantial advantage results from the uniform flow profile at the point R K achieved with the subject according to the invention and from the low average velocity v K associated therewith: since the flow losses in the water-bearing stratum substantially determine the so-called depression (difference in height h 1 between hydrostatic and operating water level in the bore-hole, FIG. 2), the depression is also correspondingly lowered as the flow velocity v K averaged over the drainage length L E is further reduced. This results in a still lower energy requirement for pumping the water compared with the conventional SCC.
For the transverse slotting the slot factor can be varied according to several possibilities: by means of the slot width (tangential extent), the slot height (axial extent) and the slot separation (axial spacing of the slots with respect to each other). Because of the varying degree of ovalness of the tubes practical difficulties arise in the case of the first possibility in relation to precisely maintaining the slot widths specified for each step and consequently the specified passage areas. In the case of the second possibility the manufacturing cost is particularly high because the height of the slots and consequently the thickness of the saw blades used varies from step to step. The third possibility of a variable slot separation is the least costly manufacturing technique and therefore forms the basis of the following exposition.
In the same way the slot factor can also be varied with a longitudinal slotting which is effectively identical but on which a natural limit is imposed by the slot width (in this case axial extent) in view of the fine gradation of the slot factor.
Further advantages, details and features of the invention are explained in more detail in the description given below of an exemplary embodiment of the invention with reference to the diagrammatic drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the cross-sectional view of a conventional SCC which is in operation,
FIG. 2 shows the sectional view of an SCC according to the invention which is in operation,
FIG. 3 shows the function curve of the slot factor a.sub.(x) and the slot velocity v SCC (x) over the drainage length L E and
FIG. 4 shows the qualitative representation of the vertical flow velocity inside the control element over the drainage length L E as a function of x.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the non-uniform flow distribution over the drainage length L E in the slots of the collection element, which must inevitably lead to an equally non-uniform flow distribution at the oint R K with a constant slot factor over the drainage length.
In FIG. 2 the flow relationships of a well equipped with the subject according to the invention are depicted. In the region of the water-bearing stratum the collection element 13 according to the invention is disposed within a well filter tube 11 surrounded by a filter-gravel fill 12.
The tube has a multiplicity of horizontal transverse slots 14 which are incorporated in the wall thereof as circular-segment slots in several rows uniformly over the circumference of the collection element 13. The vertical ridges in the wall left between the rows of slots ensure the overall solidity of the collection element 13. All the slot segments 14 have the same width, length and height. It is only the spacing of adjacent slots in the axial direction which decreases from top to bottom in accordance with the calculations set forth in detail below. The subaqueous pump 15 is enclosed by a continuous tube 16 to which the collection element 13 adjoins at the bottom and is so disposed in the wellhole that even at maximum suction power it is always below an operating water level denoted by 17. The latter lies below the hydrostatic water level 10 by the amount of the depression H L .
The flow effect which is achieved with the subject according to the invention is derived mathematically below. According to the explanations cited above, at any randomly chosen point x there flows through an element of area
ΔA=π·D.sub.i ·Δx (1)
the partial quantity
ΔV=ΔA·a.sub.(x) ·V.sub.S(x) =const; (2)
here:
D i =the inside diameter of the collection element 13;
a.sub.(x) =ΔA S (x) /ΔA: the slot factor which is variable over the drainage length L E ;
ΔA S (x) =the total slot area, which is dependent on x, in the element of area ΔA;
v SCC (x) =the flow velocity in the slots, which is variable over the drainage length L E .
In the SCC according to German Offenlegungsschrift No. 2,401,327, using a suitable construction of the SCC wall an attempt was made by artificially increasing the flow resistance to render v SCC (x) constant over the drainage length L E . In this case it was also possible to keep a.sub.(x) constant over the drainage length L E in order to fulfil equation (2). Investigations performed within the scope of the invention showed, however, that the requirement v SCC (x) =const is only inadequately fulfilled. The flow losses in the vertical direction in the inner tube of the SCC according to German Offenlegungsschrift No. 2,401,327 are by no means negligible compared with the radial flow resistances of the SCC wall with the result that flow losses which vary as a function of x arise along the individual flow filaments from the entry of the water into the slots of the SCC right up to the pump, which losses inevitably produce a non-uniform flow towards the control.
The conclusion to be drawn from this is that the desired effect can consequently be achieved only by a variable slot distribution over the drainage length L E . This distribution can only be determined if the flow velocity v SCC (x) is known. The latter is therefore calculated below. According to the energy theorem, the following applies for flow which is subject to friction:
(1+ζ)Kv.sub.h(L).sup.2 =p.sub.a(L) -p.sub.i(L) (3)
Here ζ expresses the flow resistances of the slots 14 in the wall of the collection element 13. ζ depends on the slot shape and the wall thickness of the collection element 13 and is approximately 0.5 for thin-wall tubes. The constant K=γ/2g is the quotient obtained from the specific gravity of the water and the acceleration due to gravity. v h (L) represents the horizontal flow velocity of the water in the slot at the point x=L. The vertical position of the collection element 13 is represented by the running coordinate x, the so-called running length, x being=0 at the lower end of the collection element 13 and x being=L at the upper end, i.e. pump end of the effective drainage length L E of the collection element 13. P a denotes the pressure outside the collection element 13 and P i the pressure inside the latter.
The following apply for the pressure P a (x) and P i (x) :
p.sub.a(x) =p.sub.a(L) +γ(L-x) (4)
p.sub.i(x) =p.sub.i(L) +γ(L-x)+Δp.sub.v.sbsb.v(x) +Δp.sub.dyn.sbsb.v(x) (5)
In these equations γ(L-x) expresses the hydrostatic pressure difference between the points L and x, Δp vv (x) expresses the frictional losses of the vertical flow in the slotted tube from x to L and Δp dynv (x) expresses the dynamic pressure difference of the vertical flow in the slotted tube resulting from the acceleration of the water flow towards the upper tube end (x=L).
Since the equation (3) is valid not only for x=L but for any randomly chosen value of x, it can be rewritten as
(1+ζ)(γ/2g)v.sub.h.sup.2 (x)=p.sub.a(L) -p.sub.i(L) -Δp.sub.dyn.sbsb.v(x) -Δp.sub.v.sbsb.v(x)
Using equation (3) again and solving the resulting equation for v h (x) taking η=0.5, the horizontal flow velocity v h (x) is found to be ##EQU1## To determine the distribution of the horizontal flow velocities in the slots over the drainage length it would therefore be necessary to calculate the pressure differences due to the frictional losses of the vertical flow Δp vv (x) in the interior of the collection element and those of the dynamic pressure differences Δp dynv (x). This cannot, however, be precisely represented in closed form since a resistance coefficient λ, which is normally a constant for specified tube currents and lengths, is dependent in the present case on x and the vertical volumetric flow in the interior of the collection element 13 which varies with x. This is due to the fact that on the one hand, for each element of length Δx constant partial currents ΔV flow into the interior of the collection element 13 and, on the other hand, the intensity of the water which passes into the interior of the collection element 13 through the slots 14 and the flow surges of which produce turbulences in the vertical water flow and consequently an apparent wall roughness λ, is variable over the length x.
Accordingly, therefore, the vertical flow velocities in the interior of the collection element 13, and also the frictional losses, which are proportional to λ, increase as x increases.
Lengthy investigations which were carried out within the scope of the invention have shown that λ has to be determined experimentally in each case for a collection element size and a specified delivery rate V.
By solving corresponding equations and transforming several times the following is obtained for ##EQU2## After corresponding transformations the following is obtained for Δp dynv (x) : ##EQU3## If, for example, V is set equal to 0.07 m 3 /s, D i to 0.25 m and L to 6 m, it emerges that Δp dynv (x=0) ≈2.1.Δp vv (x=0) if the averaged resistance coefficient λ≈0.06 is used over the collection element length L.
In order to obtain an optimum flow distribution it is then also necessary to specify what the ratio b of the horizontal flow velocities v h at the points x=0 and x=L shall be. In the slot nearest the pump, i.e. at x=L, the horizontal flow velocity v h (x=L) is clearly larger than in the slot at the lower end of the collection element at x=0, with the result that v h (x=0) <v h (x=L) and consequently it may be assumed that b<1. Using (7) and (8) the following is therefore obtained from equation (6) for x=0: ##EQU4## Now that the maximum velocity v h (L) is known, the distribution of the horizontal flow velocities v h (x) over the running length x can also be determined by substituting the equations (7), (8) and (9) in equation (6). The following is then obtained: ##EQU5## It is now intended to calculate the actual slot distribution below. As explained earlier, the assumption for the distribution of the slots 14 over the vertical running length x consists in the fact that the same quantity of water ΔV shall approach each partial element Δx. In determining the slot factor a(x) allowance should be made for the fact that the passage area of a slot which becomes hydraulically active is smaller than the geometric slot area. This is due to the constriction effect of the water jet passing into the respective slot 14 and is allowed for by a contraction index α which enters into the equation and which reduces the volumetric flow for an element of area under consideration correspondingly. The following thus applies:
ΔV=πD.sub.i ·Δx·v.sub.h(x) ·a(x)·α (11)
Since the partial volumetric flow should be constant for any element of area considered, a direct dependence of the slot factor on the horizontal flow velocity is produced. The slot factor a(x) can now be calculated separately for any element of area considered. For example, in a collection element 13 having an effective drainage length L E of 3 m and 15 steps, the corresponding step length Δx=0.2 m. The required 15 different slot factor values can therefore be determined without difficulty using equation (11). In particular, the ith slot factor is then: ##EQU6## FIG. 3 shows both the slot velocity profile at the point D i for the horizontal flow velocity v SCC (x) and also the slot profile over the length of the collection element 13 plotted in diagrammatic form as they may be calculated using the above system of equations.
For the sake of clarity and easier intelligibility a calculated example may now be given at this point. The following values are assumed:
V=0.06 m 3 /s
D i =0.192 m
L=6 m
λ=0.06
v h (L) =2.5 m/s
Whereas the resistance coefficient averaged over L E is taken as λ=0.06, the value for v h (L) corresponds approximately to the value determined experimentally. On solving equation (9) for b and after substituting the above numerical values, the following is obtained:
b=0.506→v h (x=0) =1.265 m/s
The horizontal slot flow velocity at the lower end is therefore about half as great as the horizontal flow velocity at the upper end of the collection element 13.
Equation (10) can be rewritten as ##EQU7## where the following abbreviations have been introduced: ##EQU8## After substituting the values of the numerical example, the following are obtained: A=2.072; B=1.454; C=0.00193. In the present numerical example v h can therefore be calculated as a function of the running length x in closed form for any randomly chosen value of x.
In order at this point to arrive at the slot profile, the step length Δx of each calculation section must be specified. Although it would be possible also to choose any arbitrarily smaller gradation, it is, however, appropriate in the present example to choose Δx=0.4 m, with the result that L=15, Δx=6 m. For the quantity of water ΔV which has to be drawn off per step, the following then applies
ΔV=0.06/15=0.004 m 3 /s
Equation (12) for the slot factor of the ith step can now be rewritten in the following manner: ##EQU9## where for α≈0.6 (rectangular inlet, see specialist literature) ##EQU10## and in the present example E=0.0276 m/s.
For strength reasons the individual slots are, as was explained earlier above, symmetrically divided up into several circular-segment slots disposed in vertical rows between which solid bridges extend as part of the wall of the collection element 13. The area of a slot A S .sbsb.(1) can therefore be expressed as
A.sub.S.sbsb.(1) =β·π·D.sub.i ·s,
where s denotes the slot height and in the present numerical example is chosen to be s=1 mm. β is the ratio of the total length of all the circular-segment slots located at a height x to the circumference of the collection element and is here taken as 0.6. Consequently the following results:
A S .sbsb.(1) =0.000362 m 2
and the number Z of the slots (not to be confused with the number of circular-segment slots) per area of a step length Δx is ##EQU11## The slot pattern calculated for the above numerical example is evident from the following table.
______________________________________ x v.sub.h(x) ##STR1## ##STR2##______________________________________0.2 1.26 0.02187 60.5 bottom0.6 1.2726 0.0217 601.0 1.273 0.0213 591.4 1.3295 0.021 581.8 1.377 0.02 552.2 1.436 0.0192 532.6 1.5074 0.0183 50.53.0 1.53 0.0174 483.4 1.6835 0.0164 453.8 1.787 0.0155 434.2 1.9 0.0145 404.6 2.02 0.0137 385.0 2.15 0.013 365.4 2.28 0.0121 33.5 top5.8 2.43 0.0114 31.5______________________________________
Preferably 4 to 6 slot rows of circular-segment slots are provided distributed over the circumference.
The newly developed method is applicable in a similar manner and with a similar effect also directly to well filter tubes: instead of a conventional well filter tube the bore-hole is lined with a slotted tube of the new constructional type in the region of the water-bearing strata, i.e. the water passage area increases in this well filter tube in the region in question from top to bottom in a specified manner. In this case the well construction is completely conventional, i.e. around the novel well filter tube filter gravel is packed in the conventional manner, a continuous well tube of conventional construction adjoins the novel well filter tube in the upwards direction and the subaqueous pump is installed without being provided with SCC in a manner such that its bottom edge lies exactly in the plane of the welding joint between the continuous well tube and the filter tube. The desired uniform flow profile will likewise already be present at the transition point R K from the aquifer, i.e. from the water-bearing strata, to the gravel fill.
According to a further advantageous embodiment of the invention an additional outer tube is provided which surrounds the collection element 13. The outer tube has a multiplicity of relatively large-area slots so that the relative water passage area of the outer tube is considerably greater than that of the collection element 13. A ratio of from 10 to 15:1 for the relative water passage areas of the outer tube and the collection element has proved to be particularly suitable.
With this additional outer tube the uniformity of the water flow in the region of the well filter tube can be improved still further with the result that a flow which approximates still further to laminar flow is established.
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In a well with filter tube and filter gravel fill a slot profile for a collection element forming the suction tube has larger suction cut-outs at the bottom than at the top and effects an equalization of the flow velocity of the water passing into the filter gravel layer on the basis of the combination of calculations and empirical investigations.
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BACKGROUND AND SUMMARY OF THE INVENTION
Exemplary embodiments of the present invention relate to a high frequency (HF) front end in a multilayer structure. This HF front end is designed for use as a transmission/reception module, transmission module or reception module.
The present invention can be used, inter alia, in active antennas (active electronically steerable antennas AESA) in radar systems, SAR (synthetic aperture radar), electronic warfare (EW) or operations command systems, as well as for navigation and communications systems. Possible platforms are ground and marine systems, aircraft, satellites, drones and missiles as well as building-based or vehicle-based systems. The multilayer structure of these modules allows for a high degree of miniaturization of the modules, as well as their arrangement in conformal and/or structurally integrated antenna arrays.
European Patent Publication No. EP 1 328 042 B1 discloses a transmission/reception module for a radar system that consists of several substrate layers stacked one above the other, which are joined by solder balls. Because of the finite extent of the solder balls, gaps remain between adjacent substrate layers. Moisture and other contaminants can penetrate into the interior of the module through these gaps, which can influence the electrical function of the individual components, e.g., electrical components, within the module or even damage them to the extent of total failure. Despite the solder connection between the individual layers described in EP 1 328 042 B1, hermetic sealing of the interior of the module is not guaranteed. This hermetic sealing is, however, required for using these modules for space travel applications and platforms in critical ambient conditions.
PCT Publication No. WO81/00949 describes a semiconducting component package comprising a chip carrier, wherein the chip carrier is constructed from a plurality of layers of insulating material. These layers comprise metallic grooves at their edges, with which electrical contact can be made with adjacent layers.
U.S. Pat. No. 5,311,402 discloses a semiconducting arrangement, wherein an integrated circuit is attached to a circuit board and a cover is provided for hermetic sealing.
U.S. Pat. No. 3,403,300 discloses a stack of circuit boards.
Protection against ambient influences is possible using external measures, such as additional welded protective casings, which increase the cross-sectional dimensions of the transmission/reception modules. In addition, mechanical forces act on the multilayer structure due to the deformation of such protective casings during welding, which influences the long-term stability of the modules or can break the solder joints between the module layers. In addition, such protective casings, e.g., of plastic (e.g., polymers), provide only limited sealing, but not hermetic sealing. Furthermore, such plastics can degas over time and thus damage the components and their joints to the substrates.
Exemplary embodiments of the present invention provide a generic HF front end (e.g., transmission/reception module with integrated radiator element) with a hermetically sealed interior space.
The HF front end according to the invention is implemented in a multilayer structure and comprises electronic components, wherein the multilayer structure contains a plurality of substrates stacked one above the other and carrying the components. The module includes grooves formed in the substrates (at the edge regions of the respective layer structure) and sealing elements (e.g. metallic frames or covers) are provided between the substrates for the purpose of hermetic sealing and are deployed within the grooves, whereby the sealing elements engage in grooves of adjacent substrates. According to the invention, adjacent substrates are soldered together.
In a first embodiment of the invention the sealing element is an open frame element, which engages in the grooves of two adjacent structures. In a second embodiment of the invention the sealing element is a closed cover element, which ensures hermetic sealing of each individual substrate (module layer).
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The invention is explained in more detail below using figures, in which
FIG. 1 a shows a schematic side view of an HF front end according to the invention in the first embodiment with a groove running in the inner region,
FIG. 1 b shows an enlarged illustration of the groove from region A in FIG. 1 a,
FIG. 1 c shows a schematic illustration of a frame element according to the invention of the first embodiment,
FIG. 2 shows a schematic illustration of an HF front end according to the invention in the first embodiment with a groove running in the outer region, and
FIG. 3 shows a schematic side view of an HF front end according to the invention in the second embodiment.
DETAILED DESCRIPTION
A first embodiment of an HF front end according to the invention (e.g. a transmission/reception module) is illustrated in FIG. 1 a . It shows two substrates 1 , 2 stacked one above the other, each carrying (at least) one component 3 , 4 , e.g., amplifier, phase shifter, amplitude controller, transmit-receive switch (circulator), control electronics (e.g., application specific integrated circuits (ASIC) or field programmable gate arrays (FPGA)) or antenna element. Each substrate 1 , 2 comprises a groove 7 appropriately running along the periphery of a substrate. A frame sealing element 5 (preferably metallic or plastic with external metallization) is introduced into this groove 7 ( FIG. 1 c ). This frame element 5 engages in the grooves 7 of the two adjacent substrates 1 , 2 . The frame element 5 is suitably soldered or glued into the grooves (see contact areas 9 in FIG. 1 b ).
The height H of the frame element 5 is appropriately selected so that there is a gap S between the two substrates 1 , 2 . The height H of the frame element 5 is adapted to the size of the gap S, which results from the melting of the solder balls for making electrical and thermal connection between the adjacent substrates 1 , 2 . An electrical connection between the solder balls 6 and the frame element 5 is to be avoided, otherwise this could lead to an electrical short circuit and thus failure of the HF front end.
FIG. 1 b shows an arrangement with the frame element 5 soldered on the contact areas 9 in the inner region of two module substrates 1 , 2 . The arrangement implements hermetic sealing for the inner region of the adjacent module layers 1 , 2 .
FIG. 1 a further shows that an open interior space I is formed between the two components 3 , 4 of the adjacent substrates 1 , 2 with the frame element 5 used. The solder balls 6 are located in the outer region and are thus advantageously accessible for electrical measurements (e.g., after preparing the modules for testing the electrical function of the individual module layers). The possibility of fouling in this connection region is disadvantageous for this arrangement and could lead to degradation of the electrical operation or failure. This can be prevented by suitable environmental technology constraints (e.g., air filters).
FIG. 2 shows a section of an HF front end according to the invention corresponding to region A in FIG. 1 a , with the difference that the groove 7 runs in the outer region of the substrates 1 , 2 , i.e., facing away from the inner region I. The frame element 5 is then soldered to the illustrated contact areas 9 in the outer region of two module substrates 1 , 2 . This arrangement provides hermetic sealing for the inner region I of the adjacent substrates 1 , 2 (module layers). The solder balls 6 are located in the protected inner region and are thus not accessible for subsequent electrical measurements. The complete module design and the integrated components are advantageous, since full hermetic sealing is provided. Additional environmental constraints are not necessary.
A second embodiment of an HF front end according to the invention is illustrated in FIG. 3 . The same components are respectively given the same reference numbers as in FIG. 1 . The embodiment in FIG. 3 differs from the embodiments shown in FIG. 1 and FIG. 2 in that an open frame element is not used, but instead a closed cover element 8 (e.g. a metallic cover) is used.
The cover element 8 is essentially characterized in that the respective interior space of a module substrate is closed separately and is thus hermetically sealed. In addition, the adjacent interior space I of the adjacent substrates 1 , 2 are separated from each other, and hence the electromagnetic coupling of the components on the various module substrates is prevented. The cover elements 8 can be, for example, thin metal strips, which can be soldered into the grooves 7 of the substrates 1 , 2 using conventional manufacturing methods (e.g. soldering or gluing to the contact areas 9 ). The second embodiment of the invention provides further advantages in addition to the hermetic sealing of the individual substrates, such as, for example:
preliminary electrical tests with the closed substrates before the electrical connection of the individual substrates using the solder balls, repair options by replacing individual substrates following unsoldering of the solder balls, simple modernization of the individual substrates by replacing these substrates with improved integrated components, e.g. circuits occurring as a result of new technologies within the integrated components, modular antenna structures through the combination of standardized and application-dependent module substrates. modular module structure, which enables transmission/reception modules, transmission modules or reception modules by combining suitable module substrates. In addition, the topmost module substrate with integrated radiating element can be integrated in the overall module or omitted depending on the application.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
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A hermetically sealed HF front end (e.g. a transmission/reception module) in a multilayer structure that includes electronic components is provided. The multilayer structure contains a plurality of substrates stacked one above the other and carrying the components. Grooves are formed in the substrates and sealing elements are provided between the substrates, which sealing elements engage in the grooves, and the substrates are soldered together.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a non-intrusive portable safety seal to collect human organic residues in order to obtain DNA and genetic patterns from fingerprinting.
In addition, the invention has all the characteristics of a safety seal to stamp, record, or adhere people's imprints and their DNA. The invention provides a rapid, effective, and safe method for the accreditation of identities and genetic patterns. This is made possible by obtaining recordings of thumb imprints on the adhesive of the seal, as well as obtaining remnant particles of epithelial dead cells and organic residues (such as from the humidity and grease of the finger, etc.) bonded to the same adhesive or on the graphite or granulated sheets for testing the DNA by using certain reagents in an appropriate laboratory.
The non-intrusive characteristic of the present invention me that it is not necessary to compulsively introduce into the human body any strange elements to obtain DNA, as would be currently required when taking blood samples with syringes or when introducing swabs into the mouth to obtain DNA samples.
The proposed seal comprises four overlapped basic components: a sheet paper or base forming a triptych, which serves to support the entire set; an adhesive-covered central sheet bearing a safety seal on the front side; a two-faced sheet with double adhesive and a graphite or granulated sheet bonded to it. In addition, the stamp has two safety flaps that protect the entire set.
A double safety feature is achieved through the implementation of the seal: the person's fingerprint and DNA. The present invention is applicable to procedures to obtain genetic patterns and to preserve identities or to determine the forgery of identities.
2. Description of the Prior Art
It is known that U.S. Pat. No. 6,659,038 of the same applicant solves the problem of fingerprinting without the use of ink and introducing a graphite sheet.
The same applicant has filed another Argentinean patent application (No. P 04 01 01743, filed May 19, 2004) that reveals a safety seal sticker which includes graphite or a granulated sheet that provides a safety element to replace traditional fingerprints stained with ink on identity documents, cards, licenses, passports, commercial documents, etc. This application also provides a portable and alternative process to be used by police, scientific, judicial, forensic, or security forces, to facilitate people's identification on the street and to safely carry the fingerprint and DNA obtained.
The current invention utilizes this last method and proposes improvements as a safety seal intended to take fingerprints and DNA in public places or any other place.
Another purpose of this invention is to provide a portable safety seal that incorporates a graphite or granulated sheet for fingerprints and DNA, which presents a special configuration for this use because it introduces additional safety measures to avoid tampering and contributes to the adequate preservation of the collected genetic material from its collection and transportation until the final reception at the laboratory or site where its organic content will be analyzed.
SUMMARY OF THE INVENTION
The present invention, as previously explained, relates to a portable safety seal to stamp, record, or adhere people's fingerprints and their DNA, aimed to be a rapid, effective, non-intrusive, and safe method for the accreditation of identities. This is possible by recording of thumb imprints or any other finger on the adhesive of the seal, as well as obtaining the remnant particles of epithelial cells and organic residues (such as from the humidity and grease of the finger, etc.) that bond to the same adhesive and enabling the DNA to be tested with certain reagents in an appropriate laboratory.
The final product is highly functional, given the practical way to manipulate it. It is hygienic, given that the remnants of graphite disappear by slightly rubbing the surface impregnated with a simple tissue paper or bond paper or even by rubbing with another finger. It is safe because it neither produces allergies nor any kind of adverse reactions. It is economical and versatile because it adjusts to the different user's needs, according to different special or universal measures to be adopted for its final configuration (for only one fingerprint or for all 5 fingers, left or right, for example). Moreover, it provides safety and inviolable measures necessary for the fingerprints and DNA to be taken to the approved control agency, such as police, firemen, airports, hospitals, private laboratories, etc., where they will be processed in order to identify the person's identity.
A distinctive aspect to be highlighted in relation to the prior art is that once the portable safety seal was used according to the techniques and mechanisms herein explained, there is no need to keep the organic remnants and DNA at preservation temperatures in refrigerators, as is the case with DNA collected by traditional intrusive systems such as blood collected through syringes or swabs introduced into the person's mouth to collect saliva.
These two intrusive systems present, on one hand, the danger to contaminate the person who manipulates them, as is the case of blood collected with a syringe that may contain HIV. On the other hand, it is worthwhile noting that, upon obtaining DNA through intrusive methods, from the very moment when the blood or saliva is collected, it is exposed to the possibility that the person taking the sample may use these samples for other purposes, constituting a high risk of inappropriate use.
The great disadvantage of these traditional methods is that they allow the unduly or non-authorized use of the organic samples collected. Therefore, human DNA as an identification tool is currently a double-edged sword when present systems are able to manipulate genetic information taken for criminal purposes since the only thing that prevents a drop of blood or a sample of saliva from that collection to appear in other scenarios is the honesty of the person who has collected the sample and taken it to its final destination.
This requirement of the present technology can be satisfied with this invention, which provides an inviolable safety seal for obtaining and transporting genetic samples collected, making them impossible to manipulate at will.
It must be taken into account that epithelial cell manipulation can only be done at specialized laboratories, thus eliminating the risk of unduly using DNA incorporated in the seal. To obtain a genetic pattern from the epithelial cell sample, said cell has to undergo a process named “PCR” (polymerase multiplication) which consists in multiplying the same genetic patterns so as not to lose information and then to work with the genetic information so multiplied. This genetic information lady processed by the PCR technique cannot be manipulated in another scenario, since it is no longer the original source. It will also be impossible to remove cells from the adhesive-covered side of the seal since said cells will contain remnants of adhesives thereby providing evidence of its impurity and doubts to its origin.
This does not currently happen with blood or saliva, since these intrusive techniques allow one to manipulate DNA from its original phase, even enabling tampering or forging at its preservation site, where intentional changes to bottle or vial labels containing samples could be performed.
The undue use of or tampering of the samples would not be possible with the safety seal currently proposed. It must be highlighted that once the seal is used, it is hermetically sealed by a colored adhesive-covered sheet that contains the safety printing that reveals at first sight if it was broken or tampered with.
It is worth mentioning that every manufacture and production stage of the safety seal is carried out in a sterilized and contamination-free environment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the safety seal of this invention, closed, with unopened safety flaps, ready for use.
FIG. 2 is a front perspective view of the seal when opened, showing three parts of a triptych.
FIG. 3 is a top plan view of the completely opened seal, which shows how the graphite or granulated sheet should be detached.
FIG. 4 shows the details of a user rubbing his thumbs on the graphite or granulated sheet already detached from the seal.
FIG. 5 is a top plan view of a seal being used by a user wherein the user stamps a fingerprint on the lateral sheet with two-faced adhesive.
FIG. 6 represents a step in which a user detaches the central safety adhesive-covered sheet that will serve to close the set after the fingerprint is stamped on the seal.
FIG. 7 is a perspective view of a safety seal during the closing process in order to protect the fingerprint previously stamped.
FIG. 8 is a top plan view of the seal that shows how the seal closed by its safety flaps on its top and bottom edges appears.
FIG. 9 shows the last stage of the process, which consists of sticking the safety adhesive-covered sheet on the only opened lateral edge of the seal.
FIG. 10 shows a step in which attempts are made to remove or detach the safety sheet of the seal, once it has been sealed and the sheet bonded, leaving on sight the safety printing transferred to the visible frontal side of the set.
FIG. 11 shows a second embodiment in which the seal is unfolded, and it consists of a seal to stamp the other four fingers.
FIG. 12 shows the consecutive steps of the process of using said second embodiment, i.e., firstly, to detach the graphite or granulated sheet and secondly, the silicone protective sheet.
FIG. 13 shows a top plan view of the unfolded seal in its second embodiment, with four fingerprints already stamped.
FIG. 14 shows a step consisting of protecting the stamped fingerprints by placing on them the silicone protective sheet previously completely removed or partially detached.
FIG. 15 illustrates the closing process of this alternative embodiment of the safety seal, folding one side over the others.
FIG. 16 illustrates the structure of a graphite sheet.
FIG. 17 illustrates the structure of a granulated sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
When the user needs to identify a person through the seal proposed, the steps are as follows.
The seal is taken and the two safety flaps that close the top and bottom edges are detached. The main body of the triptych-configuration is opened and the graphite or granulated adhesive-covered sheet on one of the internal sides of the triptych is removed from the safety seal ( FIG. 3 ).
Then, the finger of a subject from which the visible or latent printing needs to be obtained is selected. The print for the subject's fingerprint and DNA is visible if a graphite sheet is used or latent if a granulated sheet is used). Generally, the thumb is selected, although it could be any other finger. The selected finger is sufficiently rubbed on the detached graphite or granulated sheet ( FIG. 4 ), such that the graphite of the graphite sheet is transferred to the selected finger, impregnating and covering most of the surface of the finger where the fingerprint is to be obtained.
Once the finger is impregnated with the dried graphite dust taken from the sheet, that finger is lightly pressed on the two-adhesive covered sheets that remained uncovered on one of the triptych sides where the graphite sheet was initially detached ( FIG. 5 ).
The reaction produced between the wet adhesive and the dry graphite dust that is on the finger is as follows: The adhesive keeps the graphite dust attached to the surface of the external papillae (ridge) of the finger impregnated with graphite. When the finger is stamped and pressed on the adhesive-covered surface of the sheet, the drawing of the fingerprint will be stamped on the surface of the sheet. The fingerprint will be clear and visible in its original state without deformations. Such fingerprint identifies the person who stamped it according to the dactyloscopic system that classifies it, and to the organic remnants collected from the genetic patterns of the person's DNA.
In this way, the covering of the intermediate papilla grooves between ridges is prevented, as does sometimes occur with the wet or paste ink traditionally used to take fingerprints.
Once the fingerprint is collected, the main triptych body must be closed, for which the propylene adhesive-covered sheet on one side and attached to the central panel of said triptych must be detached ( FIG. 6 ). This sheet can be easily distinguished since it is preferably presented in colors.
Then two lateral panels of the triptych ( FIG. 7 ) are closed, which include the one that contains the fingerprint collected and the other one with space to manually fill in information concerning the person whose identity is to be verified. The two-surfaced adhesive-covered sheet ( 9 ) containing the fingerprint ( 11 ) will not stick to the central panel ( 4 ) when two lateral panels are folded one over the other, because said central panel ( 4 ) is treated by silicone and the adhesive of the sheet ( 9 ) cannot stick to the central panel ( 4 ). This structure perfectly preserves the fingerprint as well as genetic material collected.
Once the triptych is closed, the safety flaps of the top and bottom edge are bonded again ( FIG. 8 ). The polypropylene safety adhesive-covered sheet previously detached is used as a seal to close the only lateral edge of the triptych that remains open ( FIG. 9 ).
As said polypropylene sheet has adhesive on one side and the external surface of the triptych has no silicon, said polypropylene sheet will stick firmly to the non-silicone paper. If broken or detached, the seal could not be re-used because the statement on the seal indicating that it has been removed ( FIG. 10 ) will be visible, as a result of the safety process through which a warming statement is printed on the colored side of the sheet.
This method of use, as previously explained for the graphite sheet, is the same as the alternative one with the granulated sheet.
The difference between the procedure for use explained above and the example below lies in the fact that rubbing the finger on the granulated sheet results in a higher degree of skin exfoliation of the finger compared to stamping it using graphite on the two-faced adhesive-covered sheet. It allows a higher concentration of epithelial cells, thus obtaining a higher quantity of DNA.
The alternative process of stamping the other four fingers of the person being identified is similar to the preferred way. In this case, the top and bottom safety flaps are also detached and the four panels of the seal are unfolded: one panel with the polypropylene safety adhesive-covered sheet and three other panels with the graphite or granulated sheet ( FIG. 11 ).
Then, the graphite or granulated sheet and the polypropylene protective sheet with silicone on one side must be detached ( FIG. 12 ). The four fingerprints must be stamped on the space assigned to said purpose ( FIG. 13 ). Then, the same polypropylene protective sheet silicone on one side must be placed again ( FIG. 14 ). The function is to prevent the stamped fingerprints from getting stuck together once the sides of the panel to seal are folded ( FIG. 15 ). This silicone protective sheet can be totally detached and left aside. Then, the process of collecting the fingerprints starts. After that, the protective sheet is re-attached to protect the stamped fingerprints. Alternatively, upon detaching and pulling the protective sheet up, it may not be necessary to remove the sheet completely, given that on the right lateral panel there may be a stopper to prevent the total detachment of the set and its possible loss.
According to the figures attached, the preferred embodiment of the safety seal ( 1 ) basically comprises four sheets or basic related components. By “basically comprises four sheets”, we mean that, as it will be detailed below, some of these four sheets are composed of several layers or sub-sheets, although they are not visible to the user.
The first sheet ( 2 ) is a base support. It is preferably a Kraft-type sheet of paper with a super-calendared glassine type of high strength and a low gram density (flexible) or high gram (90-120 g semi-rigid). The three external sides, including external sides ( 2 a ), ( 10 ), and the central back side (not shown), does not have a silicone layer, while the internal sides ( 8 ), ( 4 ), and ( 7 ) are covered by silicone.
The second sheet ( 5 ) is placed on the center of the seal. It is a polypropylene film with adhesive on one side and is treated for safety printing, preferably in color, to prevent the reuse of the seal or fringe during transport of the seal. The adhesive used may be PSA type of aqueous acrylate or, preferably, other adhesive with higher tack. The second sheet is preferably a 10-20 micron polypropylene film, which is 11 g/m 2 gram, 12.5 micron-thick, and 1,400-kg/square inch in tensile strength.
The safety treatment of said film is known as transfer technique. Such technique consists of a first process of photogravure printing with the pertinent security statement and then applying the printing all over the surface of the film.
FIG. 10 shows what happens if a malicious user tries to detach the self-adhesive safety sheet, which is the second sheet ( 5 ), from the seal already closed. The graphic security statement of the safety sheet will inevitably be transferred to the external side ( 2 a ) of the seal. This will be the evidence that the seal has been broken or manipulated. Thus, a second use of the same seal should not be allowed. The recipient of the seal should acknowledge that the seal has been broken at a certain time during its transportation. More specifically, from the moment the fingerprints were collected and the seal was closed up to when the pertinent department receives it.
The third sheet of this safety seal comprises a graphite or granulated sheet ( 6 ) inserted on the lateral internal side ( 7 ) of the seal. A user can detach the graphite or granulated sheet and rub one finger on it. Afterwards, the user can stamp the finger on a two-faced adhesive-covered sheet ( 9 ) (the fourth sheet as explained below) that is available on said lateral internal side ( 7 ), thus leaving a visible or latent fingerprint ( 11 ) with all its organic components adhered to the sheet.
The fourth sheet of the seal comprises the adhesive-covered sheet ( 9 ) on which the graphite or granulated sheet ( 6 ) is mounted. This supporting material comprises a two-faced adhesive on both sides. This sheet is preferably a 10-20 micron polypropylene film treated on both sides (two-faced) with a PSA type adhesive of aqueous acrylate that does not produce allergic reactions, is not thermo-sealable and with high tensile strength. This two-faced sheet ( 9 ) has a weight of: 11 g/m 2 gram, a thickness of 12.5 micron, and a tensile strength of 1,400-kg/square inch. Its color is preferably crystal white.
The entire set of the safety seal which comprises these four overlapped sheets is completed with two additional elements that are the safety flaps ( 3 ) also in polypropylene and with adhesive on one side. These flaps ( 3 ) may be initially treated with security printings that help to detect if they were opened or tampered with. If so, the flaps will transfer a warning inscription to the external surface on the top and bottom edges of the seal.
The complete set of the safety seal with incorporated graphite sheet or granulated sheet may be available in different measurements and designs. For hygienic reasons, it could be available in a heat-sealed tearable-layer package. The preferred embodiment illustrated presents a square ornamental aspect whose approximate measurements of the sides range from 50-55 mm. Likewise, according to the user's specific needs, the proposed safety seal can be manufactured with all the alternative possible sheets. For example, the graphite sheet may be on the left side rather than on the right side. The polypropylene (OPP) sheet may be transparent or in different colors. The adhesive of the central sheet may be colored or transparent, etc.
The second alternative embodiment illustrated in FIGS. 11 to 15 , are designed to take fingerprints of the other four fingers of the person being identified. This embodiment comprises the same four sheets used in the preferred embodiment, with a fifth separation sheet ( 200 ) being added between the graphite sheet ( 106 ) and the central sheet ( 109 ) with double adhesive.
The configuration of this alternative embodiment is not a triptych like the preferred one, but it has four sides separated in folds that favor the folding of the lateral sides over the central side, which is the one that bears the adhesive-covered safety flaps ( 103 ).
Hence, this second alternative embodiment comprises a first sheet ( 110 ) having four panels side by side, each panel foldably connected to the next panel, wherein, when the four panels are in the fully extended position, each of the four panels has a silicone treated upper surface ( 104 , 107 ) facing the same direction; a second sheet ( 105 ) adhering to the upper surface ( 104 ) of the first base sheet ( 110 ) and being treated for safety printing on one of its sides; a third sheet comprising a detachable graphite or granulated sheet ( 106 ); a fifth sheet comprising a separation sheet ( 200 ) with an upper surface that is not silicone treated and a lower surface that is silicone treated; and a fourth central sheet ( 109 ) having adhesives on its upper and lower surfaces, wherein the lower surface of the fourth central sheet ( 109 ) adheres to the upper surfaces of the first sheet ( 110 ), the lower surface of the separation sheet ( 200 ) of the fifth sheet adheres to the upper surface of the fourth central sheet ( 109 ), and the detachable graphite or granulated sheet ( 106 ) adheres to the upper surface of the separation sheet ( 200 ) of the fifth sheet.
On opening the seal and unfolding the four sides of the set, the user will detach the graphite or granulated sheet ( 106 ) and rub it on his/her fingers, as in the preferred way. However, he/she must remove the separation sheet ( 200 ) that is underneath, to finally place his/her fingerprints ( 111 ) on the central sheet ( 109 ) with double adhesive.
The graphite or granulated sheet ( 106 ) may be detached and completely removed. Alternatively, a sheet may be simply partially detached so as to leave a space for the fingerprint, lining the seal by means placed on one of its corners ( 107 ).
The adhesive used, both in this embodiment and in the preferred embodiment, is preferably PSA type that is an acrylate co-polymer in aqueous dispersion.
Lastly, the user must place the separation protective sheet ( 200 ) again, by making contact between its backside with the central sheet ( 109 ) which bears the stamped fingerprints.
This back side of the separation sheet ( 200 ) contacting the adhesive of the two-faced central sheet ( 109 ) is treated with silicone, thus preventing both sheets from sticking together and preventing the fingerprints and genetic material collected from deformation or damage.
Although the preferred embodiment is for a single fingerprint (thumb) and the second embodiment is used for the four remaining fingerprints; evidently, if only one seal is necessary to cover the five fingerprints, the second embodiment can be amended by adding an extra panel. In that way five fingerprints can be printed instead of four.
Both processes are designed to collect latent fingerprints on surfaces and to collect fingerprints in situ to people to be identified at a certain time. For example, police staff could use it to identify a person, either being alive or deceased, whose true identity must be checked.
This seal will also be useful for security forces, particularly firemen and police or forensic doctors to collect fingerprints and DNA of people who might have had road accidents or might have committed a crime and do not carry identity cards with them.
In case, for example, the seal were to be used in any of its two embodiments to collect latent fingerprints on certain surfaces, this would be possible by pulling up the graphite or granulated sheet ( 6 , 106 ) and placing the adhesive-covered surface ( 9 , 109 ) of the central sheet on the surface where the latent surface might be.
In case of using the alternative process for this task, the separation sheet ( 200 ) must also be detached ( 200 ).
In both cases, the invention solves the problem of having an inviolable safety seal for the collection and carrying of genetic samples, making it impossible to be manipulated at will or tampered with.
A third embodiment is provided, with the intention to reduce production costs and achieves an economical version, without being less effective.
This third version of the seal comprises only two sheets, eliminating the third sheet ( 6 ) (graphite or granulated) and the fourth sheet ( 9 ) (with adhesive on two surfaces) of the preferred embodiment.
This embodiment comprises the triptych base sheet and central sheet of polypropylene with adhesive on only one side. The difference is that an adhesive and a fine layer of ground pumice stone grains are spread on one internal surface so that the surface becomes rough or granulated. This is not a detachable or disposable sheet but the rough or granulated surface is a part of the same base sheet on one of the internal lateral sides.
In this case, the genetic material collected is included in the granulated surface and deposited between the micro-interstices generated by the space left between crushed granules of pumice stone. The difference with the previous embodiments is that while the genetic sample adhered to the two-faced adhesive, in this case, it is incorporated into the granulated surface.
Detail of the Structure of the Graphite Sheet:
The graphite sheet ( 6 , 106 ) incorporated into the two-surfaced sheet ( 9 , 109 ) of the safety seal, seems to be only one sheet at first sight. However, it is composed of three different layers. The first layer is a text paper. The second layer is made of silicone, and the third layer includes graphite itself.
Description of Component Elements:
The surface material is a piece of silicone text paper over which ground graphite is spread. The text paper is of high strength and density glassine type, with silicone on one side that provides a smooth and semi-glossy finish. The typical gram ranges are from 75 to 85 g/m 2 , and it may vary according to its application. The thickness is approximately 65-75 mic, according to the type of material. The longitudinal tensile strength is between 15-20 kg/ln, while transversal tensile strength ranges from 7.5-11 kg/ln. The color of the text paper is preferably white. It is presented as 70-75 mm diameter coils.
The graphite layer comprises a safe organic component as from graphite ground as dry-talcum powder.
For that purpose, it has been proven that the provision of a granulated sheet of rough surface facilitates the collection of higher quantity of genetic information given that the dead cells or organic remnants on fingertips are easily detached if they are slightly rubbed with a rough surface as the one of the granulated sheet. For this reason, the present invention provides, as an alternative, a safety seal with the same structural characteristic of the variants detailed previously, with the only difference being that graphite sheet is to be replaced by a granulated sheet, whose characteristics are detailed below.
Detail of the Structure of the Granulated Sheet:
The granulated sheet ( 6 , 106 ) incorporated to the two-surfaced sheet ( 9 , 109 ) of the seal, seems to be only one sheet at first sight. However, it is composed of three different layers. The first layer is 50-80 g bond paper. The second layer is PSA adhesive. The third one is a layer of fine pumice stone grains.
Description of Component Elements:
The surface material is a piece of adhesive-covered bond paper over which fine grains of ground pumice stone are spread. The bond paper has high strength and density, with adhesive-covered on one side. The typical gram ranges from 50 to 80 g/m2 (it may vary according to its application. The thickness is approximately 30-50 mic. The longitudinal tensile strength is between 10-15 kg/ln, while transversal tensile strength ranges from 7.5-10 kg/ln. The color of bond paper is preferably white. It is presented as 70-75 mm diameter coils.
The pumice stone grains comprise a safe organic component derived from the pumice stone being ground as a dry granulated powder.
The embodiment of the seal with incorporated granulated sheet is useful for the cases in which a higher quantity of DNA is required, since by rubbing the finger on the granulated sheet, a higher degree of skin exfoliation of the finger rubbed will be obtained. By stamping it in a latent way, without using graphite, on the two-surfaced adhesive-covered sheet, a higher concentration of epithelial cells will be obtained.
On implementing the safety seal exemplified and described, modifications and/or variants of the embodiments may be introduced. All of which must be considered within the scope of protection of the present invention.
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A non-intrusive portable safety seal to collect human organic remnants in order to obtain DNA and genetic patterns of fingerprints is provided. The proposed seal comprises four related basic components: a sheet of paper or base forming a triptych, which serves to support the entire set, an adhesive-covered central sheet bearing a safety seal on the front surface, a two-surfaced sheet with adhesive on both surfaces and a graphite or granulated sheet adheres to it. In addition, the seal has two adhesive-covered safety flaps that protect the entire set. An alternative seal comprises a base sheet that is able to receive four fingerprints of four fingers, containing a fifth separation sheet between the graphite or granulated sheet and the two-surfaced adhesive layer.
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[0001] The present invention relates to a jacketed yarn of natural appearance. The present invention also relates to a textile produced from a jacketed yarn of natural appearance. The present invention also relates to a method of manufacturing a jacketed yarn of natural appearance.
[0002] Despite a growing commercial demand, it is still not known how to manufacture yarns based on thermoplastics that have both excellent mechanical properties and a natural appearance discernible both to sight and to feel. Furthermore, the environmental requirements are rarely met as regards the use of natural materials and the ability of being recycled in order to obtain products based on yarns intended for any use, for example textiles. This is particularly the case for textiles used in outdoor applications, that are subjected to foul weather and to sunshine, and for textiles that have to be fire-resistant.
PRIOR ART
[0003] Document FR-2 781 492 discloses a thermoplastic comprising fibers of plant origin, that are intended to improve the appearance as perceived by the consumer.
[0004] However, the external appearance of the products obtained proves to be relatively disappointing and very barely compatible with what is presently sought by the consumer.
[0005] Also disclosed, from document FR-2 617 205, is a jacketed yarn and a method of manufacturing a yarn by jacketing a core with a fire-resistant composition, in order to obtain a yarn and subsequently a fabric with fire resistant properties.
[0006] However, the yarn obtained still has a smooth feel, not very favorable to a range of products classed as being “environmentally friendly” and able to fall only with difficulty within environmentally friendly considerations.
SUMMARY OF THE INVENTION
[0007] A first problem that arises is how to develop a novel type of jacketed yarn exhibiting excellent mechanical properties and excellent usage properties such as fire resistance, weatherability, resistance to sunshine, etc. A second problem that arises is how to obtain a yarn having an external appearance generating particularly pleasant visual, tactile and olfactory sensations. A third first problem that arises is how to produce a yarn incorporating materials of natural origin. A fourth problem that arises is how to develop an effective method of manufacturing a yarn based on thermoplastics.
[0008] According to a first aspect of the invention, a jacketed yarn of natural appearance, having a core yarn and a jacket made of a thermoplastic, is characterized in that the thermoplastic of the jacket contains less than 20% by weight of staple fibers.
[0009] In other words, with an amount of fiber of less than or equal to 0.20% present in the jacket, the yarn will have a particularly advantageous external surface appearance. In a first embodiment, and so as to increase the strength, the core yarn may be a multifilament yarn. The core yarn may be a polyester, polyvinyl alcohol, or polyamide yarn. The thermoplastic of the jacket may preferably be chosen, by itself or as a blend, from the group of polymers and copolymers comprising polyolefins, polyesters, polyamides, polyvinyl chlorides, polyvinyl alcohols, silicones and fluoropolymers.
[0010] Advantageously, the amount of fiber in the thermoplastic of the jacket may be between 1% and 15% by weight. Preferably, this amount may be between 4% and 12% by weight. Very preferably, this amount may be between 6% and 9% by weight. Advantageously, the staple fibers may be chosen, by themselves or as a blend, from the group comprising natural fibers and synthetic fibers. The natural fibers may be hemp fibers. The staples fibers may advantageously have a mean length of between 10 μm and 500 μm. Preferably, this length may be approximately equal to 100 μm. The staple fibers may have a mean diameter of between 3 μm and 100 μm. Preferably, this diameter may be approximately equal to 20 μm.
[0011] According to a second aspect of the present invention, the textiles are characterized in that they are produced from the jacketed yarn as described above.
[0012] According to a third aspect of the invention, a method of producing a jacketed yarn of natural appearance as described above is characterized in that it includes the step consisting in jacketing a core yarn, by extrusion through a die, with a thermoplastic containing less than 20% by weight of staple fibers.
[0013] The thermoplastic containing less than 20% by weight of fiber may advantageously be obtained by blending, one or more times, a non-fiber-filled thermoplastic with a masterbatch containing from 5% to 80% by weight of fiber. The masterbatch may preferably contain between 20% and 70% by weight of fiber. And very preferably, the masterbatch may contain between 40% and 60% by weight of fiber.
DESCRIPTION OF THE DRAWING
[0014] The invention will be better understood and its various advantages and features will become more clearly apparent from the following description of nonlimiting illustrative examples, with reference to the appended schematic drawing in which:
[0015] [0015]FIG. 1 shows an enlarged longitudinal view of a jacketed yarn according to the prior art and of a jacketed yarn according to the invention;
[0016] [0016]FIG. 2 shows a cross-sectional view taken in an optical microscope of the jacketed yarn according to the invention; and
[0017] [0017]FIG. 3 shows an enlarged top view of a textile made from jacketed yarn.
DETAILED DESCRIPTION
[0018] The core is covered, by extrusion or coating, with a layer of peripheral polymer material. The photographs, enlarged about 20 times in FIG. 1, show a comparison between a jacketed yarn ( 1 ) according to the prior art (on the left), represented by document FR-2 617 205, and a jacketed yarn ( 2 ) according to the present invention (on the right). Owing to the presence of staple fibers, the external surface of the yarn ( 2 ) obtained by the method according to the invention has an irregular appearance and resembles string. The mean diameter may thus be less than 1 mm and vary between 0.6 mm and 0.9 mm. In contrast, the external surface of the conventional jacketed yarn ( 1 ) is smooth.
[0019] Advantageously, and in practice, the core yarn is a high-tenacity multifilament yarn, that is to say one having a tenacity of around at least 50 cN/tex. The many filaments of the core may or may not be twisted, may or may not be interlaced, may or may not be assembled and may or may not be texturized, depending on the final jacketed yarn desired.
[0020] [0020]FIG. 2 shows a cross section through the jacketed yarn ( 2 ) taken in an optical microscope with a magnification of about 150 times. In this embodiment of the jacketed yarn ( 2 ), the many polyester filaments ( 3 ) of the core ( 4 ) appear at the center. The jacket ( 6 ) based on a PVC compound surrounds the core ( 4 ). As this photograph shows, the jacket ( 6 ) incorporates hemp fibers ( 7 ) embedded in the PVC. The perimeter of the jacket ( 6 ) is very irregular, giving the overall yarn a natural feel.
[0021] In another embodiment, the core and the jacket are produced directly by coextrusion.
[0022] Advantageously, and in practice, the jacket ( 6 ) is extruded around the core yarn ( 4 ). The thermoplastic polymer compositions of the jacket furthermore advantageously include supplementary additives, namely at least one UV stabilizer and/or at least one biocide and/or at least one mineral filler and/or at least one pigment and/or at least one fire retardant. The fire retardant may be mineral fire-retarding fillers such as, for example, antimony oxides, alumina trihydrate, zinc oxide or magnesium oxide.
[0023] The weight ratio of the core yarn ( 4 ) to the jacket ( 6 ) depends both on the final applications envisioned and on the extrusion or coating equipment available.
[0024] Such yarns may be employed in many applications, and especially in the manufacture of furniture, typically camping seats, automobile fabrics, floor and wall coverings, solar protection devices, articles of luggage, protective fabrics, and yet others.
[0025] [0025]FIG. 3 shows an example of a textil enlarged about 10 times, entirely made from yarns ( 2 ), with a 100% polyester core jacketed with a PVC compound containing hemp fibers according to the invention, and heat-set. The textile comprises a warp yarn ( 8 ) in the horizontal direction and two weft yarns ( 9 and 11 ) in the vertical direction. It will be noted that the yarns are differently colored.
ILLUSTRATIVE EXAMPLES
[0026] A jacketed yarn ( 2 ) according to the present invention was produced in the following manner. An 1100 dtex polyester yarn, sold by Rhodia under the name “Type 156”, was jacketed by extrusion through a die. The run speed of the yarn was 300 m/min.
[0027] The extruded jacketing composition comprised:
[0028] 7% of hemp fibers; and
[0029] 93% of plasticized, formulated and pigmented PVC.
[0030] Thus, a 4700 dtex jacketed yarn having a mean diameter of 0.67 mm was obtained; in other words, the polyester core yarn represented 23.4% by weight and the fiber-containing jacket represented 76.6% by weight.
[0031] In addition, the jacketed yarn obtained had the following characteristics and mechanical properties:
[0032] tensile strength: 9.6 daN; and
[0033] elongation at break: 14.5%.
[0034] This yarn was therefore perfectly suitable for the manufacture of textiles that can be heat-set.
[0035] The present invention is not limited to the embodiments described and illustrated. Many modifications may be made, without thereby departing from the context defined by the scope of the set of claims.
[0036] For example, it would be possible to devise a core made of various materials, such as glass fibers, optical fibers or one or more wires.
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A sheathed yarn having a natural appearance comprises a core yarn and a sheath which is made from a thermoplastic material. The thermoplastic material of the sheath comprises less than 20 wt.-% of staple fibers.
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FIELD OF THE INVENTION
The invention relates to filling or packaging machines used to place solid or liquid goods inside pre-formed cardboard cases or containers, hereinafter called with the generic term containers. The containers arrive from the paper manufacturer with a tubular and flattened shape, so that they can be fed in great quantity as piles in vertical magazines. Frequently the containers are piled with an inclination of about 45-60° with respect to the horizontal, in order for the piles to be longer and more ample and positioned lower and so that they can be more easily fed by an operator with respect to the vertical magazines.
BACKGROUND OF THE INVENTION
The present practice is to use vertical magazines having a great length so that they can contain a great quantity of containers, but said lengthy magazines have their terminal or end portion at a considerable distance from the ground. Consequently, such magazines are not easily reached by the operator who must cyclically supply them. It will also be appreciated that often the magazines are arranged in pairs side by side, in order to increase the working ability of the packaging machine.
The technical problem that actually is found in the packaging machines with manual re-filling of the magazines is therefore of double aspect and consists, on one hand, in the discomfort for the operator to execute the re-filling operation and, on the other hand, in the difficulty for only one operator to supply the magazines of a plurality of packaging machines placed in the same working environment and simultaneously operating.
SUMMARY OF THE INVENTION
The invention resolves these problems with the following solution. Under the inclined and traditional vertical magazine, called the main magazine, which can be structured with a great length and consequently with a great working ability, there is mounted an ancillary magazine which is initially in a loading position almost horizontal so as to be easily re-filled with containers by the operator. The ancillary magazine can thus support a pile or series of containers between longitudinal ends and by a portion of the lower or bottom plane or side, so that with the support of this bottom plane the free lateral portions of the pile are free both laterally and at the top. The main magazine is provided with an upper back portion having a length proportional to the length of the ancillary magazine, which upon suitable control may open and close itself downwardly. When the upper portion of the main magazine is emptied of the containers, the upper back portion is opened and the upward movement of the ancillary magazine is effected to insert its pile of containers in the main magazine. Subsequently, the upper back portion is closed again to retain the pile of containers therein and to allow to the ancillary magazine to return empty in the lower loading position for repeating a new working cycle.
The advantages arising from this solution include an easy cyclic feeding of the containers to the ancillary magazine which in the phase of loading is at man-height and in an almost horizontal position. Thus, the feeding of the containers to the ancillary magazine can be effected during the long time interval which passes from the filling of the main magazine until the substantial emptying of said main magazine, so that an operator has a lot of time to feed several such ancillary magazines simultaneously operating several packaging machines. The working ability of the composite magazine according to the invention is now derived from the sum of the capability of the main magazine and the capability of the ancillary magazine. It will also be appreciated that the presence of the ancillary magazine does not substantially modify the overall plan dimensions of the main magazine, because the ancillary magazine can be substantially placed under the main magazine.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the invention, and the advantages deriving therefrom, will be evident from the following description of a preferred embodiment of the invention made with reference to the figures of the attached sheets of drawings, in which:
FIG. 1 is a side elevation view of the composite magazine, with the ancillary magazine shown in the two working positions;
FIGS. 2 and 3 are views respectively in plan from the top and in frontal elevation of the composite magazine with the ancillary magazine shown in the two working positions;
FIG. 4 shows details of the main magazine in the phase of grasping of the containers from the ancillary magazine located in the raised position, taken along the section line IV—IV of FIG. 1; and
FIG. 5 is a schematic and top view of the ancillary magazine inserted into the main magazine, taken along the section line V—V of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
The drawings generally show an example of the present invention with two main magazines arranged side by side, and with the associated ancillary magazines in the two different working positions. It is to be understood that the invention referred to below is intended as well for a composite magazine of a more simple type, that is a magazine formed by only a main magazine with a single associated ancillary magazine.
In the figures, with references MP 1 and MP 2 there are respectively indicated the two main magazines. These main magazines are inclined as shown, and differ from the magazines of the known type by having a greater length and therefore for having an upper end at a higher distance from the ground. Each main magazine is a tubular structure formed by longitudinal guides 1 , for example steel rods, which support and guide upwardly, downwardly and laterally the pile P of containers. The guides 1 are, in their turn supported at the ends thereof by transversal structures or supports 2 , 2 ′ of annular type (FIGS. 4 and 5 ). In particular, the lower support 2 ′ is fixed to the frame 3 of the packaging machine and is connected to the upper structure 2 by beams 4 fixed (in their turn) to the frame 3 by tie rods 5 .
According to the invention, the long or upper back portion of each main magazine which is comprised between the transversal structures 2 , 2 ′ has at least the lower guides 1 ′ which, upon command, can be opened like a door—that is in such a manner that the lower guides 1 ′ can pass from the position shown in FIG. 4 with a continuous line to the one shown with a dotted line and vice versa, in order to open and close vertically the associated upper back portion of the main magazine. From the FIGS. 1 and 4 it is pointed out that the lower guides 1 ′ are welded for example onto respective “L” shaped section bars 6 , which bars 6 carry fixed at their ends the levers 7 which are in their turn fixed upon a shaft 8 parallel to the section bar 6 , and which shafts 8 are supported rotatably at the ends by means of supports 2 , 2 ′.
At least one of the levers 7 extends beyond the fulcrum shaft 8 with a shaft 107 articulated to the rod of a jack 9 which is articulated at joint 10 to the near support 2 . All the jacks of the apparatus referred to can be of the fluid pressure type or of the electromechanical screw-nut screw type. The jacks 9 , if they are of the fluid pressure type, are preferably of the simple effect type and normally extended, to maintain the guides 1 normally in a closing position of the main magazine.
From FIG. 5 it can be noted that the lower movable guides 1 ′ terminate beyond the initial ends of lower fixed guides 1 ″ in order to ensure continuity of support to the containers during the forwards displacement from 1 ′ to 1 ″. The initial ends of the guides 1 ″ are shaped so as to favor the reception of the containers, for example with a suitable downward bending.
At least the lateral lower guides 1 ″ of each main magazine can be provided with longitudinal and continuous fins 11 . Fins 11 are downwardly oriented and outwardly diverging, in order to form a reception zone which facilitates the inlet of the pile of containers cyclically fed into the main magazine, as mentioned further on.
For and under each main magazine, there is provided a respective ancillary magazine MA 1 and MA 2 which comprises a flat surface plane 12 having a width for example substantially equal to the distance which passes between the lower fixed guides 1 ″ of the main magazine (FIG. 5) and having a length a little less than the length of the movable guides 1 ′. Plane 12 is connected to a motion means of any suitable kind which causes plane 12 to pass from a low and substantially horizontal loading position, as indicated in FIG. 1 with dotted line, to a raised unloading position in which said plane 12 is inserted in the upper back portion of the associated main magazine. In the raised position, the plane 12 of the ancillary magazine is located immediately upwardly from, co-planar with, and longitudinally aligned with the inferior and fixed guides 1 ′.
According to a preferred embodiment, the motion means 20 of the plane 12 are constituted by an articulate quadrilateral which comprises a lever 13 and a pair of levers 14 respectively articulated in joints 15 and 16 to end appendices 17 and 18 of the plane 12 , and respectively articulated in joints 19 and 20 to a raised base portion 121 of a base 21 . Base 21 bears onto the ground and has articulated thereto in joint 22 the body of a jack 23 , in its turn articulated by the rod thereof at joint 24 to the intermediate portion of the pair of levers 14 . It is to be understood that the movements of the plane 12 can be effected with different means than the articulated quadrilateral, for example with direct articulation of said plane to the main magazine or to the frame 3 of the packaging machine, although the utilization of the articulated quadrilateral system is preferred because it eliminates the limitations that can derive from the overall dimensions of the frame of the packaging machine and because it allows the plan 12 , when it is in the lower loading position, to be advantageously out from the plan overall dimensions of the main magazine so that the main magazine does not hinder the operator which provides for the cyclic feeding of the containers.
The plane 12 carries, at a right angle, upon the end farthest to the articulation system, a fixed and upwardly oriented head board 25 , while on the other end it carries a head board 26 , parallel to the previous one but which in a different manner can be withdrawn upon command below the plane 12 . For this purpose the board 26 is mounted upon a slide 27 (FIGS. 1 and 3) slidable upon a guide 28 , fixed to an appendix 29 under the plane 12 and upon which is fixed the body of an actuator 30 of said slide 27 , for example the body of a jack.
When the plane 12 is in the low loading position, plane 12 is preferably arranged with a slight inclination with respect to the horizontal position and the board 26 is in the high position, so that the operator can arrange against board 26 the packages or containers P put on their edge upon the plane 12 , until containers P constitute a pile or series that results and is sufficiently compressed between the head boards 26 and 25 .
Laterally to the plane 12 there is a vertical and parallel plane 31 . Plane 31 is fixed, for example, to the frame 21 , and the containers P bear against plane 31 as the containers are piled in the ancillary magazine. The containers P thus laterally project with the same length from the plane 12 and with their sides in alignment.
From FIGS. 1, 2 and 3 it can be seen that the ancillary magazines are preferably placed inside a box 32 which also contains the main magazines and which is laterally provided with doors 132 controlled by microswitches which activate the working of the apparatus only when the doors 132 are closed. Once the ancillary magazine is filled in the low loading position and once the doors 132 are closed, and when in the main magazine the containers P come to occupy only the lower fixed guides 1 ″, a control device such as sensor 33 (FIG. 1) detects this condition and actuates the following steps. The inferior and mobile guides 1 ′ of the main magazine are opened as shown with dotted line in FIG. 4 and the filled plane 12 of the ancillary magazine is raised as shown in FIG. 4 and as shown with the continuous line in FIG. 1 .
Next, the guides 1 ′ return in the active position indicated with continuous line in FIG. 4, in order to support the new pile or series of containers inserted in the main magazine by the filled ancillary magazine. Then the movable board 26 is moved downwardly to release the pile of containers P, and the empty plane 12 is carried back in the low position for the repetition of a new working cycle.
In order to avoid dead times during the working phase, it can be provided that after the ancillary magazine is filled with containers and after the closure of the doors 132 of the box 32 , the filled ancillary magazine raises part way up and conveniently gets near to the main magazine, in order to reduce the times of the next supply travel of the filled ancillary magazine.
If the main magazine has a considerable length, in the portion of the main magazine which is defined by the movable guides 1 ′, there can be laterally provided motorized conveyers 34 (FIG. 3 ). Conveyors 34 operate with friction on the sides of the pile of containers P, in order to feed progressively the containers P upon the fixed guides 1 ″. In this manner, conveyors 34 avoid the exertion of any excessive thrust on the bottom or front-most container P that cyclically must be extracted from the head retainers 35 of the main magazine by means of the suction cups 36 which are provided for the cyclical insertion of the front-most container inside the packaging machine. The conveyers 34 are, for example, provided to oscillate upon fulcrums 37 in order to be spaced during the phase of insertion of the pile of containers in the main magazine, so that they do not interfere with this procedure. The actuation means of the conveyers 34 are not shown in the drawings, because they are conceivable and easily realizable by persons skilled in the art.
Several variations and modifications to the above invention can be appreciated. For example, the utilization of different means from those described for the operation of the movable guides 1 ′ are possible, so that such means could derive their motion from the movement of the plane 12 , for example by means of suitable cams. Other variants can be appreciated where in the portion of the main magazine cyclically fed by containers, also the lateral guides are movable in addition to the bottom guides 1 ′, to avoid undesired interferences of the pile of containers with the lateral guides. For this purpose, the lateral guides could be, for example, combined with the oscillating structure which provides for the movements of the conveyers 34 .
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A composite magazine for feeding to a filling or packaging machine pre-formed and flattened containers includes a main magazine suitably inclined in which the containers are piled up. The main magazine includes a long upper back portion which can be opened and closed downwardly. Below the main magazine there is provided an ancillary magazine which initially is in a substantially horizontal loading position in order to be easily supplied with a pile of containers on a bottom plane which leaves uncovered lateral portions of the bottom of the pile. When the upper back portion is emptied, the upper back portion is opened and the ancillary magazine is raised to insert the pile of containers in the main magazine. The upper back portion then closes to retain the pile, while the ancillary magazine returns in the low loading.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of parent application No. 07/248,733, filed Sep. 26, 1988 by Butler et al, now abandoned, itself a continuation-in-part of application No. 07/034,429, filed Apr. 3, 1987, also abandoned.
FIELD OF THE INVENTION
This invention concerns improvements in and relating to the preparation of improved draw-textured yarns that consist essentially of polyester filaments that are cationic-dyeable, and more particularly of such filaments that are concentric sheath/core bicomponent filaments.
BACKGROUND OF THE INVENTION
Synthetic polyester multifilament yarns have been known and used commercially for several decades, having been first suggested by W. H. Carothers, U.S. Pat. No. 2,071,251, and then by Whinfield and Dickson, U.S. Pat. No. 2,465,319. Most of the polyester polymer that has been manufactured and used commercially for such continuous filament yarns has been poly(ethylene terephthalate), sometimes referred to as 2G-T. This polymer is often referred to as homopolymer, although it is known that, in addition to the residues of ethylene, from ethylene glycol, and terephthalate residues, from dimethyl terephthalate or terephthalic acid, there are also residues from diethylene glycol. For textile (apparel) purposes, such commercial homopolymer is usually of intrinsic viscosity about 0.6; it can vary up to about 0.65 or even 0.67, and can also be of somewhat lower viscosity. Commercial homopolymer is notoriously difficult to dye. Such homopolymer is mostly dyed with disperse dyestuffs at high temperatures under elevated pressures, which is a relatively expensive and inconvenient process (in contrast to processes for dyeing several other commercial fibers at atmospheric pressure, e.g. at the boil), and so there have been several suggestions for improving the dyeability of polyester yarns.
Accordingly, Griffing and Remington, U.S. Pat. No. 3,018,272, suggested the use of cationic-dyeable copolyesters, in which the poly(ethylene terephthalate) structure is modified by inclusion of sulfonate groups that provide an affinity for cationic dyestuffs. Such cationic-dyeable copolyester consisting essentially of poly[ethylene terephthalate/ 5-(sodium sulfo) isophthalate] containing about 2 mole % of the 5-(sodium sulfo) isophthalate groups in the polymer chain has been used commercially as a basis for polyester yarns for some 20 years, and is sometimes referred to as 2G-T/SSI. Although this cationic-dyeable copolyester is significantly more expensive than the homopolymer, which is not cationic dyeable, and has also provided weaker fibers than does homopolymer, cationic-dyeable copolyester has been used on a large scale for various applications, especially as staple fiber, for spun yarns, because, in addition to the useful and improved dyeing capability of the copolyester, the individual fibers break more readily than 2G-T fibers, and this tendency to break is of great advantage in spun yarns, in providing improved pilling performance. In contrast, the lower strength has generally been a disadvantage of the cationic dyeable copolyester in filament yarns.
2G-T/SSI has also been used in heather multi-filament yarns, wherein cationic-dyeable copolyester filaments are intermingled with homopolymer filaments, that are not cationic dyeable. Heather yarns were disclosed by Reese in U.S. Pat. No. 3,593,513, and Lee in U.S. Pat. No. 4,059,949. Heather yarns were preferably made by cospinning the filaments so as to mix the filaments during their spinning.
The present invention is not concerned with heather yarns, i.e. yarns that contain significant amounts of differently-dyeable filaments, This invention is concerned only with a need to make useful textured yarns that consist essentially entirely of filaments that have cationic-dyeable characteristics.
A large amount of homopolymer has been used to make draw-textured polyester yarns from draw-texturing feed yarns (DTFY) that are substantially amorphous spin-oriented multi-filament (continuous filament) yarns prepared by spinning at withdrawal speeds of the order of about 3000 ypm or more. This concept was first suggested by Petrille in U.S. Pat. No. 3,771,307 and Piazza and Reese in U.S. Pat. No. 3,772,872.
As indicated, conventional homopolymer DTFY has been manufactured in large quantities and has been draw-textured. Hitherto, however, although 2G-T/SSI copolymer has been used satisfactorily for many years to make other types of polyester yarns as indicated, customers have complained about DTFY from 2G-T/SSI and about the results of texturing DTFY made from 2G-T/SSI copolyester. Despite many efforts over the years hitherto, it has not proved possible to improve 2G-T/SSI copolyester DTFY to meet customer requirements in this regard at an economic price.
It is an object of the invention to provide a cationic-dyeable copolyester DFTY that meets such requirements. In other words, the problem has been to provide DTFY that consists essentially of filaments having cationic-dyeability, but that does not give rise to the defects complained of heretofore.
Cemel et al., U.S. Pat. No. 4,233,363, disclosed heather DTFY. In other words, Cemel required a mixed filament DTFY, that must have two different types of spin-oriented filaments, one type being of a cationically-dyeable copolymer and the other being differently dyeable, namely homopolymer. Most of Cemel's disclosure is about the need for intimate mixing (measured as high DFI) and closely matching elongations of the two different components (so as to get the desired heather). All Cemel's working Examples cospin conventional (monocomponent) filaments of the two types of differently dyeable filaments. In column 10, lines 54-57, Cemel adds that, if desired, some of the filaments may be of a sheath-core structure, as disclosed, e.g. in Lee, referred to above. As indicated already, the present invention is not concerned with heather yarns.
Reference is also made to EP A2 0285437, which discloses an improved cationic-dyeable DTFY of concentric sheath/core bicomponent filaments, with a sheath of 2G-T/SSI copolyester and a core of 2G-T homopolymer. Further reference will be made to this hereinafter, as an object of the invention is to provide a further improvement, beyond that disclosed specifically in the Examples of EP A2 0285437.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a process for preparing a yarn consisting of spin-oriented cationic-dyeable copolyester filaments, wherein concentric sheath/core bicomponent filaments, whose core consists essentially of poly (ethylene terephthalate) of intrinsic viscosity about 0.6, and whose sheath consists essentially of poly[ethylene terephthalate/5-(sodium sulfo)isophthalate] containing about 2 mole % of the 5-(sodium sulfo)isophthalate groups in the polymer chain, are melt-spun through capillaries and quenched by cooling gas at a withdrawal speed of the order of about 3 Km/min or more, and wherein the molten filamentary streams emerging from the capillaries are shielded from the cooling gas by a screen and/or a solid shield, and wherein the spin-oriented filaments are interlaced and wound into a package.
According to another aspect, there is provided a process for preparing a textured yarn consisting of cationic-dyeable copolyester filaments, wherein a package of yarn of spin-oriented bicomponent filaments is prepared according to the process of claim 1, and said package of yarn is used as a feed yarn in a draw-texturing process to prepare the textured yarn.
According to another aspect, there is provided an improved draw-texturing feed yarn, consisting of spin-oriented cationic-dyeable copolyester filaments, wherein the cationic-dyeable copolyester consists essentially of poly[ethylene terephthalate/ 5-(sodium sulfo)isophthalate] containing about 2 mole % of the 5-(sodium sulfo)isophthalate groups in the polymer chain, the feed yarn is a substantially amorphous spin-oriented multi-filament yarn prepared by spinning the filaments at a withdrawal speed of the order of about 3 Km/min or more, and the filaments are concentric sheath/core bicomponent filaments, wherein the sheath consists essentially of the cationic-dyeable copolyester, and the core consists essentially of poly(ethylene terephthalate) of intrinsic viscosity about 0.6, and wherein the filament structure is such that the differential birefringence between the filament surface and the filament core is not more than about 0.013.
According to another aspect, there is provided a false-twist textured polyester yarn consisting of cationic-dyeable copolyester filaments, wherein the cationic-dyeable copolyester consists essentially of poly[ethylene terephthalate/5-(sodium sulfo)isophthalate] containing about 2 mole % of the 5-(sodium sulfo)isophthalate groups in the polymer chain, such filaments being concentric sheath/core bicomponent filaments, wherein the sheath consists essentially of the cationic-dyeable copolyester, and the core consists essentially of poly(ethylene terephthalate) of intrinsic viscosity about 0.6, and having a tenacity of at least about 2-5 gpd and an elongation of at least about 20%.
DETAILED DESCRIPTION OF THE INVENTION
The preparation of monocomponent polyester DTFY has been amply described in the prior art, e.g. in the aforesaid U.S. Pat. Nos. 3,771,307 and 3,772,872, the disclosures of which are hereby incorporated by reference. These conventional techniques need to be modified by providing for the spinning of concentric bicomponent filaments, for example, by using a spinneret of the type disclosed on the left hand side of FIG. 1 of aforesaid U.S. Pat. No. 4,059,949 (Lee), the disclosure of which is also hereby incorporated by reference; (it must be recognized that Lee's process and apparatus is restricted to the preparation of mixed filament yarns; i.e. Lee makes not only drawn concentric bicomponent filaments (but also monocomponent drawn filaments, whereas such mixed filament yarns are not the concern of the present invention; and Lee does not make DTFY). The preparation of bicomponent filaments for polyester DTFY is disclosed in Mirhej, U.S. Pat. No. 4,157,419, it being recognized that Mirhej discloses the preparation of eccentric bicomponent filaments that are intended to break during draw-texturing and provide a helical crimp, on account of the eccentric nature, whereas the bicomponent filaments according to the present invention are concentric, and are intended to resist breaking during normal draw-texturing operations. Details of preparing wholly bicomponent (concentric) multifilamentary yarns are also given in EP A2 0285437, the disclosure of which is also incorporated herein by reference. Further details for preparing preferred concentric bicomponent filaments and DTFY according to the present invention are given in the following Examples, as are details of their texturing.
The preparation of fabrics and garments from the resulting textured yarns may be carried out by conventional techniques, as disclosed in the art, e.g. in the following Bulletins, published as indicated, and available from the Textile Fibers Department, Technical Services Section, E. I. du Pont de Nemours and Company, Wilmington, Delaware, 19898, relating to Dacron polyester fiber, Bulletin D-244, August, 1970, Bulletin D-281, June, 1974, Bulletin D-295, December, 1976, Bulletin D-296, December, 1976, and Bulletin D-300, December, 1977.
The advantages of improved (reduced) BFC and of increased bulk obtained in comparison with monocomponent 2G-T/SSI copolymer filament yarns are quite significant. A further advantage is that the cost of the homopolymer, that provides the core of the novel bicomponent filaments, is considerably cheaper than for the 2G-T/SSI copolymer, so the cost of the raw materials for the bicomponent filaments is considerably less than for monocomponent filaments of 2G-T/SSI.
The invention is further described and illustrated in the following Example, in which important advantages in tensile properties are demonstrated. Reference may be made to Knox, U.S. Pat. No. 4,156,071 for most of the various test measurements. For the tensile properties, however, there was used a six-inch sample length, without twist at a 200% per minute rate of extension. "Natural Draw Ratio" (NDR) is determined from a stress-strain curve as described by Ludewig in Polyester Fibres, Section 5.4.1 (pages 174-177), John Wiley & Sons, Ltd., 1971. "Natural Draw Force" (NDF) is the value of the tensile stress on the yarn taken from the straight-line portion of the stress-strain curve located in the yield zone below the natural draw ratio. As reported here, NDR and NDF are determined from a stress-strain curve measured on an Instron tensile testing machine at 703F and 65% RH using a sample length of five inches and a rate of elongation of 400% per minute. Crimp Contraction (CCA 5 ) and differential birefringence were measured essentially as in Frankfort et al., U.S. Pat. No. 4,134,882. The method for determining LRV is disclosed in Most, U.S. Pat. No. 4,444,710.
EXAMPLE 1
A). A 245/34 bicomponent feed yarn was prepared essentially as described and illustrated in Lee U.S. Pat. No. 4,059,949 at a withdrawal speed of 3550 ypm, but with all filaments being 50/50 by weight of 2G-T of 19.4 LRV (intrinsic viscosity 0.61) in the core and with 98/2 2G-T/SSI copolyester of 13.0 LRV (intrinsic viscosity 0.49) in the concentric sheath, using a block temperature of 286 C. The filaments were treated with a commercial draw-texturing finish and interlaced. The resulting yarns had the following properties, Tenacity 1.3 g/d, Elongation 117%, Modulus 24 g/d, Natural Draw Ratio 1.4, Natural Draw Force 150 g, Shrinkage 45%, Density 1.347 and Birefringence 0.02. This yarn was textured on a Barmag FK-6-900 texturing machine at a speed of 600 m/min, and the textured yarn properties are compared in Table 1A with those of a similarly textured commercial monocomponent 98/2 2G-T/SSI copolyester yarn of 13.0 LRV.
TABLE 1A______________________________________ BICOM- MONOCOM- PONENT A PONENT A______________________________________CCA5 % 8.9 6.2BFC (FRAY COUNT) 4 10TENACITY GPD 2.3 2.8ELONGATION % 18.7 25.5______________________________________
These show significant advantages in bulk (crimp contraction, CCA5) and broken filament count (BFC) for the bicomponent yarn over the monocomponent yarn, but unfortunately, the tensile properties of the bicomponent yarn are significantly worse than those of the monocomponent yarn, (which are already poor, in comparison with those of homopolymer 2G-T yarns). When differential birefringence (birefringence of the filament surface minus that of the core of the filament) for the bicomponent filaments was measured, this was determined to be 0.015, whereas differential birefringence for the monocomponent was only 0.004.
B.) Accordingly, a different 245/34 bicomponent feed yarn was prepared using a withdrawal speed of 3345 ypm, with 50/50 by weight of 2G-T of 19.3 LRV (intrinsic viscosity of 0.61) in the core and with 98/2 2G-T/SSI copolyester of 13.0 LRV (intrinsic viscosity of 0.49) in the concentric sheath, using a block temperature of 284 C. This time, however, a 5 inch length of 30×30 mesh screen wire was used according to the invention to surround the filament bundle as the molten filamentary streams emerged from the spinneret (using an arrangement similar to that described and illustrated in U.S. Pat. No. 4,529,368) thus partially shielding the emerging filamentary streams from the cross-flow cooling air for such a distance of approximately 5 inches below the spinneret. Spinning conditions were otherwise again essentially as described and illustrated in Lee, U.S. Pat. No. 4,059,949. This feed yarn was also textured on a Barmag FK-6-900 texturing machine at a speed of 600 m/min and the properties of the resulting textured yarn are compared in Table IB with those of a similarly textured commercial monocomponent 98/2 by weight 2G-T/SSI DTFY, and the results are shown in Table 1B.
TABLE 1B______________________________________ BICOM- MONOCOM- PONENT B PONENT B______________________________________CCA5 % 7.2 6.1BFC (FRAY COUNT) 2.25 6.25TENACITY, GPD 2.6 2.6ELONGATION 23.6 20.2______________________________________
As can be seen, this bicomponent yarn exhibited not only improvements in broken filament count (BFC) and bulk (CCA5) over the monocomponent, but also had tensile properties that were improved over those of bicomponent A, and essentially equivalent to those of the monocomponent yarn. The differential birefringence of this bicomponent B feed yarn was determined to be 0.013 (in contrast to 0.015 for bicomponent A). It is surprising that such a small reduction in birefringence of the feed yarn has so significantly improved the tensile properties of the textured bicomponent yarn, so that they are comparable to those of the monocomponent yarn whose differential birefringence (of the monocomponent B feed yarn) was 0.004 (like that of monocomponent A).
For convenience of comparison, Table 1C combines Tables 1A and 1B and shows a significant advantage in using bicomponent filaments (B), according to the invention, over bicomponent filaments (A), so far as tensile properties are concerned, while retaining significant advantages in improved bulk and lower BFC over monocomponent filaments (A or B)
TABLE 1C______________________________________ BI- MONO- COMPONENTS COMPONENTS A B B A______________________________________Textured YarnsCCA5, % 8.9 7.2 6.1 6.2BFC 4 2.25 6.25 10TENACITY, GPD 2.3 2.6 2.6 2.8ELONGATION, % 18.7 23.6 20.2 25.5Feed YarnsBirefringence 0.015 0.013 0.004 0.004______________________________________
Accordingly, the present invention solves a difficulty observed with bicomponent filaments A that were prepared according to EP A2 0285437, referred to above.
It will be noted that the delayed quenching arrangement in Example 1B provides a significant advantage over Example 1A, as disclosed above. Such delayed quenching is preferably obtained as disclosed in Makansi in U.S. Pat. No. 4,529,368, the disclosure of which is hereby incorporated by reference, but may be obtained by alternative means.
We have demonstrated that textured bicomponent yarns of the invention are obtainable with significantly more bulk than the comparison monocomponent yarns. This is an important advantage, since an increase in bulk in textured yarn translates into appreciably more stretch in a fabric (and in garments) which is very desirable.
The Example has illustrated feed yarns of approximately 7 denier per filament (dpf), and it should be noted that the present invention can also be applied to preparing of feed yarns of higher and lower dpf. In fact, the present invention is expected to be at least as effective in providing improved tensile properties of bicomponent yarns of dpf of about 5 or less.
As indicated, the sheath/core (DTFY) filaments in the foregoing Example contained about 50/50 by weight of homopolymer/copolymer, and correspondingly about equal amounts by area of cross-section, since the densities are approximately equal. The diameter of the core (which is the same as the internal diameter for the sheath) was about 10.5 microns, whereas the external diameter of the sheath (and of the total filament) was about 15 microns. In other words, the thickness of the sheath (on either side) was only about 2 microns. A decrease in the thickness of the sheath in the feed yarn may lead to more bulk in the textured product, and possibly lower broken filaments and lighter dyeing. Increased dyeing capability could possibly be achieved by increasing the proportion of SSI in the copolyester used for the sheath, if desired. Thus, although this Example has demonstrated use of the 2G-T/SSI copolymer that has been preferred for many years and has been available commercially, it will be understood that variations of the precise compositions and proportions of the polymers and of their conditions of preparation can be made without departing from the essence of the invention, both for the copolymer sheath and for the homopolymer core of bicomponent filaments and yarns, according to the present invention. For instance, the viscosity of the homopolymer may vary from about 0.6 to about 0.67. It is also conventional to use additives, such as pigments or delustering agents, such as titanium dioxide, if desired.
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A cationic-dyeable copolyester draw-texturing feed yarn of concentric sheath/core bicomponent filaments, with a sheath of cationic-dyeable polyester, and a core of homopolymer, whereby such feed yarn may be draw-textured on commercially-available machines to give cationically-dyeable textured yarns with a combination of good tensile properties, low broken filament counts and good bulk at economically viable cost.
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BACKGROUND OF THE INVENTION
[0001] This application claims the priority of Korean Patent Application No. 10-2004-0089166, filed on Nov. 4, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
[0002] 1. Field of the Invention
[0003] The present invention relates to an secure digital (SD) memory card for extension of function, and more particularly, to an SD memory card for extension of function, the SD memory card having functions of a contactless integrated circuit (IC) card and a contactless and/or contact IC card reader so as to be utilized in various application fields such as a traffic card, an access control, or the like based on its compact size, fast reading velocity, and large capacity.
[0004] 2. Description of the Related Art
[0005] A contactless IC card includes a radio frequency (RF) module for processing an analog signal, a signal processing module for processing a contactless protocol and a digital interface signal, a central processing unit (CPU), a memory (a random access memory (RAM) or read-only memory (ROM), and the like.
[0006] The contactless IC card is classified into a contactless (closes coupling) IC card (CICC) and a remote coupling IC card which is classified into a proximity IC card (PICC), a vicinity IC card (VICC), and an RF IC card.
[0007] The CICC is standardized in ISO-10536. The PICC is standardized in ISO/IEC-14443, and the VICC is standardized in ISO-/IEC-15693. The CICC obtains a power source through capacitive coupling, and the remote coupling IC card obtains a power source through inductive coupling.
[0008] The contactless IC card does not to be inserted into a card reader and into an exact card position. Thus, the contactless IC card can be easily designed and manufactured. Also, a terminal can be firmly and inexpensively manufactured. Thus, maintenance cost can be reduced. In addition, the contactless IC card does not include a mechanical contact surface and thus is robust to static electricity, chemical damage, moisture, pollution, dust, friction, or the like. Thus, the contactless IC card can be used for a long period of time. Since a direct access to the contactless IC card is impossible, contents cannot be interpreted and thus cannot be forged.
[0009] Application fields of the contactless IC card include electronic cash, a traffic card, access control, fractional currency, and the like. In other words, the contactless IC card is used in a mobile phone, a physical distribution system, a vehicle control and a livestock identification card according to a system to which the contactless IC card is applied.
[0010] In a contactless and/or contact card reader, a contactless IC card reader supports physical characteristics and protocols (for an RF power source, a signal connection, initialization, and anti-collision) of a contactless IC card and communicates information to the contactless IC card by wireless.
[0011] The contactless card reader is classified into a simple card reader for simple communication between the contactless IC card and a system and a complex card reader performing an application without being linked to the system.
[0012] The simple card reader must satisfy ISO/IEC 14443 Types A and B and provides functions of a Type A and B compatible module, a CPU used for control, a memory storing programs and data, a key pad and a display used for a user, supporting of a hardware module such as a communication port for communication with an external source and applications, downloading of programs, and anti-collision.
[0013] The complex card reader is used for an EFT-POS, a Pay TV, a CD-ATM, a mobile terminal, and so on and provides applications through wire communication with a contact IC card.
[0014] The contact IC card reader for using the contact IC card satisfies ISO/IEC 7816 protocols and has similar functions to those of a contactless IC card reader except a wireless communication function.
[0015] An SD memory card is a kind of standard of a new compact SD memory card announced by the joint of Matsushita, SunDisk, and Toshiba in 2000 and includes a plurality of flash memories and one microprocessor chip manufactured by silicon semiconductor technology. The SD memory card is compact, light, and has fast storage and reading velocities and large capacity, and thus widely applied to computer peripheral devices, personal digital assistants (PDAs), digital cameras, digital workermans, or the like.
[0016] However, since the conventional SD memory card includes a plurality of flash memories and one microprocessor, the conventional SD memory card does not include wire and wireless interfaces performing functions of the above-described contactless IC card and the contactless and/or contact IC card reader and a control function. In order to include the functions of wire and wireless interfaces, the conventional SD memory card must include a controller chip for controlling the contactless IC card and the contactless and/or contact IC card reader and three or four controller chips for controlling an SD memory card interface and be controlled by each microprocessor. Thus, the conventional SD memory card is disadvantageous in terms of the installation of components.
SUMMARY OF THE INVENTION
[0017] The present invention provides an SD memory card for extension of function, the SD memory card having functions of a contactless IC card (ISO 14443 Types A and B), a contactless IC card reader (Types A and B), and a contact IC card reader so as to provide a combination of the functions of the contactless IC card and the contactless IC card reader, and a controller for controlling the contactless IC card, the contactless and/or contact IC card reader, an SD memory card interface, and an access to a memory using one microprocessor.
[0018] The present invention also provides an SD memory card supporting a security mechanism such as an access control for restricting an access to files stored in a flash memory, encoding and decoding of the files, authentication of the files, or the like.
[0019] According to an aspect of the present invention, there is provided a secure digital memory card for extension of function, including: a flash memory installed in a host device and storing data generated by the host device; a controller controlling an access interface to the flash memory; a radio frequency circuit performing functions of a contactless integrated circuit card and a contactless integrated circuit card reader through a wireless interface control of the controller; an antenna unit connected to the radio frequency circuit to perform a function of a transmission and reception antenna; and a contact integrated circuit card adapter performing the function of the contact integrated circuit card reader through a wire interface control of the controller.
[0020] According to another aspect of the present invention, there is provided a secure digital memory card for extension of function, including: a flash memory installed in a host device and storing data generated by the host device; a controller controlling an access control to the flash memory; a radio frequency circuit performing functions of a contactless integrated circuit card and a contactless integrated circuit card reader through a wireless interface control of the controller; a first antenna connected to the radio frequency circuit and performing a function of a transmission and reception antenna; and an antenna connector connected to a second antenna installed outside the secure digital memory card and connected to the radio frequency circuit to perform a function of a reader transmission and reception antenna.
[0021] According to still another aspect of the present invention, there is provided a secure digital memory card for extension of function, including: a flash memory installed in a host device and storing data generated by the host device; a first controller controlling an access interface to the flash memory; a contact integrated circuit card adapter performing a function of a contact integrated circuit card reader through a wire interface control of the first controller; and a connector connected to an extension module performing functions of a contactless integrated circuit card and a contactless integrated circuit card reader and installed outside the secure digital memory card.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
[0023] FIG. 1 is a block diagram of an SD memory card for extension of function according to an embodiment of the present invention;
[0024] FIG. 2 is a block diagram of an RF circuit shown in FIG. 1 ;
[0025] FIG. 3 is a block diagram of a card module shown in FIG. 2 ;
[0026] FIG. 4 is a block diagram of a reader module shown in FIG. 2 ;
[0027] FIG. 5 is a block diagram of an antenna unit shown in FIG. 1 ;
[0028] FIG. 6 is a block diagram of an SD memory card for extension of function according to another embodiment of the present invention; and
[0029] FIG. 7 is a block diagram of an SD memory card for extension of function according to still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Hereinafter, an SD memory card for extension of function according to the present invention will be described in detail with reference to the attached drawings.
[0031] FIG. 1 is a block diagram of an SD memory card for extension of function according to an embodiment of the present invention. An SD memory card 100 has wire and wireless interface functions and performs wire and wireless communications using communication protocols of a contactless IC card and a contactless and/or contact IC card reader.
[0032] Referring to FIG. 1 , the SD memory card 100 includes an antenna unit 110 , an RF circuit 120 , a controller 130 , a flash memory 140 , and a contact IC card adapter 150 .
[0033] The RF circuit 120 is a wireless connection module for performing functions of a contactless IC card and a contactless IC card reader and connected to the controller 130 .
[0034] The antenna unit 110 includes a signal transmission and reception antenna connected to the RF circuit 120 so that the RF circuit 120 performs a function thereof.
[0035] The controller 130 includes an SD card interface 131 , a memory interface 132 , a microprocessor (uP(RISC)) 133 , an encoding module 134 , a RAM 135 , a ROM 136 , a peripheral module 137 , and a link interface 138 .
[0036] The SD card interface 131 is connected to signal pines DAT 0 through DAT 3 , GND, VDD, and CLK so as to be connected to a host device (for example, a laptop computer, a PDA, a mobile phone, a device with an SD memory card adapter, or the like) in which the SD memory card 100 is mounted.
[0037] The memory interface 132 is connected to the flash memory 140 .
[0038] The encoding module 134 performs an encoding algorithm function for performing security functions such as encoding, decoding, and authentication for protecting data stored in a memory.
[0039] The RAM 135 performs a function of a work buffer memory used in the execution of a program.
[0040] The ROM 136 stores execution programs such as a program for controlling protocols of the contactless IC card and the contactless and/or contact IC card reader, a program for controlling the SD card interface 131 , a program for controlling the encoding module 134 , and the like.
[0041] The peripheral module 137 is used to perform and extend a function of the microprocessor 133 via a timer, a random number generator, or the like.
[0042] The link interface 138 links the RF circuit 120 and the contact IC card adapter 150 to the controller 130 .
[0043] The microprocessor 133 executes the execution programs stored in the ROM 136 and controls higher protocols than the protocols of the contactless IC card and the contactless and/or contact IC card reader, the SD card interface 131 , and a memory access to the flash memory 140 . The microprocessor 133 controls the components of the controller 130 and controls the RF circuit 120 and the contact IC card adapter 150 via the link interface 138 .
[0044] The flash memory 140 may be a flash ROM or an electrically erasable programmable ROM (EEPROM) used for an SD memory card and includes a system area, a project area, and a general user area.
[0045] The contact IC card adapter 150 is a wire connection module providing a wire physical contact point for using the contact IC card and connected to the controller 130 .
[0046] FIG. 2 is a block diagram of the RF circuit 120 shown in FIG. 1 . Referring to FIG. 2 , the RF circuit 120 includes a card module 200 performing the function of the contactless IC card and a reader module 220 performing the function of the contactless IC card reader. The card module 200 will be described with reference to FIG. 3 , and the reader module 220 will be described with reference to FIG. 4 .
[0047] FIG. 3 is a block diagram of the card module 200 shown in FIG. 2 . Referring to FIG. 3 , the card module 200 includes an amplifier 300 amplifying a signal input from an external apparatus via the antenna unit 110 , a clock generator 310 receiving an output of the amplifier 300 to generate a card clock, a first card demodulator 320 (performing the function of the ISO/IEC 14443 Type A) and a second card demodulator 330 (performing the function of the ISO/IEC 14443 Type B) receiving the output of the amplifier 300 to extract card input data.
[0048] The card module 200 further includes first and second card modulators 350 and 360 (respectively performing the functions of ISO/IEC 14443 Type A and B) modulating card transmission data input from the controller 130 to convert the card transmission data into an output signal to be output to the external apparatus.
[0049] As shown in FIG. 3 , the card module 200 includes the first and second card demodulators 320 and 330 and the first and second modulators 350 and 360 so as to constitute the SD memory card 100 including the contactless IC card satisfying the ISO/IEC 14443 Types A and B.
[0050] FIG. 4 is a block diagram of the reader module 220 shown in FIG. 2 . Referring to FIG. 4 , the reader module 220 includes an oscillator 400 generating a reader clock, a transmitter 420 converting reader transmission data into the output signal to transmit the output signal, and a receiver 440 receiving a reader input signal to convert the reader input signal into reader reception data.
[0051] The transmitter 420 includes first and second reader modulators 422 and 424 (performing the functions of the ISO/IEC 14443 Types A and B) modulating the reader transmission data input from the controller 130 and an output circuit 426 converting a reader modulation signal output from the first and second modulators 422 and 424 into the output signal and transmitting the output signal to the external apparatus.
[0052] The receiver 440 includes a band pass filter (BPF) 442 filtering and outputting only a signal in a predetermined band, of signals input from the external apparatus via the antenna unit 110 and outputting the filtered signal, an amplifier 444 amplifying the band signal output from the BPF 442 , and first and second reader demodulators 446 and 448 (respectively performing the functions of the ISO/IEC 14443 Types A and B) demodulating the signal amplified by the amplifier 444 to generate the reader reception data and outputting the reader reception data to the controller 130 .
[0053] As shown in FIG. 4 the reader module 220 includes the first and second modulators 422 and 424 and the first and second demodulators 446 and 448 so as to constitute the SD memory card 100 performing the function of the contactless IC card reader satisfying the ISO/IEC 14443 Types A and B.
[0054] FIG. 5 is a block diagram of the antenna unit 110 shown in FIG. 1 . Referring to FIG. 5 , the antenna unit 110 includes first and second antennas 500 and 520 so as to support the functions of the contactless IC card and the contactless IC card reader.
[0055] As shown in FIG. 5 , the antenna unit 110 includes the first and second antennas 500 and 520 to constitute the SD memory card 100 having the functions of the contactless IC card and the contactless IC card reader satisfying the ISO/IEC 14443 Types A and B.
[0056] FIG. 6 is a block diagram of an SD memory card for extension of function according to another embodiment of the present invention. Referring to FIG. 6 , unlike the antenna unit 110 shown in FIG. 1 ; an antenna unit shown in FIG. 6 includes a second antenna 600 connected to an RF circuit 120 via a first antenna 160 built in an SD memory card 100 and an antenna connector 170 of the SD memory card 100 and installed outside the SD memory card 100 .
[0057] The other elements shown in FIG. 6 are denoted by the same reference numerals as those of the elements shown in FIG. 1 , and thus undescribed elements are as described with reference to FIGS. 1 through 5 .
[0058] In the present embodiment, the second antenna 600 is connected to the RF circuit 120 via the antenna connector 170 . Thus, a wireless communication capacity of the SD memory card 100 shown in FIG. 6 can be further extended compared to the SD memory card 100 including two antennas as shown in FIG. 1 (or FIG. 5 ).
[0059] Also, in a case where the SD memory card 100 wireless communicates with a device at a predetermined distance therefrom, the second antenna 600 can more improve transmission and reception efficiency of an electric wave than when the second antenna 600 is installed in the SD memory card 100 .
[0060] However, the structure in which the second antenna 600 is installed outside the SD memory card 100 may not be easily handled. Thus, in a case where a host device including the SD memory card 100 shown in FIG. 6 does not need the function of the contactless IC card reader, the second antenna 600 having a module structure may be separately used.
[0061] FIG. 7 is a block diagram of an SD memory card for extension of function according to still another embodiment of the present invention. Referring to FIG. 7 , an SD memory card 700 is separated from a contactless IC card and contactless card reader function extension module 750 .
[0062] The SD memory card 700 operates as a general SD memory card and includes a first controller 730 , a flash memory card 720 , a contact IC card adapter 710 , and a connector 740 for connecting the SD memory card 700 to the contactless IC card and contactless card reader function extension module 750 . The flash memory 720 may be a ROM or EEPROM used for an SD memory card and include a system area, a project area, and a general user area.
[0063] The contact IC card adapter 710 is a wire connection module providing a wire physical contact point for using the contact IC card and connected to the first controller 730 .
[0064] The first controller 730 includes an SD card interface 731 , a memory interface 732 , a microprocessor (uP(RISC)) 733 , a RAM 735 , a ROM 736 , a link interface 738 , and a contactless IC card and/or reader interface 739 .
[0065] The SD card interface 731 is connected to signal pines DAT 0 through DAT 3 , GND, VDD, and CLK so as to be connected to a host device in which the SD memory card 700 is built.
[0066] The memory interface 732 is connected to the flash memory 720 .
[0067] The RAM 735 performs a function of a work buffer memory used in the execution of a program.
[0068] The ROM 736 stores execution programs such as a program for controlling protocols of a contactless IC card and a contactless and/or contact IC card reader, a program for controlling the SD card interface 731 , and the like.
[0069] The link interface 738 links the contact IC card adapter 710 to the first controller 730 .
[0070] The microprocessor 733 executes the execution programs stored in the ROM 736 and controls higher protocols than the protocols of the contactless IC card and the contactless and/or contact IC reader, the SD card interface 731 , and a memory access to the flash memory 720 . The microprocessor 733 controls the components of the first controller 730 and controls the contact IC card adapter 710 via the link interface 738 .
[0071] The first controller 730 has the same function as the controller 130 shown in FIG. 1 except that the first controller 730 includes the contactless IC card and/or reader interface 739 but does not include the encoding module 784 and a peripheral module 787 .
[0072] The contactless IC card and/or reader interface 739 is connected to the contactless IC card and contactless IC card reader function extension module 750 via the connector 740 .
[0073] The contactless IC card and contactless card reader function extension module 750 includes a first antenna 760 , an RF circuit 770 , and a second controller 780 .
[0074] The RF circuit 770 is a wireless connection module performing the functions of the contactless IC card and contactless IC card reader and is connected to the second controller 780 .
[0075] The first antenna 760 includes a signal transmission and reception antenna connected to the RF circuit 770 so that the RF circuit 770 performs a function thereof.
[0076] The second controller 780 controls the contactless IC card and the contactless IC card reader and includes a contactless IC card and/or reader interface 781 , a microprocessor 782 , the encoding module 784 , a RAM 785 , a ROM 786 , and the peripheral module 787 .
[0077] The encoding module 784 performs an encoding algorithm function for performing security functions such as encoding, decoding, and authentication of data, and the like for protecting data stored in a memory.
[0078] The peripheral module 787 is used to perform and extend a function of the microprocessor 783 using a timer, a random number generator, or the like.
[0079] Here, the contactless IC card and/or reader interface 781 is connected to the SD memory card 700 via the connector 740 .
[0080] The second controller 780 is connected to the RF circuit 770 . Here, the second controller 780 performs the same function as the first controller 730 except that the second controller 780 does not perform the functions of the contactless IC card and/or reader interface 781 and the flash memory 720 and thus will not be described in detail herein.
[0081] As shown in FIG. 7 , the SD memory card 700 may be generally used an SD memory card device and may be connected to the contactless IC card and contactless card reader function extension module 750 including the second controller 780 performing the functions of the contactless IC card and contactless IC card reader, the RF circuit 770 , and the first antenna 760 so as to extend a communication interface function.
[0082] As a result, components can be easily mounted in the SD memory card 700 . Also, the SD memory card 700 can be arbitrarily to the contactless IC card and contactless card reader function extension module 750 to add a wireless interface function thereto.
[0083] In the embodiments described with reference to FIGS. 1, 6 , and 7 , a method of setting a host device connected according to the wire and wireless interface functions will now be described.
[0084] In a wire and wireless communication way of a contactless IC card and contactless and/or contact IC card reader, the contactless IC card and the contactless and/or contact IC card reader may mainly communicate with a specific one of devices within a communication range. In this case, the contactless IC card and contactless and/or contact IC card reader requires information for specifying a counterpart device to be connected. For example, the contactless IC card and the contactless and/or contact IC card reader registers their pin codes and a pin code of the specific device as set information in advance and communicates with the specific device based on the set information. The set information is stored in advance in a protection memory area of a flash memory.
[0085] Referring to FIG. 1 , in the case of the SC memory card 100 shown in FIG. 1 , set information recorded in a protection memory area of the flash memory 140 may be read according to the controller 130 that may control wire and wireless interfaces and a memory interface. The contactless IC card and the contactless and/or contact IC card reader can communicate with a specific counterpart device using the set information.
[0086] Only a specific host device having public key information can be accessed according to an authenticator of the SD memory card 100 . Such an access control is performed to realize protection technology via an authenticator installed in a host device corresponding to the SD memory card 100 . When data is read and written, the data is exchanged using encoding performed based on the public key information the host device and the SD memory card 100 commonly have. Thus, the access control is performed to prevent the data from being copied.
[0087] Thus, as described above, the SD memory card 100 can be installed in an arbitrary host device so as to communicate with a pre-set connection counterpart according to the host device. The SD memory card 100 must be installed in a specific host device to change the connection counterpart or read set information.
[0088] As described above, an SD memory card for extension of function according to the present invention can have wire and wireless interface functions. Thus, the SD memory card can be added to an information processor to be used for extension of function.
[0089] Also, the SD memory card can easily protect information using encoding and decoding and authentication functions by providing convenience of the SD memory card and an encoding module.
[0090] In addition, the SD memory card can include a combination of functions of a conventional contactless IC card and a conventional contactless and/or contact IC card reader. Thus, the SD memory card can be used in contactless IC card applications including a traffic card, access control, and the like.
[0091] Moreover, the SD memory card can uses the contactless IC card reader and the contact IC card reader as one. Thus, production cost can be reduced, and the contactless IC card reader and the contact IC card reader can be conveniently used and simply manipulated.
[0092] Furthermore, the SD memory card can include a multipurpose controller. Thus, the SD memory card can process information and include various applications such as functions of a storage memory, the contactless IC card and contactless and/or contact IC card reader, and the like. As a result, the SD memory card can be used as an application platform.
[0093] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
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Provided is a secure digital memory card for extension of function, including: a flash memory installed in a host device and storing data generated by the host device; a controller controlling an access interface to the flash memory; a radio frequency circuit performing functions of a contactless integrated circuit card and a contactless integrated circuit card reader through a wireless interface control of the controller; an antenna unit connected to the radio frequency circuit to perform a function of a transmission and reception antenna; and a contact integrated circuit card adapter performing the function of the contact integrated circuit card reader through a wire interface control of the controller.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for the preparation of peroxides and more especially to a process for the preparation of bivalent metal peroxides.
Peroxides of bivalent metals are being used increasingly for technological applications. Thus, for example, alkaline earth metal peroxides are used for medical and pharmacological purposes and in cosmetics. Recently, CaO 2 has been growing in importance, as it serves to improve the growth of cultivated plants. In sewage treatment, the potential of the slow release of oxygen by peroxide compounds is being utilized. Metal peroxides are also used in the technical fields of vulcanizing and welding.
Peroxides of bivalent metals are generally prepared by producing peroxide-containing reaction mixtures from aqueous solutions or dilute suspensions of their salts, oxides or hydroxides by means of conversion with aqueous hydrogen peroxide solutions, centrifuging or filtering the mixture and drying them on rack or tray drying apparatus. The dry substances are ground and possibly screened in a conventional manner.
A process for the preparation of CaO 2 is known from German Offenlegungsschift No. 15 42 642, wherein a highly dilute solution of hydrogen peroxide is reacted with an excess of calcium hydroxide at temperatures below 30° C. to produce calcium peroxide-octahydrate, which then is converted in an additional drying stage into the anhydrous peroxide.
All of these known processes have numerous disadvantages. They are costly, because of the need of separating the mother liquor by centrifuging and the grinding of the product dried on racks or trays. Furthermore, the economy of the process is limited, because significant losses of peroxide are generated by decomposition of hydrogen peroxide as the result of the large volumes of mother liquor caused by the relatively dilute suspensions, and in the drying process, as the result of long retention times.
Furthermore, because of the strong dilution of the reaction mixture, large volumes of water must be transported unnecessarily and they must be removed in an energy-intensive drying stage. In addition, supplemental control devices are required for temperature control as well as additional process stages for the removal of the excess calcium hydroxide. A further disadvantage is a certain lack of homogeneity of the end product, resulting from decomposition during drying and the subsequent grinding process.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved process for the preparation of peroxides. It is a particular object of the invention to provide an improved process for the preparation of peroxides of bivalent metals.
Another object of the invention resides in the provision of a process for the production of bivalent metal peroxides which eliminates the disadvantages of the known processes.
In accomplishing the foregoing objects, there has been provided in accordance with the present invention a continuous process for the production of bivalent metal peroxides, comprising the steps of introducing into an intensive mixing apparatus a solid, anhydrous or hydrated oxide or hydroxide of a bivalent metal; simultaneously introducing into the intensive mixing apparatus a solution of hydrogen peroxide, whereby the solid bivalent metal compound and the peroxide are intensively mixed and react to produce a reaction mixture containing bivalent metal peroxide; transporting the reaction mixture directly to a rapid dryer; and rapidly drying the reaction mixture to produce the bivalent metal peroxide in solid form.
Preferably, the bivalent metal comprises a metal of Group II of the Periodic System, most preferably an alkaline earth metal or zinc. In amother preferred aspect, the average residence time for the reactants between entry into the intensive mixing apparatus and entry into the rapid dryer is between about 0.1 and 15 minutes, preferably between about 0.5 and 5 minutes.
Further objects, features and advantages of the present invention will become apparent from the detailed description of preferred embodiments which follows.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to the invention, solid, anhydrous or hydrated oxides or hydroxides are reacted in an intensive mixing apparatus, directly with hydrogen peroxide, possibly with cooling and transporting the reaction mixture directly to a rapid dryer for the drying process.
Although a process, not previously published (German Patent Application No. P 29 18 137) already exists for the preparation of alkali metal or alkaline earth metal peroxides wherein the spray drying process is used for the drying of the reaction mixture, this process does not employ solid oxides or hydroxides, but initially prepares an oxide or hydroxide suspension, which is then reacted with H 2 O 2 .
In view of the state of the art, it was surprising to find that solid oxides and/or hydroxides may be converted on an industrial scale directly with hydrogen peroxide in a simple process, without incurring heavy losses of active oxygen.
All commercially available solid, anhydrous or hydrated metal oxides or hydroxides may be used, wherein naturally the intended later use of the peroxide determines the choice of the raw material to be employed. Thus, it is necessary to select the purity of the initial raw material accordingly, if the peroxides to be prepared are intended for utilization in the human or veterinary fields.
A commercially available hydrogen peroxide may be used, which may also contain known stabilizers of active oxygen. It is preferred to select an H 2 O 2 concentration of from about 30 to 70% by weight.
According to the process of the invention, both of the reactants are fed continuously, directly into the intensive mixing apparatus, where they are immediately processed into a homogeneous mixture, while simultaneously reacting with each other.
Devices making possible the rapid, intensive mixing of the two reactants are employed as the intensive mixing apparatus. Particularly suitable is, for example, a rapidly rotating excentric pump, which provides good homogenization, while also transporting the reaction mixture. But, for example, a plough share mixer, in combination with conveying means for transporting the reaction mixture, may also be used. To remove part of the heat of solution and reaction heat, the mixing apparatus may be equipped with a cooling jacket.
One possible embodiment of operation consists of feeding the solid material by means of a conveyor screw equipped with a hollow shaft into the intensive mixer and conducting the hydrogen peroxide through the hollow shaft into the mixer, so that the two reactants are combined only inside the mixer and then processed into a homogeneous mixture.
The continuously introduced streams of material are coordinated with one another so that the reactants are added preferably in an approximately stoichiometric ratio, i.e., with deviations of about ±20 mole % from the proportions according to the reaction equation. It is possible, however, to deviate further from the stoichiometric proportions. If, for example, products with a definite, low active oxygen content are to be produced, it may be advantageous to prepare this product directly by deviating from the stoichiometric proportion, rather than producing a more highly concentrated product which would result from maintaining the stoichiometric proportion and which subsequently must be adjusted to the active oxygen content desired by means of dilution with inert substances.
The mixture leaving the intensive mixing apparatus is transported directly into a rapid dryer, wherein, optionally, means to equalize the product flow, for example, a surge vessel, may be provided. A particularly preferred process operates in a manner so that the average retention time of the material stream, i.e., the mixture of the reactant components and/or the reaction products in the region between their entry into the intensive mixing apparatus and their entry in the rapid dryer, amounts to from about 0.1 to 15 minutes and more preferably from about 0.5 to 5 minutes.
As the rapid dryer, drying apparatuses are used which are capable of drying the continuous stream of material without extensive thermal stress. Drying temperature are adjusted in accordance with the throughput and the specific peroxide.
The use of spray dryers has been found to be well suited for this purpose, with spray dryers having centrifugal atomizers being preferable. For this type of dryer, the reaction mixture to be dried should be within the range of easily pumpable to just still pumpable. For reaction mixtures with a higher solids content, a flash dryer may be used with advantage.
The following advantages are characteristic of the process according to the invention, with respect to the state of the art:
(a) By introducing the reactants in their approximate stoichiometric proportions and by working with concentrated reaction mixtures, the proportion of the ballast to be carried along (water, excessive amounts of a reactant) may be kept extremely low.
(b) The direct spray drying of the reaction mixture eliminates costly separation and purifying stages. In addition, the product is obtained directly as a free flowing powder, and no final treatment in a subsequent comminution installation is necessary.
(c) The process operates continuously.
(d) By virtue of the short reaction period, losses due to the decomposition of active oxygen may be reduced.
(e) By utilizing the heat of solution and the heat of reaction, at least part of the energy otherwise required for drying may be saved.
(f) The process is extremely safe for the environment, since practically no waste water is produced.
The product obtained by the process according to the invention is similarly characterized by advantages with respect to the state of the art:
(a) The prevention of local decomposition reactions insures a good homogeneity of the product.
(b) Spray drying provides good flowability, uniform crystall structures and a narrow, uniform grain size distribution.
Several embodiments of the process according to the present invention are illustrated by the examples which follow hereinafter; however, these examples are merely illustrative and in no sense are to be considered as limiting.
EXAMPLE 1
From a solid reservoir, 84 kg/h of a Ba(OH) 2 .H 2 O powder are fed continuously by means of a conveyor screw into an intensive mixing apparatus. Simultaneously, from a H 2 O 2 reservoir, 36.8 l/h of a 39.2% by weight H 2 O 2 solution (stabilized with 300 mg PO 4 3- /l) are introduced continuously into the intensive mixing apparatus through the hollow shaft of the conveyor screw. As the intensive mixing apparatus, a mixer pump (Supraton R 207) is used. A barium peroxide suspension is formed, with the release of heat. This suspension is transported immediately by way of an inserted equalizing or surge vessel, serving to equalize the product flow exiting intermittently from the mixer pump, to the centrifugal atomizer of a spray dryer. Drying temperatures are adjusted to the constant product flow and amount at the dryer inlet to 300° C. and at the outlet of the dryer to 80°-90° C. The product obtained (75,8 kg/h) contains 92.3% by weight BaO 2 and has an average particle diameter of approximately 5 μm. The average retention time of the reaction mixture between entry into the intensive mixing apparatus and entry into the rapid dryer amounts to 2.5 min.
Further experiments are carried out as described in Example 1. The different process parameters and the results of the experiments may be found in the table hereinbelow.
Abbreviations in the table have the following significance:
TABLE______________________________________Example 2 3 4 5______________________________________Solid MgO Ca(OH).sub.2 Sr(OH).sub.2 ZnO 8 H.sub.2 OKg Solid/h 11.6 47.2 92.4 38.81 H.sub.2 O.sub.2 /h 21 52.9 28.9 39.3DT-inlet 250 250-300 250-300 250DT-outlet 110-120 110-120 50 110-120ProductType MgO.sub.2 CaO.sub.2 SrO.sub.2.H.sub.2 O ZnO.sub.2 (45%) (75%) (92.2%) (67.4%)kg/h 16.1 46.2 47.9 43.8D.sub.a 10 μm 5 μm 5 μm 0.5 μmrt.sub.a 1 min. 2 min. 2.5 min. 1.5 min.______________________________________ DT dryer temperature in °C. D.sub.a average particle diameter rt.sub.a average retention time % % by weight
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Disclosed is a continuous process for the production of bivalent metal peroxides, comprising the steps of introducing into an intensive mixing apparatus a solid, anhydrous or hydrated oxide or hydroxide of a bivalent metal; simultaneously introducing into the intensive mixing apparatus a solution of hydrogen peroxide, whereby the solid bivalent metal compound and the peroxide are intensively mixed and react to produce a reaction mixture containing bivalent metal peroxide; transporting the reaction mixture directly to a rapid dryer; and rapidly drying the reaction mixture to produce the bivalent metal peroxide in solid form.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a frequency divider for obtaining signals corresponding to the dividing ratio indicated by dividing ratio data, and in particular to a frequency divider applicable to such circuits as a tone source circuit in an electronic musical instruments, etc.
2. Description of the Prior Art
To obtain a tone source signal corresponding to the pitch of a musical tone to be produced, a frequency divider for dividing a master clock pulse of a predetermined frequency is employed in the tone source circuit of an electronic musical instrument. For a prior art frequency divider of the above type, its dividing ratio must be set at a considerably large value so as to minimize frequency error (cent error) of each tone source signal obtained by the division, and the circuit composition for the divider has become unfavorably complicated.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide a frequency divider of a simple composition capable of providing a divided output of a large dividing ratio.
Another object of the present invention is to provide a frequency divider capable of attaining the simplification of the system for an electronic musical instrument when the divider is used as a tone source circuit.
According to the present invention, a cycle data is formed in which a signal "1" is generated at a single bit only based on the output of a counter driven by a predetermined clock pulse, and the ratio at which the above signal "1" generates corresponds to the weight of each bit. The cycle data and dividing ratio data are compared for each corresponding bits, and when a signal "1" occurs at a corresponding bit in each data, counting operation of the counter is suspended for one count, whereby the dividing output corresponding to the dividing ratio data is obtained from the output of the counter.
The present invention will now be described in detail in connection with the accompanying drawing in which presently preferred embodiments of the invention are illustrated by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings
FIG. 1 is a block diagram showing the outline of the divider according to the present invention;
FIGS. 2 through 4 are circuit diagrams showing an embodiment of the divider according to the present invention;
FIG. 5 is a block diagram showing an example of the electronic musical instrument employing the divider according to the present invention; and
FIG. 6 is a circuit diagram showing the detail of the divider of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a counter 10 is a binary counter (preferably a synchronous type counter) driven by a predetermined clock pulse φ. A count output Q of the counter 10 is applied to a cycle data forming circuit 20. The cycle data forming circuit 20 forms a cycle data CD in which the content of only one bit becomes "1", and the ratio at which the content of each bit becomes "1" corresponds to the weight of each bit. In order to facilitate the understanding of said cycle data CD, an example of the cycle data CD in which the number of bits of the counter 10 is four is shown in Table 1.
TABLE 1______________________________________Counter Output Q Cycle data CDQ.sub.4Q.sub.3 Q.sub.2 Q.sub.1 CD.sub.4 CD.sub.3 CD.sub.2 CD.sub.1______________________________________0 0 0 0 0 0 0 00 0 0 1 1 0 0 0 *0 0 1 0 0 1 0 00 0 1 1 1 0 0 0 *0 1 0 0 0 0 1 0 *0 1 0 1 1 0 0 0 *0 1 1 0 0 1 0 00 1 1 1 1 0 0 0 *1 0 0 0 0 0 0 1 *1 0 0 1 1 0 0 0 *1 0 1 0 0 1 0 01 0 1 1 1 0 0 0 *1 1 0 0 0 0 1 0 *1 1 0 1 1 0 0 0 *1 1 1 0 0 1 0 01 1 1 1 1 0 0 0 *______________________________________
Referring to Table 1, Q4-Q1 show bits of the count output Q of the counter 10, while CD4-CD1 show bits of the cycle data CD formed by the cycle data forming circuit 20. That is, the cycle data CD4-CD1 shown in Table 1 are repeatedly generated by the cycle data forming circuit 20 in response to the count outputs Q4-Q1. Out of the bits of the cycle data CD 1 through CD 4 , any one, and only one, of them becomes "1" and the ratio at which each bit CD 4 -CD 1 becomes "1" are 8:4:2:1, that is, the ratio corresponds to the weights of respective bits "8", "4", "2" and "1".
The cycle data CD generated at the cycle data forming circuit 20 is fed to an inhibit circuit 30. At the same time, a dividing ratio data DD representing dividing ratio is applied to the inhibit circuit 30. This dividing ratio data DD is a binary data composed of the same number of bits as the cycle data CD. The inhibit circuit 30 compares the cycle data CD fed from the cycle data forming circuit 20 with the dividing ratio data DD for each corresponding bits, generates an inhibit signal IS when corresponding bits are "1" simultaneously, and suspends the counting operation of the counter 10 for one count. For example, when the dividing ratio data DD is "0000" and the cycle data CD are as shown in Table 1, the values of the corresponding bits of the cycle data CD and the dividing ratio data DD do not become "1" simultaneously within one cycle of the cycle data CD (CD4-CD1). Accordingly, the counter 10 operates, without being suspended, with one cycle being 16×φ p where φ p is a period of the clock pulse φ. On the other hand, when the dividing ratio data DD is, for example, "1011", the inhibit signal IS is generated at the inhibit circuit 30 each time the cycle data CD becomes the values indicated by * mark in Table 1, and the counting operation of the counter 10 is suspended for one count by this signal IS. Accordingly, one cycle of the counter 10 is extended by 8·φ p +2·φ p +φ p =11·φ p and the counter 10 operates with a cycle of 27·φ p .
The relation between the dividing ratio data DD and cycle T of the counter 10, when the dividing ratio data DD is composed of 4 bits DD4-DD1 in the case that the number of bits of both the counter 10 and the cycle data CD is four, can be expressed by the following general equation:
T=(2.sup.4 +DD.sub.4 ×2.sup.3 +DD.sub.3 ×2.sup.2 +DD.sub.2 ×2+DD.sub.1)×φ.sub.p (1)
The above relation is summed up as shown in Table 2.
TABLE 2______________________________________Dividing ratio data DDDD.sub.4 DD.sub.3 DD.sub.2 DD.sub.1 Cycle T of counter 10______________________________________0 0 0 0 16 · φ.sub.p0 0 0 1 17 · φ.sub.p (= 16 + 1)0 0 1 0 18 · φ.sub.p (= 16 + 2)0 0 1 1 19 · φ.sub.p (= 16 + 2 + 1)0 1 0 0 20 · φ.sub.p (= 16 + 4)0 1 0 1 21 · φ.sub.p (= 16 + 4 + 1)0 1 1 0 22 · φ.sub.p (= 16 + 4 + 2)0 1 1 1 23 · φ.sub.p (= 16 + 4 + 2 + 1)1 0 0 0 24 · φ.sub.p (= 16 + 8)1 0 0 1 25 · φ.sub.p (= 16 + 8 + 1)1 0 1 0 26 · φ.sub.p (= 16 + 8 + 2)1 0 1 1 27 · φ.sub.p (= 16 + 8 + 2 + 1)1 1 0 0 28 · φ.sub.p (= 16 + 8 + 4)1 1 0 1 29 · φ.sub.p (= 16 + 8 + 4 + 1)1 1 1 0 30 · φ.sub.p (= 16 + 8 + 4 + 2)1 1 1 1 31 · φ.sub.p (= 16 + 8 + 4 + 2 + 1)______________________________________
That is, in this case, cycle T of counter 10 can be varied over the range from 16·φ p to 31·φ p in response to the contents of the dividing ratio data DD4-DD1. Generally, when the number of bits of the counter 10 is N and the dividing ratio data DD is composed of "N" bit DDN-DD1, cycle T of the counter 10 is expressed by the following general equation, ##EQU1## The counter 10 will operate with the cycle from 2·φ p to (2 N=1 -1)×φ p corresponding to the content of the dividing ratio data DNN-DD1.
In this manner, cycle T of the counter 10 varies in response to the dividing ratio data DD, and as a result the count output Q of the counter 10 varies at a speed corresponding to the signal resulted from dividing the clock pulse φ at a dividing ratio corresponding to the dividing ratio data DD. The count output Q of the counter 10 is output as output data OD.
Referring now to FIG. 2, the counter 10 of this embodiment is comprised of four adders 11-14, and four delay flip-flops 15-18. Each combination of the adder 11 and delay flip-flop 15, the adder 12 and delay flip-flop 16, the adder 13 and delay flip-flop 17, and the adder 14 and delay flip-flop 18 forms an adder circuit executing adding operation synchronized with the clock pulse φ. The counter 10 is constructed as a 4-bit binary synchronous type counter with four such adders connected in series. When a signal applied to a carry input Ci of the adder 11 which corresponds to the first bit (the least significant bit) is "1", the counter 10 performs counting synchronized with the clock pulse φ, and stops counting when the above signal becomes "0".
The cycle data forming circuit 20 consists of four 2-input AND circuits 21-24, wherein fed to each AND circuit 21-24 are both the signal applied to the carry inputs Ci of the adder 11-14 and the adder outputs S1-S4 (count output Q1-Q4), respectively.
In the case that signal Ci1-Ci4 are applied to the carry input Ci of individual adders 11-14 of the counter 10 respectively, and the signal Ci1 is "1" (as mentioned later, the signal Ci1 is "1" during the period when a predetermined condition is not established at the inhibit circuit 30), the operation of the counter 10 and signals D1-D4 generating at AND circuits 21-24 in response to the counter operation will be as shown in Table 3.
TABLE 3______________________________________Ci.sub.1S.sub.1 Ci.sub.2 S.sub.2 Ci.sub.3 S.sub.3 Si.sub.4 S.sub.4 D.sub.1 D.sub.2 D.sub.3 D.sub.4______________________________________1 0 0 0 0 0 0 0 0 0 0 01 1 0 0 0 0 0 0 1 0 0 01 0 1 1 0 0 0 0 0 1 0 01 1 0 1 0 0 0 0 1 0 0 01 0 1 0 1 1 0 0 0 0 1 01 1 0 0 0 1 0 0 1 0 0 01 0 1 1 0 1 0 0 0 1 0 01 1 0 1 0 1 0 0 1 0 0 01 0 1 0 1 0 1 1 0 0 0 11 1 0 0 0 0 0 1 1 0 0 01 0 1 1 0 0 0 1 0 1 0 01 1 0 1 0 0 0 1 1 0 0 01 0 1 0 1 1 0 1 0 0 1 01 1 0 0 0 1 0 1 1 0 0 01 0 1 1 0 1 0 1 0 1 0 01 1 0 1 0 1 0 1 1 0 0 0______________________________________
As evident from Table 3, the output signals D1-D4, of the AND circuits 21-24 correspond to bits CD4-CD1 of the cycle data CD shown in Table 1, respectively. The output signals D1-D4 are applied to the inhibit circuit 30 as the cycle data CD4-CD1.
The inhibit circuit 30 is provided with four 2-input AND circuits 31-34, and to the AND circuits 31-34 are applied both corresponding bits of the cycle data CD4-CD1 output from the AND circuits 21-24 of the cycle data forming circuit 20 and the dividing ratio data DD4-DD1 specifying dividing ratio of frequency division. The outputs of these AND circuits 31-34 are fed to an OR circuit 35. Accordingly, when corresponding bits in each of the cycle CD4-CD1 and the dividing ratio data DD4-DD1 become "1" simultaneously, the output of OR circuit 35 changes from "0" to "1", which is fed to an OR circuit 39 through a delay flip-flop 36, and an inverter 38. The output of the delay flip-flop 36 is also fed to the OR circuit 39 via a delay flip-flop 37. As a result, when it happens that a certain corresponding bit in each of the cycle data CD4-CD1 and the dividing ratio data DD4-DD1 becomes "1", a signal whose value is "0" only during the next count timing of the counter 10 is generated. This signal is fed to the carrying input Ci of the adder 11 of the counter 10. That is, when a certain corresponding bit "1" in each of the cycle data CD4-CD1 and the dividing ratio data DD4-DD1 is "1", subsequent counting operation of the counter 10 is inhibited by one count.
In this manner, a dividing signal with dividing ratio corresponding to the dividing ratio data CD4-CD1 can be obtained from the output S1-S4 of the adder 11-14 of the counter 10.
Referring now to FIG. 3 another embodiment is shown which differs greatly from the embodiment shown in FIG. 2 in that this embodiment employs an ordinary binary counter as the counter 10 and the clock pulse φ to be fed to the counter 10 is inhibited by the inhibit circuit 30 for inhibiting count operation of the counter 10. Furthermore, a different configuration is used for the cycle data forming circuit 20. However the basic operation is totally identical between these two embodiments. Accordingly, description is simplified by using the same reference numbers and symbols as those of the circuits shown in FIG. 2.
The counter 10 is driven by the clock pulse φ applied through an AND circuit 300 of the inhibit circuit 30, and count output Q (Q1-Q4) is fed to the cycle data forming circuit 20. The cycle data forming circuit 20 includes four delay flip-flops 201-204, exclusive OR circuit 211-214, and AND circuits 221-224. The operation of the cycle data forming circuit 20 will be described in conjunction with the flip-flop 201, the OR circuit 211 and the AND circuit 221 which correspond to the first bit. The output Q1 at the first of the counter 10, and a signal which is formed by delaying the output Q1 by one cycle of the clock pulse φ (i.e. the output Q1 at one count operation before) are compared by applying both to the exclusive OR circuit 211, and if the values of the two signals differ, the AND circuit 221 outputs a signal provided that the output Q1 of the counter 10 is "1". Thus, only when the output Q1 has changed from "0" to "1", the output of the AND circuit 221 becomes "1". To other bits, the same operation takes place. In such composition, the relation between the input and output of the cycle data forming circuit 20 becomes identical with that of the cycle data forming circuit 20 shown in FIG. 2. That is, the cycle data forming circuit 20 generates the cycle data CD4-CD1 shown in Table 1 in response to the count value of the counter 10. The cycle data CD4-CD1 and the dividing ratio data DD4-DD1 are compared for each corresponding bit at the AND circuits 31-34 of the inhibit circuit 30, and when it happens that a certain corresponding bit becomes "1" simultaneously both in the cycle data CD4-CD1 and the dividing ratio data DD4-DD1, a signal "1" is output from the OR circuit 35. This signal "1" is fed to the OR circuit 39 through the flip-flop 36 and the inverter 38, the AND circuit 300 is made inoperative by the output of the OR circuit 39 during the next count timing of the counter 10, and the counter 10 is inhibited to perform count operation by one count.
Referring to FIG. 4, the third embodiment is shown in which the cycle data forming circuit 20 of different configuration is used. The cycle data forming circuit 20 in this embodiment is comprised of three AND circuits 232, 233, and 234, and three inverters 241, 242, and 243. The cycle data forming circuit 20 operates in such a way that the first bit output Q1 of the counter 10 is directly output as data CD4, the second bit output Q2 is output as data CD3 via the AND circuit 232 provided that the first bit output Q1 of the counter 10 is "0", the third bit output Q3 is output as data CD2 via the AND circuit 233 provided that both the first and the second bit outputs Q1 are Q2 and "0", and the fourth bit output Q4 is output as data C1 via the AND circuit 234 provided that the first to third bit output Q1 to Q3 are "0". Such configuration can provide the same signal as the cycle data CD4-CD1 shown in Table 1, and the same operation as those of the embodiments shown in FIGS. 2 and 3 can be obtained. For the counter 10 and the inhibit circuit 30 shown in FIG. 4, the same configuration as the same numbered counter 10 and the inhibit circuit 30 of FIGS. 2 and 3 is employed.
Though the embodiments shown in FIG. 2 through FIG. 4 are in 4-bit configuration, configuration with any desired number of bits may also be employed. The configuration of the cycle data forming circuit 20 is not limited to that described above. What is required of the cycle data forming circuit 20 is that a signal occurs at an optional bit only in response to the count output Q of the counter 10, and that a cycle data CD wherein the ratio at which a signal occurs at each bit corresponds to the weight of each bit. The counter 10 may be of a variety of configurations of synchronous or asynchronous type. Further, the operation suspension means of the counter 10 by the use of the inhibit circuit 30 is not limited to the configuration shown in the above-mentioned embodiments. For example, the operation of the counter 10 can be suspended substantially by presetting the same content as the current count value. Further, although the number of count operation of the counter 10 to be inhibited by the inhibit circuit 30 is one in any of the aforementioned embodiments, more than one count may be inhibited. Further still, the AND circuits 21-24 (221-224) of the cycle data forming circuit 20, and the AND circuits 31-34 of the inhibit circuit 30 may be combined into 3-input AND circuits.
FIG. 5 shows an example of and electronic musical instrument to which the frequency divider according to the present invention is applied. A keyboard circuit 40 is provided with key switches corresponding to individual keys of the keyboard, and a depressed key detection/tone production assignment circuit 41 assigns a key code KC identifying the not to be produced to available one of the tone production channels which correspond to the number of the maximum simultaneous tone productions N by detecting the state (ON or OFF) of each key switch of the keyboard circuit 40. Each tone production channel is a time division channel wherein a specific time slot is designated, and the key code KC identifying the note to be produced and the key-on signal KON indicating the depressed state of said key are assigned to the time slot corresponding to each tone production channel, being output on the time division basis. The key code KC output from the depressed key detection/tone production assignment circuit 41 is comprised of a note code NC inidicating note name of the note to be produced, and an octave code OC indicating octave region of the note, and the note code NC is fed to a dividing ratio data memory 43 via a decoder 42, while the octave code OC being fed to a shift circuit 48.
The dividing ratio data memory 43 stores twelve dividing ratio data DD corresponding to twelve note name C♯ through C. In this embodiment, 7-bit data DD7-DD1 is used for the dividing ratio data DD. An example of the dividing ratio data DD with respect to each note name is as shown in Table 4.
TABLE 4______________________________________Dividing ratio data DDNote name DD.sub.7 DD.sub.6 DD.sub.5 DD.sub.4 DD.sub.3 DD.sub.2 DD.sub.1______________________________________C.sup.♯ 1 1 1 0 1 1 0D 1 1 0 1 0 0 0D.sup.♯ 1 0 1 1 0 1 1E 1 0 0 1 1 1 1F 1 0 0 0 0 1 1F.sup.♯ 0 1 1 1 0 0 0G 0 1 0 1 1 1 0G.sup.♯ 0 1 0 0 1 0 0A 0 0 1 1 0 1 1A.sup.♯ 0 0 1 0 0 1 0B 0 0 0 1 0 1 0C 0 0 0 0 0 1 0______________________________________
In response to a signal indicating the note name of the note assigned to each tone production channel which is output from a decoder 41 in time division manner, the dividing ratio data memory 45 reads out the dividing ratio data DD (DD7-DD1) corresponding to the note name in time division manner, and applies it to an adder 46.
In this embodiment, in order to give a specified vibrator to the produced musical tone, a vibrato counter 44 and a vibrator data memory 45 are provided. The vibrator data memory 45 stores vibrato data VD for performing the vibrator (to increase or decrease the dividing ratio data DD by a value corresponding to the vibrato waveform) of the dividing ratio data DD. The vibrato data memory 44 reads out the vibrato data VD by using the vibrato counter 44 driven by a clock pulse CP corresponding to the vibrato speed as an address counter, and applies the vibrator data VD thus read to the adder 46. The vibrato data memory 45 can be designed so as to store the vibrato data VD which differs according to the note name, and to be addressed by both the output of the decoder 42 indicating the note name and the output of the vibrato counter 44. In this case, the vibrato data VD which differs according to the note name is read out from the vibrato data memory 45. The vibrato memory 45 also operates at the time slot corresponding to the tone production channel in time division manner.
The dividing ratio data DD output from the dividing ratio data memory 43 is added to the vibrato data VD outputted from the vibrato data memory 45 at the adder 46, and the resulting data is fed to a frequency divider 47 as a dividing ratio data DD' (DD'7-DD'1).
The divider 47 according to the present invention forms a divided output OD (OD7-OD1) corresponding to the dividing ratio data DD'. This divider is detailed in FIG. 6. The divider 47 shown in FIG. 6 is identical to the circuit shown in FIG. 2 except that the number of bits of the former is seven, and that the operations are performed in time division manner corresponding to the tone production channels (time slots) number of which is as many as N. That is, the circuit shown in FIG. 6 comprises nine N-stage 1-bit shift registers SR1-SR9 to be driven by the clock pulse φ, adders AD1-AD7, 3-input AND circuits AN1-AN7, OR circuits OR1-OR2 and an inverter IN. In this circuit, a time division counter is formed by the shift registers SR1-SR7 and the adders AD1-AD7, the cycle data forming circuit and one part of the inhibit circuit are formed by the 3-input AND circuits AN1- AN7, and the other part of the inhibit circuit is formed by the OR circuits OR1-OR2, the shift registers SR8-SR9 and the inverter IN. The operation of this circuit is now described briefly. The circuit composed of the shift registers SR1-SR7 and the adders AD1-AD7 performs count operation by the clock pulse φ in time division manner. Accordingly, if a particular channel is observed, the circuit performs count operation synchronized with a clock pulse whose cycle is N·φ p . The time width of the time slot of each tone production channel is designed to be equal to one cycle time of the clock pulse. Outputs S1-S7 of the adders AD1-AD7, and signals Ci1 -Ci7 to be fed to the carry input Ci become input signals to be fed into two inputs of the 3-input AND circuits AN1-AN7, respectively. Fed to the remaining input of each AND circuit AN1-AN7 is the dividing ratio data DD'7-DD'1 output from the adder 46. Accordingly, among the AND circuits AN1-AN7, AND condition is established only at the AND circuits whose corresponding bits in the dividing ratio data DD'7-DD'1 are "1". The ratio at which AND condition is established corresponds to the weight of the bit. The AND circuits in which AND condition is established output the signal "1". This signal is fed to the shift register SR8 via the OR circuit OR1, and the output of the shift register SR8 is fed to the OR circuit OR2 through the inverter IN and the shift register SR9. The output of this OR circuit OR2 controls the count operation of a counter comprised of the shift registers SR1-SR7 and the adders AD1-AD7.
The count output (the output of the shift register SR1-SR7) of the counter which comprises the shift registers SR1-SR7, and the adders AD1-AD7 whose count operation is controlled in response to the dividing ratio data DD7-DD1, is output as the divided output OD (OD1-OD7). The cycle To of this divided output OD can be given as follows, if the dividing ratio data DD'7-DD'1 is, for example, "1001111".
To=(2.sup.7 +1×2.sup.6 +1×2.sup.3 +1×2.sup.2 +1×2.sup.1 +1×2.sup.0)N·φp (3)
Thus the cycle of the divided output OD corresponds to the dividing ratio data DD'7-DD'1.
The divided output OD formed at the divider 47 is fed to a shift circuit 48, and shift-controlled in response to the octave code OC output from the tone production assignment circuit 41. As a result of this shift control, a signal whose frequency corresponds to the octave region of the tone to be produced, i.e., a cycle signal corresponding to the tone to be produced, is formed.
A musical tone waveform generating circuit 49 receives the key-on signal KON output from the depressed key detection/tone production assignment circuit 41, forms a musical tone signal indicating the tone to be produced, and applies the signal thus produced to a sound system 50, causing it to produce a musical tone. A variety of known circuits such as those employing the waveform memory system and the frequency modulation system may be used as the musical tone waveform generating circuit 49. When the waveform memory system is used in the musical tone waveform generating circuit 49, the musical tone waveform generating circuit 49 can be simplified, since the output of the shift circuit 48 can be used directly as an address signal of the waveform memory.
In the system shown in FIG. 5, the shift circuit 48 may be replaced with an octave selector for selecting a predetermined bit signal of the output the divider 47, and the output of the octave selector (square wave tone source signal) is taken as a tone source signal, on the basis of which a musical tone signal is formed.
As has been described above, a divider capable of giving a high dividing ratio by a simple configuration can be realized according to the present invention, and in particular, when the divider is used as a tone source circuit of the electronic musical instrument, a favorable effect can be obtained for the simplication of the system.
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A frequency divider which divides clock pulses to obtain the clock frequency of a desired dividing ratio comprises a binary counter, cycle data forming circuit and inhibit circuit to which the dividing ratio is fed in the form of the dividing ratio data.
The counter counts the clock pulses, and the cycle data forming circuit converts the count value of the binary counter to a cycle data in which a certain single bit only becomes a logical state "1" and the rest of the bits are a state "0". The bit which becomes "1" in the cycle data is uniquely determined by the count value. Further, each bit of the cycle data becomes "1" in proportion to the weight of the each bit. With the cycle data being thus formed, the dividing ratio data is simplified.
The inhibit circuit receives the cycle data and the dividing ratio data to suspend the counting operation of the binary count if the bit of the dividing ratio data corresponding to the bit of the cycle data whose state is "1" is also "1". This suspension enables the binary counter to perform a nonbinary counting operation, whereby the frequency-dividing based on the desired dividing ratio in the binary counter is implemented. By relating the diving ratio data to the pitch of a note, the frequency divider may be applicable to an electronic musical instrument.
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BACKGROUND OF THE INVENTION
This invention relates to cosmetics in general and more particularly to a product incorporating a cosmetic component supported in a fibrillated polymer matrix.
Cosmetics have been used since early times to beautify the skin and hair. The manufacture of cosmetics is a 20th century development under the influence of Hollywood in the 1920's coupled with the development of mass production and mass marketing techniques. As a consequence, cosmetics were offered to the public at cheap prices. As one can ascertain, the cosmetic industry today is huge and there are a tremendous number of products utilized.
While most cosmetics are relatively simple, they contain many ingredients which are employed to formulate the various cosmetic preparations. Essentially a cosmetic chemist uses a variety of materials which are often based on emulsified mixtures of oils, water or water soluble products, pigments, talcs and so on.
Manufacturing processes of cosmetics can normally be divided into three main lines, as lipsticks and related sticks, creams and lotions, and compressed powders, as for example cake makeup. This application relates to compressed powder type of cosmetics, but is applicable to other cosmetic products as well.
In the prior art compressed powders were also referred to as cake makeup and are widely employed because of their ease of application and stability and also because they adhere to the skin easily. The most well known is a compressed face powder which usually is made from a mixture of talc, kaolin, zinc oxide and precipitated chalk. It also includes lanolin derivatives, wax and pigment such as titanium and iron oxides. The liquid constituents, including a humectant and perfume are sprayed into the powder while it is in a ribbon mixer. The product is milled to make it homogenous and left to stand to allow air that has been entrained to escape and then pressed by one or more stages employing pressures between 200-250 psi to form a cake.
Cake eye shadows contain about 60% talc and an emollient which is a skin softening agent which allows the cake to be transferred by pressing out. Approved pigments are also added as for example a black coloration being provided by iron oxide. Eye shadows of a metallic luster use finely ground metal such as aluminum or natural or synthetic pearlized materials. The formulation of such cosmetic products comprises a great deal of material including fairly extensive labor processes as well as other time consuming operations.
It is indicated that the dispersion of pigments in cosmetics may require different materials as above indicated and many different steps in order to provide the final product. These steps usually take an extreme amount of time and are labor and capital intensive.
It is an object of the present invention to provide a simple and efficient cosmetic which essentially contains a cosmetic component as a pigment supported by a polymer matrix.
As one will ascertain from the prior art, certain polymers, such as for example Teflon, possess a property called fibrillation. The use of fibrillatable polymers is well known in the prior art. Such polymers have been employed to support various elements and can disperse with such elements as such polymers are relatively non-reactive with the environment into which it's been used. Fluorocarbon and polypropylene polymers have such suitable characteristics and are capable of being fibrillated. As will be further explained, the term fibrillation means that such polymers, when exposed to pressure and/or heat, explode producing fibrils or minute fibers. These fibers are minute fiber particles which are developed in situ from the fibrillatable polymers during processing. As such the fibrils intermesh in a matrix-like form and are used with other components to provide various products.
For examples of prior art techniques using fibrillatable polymers, reference is made to the following U.S. patents. See U.S. Pat. No. 4,332,698 issued on June 1, 1982 and entitled "Catalyst Sheet And Preparation" by P. Bernstein, et al. This patent shows techniques employing fibrillatable polymers. U.S. Pat. No. 4,358,396 issued on Nov. 9, 1982 and entitled "Particulate Catalyst And Preparation" to P. Bernstein, et al. shows additional techniques. See U.S. Pat. No. 4,396,693 issued on Aug. 2, 1983 and entitled "Production Of A Cell Electrode System" by P. Bernstein, et al. See U.S. Pat. No. 4,433,063 issued on Feb. 21, 1984 and entitled "Hydrogen Sorbent Composition" by P. Bernstein, et al.
As indicated, the above patents are some examples of the use of fibrillatable materials which operate in conjunction with various compositions.
In any event, it has been determined that the use of a fibrillatable polymer in conjunction with a cosmetic pigment produces a cosmetic article or product which has extremely desirable characteristics, such as a tendency to be water resistant, a smooth silky feeling when applied to the skin of the user, extreme sheen, non-abrasive qualities and overall a superior cosmetic product as compared to prior art products as above indicated.
SUMMARY OF THE INVENTION
A cosmetic product comprising a matrix of a fibrillated polymer supporting at least one cosmetic pigment.
DETAILED DESCRIPTION OF THE INVENTION
It is believed that this specification does not require drawings as the products and compositions are adequately described and understood.
As indicated, this invention employs a fibrillatable polymer in conjunction with a cosmetic component as a pigment to produce a cosmetic product having superior qualities. The fibrillatable polymer is compatible with the pigment and is capable of dispersing in it and is totally non-reactive with both the pigment and the environment in which it is to be used. The combination of the polymer and pigment can provide cosmetic products which can be processed using pressing, extruding and various other techniques to produce a wide range of different products, all of which can impart a desired color to the skin. The product, by the use of a polymer such as Teflon, is extremely smooth, lubricious, simple, and inexpensive. It is immediately ascertained that the product essentially comprises a given percentage of a fibrillatable polymer in conjunction with a pigment and will have all the properties of prior art cake-type cosmetics with many advantages.
As is known, fluorocarbon and polypropylene polymers have the capability of fibrillation. According to the techniques of the present invention, it is advantageous for the polymer to be fibrillatable in a dry-type process. In any event, such polymers are known. For example, polytetrafluoroethylene (PTFE) can be fibrillated from a dry powder and is commercially available as duPont's Teflon 6A and 7A. Fibrillatable polypropylene is available for example as strands, tapes or films which can be used as such or chopped to appropriate sizes.
As will be further understood, according to the techniques of the present invention these fibrillatable polymers are employed as a support for a cosmetic component as a pigment. The fibrillatable polymer, when fibrillated, explodes into strands or fibers into which strands are enmeshed the cosmetic pigment. The cosmetic pigment is held in intimate contact with the polymer and can be applied to the skin together with the polymer to provide a unique type of cosmetic product. The strands of fiber intermesh to form a support matrix which encloses and surrounds the cosmetic component.
As indicated, polytetrafluoroethylene (PTFE) is a fluorocarbon resin which undergoes the phenomenon known as fibrillation when the PTFE powder is exposed to shear. This is done with an extreme change in temperature or change in its pH environment. For example, duPont manufactures a PTFE as Teflon 7A which is a powder of high bulk density usually used to mold large shapes. It has been discovered that when Teflon 7A is placed in a high shear mixer, such as a Waring blender, and mixed for two minutes, the powder is converted to a fibrillated mass. When these fibers are compacted they hold the shape of any container in which they were compressed. Thus one can make a mixture of pigment and the fibrillated Teflon in 5%, 10% and 20%concentrations of Teflon 7A with a suitable pigment or cosmetic component.
The pigments employed are cosmetic pigments widely used for coloration and for example such pigments can be ultramarine violet-3516 iron oxide, metallic pigments and so on. In one case 9 grams of ultramarine violet-3516 was blended with 1 gram of Teflon 7A (PTFE) for two minutes in an IKA-WERK miniblender at room temperature. During the mixing the blender was inverted or shaken a number of times to insure complete mixing of the PTFE with the pigment. The pigment coated PTFE was taken from the blender and pressed into an eye shadow pan. The formulation containing only the two components with 90% of the pigment and 10% of the Teflon held the shape of the pan, had a silky feeling and showed an extremely good payoff.
Other processing techniques will operate as well such as milling, extruding and injection molding of the fibril supported pigments. Milling the pigment and PTFE combination produces sheets of materials which are then die cut into various shapes. One can also extrude the mixture to obtain cylinders of material which are cut into various desired lengths for cosmetic pencils, sticks and so on. The mixture can be pelletized to provide cosmetic pellets for skin coloration or other purposes. The fibril supported pigment has applications in conjunction with various other cosmetic products, such as lipsticks, eye shadows, eye liners, creams and other cosmetics and toiletries. It is of course understood that a perfume or fragrance can be added to the pigment supported polymer to impart a desired fragrance to the same. It is understood that other polymers which are capable of fibrillation, such as polypropylene and so on, can also be used.
As one can ascertain from the above, the processing techniques are extremely simple as utilizing a mechanical blending process whereby based on the nature of the polymer there are no binders necessary, there is no talc necessary and the resulting product is extremely smooth to the feel and is capable of easy and smooth application. The combination of pigment and Teflon fibers can be extruded to produce for example Teflon sheets which sheets can then be cut by means of die cutting techniques to provide various cosmetic shapes which will impart the pigment color to the skin of a user as well as the PTFE fibers. Thus, the product can be extruded, milled, compression or injection molded while it maintains integrity and isolation.
It is further understood that the product is relatively hydrophobic or waterproof due to the properties of PTFE and hence the product is relatively water resistant as compared to other cosmetic formulations. One can employ any of the conventional cosmetic pigments, such as iron oxides and the same types of pigments which are presently utilized in pressed caked techniques or for cosmetic preparations. The amount of PTFE employed is between 1-25% by weight of the product with the remainder being a cosmetic component or a pigment. These percentages can be varied accordingly and according to the particular product desired. Hence, one may include as much as 50% of the polymer together with 50% of pigment and additional fragrances as so desired.
The cosmetic product is relatively stick free, water resistant and, as indicated, completely eliminates the necessity for any binder to be utilized. Thus, as one can ascertain, the product consists completely of a cosmetic component as pigment and the polymer fibrils and need not include any additional cosmetic components as binders, oils and so on.
It is of course understood that the polymer can be utilized together with some talc and pigments as other cosmetic components and one can compress the mixture and mold the mixture in any particular manner desired. For example, the material can be fabricated into sticks employing a ram extrusion technique which essentially compacts the material in a cylinder and then a dye is used to force the material out of the cylinder through a suitable aperture. The combination pigment and polymer has the appearance of a cylinder of colored cosmetic material or appears as a piece of colored chalk. This cosmetic product can be applied directly to the skin and exhibits an extremely smooth feeling while having all the attributes as indicated above.
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A cosmetic product includes a cosmetic component as a pigment maintained within a matrix of fibrillatable polymer. The pigment and polymer composition provides a cosmetic which can be employed for coloration of the skin and utilized as eye makeup, powder, or other cosmetic products by employing suitable processing techniques as extrusion, milling, compacting and so on.
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This application is a continuation of U.S. application Ser. No. 07/926,004, filed Aug. 5, 1992, now abandoned, for BUSINESS CAROUSEL INDEX SYSTEM.
BACKGROUND
1. The Field of the Invention
The present invention relates generally to a card indexing or filing system. More specifically, the present invention relates to a portable, compact business card holder capable of being carried within a briefcase.
2. Background Art
A variety of organizational devices, known as card indexing systems or card filing systems are utilized to index and store cards which contain information for later reference or review.
Such indexing and filing systems typically consist of a horizontal storage channel wherein cards such as three inch by five inch cards are placed. A recipe card box is a typical example. The cards can be arranged alphabetically, by subject, or in some other manner, sections of which are separated by dividers indicating the alphabetical sequence or subject of the section of cards.
The user must scan these dividers until the proper section of cards is found, and must then further consult the cards within that section for the specific card desired.
Various-sized cards and papers are often loosely stored within a recipe box type indexing system. The variation in size, color, thickness, etc. of the cards and papers detracts from the organization and unity of the system and requires additional effort during searching. Moreover, although the loose placement of cards into a horizontal channel allows for their quick removal, this does not prevent a removed card from becoming lost, torn or otherwise rendered unusable.
One solution to these problems has been the rotating carousel card filing system. This system provides cards which are uniform in size, color and thickness. The desired information is written or typed onto the cards. The rotating carousel card filing system also provides for the storage and safekeeping of the cards by the use of storage rails. The cards carried on these rails have two holes punched at the bottom of each card which the storage rails penetrate. The rails can be opened, allowing for card removal, but the rails are closed when cards are not being added in order to prevent loss or mutilation of the cards.
One problem encountered with the rotating carousel card filing system is that the cards used are larger than business cards. Thus, the rotating carousel card filing system does not lend itself to the filing of business cards. Business cards do not have holes in them, and their dimensions are typically two inch by three and one-half inch, whereas the rotating carousel card filing system is designed for the filing of prepunched cards which are three inch by five inch. As a result, in order for a business card to be placed in the system, the information must be retyped onto one of the system cards or the business card itself must be attached to a system card.
Another problem with the filing of business cards in a rotating carousel card filing system is that the information is randomly located on the card such that any hole-punching done to the business cards may obliterate some of the information contained thereon.
An additional problem is that the rotating carousel card filing systems are not designed to be portably compact. In order to provide a rotatable circular array of cards, these systems have a minimum height equal to two cards plus the diameter of the carousel. This prevents rotating carousel card filing systems from being used in a portable manner because they are simply too tall.
Another problem with rotating carousel card filing systems with respect to business cards is that business cards are often obtained away from the office at some location remote from an appropriately configured hole-punch. The user must then place the card into a pocket or billfold and then remember the card when arriving back at the office. If the card does not get lost or destroyed in the meantime, the user must then wrestle with the problem of how to place the card into the rotating carousel card filing system without obliterating any of the information contained thereon. This often results in the cumbersome task of punching holes in the bottom of the business card with some hole punch found at the office which does not conform exactly to the rotating carousel card filing system.
When the business card is finally placed onto the system, its smaller size detracts from the organizational uniformity of the filing system. In order to prevent this scenario, some users will perform the cumbersome task of typing the information from the business card onto one of the system cards, or taping the business card onto one of said cards.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a portable business card carousel index system for business cards having a profile short enough such that the entire device will fit into a briefcase.
It is another object of the invention to provide a rotatable circular storage channel for the placement of business cards such that the user's eye need not scan the cards but may remain fixed in one position for review of the cards while the rotatable circular storage channel is turned by hand.
An additional object of the invention is to provide a mechanism for punching holes in business cards for placement into the portable business card carousel index system, the mechanism being attached to the system.
It is yet another object of the invention that the mechanism for punching holes in business cards be configured so as to punch holes in predetermined strategic areas such that little or no information is obliterated.
To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a business card carousel index system is provided for use capable of being transported in a briefcase. The business card carousel index system comprises a housing having a base and a lid. The lid has an upper surface from which orthogonally depend a front, back and sides. The base has a bottom, front, back and sides. The lid is hingedly attached to the base. A carousel is contained within the housing formed by the lid and base. A means for altering the position of the carousel above the base of the housing as the lid of the housing is operated is provided to allow access to cords mounted on the carousel.
An alternative embodiment may, by way of example, but without limitation, Include a ridge protruding inwardly from an inner surface of the bottom of the base. The carousel contained within the housing has rotatable circular storage rings to which business cards may be attached. The storage rings are mounted on a carousel shaft. The carousel may also further comprise a means for rotating the carousel shaft. The means for rotating the carousel shaft may by way of example, but without limitation, comprise a rotating knob.
The means for altering the position of the carousel above the base of the housing as the lid is operated includes a supporting arm attached to the carousel shaft of the carousel and a positioning mechanism attached to the lid at one end. The supporting arm is attached to the carousel shaft of the carousel at the other end. The positioning mechanism may comprise a first arm attached to the shaft of the carousel at one end and the second arm attached to the lid at one end and the first arm at the other end.
One embodiment of the business card carousel index system may further include fanning means for causing friction with the business cards so that the business cards are separated. The fanning means may by way of example, but without limitation, comprise a first arm attached at the lid at one end, a second arm attached to the shaft of the carousel at one end and the first arm at the other end, and a flexible tab positioned where the first arm attaches to the second arm.
The housing may by way of example, but without limitation, further comprise integral means for punching holes in business cards. In one preferred embodiment, the means for punching holes in business cards comprise a floor for supporting a portion of a business card as holes are punched in the business card, guides formed parallel to the sides of the base of the housing, and a stop-shelf formed perpendicular to the guides. The stop-shelf serves to limit the travel of a business card place on the floor of the receiving channel thereby positioning a business card as holes are punched therein.
Another alternative embodiment of the claimed invention includes a means for punching holes in business cards. The punching means comprises a punch enclosure, a plurality of punching studs held in the punch enclosure, a receiving slot, and ejection aperture. The receiving slot is formed in the front of the punch enclosure and is sized and configured for receiving a business card. The receiving slot has a floor and an opening. The ejection aperture is formed in the floor of the receiving slot through which punched portions of the business card may be ejected from the punch enclosure.
The invention also contemplates a method for strategically punching holes in business cards having sides at a location in the business cards where little or no information is obliterated. The method comprises the steps of positioning the business card and punching device such that holes may be punched substantially one-half way up one side of the business card and punching holes in the business card.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.
Understanding that these drawings depict only typical embodiments of the invention and are not, therefore, to be considered limiting of its scope, the invention will be described and explained with additional specificity and detailed through the use of the accompanying drawings in which:
FIG. 1 is a perspective view of the business card carousel index system illustrating a housing with the lid closed;
FIG. 2 is a longitudinal cross-section taken along lines 2--2 in FIG. 1;
FIG. 3 is a longitudinal cross-section of index system shown in FIG. 2 with the lid open at a 45 degree angle;
FIG. 4 is a longitudinal cross-section of an index system like that illustrated in FIG. 3 showing the lid fully opened at a 90 degree angle;
FIG. 5 is a longitudinal cross-section taken along lines 5--5 in FIG. 1;
FIG. 6 is a cross-section taken along lines 6--6 in FIG. 2;
FIG. 7 is a perspective view of an alternative embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A perspective view of one embodiment of a business card carousel index system 10 is illustrated in FIG. 1 in which a housing 12 comprises a lid 14 and a base 16. Housing 12 serves to shield the business cards held therein from dust and damage while the business card carousel index system is being transported within the brief case of a user.
The business card carousel index system of the present invention provides a means for rotating the carousel shaft. By way of example, without limitation, the means for rotating the carousel shaft of the embodiment illustrated in FIG. 1 comprises rotating knob 18.
Protruding out of housing 12 when housing 12 is in a closed position is a rotating knob 18 used to rotate the carousel (not shown in FIG. 1) and a punch bar 20 used in punching the holes in business cards prior to mounting the business cards on the carousel. A card slot 22 penetrates a base 16 of housing 12 to allow insertion of a business card therein whereupon actuation of punch bar 20 through a mechanism to be described later punches holes in the business card.
Base 16 and lid 14 of housing 12 are so sized and configured so as to allow the entire housing 12 to be placed within a briefcase. To accommodate this, lid 14 has an upper surface 24 which is smooth and flat. Sides 26 formed perpendicular to upper surface 24 are relatively free of protrusions except rotating knob 18. A front 28 is formed perpendicular to upper surface 24.
In addition to having smooth surfaces, business card carousel system 10 has rounded corners 32 which protect the inside of the brief case in which the business card carousel index system is transported. Lid 14 mates with base 16 at an edge 34 of sides 26 in edge 36 of front 28 to form an enclosure.
To more fully appreciate the inner mechanisms of the business card carousel index system 10, reference is now made to FIG. 2 in which a cross-section taken along lines 2--2 in FIG. 1 is depicted.
In FIG. 2, base 16 is illustrated having a bottom 38 having in inner surface 40 from which protrudes a ridge 42. Enclosed within housing 12 is a carousel 44 constructed of two, rotatable storage rings 46 mounted on a carousel shaft 48. Carousel 44 is raised out of base 16 when lid 14 is opened. A positioning mechanism 50 comprised of a first arm 52 attached to the lid 14 and a second arm 54 attached to the carousel shaft 48 work in conjunction with a supporting arm 56 to raise carousel 44 out of base 16 when the user wishes to access the cards mounted on the carousel.
Protruding from the front of base 16 is a punch enclosure 58. Punch enclosure 58 contains the mechanisms that operate to punch the business cards inserted through card slot 22 when punch bar 20 is operated. Downward pressure exerted by a user on punch bar 20 forces a punching stud 60 through an ejection aperture 62 thereby ejecting the portion of the card which is punched. A return spring 64 urges punch bar 20 back to its original position.
As illustrated in FIG. 3, as lid 14 is opened, second bracing arm 54 is pivoted in an upward direction away from first bracing on 52. As lid 14 continues to be opened, the angle between second bracing arm 54 and first bracing arm 52 becomes more obtuse until the angle equals 180° and carousel 44 is lifted from base 16. Carousel 44 travels in an arc as it is lifted from base 16, the arc being dictated by supporting arm 56 which is attached to base 16. The length of the arc through which carousel 44 travels is limited at its bottom by contact between carousel 44 bottom 38 of base 16 and at the upper end of the arc by the restrictions placed upon the travel of lid 14 and attached first bracing arm 52 and second bracing of 54.
The business card carousel index system of the present invention provides a means for moving the location of the carousel between the first position for storage and second position above the base of the housing as the lid of housing is operated. By way of example, without limitation, the means for moving the location of the carousel in the embodiment illustrated in FIG. 3 comprises first bracing arm 52, second bracing arm 54, and supporting arm 56.
As illustrated in FIG. 4, when back 30 of lid 14 becomes substantially parallel with bottom 38 of base 16, first bracing arm 52 and second bracing arm 54 cease to exert tension on carousel 44 thereby limiting the travel of carousel 44 at the upper end of its arc of travel. As lid 14 is hingedly attached to base 16 at hinge 66, back 30 of lid 14 abuts bottom 38 of base 16 preventing further travel of carousel 34. In addition to hinge 66, first bracing arm 52 and second bracing arm 54 along with supporting arm 56 are all hingedly interconnected by connecting hinges 68.
As carousel 44 is raised out of base 16, business cards 70 are forced by gravity to fall from the substantially planar array taken when the housing is closed, into a semi-circular array in which the segment of the circle that is empty is oriented opposite bottom 38 of base 16.
When a user wishes to access a particular business card, carousel shaft 48 is rotated by some mechanism such as rotating knob 18 illustrated in FIG. 1, thereby radially circulating business card 70 about the longitudinal axis of carousel shaft 48. Rotation of carousel shaft 48 causes rotation of rotatable circular storage rings 46 to which the business cards are attached.
Although the punched holes formed within the business cards allow only a slidable attachment to rotatable circular storage rings 46, friction on rotatable circular storage rings 46 caused by a plurality of business cards stacked atop each other causes the business cards to rotate concurrently with rotation of rotatable circular storage rings 46.
As also illustrated in FIG. 4, counterclockwise rotation of business cards 70 about rotatable circular storage rings 46 causes business cards 70 to come into contact with the separating tab 72. Separating tab 72 protrudes inward from first bracing arm 52 to slightly impede the progress of business cards 70. The purpose of separating tab 72 is to allow individual viewing of each business card as the business cards travel through the portion of the path of travel of the business cards which is opposite bottom 37 of base 16.
By applying torque to carousel shaft 48, a user applies pressure to the business card nearest separating tab 72 at a position indicated as A. Business cards at position A are under pressure and are urged in a counterclockwise circulation by torque applied to carousel shaft 48. As the pressure at position A becomes sufficient, the business card will pass beyond separating tab 72 and travel in an upward arc to position B where a user may grasp the card to read information contained thereon or a user may allow business card 70 to continue on to position C wherein gravity will act upon business card 70 to pull business card 70 onto the stack of business card located at position D. Although the business card illustrated in FIG. 4 are located in a substantially planar array, such an array is only accomplished when the business cards are stored within the closed housing or upon initial opening of lid 14. After the initial movement of lid 14 or of rotational movement by carousel shaft 48, gravity acts upon the cards in this substantially planar array to pull the cards down into a semi-circular array.
After use, however, the semi-circular array of cards must be reconfigured into a substantially planar array of cards to allow lid 14 to close upon base 16. To accomplish this, ridge 42 is provided protruding upwardly from an inner surface of bottom 38 to engage the business cards as lid 14 is closed upon base 16. Business cards lowered upon a front ramp 74 of ridge 42 will be guided in a direction toward punch enclosure 58. As successive cards are engaged by front ramp 74, those cards will force cards preceding them in a direction toward punch enclosure 58.
Those cards initially encountering back ramp 76, however, will be forced in a direction toward hinge 66 eventually resulting in the formation of a substantially planar array of business cards allowing rotatable circular storage rings 36 to contact the upper surface of bottom 38 thereby allowing lid 13 to close upon base 16.
The operation of separating tab 72 is further illustrated in FIG. 5 wherein separating tab 72 can be seen in slight contact with business cards 70. Also illustrated in FIG. 5 is the position of punch bar 20 in punch enclosure 58. When a user acquires a new business card, the card may be inserted into the front of housing 12 and holes may be formed therein by depressing punch bar 20 as described earlier. After appropriate holes are punched in the business card, the business card is slid between the pair of opposing card guides 78. Card guides 78 are formed integral with rotatable circular storage rings 46 and serve to transmit torque generated at rotating knob 18 and applied to carousel shaft 48 along rotatable circular storage rings 46 to card guides 78. Although the business card illustrated in the embodiment shown in FIG. 5 is punched at a point intermediate the bottom and a half-way point along the side of the card, the presently preferred location for the punching of holes within a business card is illustrated in FIG. 6 in which the punches are formed substantially half-way along the sides of the business card.
The business card carousel index system provides means for spreading apart the business cards. By way of example, without limitation, the fanning means of the embodiment illustrated in FIG. 5 comprise separating tabs 72.
In FIG. 6, business card 70 shown having sides 80 having holes 82 fall within sides 80. To determine this preferred location of the hole within a business card, a test was performed in which a one to one scale multi-element template illustrating twelve methods of punching the business cards was utilized. A business card was selected at random from a stack of approximately six-hundred cards and one by one placed under the template. Each time a card was placed in the template which, if used, would delete name, address, phone number or other important information, it was marked as a failure. The results of the test revealed that standard punch locations as used in other carousel type systems create the highest failure rate, as they punch out the greatest amount of information, which when applied to a business card application leaves the card useless. The test revealed that cards punched substantially half-way along the sides of the business card had a very small failure rate when compared to punches placed in other locations. The results of this test are included in Appendix A which is hereby incorporated by specific reference herein.
FIG. 7 illustrates an altering embodiment of the present invention having a receiving channel 83 formed within base 16. Receiving channel 83 has a floor 88 guides 90 formed parallel to the sides of base 16, a stop-shelf 92 formed perpendicular to the guides. Also illustrated in FIG. 7 are punching studs 84 formed integral with lid 14 and receiving apertures 86 formed and floor 88 of receiving channel 83. Punching studs 84 and receiving apertures 86 are sized and configured so as to cooperate in punching holes through the business card placed upon floor 88 an abutment with stop-shelf 92.
The business card carousel index system provides integral means for punching holes in business cards. By way of example, without limitation, the integral means for punching holes in business cards in the embodiment illustrated in FIG. 7 comprises a receiving channel 83 formed in the base of the housing for receiving a portion of a business card, a plurality of punching studs 84 formed in the lid capable of forming holes in the business card of a shape conforming to the rotatable circular storage rings, and the plurality of receiving apertures 86 forming the receiving channel cooperatively engaging one of the plurality of punching studs.
The receiving channel comprises a floor 88 for supporting a portion of a business card while holes are punched in the business card, guides 90 form contiguous with the floor and a stop-shelf 92 formed perpendicular to the guides, the stop-shelf serving to limit the travel of a business card placed on the floor of the receiving channel, thereby positioning the business card when holes are punched therein.
The means for moving the location of the carousel above the base of the housing and another embodiment may also comprise supporting arm 56 and positioning mechanism 50. Positioning mechanism 50 is comprised of the first bracing arm 52 attached to the shaft of the carousel at one end and the second bracing arm 54 attached to the lid at one end and to the first bracing arm 52 at the other end.
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A business card carousel index system having a housing comprised of a base and a lid. The housing encloses a carousel to which business cards are mounted. The carousel is attached through support and placement arms through the lid and a base so that operation of the lid will alter the distance between the carousel and the base. In use, a business card may be punched utilizing a flexing device located at the front of the housing, after which the punched card may be placed upon rings on the carousel. When a user wishes to access the cards contained within the housing, the lid of the housing is lifted thereby elevating the carousel above the base of the housing, so that rotational movement will be allowed. When the lid is closed, the carousel is lowered and the business cards are divided into two substantially planar arrays which allow for a reduced profile of the height which can be placed within a briefcase, while at the same time allowing for a carousel type action when the carousel is elevated above the base of the housing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a facsimile apparatus having an auto-calling function such as a one-touch dial or an abbreviated dial.
2. Related Background Art
In a prior art G3 facsimile apparatus, a personal (or confidential) communication function or a relay communication function is attained by a non-standard function such as NSF (non-standard facilities), NSS (non-standard setup) or NSC (non-standard command). Thus, it is attained only among facsimile apparatuses of the same manufacturer.
On the other hand, in the ITU-T Recommendation T.30, it is possible to attain the personal communication function and the relay communication function by using a new signal message frame by SUB (sub-address)/SEP (selective polling)/PWD (password).
However, it is troublesome for a user to designate information to be set in such a new signal message frame for each transmission.
Further, in transmission and polling reception, signal messages which can be sent to a destination station are predetermined, and the designation of the type of message by the user leads to confusion of the user, and if it is permitted to register all signal frames, a memory usage efficiency is lowered.
Methods and objects to use the new signal message frames are different from facsimile apparatus to facsimile apparatus. In such a case that a user designates the communication by using the new signal message frame, if an apparatus at a destination station does not have a function to receive the new signal message frame, there will be confusion on the user side unless the user can select whether to interrupt the communication or to continue normal communication without sending the new signal message frame.
SUMMARY OF THE INVENTION
In light of the above, it is an object of the present invention to provide an improved facsimile apparatus.
It is another object of the present invention to provide a facsimile apparatus which can set SUB/SEP/PWD while efficiently using a memory without causing troublesome operation or-confusion.
It is a still another object of the present invention to provide a facsimile apparatus which has a memory area for registering information to generate a sub-address signal (SUB), a selective polling signal (SEP) or a password signal (PWD) for calling information of a calling station used for an auto-calling function, and generates and sends a communication protocol signal in accordance with the registered information at the auto-calling to eliminate the need of the operator to set the SUB, SEP or PWD for each transmission.
Other objects of the present invention will be apparent from the following description of the embodiments and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of one embodiment of the present invention,
FIG. 2 illustrates an information table of a one-touch dial used in the above embodiment,
FIG. 3 is composed of FIGS. 3A and 3B showing a flow chart of an operation of calling by using an auto-dial of a control unit of the above embodiment, and
FIG. 4 shows a flow chart of an operation of calling by using the auto-dial of the control unit of the above embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention is now explained in detail in conjunction with the drawings.
FIG. 1 shows a block diagram of a configuration of a facsimile apparatus in accordance with one embodiment of the present invention.
An automatic document feeder (ADF) unit 101 automatically feeds a stacked document sheet to a document sheet read station by a command from a control unit and feeds the document sheet to a scanner unit 103 when the document sheet is to be read. The scanner unit 103 comprises a CCD which reads the document sheet as image data.
A control unit 105 controls an overall apparatus and comprises a CPU, a ROM and a RAM. A console unit 106 comprises a ten-key unit for dial input and LCDs for displaying states.
An image data memory unit 107 temporarily stores image data read by the scanner 103 or received image data. A printer unit 108 records the image data.
A communication control unit 109 controls calling/receiving for a communication line 112 such as PSTN or ISDN and controls G4/G3 communication.
A control bus 110 controls operations of blocks by the control unit 105 and a video bus 111 handles the image data.
FIG. 2 shows an information table of auto-dial (one-touch dial) information used in the auto-calling in the present embodiment.
As shown, a service access number area for storing a SUB signal or a SEP signal and a service access password area for storing a PWD signal are provided in addition to a dialing number and an abbreviation of a destination station, for each one-touch dial button.
FIGS. 3A and 3B, and FIG. 4 show flow charts of operations of the calling by using the auto-dialing of the control unit 105 in the present embodiment.
In S301, the information corresponding to the auto-dial number designated by the manipulation of the user is looked up from the auto-dial information table. For example, when a call is requested by using the auto-dial of one-touch 2, the destination dial of `5482-1111` is looked up and the destination abbreviation of `B division`, the service access number of `0020` and the service access password of `1234` are looked up.
In S302, a call is made to the looked-up destination dial through the communication control unit 109. When connection is made to the destination station, a CNG signal is sent from the communication control unit 109 in S303 to start the G3 communication, and in S304, a DIS signal is received from the destination station.
When the DIS signal is received, whether the communication operation by the user is for the transmission or for the polling reception is determined in S305. For example, the transmission or the polling reception is determined by whether a document sheet is present in the ADF 101 or not.
If the document sheet is present in the ADF 101 and the transmission is detected, the process proceeds to S306, and if the document sheet is not present and the polling reception is detected, the process proceeds to S320.
In S306, whether the service access number looked up in S301 has been registered or not is determined. If it has been registered, the process proceeds to S307, and if it has not been registered, the process skips to S310.
In S307, whether a function to receive the SUB signal frame indicated by the DIS signal received in S304 is present or not is determined. If it is present, the process proceeds to S309, and if it is not present, the process proceeds to S308.
In S308, a state of a soft switch `SUB/SEP/PWD transmission disable operation mode` previously registered by the user is determined. If it is in a disconnection mode, the process proceeds to S340, and if it is in a connection mode, the process skips to S310.
In S309, since the destination station has the function to receive the SUB signal frame, the SUB signal frame is prepared from the information of the looked-up service access number area.
In S310, whether the service access password looked up in S301 has been registered or not is determined. If it has been registered, the process proceeds to S311, and if it has not been registered, the process skips to S314.
In S311, whether a function to receive the PWD signal frame indicated by the DIS signal received in S304 is present or not is determined. If it is present, the process proceeds to S313, and if it is not present, the process proceeds to S312.
In S312, the state of the soft switch `SUB/SEP/PWD transmission disable mode` previously registered by the user is determined as it is in S308. If it is in the disconnection mode, the process proceeds to S340, and if it is in the connection mode, the process skips to S314.
In S313, since the destination station has the function to receive the PWD signal frame, the PWD signal frame is prepared from the looked-up service access password information.
In S314, the DCS signal indicating the page information for transmission is prepared. In S315, a multi-frame signal {(SUB)+(PWD)+(DCS)} so far prepared is sent to the destination station. In S316, the transmission is conducted thereafter.
If the polling reception is detected in S305, whether the service access number looked-up in S301 has been registered or not is determined in S320. If it has been registered, the process proceeds to S321, and if it has not been registered, the process skips to S324.
In S321, whether a function to receive the SEP signal frame indicated by the DIS signal received in S304 is present or not is determined. If it is present, the process proceeds to S323, and if it is not present, the process proceeds to S322.
In S322, the state of the soft switch `SUB/SEP/PWD transmission disable operation mode` previously registered by the user is determined as it is in S308. If it is in the disconnection mode, the process proceeds to S340, and if it is in the connection mode, the process skips to S324.
In S323, since the function to receive the SEP signal frame is present in the destination station, the SEP signal frame is prepared from the looked-up service access number.
In S324, whether the service access password looked-up in S301 has been registered or not is determined. If it has been registered, the process proceeds to S325 and if it has not been registered, the process skips to S328.
In S325, whether a function to receive the PWD signal frame indicated by the DIS signal looked up in S304 is present or not is determined. If it is present, the process proceeds to S327, and if it is not present, the process proceeds to S326.
In S326, the state of the soft switch `SUB/SEP/PWD transmission disable operation mode` previously registered by the user is determined as it is in S308. If it is in the disconnection mode, the process proceeds to S340, and if it is in the connection mode, the process skips to S328.
In S327, since the function to receive the PWD signal frame is present in the destination station, the PWD signal frame is prepared from the looked-up service access password.
In S328, a DTC signal indication the ability of its own apparatus for the polling reception is prepared, in S329, the multi-frame signal {(SEP)+(PWD)+(DTC)} so far prepared is sent to the destination station, and in S330, the polling reception operation is conducted.
In S308, S312, S322 and S326, if the soft switch `SUB/SEP/PWD transmission disable operation mode` is in the disconnection mode, the DCN signal frame is prepared in S340 to interrupt the communication, in S341, the DCN signal is sent to the destination station, and in S342, the line is released and the communication is interrupted.
In the present embodiment, the one-touch dial is used as the auto-dial function. Alternatively, an abbreviation dial may be used.
In accordance with the present embodiment, the service access number area for storing the information for generating the SUB or SEP signal and the service access password area for the PWD signal are provided for the auto-dial to eliminate the user's burden of setting SUB/SEP/PWD for each transmission.
When the call is made by the auto-dial, the SUB signal frame is prepared from the information if it is the transmission with the corresponding service access number area being registered, the SEP signal frame is prepared from the information if it is the polling reception, and the PWD signal frame is prepared if the service access password area has been registered, so that the confusion of the user due to the user's selection of the signal message to be sent in accordance with the communication operation mode is avoided and the service access number area may be shared by the SUB signal in the transmission and the SEP signal in the polling reception allowing the efficient use of the memory.
When the call is made by the auto-dial having the service access number or the service access password registered therein and if the destination station does not have the function to receive the SUB/SEP/PWD signal, the user may select through the soft switch whether to interrupt or continue the communication.
It should be understood that the present invention is not limited to the above embodiment but various modifications thereof may be made.
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A facsimile apparatus facilitates the setting of SUB/SEP/PWD of the ITU-T Recommendation T.30.
A service access number area for storing information for generating a SUB or SEP signal and a service access password area for a PWD signal are provided in an auto-dial such as one-touch dial or abbreviated dial to eliminate need of a user to set SUB/SEP/PWD for each transmission.
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BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for the coating of a travelling web, said apparatus comprising means for the supply of coating agent to the web.
The basic principle in the coating of travelling webs, in particular paper webs, is that coating agent or coating composition is supplied to the web in excess. This excess of coating agent is then drained and recirculated. A typical example are so called blade coaters where the excess is scraped off by means of a flexible blade in engagement with the web. The pressure of the blade against the web is counterbalanced by an equally large reaction pressure which arises in two different ways, namely:
(a) from the web, i.e. the blade engages the highest points of the web which are partly compressed by the blade pressure, and
(b) from the hydrodynamic pressure formed in the pool of coating composition which is present before the entrance to the blade nip.
The pressure depends on web speed, the viscosity of the coating agent, the angle of the blade to the web and the applied quantity of coating agent. In practical operation usually a combination of the reaction presssures given under (a) and (b) is at hand. In those cases wherein factor (a) is predominant, i.e. the blade is supported against the web so that coating agent will fill up only the valleys and cavities of the web, there usually will be obtained an even coating profile along and across the web.
In those cases where factor (b) is predominant (for example with paper qualities having high surface eveness and the coating weight is high) the blade will mainly "flow" on a film of coating agent. In this case the pressure of the blade will be mainly balanced by the hydrodynamic pressure which, as previously indicated, is dependent on the factors:
(c) web speed
(d) viscosity
(e) blade angle
(f) the quantity of coating composition transported up to the blade, i.e. the quantity of coating composition applied to the web.
The factors according to items (c) to (e) can with sufficient accuracy be maintained constant using techniques available today. However, factor (f) is dependent on the ability of the applicator to deposit on the web layer in the correct quantity along and across the web.
In blade coating it is conventional techniques to deposit coating agent on the web using so called coating rolls or fountain applicators. Thus, an even layer of coating agent is transferred onto the web by the applicator. The thickness of the layer can be calculated according to the following formula: ##EQU1## where t=thickness of layer from applicator (mm)
Q=dry coating weight (g/m 2 )
n=excess from applicator (times)
p=density of coating liquid (g/cm 3 )
p=coating liquid solid's contents (%)
As examples can be given ##EQU2##
In a conventional applicator the layer is deposited by passing the liquid through a slit which is formed between the web supported by a backing roll and the exit rib of the fountain or the roll surface in roll applicators. In so called jet-fountain coaters the fountain has a larger distance to the web and the liquid is supplied to the web through a narrow slit. In the so called twin-blade techniques the web is brought to engagement against the exit slit by deflecting the web across the slit.
The difficulty in coating a web with an even layer having a thickness of the order as given in the example above in machines of widths used in paper manufacture has, in practice, been found to be quite pronounced. These difficulties may for example be the following:
include varying slit dimensions between paper web and exit slit in applicators or rolls depending on manufacture tolerances, heat tensions, deflexions, etc. In jet-fountain coaters the difficulties can reside in for example clogging of the slit, tolerance of the slit opening and the pressure distribution in the extruder. In fountain applicators according to the so called twin-blade techniques, obtaining even pressure distribution in the exit slit and maintaining even tension along and across the web.
Another type of coaters is the so called Short-dwell-bladecoater where the liquid is pumped into a chamber the front wall of which is formed by the coating blade. The excess of coating agent usually is drained out in the slit between the rear wall and the web supported by the backing roll. It is true that with this coater an even layer must not be deposited before the blade whereby some of the difficulties previously described are reduced, but the difficult problem of even pressure distribution in the chamber remains. Another problem which is associated with these techniques is that enclosed air bubbles do not disappear before the blade but pass the blade and result in so called skip-coating.
SUMMARY OF THE INVENTION
The techniques according to the present invention aim at eliminating the problems described above in connection with different types of conventional coaters.
These and other objects are obtained by the apparatus according to the invention wherein the coating agent is deposited on the travelling web by means of a metering device engaging the web. This metering device can be designed in different ways but it involves in principle deposition of a coating agent in strings or strands of controlled thickness and width. These strings or strands of coating agent shall have such distribution that they merge and form a dam in front of the evening member, for example a coating blade. Moreover, it is essential to position the metering device so close to the evening member that the coating agent is not allowed to penetrate into the travelling web, thereby resulting in strands containing a higher coated quantity.
Accordingly, the invention offers and apparatus for the coating of a travelling web, especially a paper web, said apparatus comprising means for the supply of coating agent to said web. The apparatus is characterized thereby that said means comprise a metering device extending across the whole width of the web and which by an intermittent contact surface provides intermittent engagement with the web or a backing member against which the web subsequently comes to engagement. Thus, the apparatus provides for depostion of strings or strands of coating agent on the web or the backing member. It is particularly preferred to provide for an arrangement where the metering device is supported or carried over the whole length thereof.
In a preferred embodiment of the invention said metering device is constituted by a toothed blade or lamella and said blade or lamella is in contact with the web or the backing member during the application procedure.
According to an alternative embodiment of the invention said metering device is constituted by a metering rod which is provided with circumferential grooves or rings which provide for intermittent engagement with the web or the backing member during the deposition of strings or strands of coating agent. The metering rod can be rotatively mounted in a rod fixture but may, alternatively, be fixedly mounted but adjustable by rotation, the groove depth varying around the metering rod so as to enable controlled metered quantity of coating agent.
According to an alternative and preferred embodiment of the apparatus according to the invention the metering device can comprise a continuous blade defining a fixed gap determining the thickness of coating agent deposited onto the web or the backing member. The metering device further comprises a toothed blade placed downstream, said blade having teeth which are longer than the thickness of the fixed slit. This toothed blade is suitably springbiassed for successive adaptation to the web or the backing member synchronously with the wear of the teeth. The combination of these two blades thus results in the deposition of strings or strands of constant thickness and width, which in turn provides for even metering of coating agent.
It is preferred that the blades in this alternative embodiment are in engagement with each other. They can suitably be carried by a blade fixture carrying both the blade defining the slit and involving a blade holder carrying the toothed blade and further including a spring member for biasing the toothed blade against the web or the backing member, whereby the wear of the teeth is compensated by the successive feeding of the blade.
According to still another preferred embodiment of the apparatus according to the invention it is possible by using same to provide for two-sided coating of a travelling web, and the apparatus comprises for this purpose two juxtaposed metering members, the recesses of the discontinuous contact surfaces thereof being displaced side-wise relative to each other and between which the web travels. This embodiment suitably comprises two juxtaposed toothed lamellae, wherein the tooth width is less than the gap width, whereby the web in its passage between the lamellae assumes wave shape by the fact that the teeth of one lamella are juxtaposed the other lamella's gaps between the teeth. In this manner flexibility in the engagement of the two juxtaposed lamellae against each other will be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be further illustrated by non-limiting embodiments in connection with the appended drawings, wherein:
FIG. 1 is a diagrammatical view in section showing an embodiment of the apparatus according to the invention and FIG. 1A shows an enlarged detail of this apparatus;
FIG. 2 is a diagrammatical view in section of an alternative embodiment of the apparatus according to the invention, and FIG. 3 shows an enlarged detail of this apparatus;
FIG. 4 shows a diagrammatical view in section of another embodiment of the apparatus according to the invention, whereas FIG. 6 shows a cross section of the metering device in the apparatus according to FIG. 4;
FIG. 5 shows diagrammatically a section through an alternative embodiment of the apparatus according to the invention; and
FIG. 7 shows diagrammatically still another embodiment of the apparatus according to the invention intended for two-sided coating, and FIG. 8 shows an enlarged detail by the apparatus of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus shown in FIG. 1 comprises a backing roll 3 which is shown only partly and diagrammatically and the paper web 5 travelling above said roll. The backing roll 3 rotates in the direction of arrow (a). The coating apparatus further comprises a coating blade 7 attached in a conventional manner to a blade holder 9. Furthermore, FIG. 1 shows in cross section a distributing tube 10 for coating composition 11, said tube extending across the whole width of the paper web 5. Through an exit slit 13 the coating composition 11 is fed out against a metering lamella 15 which is attached to a lamella holder 16. Also this metering lamella 15 extends across the whole width of the paper web 5. A return flow 17 of coating composition is collected in a container 21 for recirculation.
In FIG. 1A there is shown in enlargement a section of the metering lamella 15 seen in the direction of arrow (b). As is clear from FIG. 1A this metering lamella 15 is provided with teeth 27 which, as is apparent from FIGS. 1 and 1a, contact the web intermittently at spaced locations, and gaps 29 between said teeth on the edge facing the paper web 5, said teeth and gaps resulting in deposition of parallel strings or strangs of composition of defined cross section at the spaced locations by the metering lamella 15 thus providing for accurate dosage of coating composition. The distance between the metering lamella 15 and the coating blade 7 is adapted so that these strands of coating composition 11 before entering the site of contact between coating blade 7 and paper web 5 merge to form a dam 23 resulting in even deposition of coating composition across the whole width of the paper web 5.
Thanks to the construction and function of the apparatus described the previously indicated problems of maintaining constancy will be eliminated and there is obtained a constant deposition quantity across the web even, for example, for varying web speed, vicosity of coating agent, blade angle etc.
In FIG. 2 there is shown an alternative embodiment of the apparatus according to the invention. In this FIGURE there is shown only the area around the metering device, whereas other details in connection with recirculation of the coating composition, the position and arrangement of the coating blade etc. are left out.
The apparatus of FIG. 2 includes a metering device in the form of a metering rod 31 which runs freely mounted in a rod holder 33. The metering rod 31 is rotatively mounted in said rod holder 33. As is clear from FIG. 3, wherein part of the metering rod 31 is shown from above, it can be considered to be an axis 37 having a circular cross section and carrying rings 39 evenly distributed along the axis. The metering rod may also, of course, be made in one piece with cut or milled grooves but can also be constructed from a central axis and rings 39 attached thereon. As seen in FIG. 2, the rings 39 contact the web intermittently at spaced locations.
The apparatus according to FIG. 2 offers the same advantages as with that shown in FIG. 1 by the fact that the metering rod 1 provides for depostion of strings or strands of coating composition having a constant cross section on the paper web 5 at the spaced locations resulting in even deposition of coating composition in spite of variations in the different factors previously indicated.
In FIG. 4 there is shown a modified embodiment comprising a fixed metering rod 41 which is fixedly mounted in rod holder 33 but which can be released and rotated to another position and fixed at said other position. In FIG. 6 this metering rod 41 is shown in cross section from which it is clear that the axis 43 of the rod is acentrically placed within rings 45 whereby the groove depth or ring height around the rod varies. By rotating the coating rod 41 in the rod holder and fixing same in the desired position the thickness of the strings or strands of coating composition deposited on the paper web 5 can thus be controlled so as to give the desired coating quantity.
In FIG. 5 there is shown another embodiment of the metering device according to the invention. This embodiment has a metering means built up from two blades 47, 49. One blade 47 extending across the whole width of the paper web 5 defines a fixed slit between blade 47 and paper web 5 to define the thickness of the deposited coating composition. Downstream of slit blade 47 and engaging same there is provided a toothed blade 49, the teeth of which have a length substantially exceeding the thickness of the deposited layer of coating composition. The teeth are evenly distributed along blade 49 over the whole width of paper web 5. Both blades 47,49 are attached in the blade fixture 51 and the blade holder 48, respectively. The blade holder 48 is movably arranged in a cavity 53 in blade fixture 51 and is biassed from below by compression springs 55 distributed in cavity 53 and acting to move the blade holder 48 and thereby the toothed blade 49 upwardly against the paper web 5. By this arrangement automatic displacement of the toothed blade 49 upwardly is obtained resulting in even engagement against paper web 5 in accordance with the wear of the teeth.
In the same way as previously described the apparatus shown in FIG. 5 provides for even deposition of strings or strands of coating composition onto paper web 5 resulting in constant metering of coating composition.
In FIGS. 7 and 8 there is shown an apparatus for two-sided coating of a paper web 5. This apparatus operates according to the so called Twin-blade principle, i.e. it comprises two juxtaposed coating blades 61,63 which are brought into engagement against the paper web 5 by pressure members 65,67. In a conventional manner blades 61,63 are attached to blade holders 69,71.
Below this Twin-blade arrangement there is arranged an applicator generally designated 73 which, as is clear from FIG. 8, comprises two juxtaposed toothed lamellae 75,77 wherein the teeth of the lamella 75,77 contact the web intermittently at spaced locations. Fig. 8 thus shows a section of the upper part of the applicator 73 as seen in the direction of arrow A-A, i.e. from above. The two juxtaposed toothed lamellae 75,77 are displaced relative to each other in a direction across web 5 so that the teeth of one lamella are placed opposite to the recesses or gaps of the other lamella. By this arrangement and if the width of the teeth is less than the width of the gaps web 5 takes wave shape in its passage through applicator 73. Since web 5 is subject to certain yield this results in reduced risk for web failure.
By means of the apparatus shown in FIGS. 7 and 8 there is thus obtained a two-sided coating of a travelling web 5, wherein even and constant metering of a coating composition is obtained in accordance with the basic principle underlying this invention.
The invention also covers an alternative apparatus for two-sided coating of a paper web, and this apparatus consists in principle of doubling the apparatus according to FIG. 1. Before engagement of paper web 5 with roll 3 a similar apparatus as that in FIG. 1 shown can be positioned, whereby there will be obtained deposition of strings of strands directly on the surface of roll 3. The other side of paper web 5 will be coated in the manner shown in FIG. 1, and in this way a two-sided coating of paper web 5 will be obtained with constant metering in accordance with the invention. This arrangement can, of course, also be applied in connection to the apparatus as according to FIGS. 2 to 6.
With regard to the embodiment according to FIG. 7 it can, of course, be modified by replacing one blade 61 thereof with a backing roll in a conventional manner.
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An apparatus for coating a travelling web (5), including supply systems (10,15,16;31,33;41;47,49;73) for the supply of coating agent (11) to the web (5), the systems including a metering device (15;31;41;47,49;75;77) extending across the whole width of the web and which by an intermittent contact surface (27,29;37,39;43,45;47;49) provides intermittent engagement with the web (5) or a backing member (3) against which the web subsequently comes to engagement, for the deposition of strands of coating agent (11) on the web (5) or the backing member (3).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a surface acoustic wave device for use in high frequency (UHF band) and a method for manufacturing the same, and more particularly to a technology relating to improvements of an overall characteristic and a cost reduction of the surface acoustic wave device.
2. Description of the Prior Art
In recent years, the surface acoustic wave device has been widely used in regions of IF band and VHF band such as in an intermediate frequency filter for a television receiver of 50 MHz-60 MHz band. In a high frequency surface acoustic wave device for use in UHF band, a width of electrode fingers of input and output interdigital electrodes (electrode fingers of metal film grating type reflector) is no more than 2 μm and a thickness of the film is less than 0.25 μm. The film is usually made of Al thin film. While a few technical reports which disclose specific numerical data have been known, some of them disclose relatively large values of film thickness. For example, manufacturing methods using wet chemical etching are reported in the Technical Report of the Institute of Electronics and Communication Engineers of Japan, 77 (171), 1977 and Journal of Association of Acoustic of Japan, 33 (10), October 1977, methods using lift-off technique are reported in 1977 Ultrasonic Symposium Proceedings, pages 792-797 and J. Electrochemical Society, 121 (11), pages 1503-1506. In those reports, the thickness of the Al film of the electrode finger is no more than 0.2 μm.
In the prior art surface acoustic wave device for use in the high frequency band, the width of the electrode finger is no more than 2 μm and the film thickness of the narrow electrode finger is no more than 0.2 μm as described above mainly because of a subsidiary acoustic effect encountered when the thickness of the Al film is thicker than the above thickness, for example large dispersion of effective surface acoustic wave velocity of the interdigital electrode and large reflection between and in the input and output electrodes. Those facts caused the designers and the researchers of the surface acoustic wave device to have a feeling of risk of reduction of design margin of characteristics when the film thickness is increased.
At least two secondary adverse effects have been reported which usually occur in the characteristics when the film thickness of the electrode finger is increased. The first effect is the increase of dispersion of effective surface acoustic wave velocity at the electrode fingers of the interdigital electrode. (1974 Ultrasonics Symposium Proceedings, pages 321-328). As an experimental example, the Technical Report of the Institute of Electronics and Communication Engineers of Japan, 75 (252), pages 25-32, 1975 and 1976 Ultrasonics Symposium Proceedings, pages 432-435 show that the dispersion increases as the film thickness increases. The other effect is that the reflection of the grating type reflector of the metal film increases but the reflection of the electrode fingers of the input and output interdigital electrodes also increases, and disturbance of band characteristic and ripple due to triple transit echo (TTE) are likely to occur.
Accordingly, it is considered that the use of the electrode having the film thickness of no more than 0.2 μm has been mandatory in designing the device.
The second reason for limiting the thickness of the Al film to no more than 0.2 μm for the electrode fingers having the width of no more than 2 μm is considered to be due to the difficulty in the manufacture as explained below. In a conventional chemical etching process frequently used in the past, the etching proceeds not only normally to the Al film surface but also laterally of the Al film (as reported in Handbook of Thin Film Technology, pages 7-45, Maissel and Glang, 1970) and a large undercut takes place because the etching solution penetrates into a boundary surface of a photoresist and the Al film. For example, the Technical Report of The Institute of Electronics and Communication Engineers of Japan, 77 (259), pages 9-16, March 1978 reports that when the line width of the electrode was 0.58 μm and 0.7 μm, the line width was reduced by 0.2 μm even when the film thickness was no more than 0.043 μm. In the lift-off process, a thin Al film must be used in order to facilitate the removal of resist and at the same time a temperature of a piezoelectric substrate must be maintained at a low temperature during deposition of the Al film. Under those conditions, in order to enhance the adhesability of the Al film to the substrate, Cr or Ti must be previously vapor-deposited. This requires additional steps and cost. An ion etching process by ion shower is advantageous for fine etching but since it is a physical etching process by ion bombardment a selection between the photoresist and the Al film is low and the Al film thickness is restricted and the surface of the substrate is significantly damaged. (Journal of Association of Electronics and Communication Engineering of Japan, 60 (11), page 1259, November 1977). Accordingly, the film thickness of approximately 0.2 μm has been necessarily considered as a barrier.
In addition to the above design problems and the manufacturing process problems, the following problems are encountered in the high frequency surface acoustic wave device which is used in a higher frequency and has an electrode finger width of no more than 2 μm and a film thickness of less than 0.25 μm. (1) Because of very thin film thickness, defect such as break of the electrode finger due to pinholes is likely to occur and a yield is low. (2) Because of large resistance of the electrode fingers of the input and output interdigital electrodes, a loss is high. (For example, 31st Annual Frequency Control Symposium Proceeding, pages 281-284, reports that the loss of 16-17 dB at the thickness of 0.16 μm increased to 19-20 dB at the thickness of 0.1 μm). (3) When an Al film grating type resonator is used, the number of grating electrodes increases significantly (200-300 electrodes) and a chip area increases accordingly. This leads to the further reduction of yield due to the pinholes. As an example in a VHF band, The Journal of the Institute of Electronics and Communication Engineers of Japan, Vol. 1, J 60-A (9), pages 875-876, September 1977, reports that more than 200 parallel-connected Al electrodes each having a thickness of 0.37 mm must be arranged on a LiNbO 3 substrate in order to attain a reflection efficiency of no less than 0.9 at 160 MHz, and more than 300 parallel-connected Al electrodes each having a thickness of 0.48 μm must be arranged on a quartz substrate to attain the same reflection efficiency. This means that a substrate length in the direction of propagation of the surface acoustic wave of approximately 2 mm for the LiNbO 3 substrate and approximately 3 mm for the quartz substrate is additionally required. If the film thickness is less than 0.25 μm, more number of electrodes are required. If an Al film thinner than the conventional thickness of 0.2 μm is used to form a grating type reflector having a reflection factor of no less than 0.9 at 500 MHz, a length of no less than 1 mm is required. When an electrode of Au 0.2 μm/Cr 0.05 μm was used, a 50-line grating type reflector presented approximately 20 dB of attenuation at 170 MHz, but since the Au electrode has a large mass, it has a very large dispersion of surface acoustic wave velocity and hence it is not appropriate to use when the high frequency input and output interdigital electrodes and wide band elements coexist on a common substrate. (4) In a device in which not only the UHF band input and output electrodes and grating type reflector but also the VHF band input and output electrodes (no higher than 300 MHz) and grating type reflector are to be formed on a common substrate, if an Al film thinner than the conventional thickness of no more than 0.2 μm is used, the number of electrodes of the VHF band grating type reflector increases as seen from the previous example and hence the area of the substrate increases. Contrarily, if the film thickness of the VHF band devices is increased in order to reduce the number of electrodes of the VHF band grating type reflector, the steps of Al film deposition and photoresist application increase. This eventually increases the cost in view of yield, substrate area and the number of steps. (5) It is difficult to maintain bonding with the Au wires in a stable state for a long time period. To resolve the problem, the thickness of only that portion of the Al film to which the Au wire is wire-bonded may be locally increased but this increases the number of steps. By bonding Al wire instead of Au wire by an ultrasonic bonding method, long life bonding may be attained but this method has lower workability than the Au wire bonding method and makes automation and mass production difficult.
As described above, the prior art high frequency band surface acoustic wave devices have many problems and are expensive. This has made the application of the devices to commercial equipments difficult.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a high frequency (UHF) band surface acoustic wave device which has less defect such as break of electrode fingers due to pinholes, a low electrode finger resistance, a low loss and a good characteristic.
It is another object of the present invention to provide a high frequency band surface acoustic wave device which facilitates the Au wire bonding work and assures long life of the bonding area.
It is a further object of the present invention to provide a high frequency band surface acoustic wave device which has a reduced number of electrodes of a grating type reflector when the grating type reflector having Au film is used.
It is a still further object of the present invention to provide a method for manufacturing the high frequency band surface acoustic wave device described above.
In order to attain the above objects, in accordance with the surface acoustic wave device of the present invention, when high frequency band metal strips having a width of no more than about 2 μm are used in functional elements such as input and output interdigital electrodes of metal strips and a grating type reflector arranged on a piezoelectric substrate and a portion or all of other wiring electrodes arranged on the same substrate, at least the metal strips having the width of no more than about 2 μm have the film thickness of no less than about 0.25 μm at at least a portion thereof or at any portions thereof but no more than an upper limit of an effective film thickness determined by the characteristics required for the surface acoustic wave device so that a reflection factor of the grating type reflector for compensating and controlling a transfer charactersitic of the surface acoustic wave device is increased and a loss due to a D.C. resistance of the input and output electrodes is reduced.
The term functional elements herein used means components responsible to elementary functions for carrying out overall function of the surface acoustic wave device, such as interdigital electrodes, grating electrodes, absorbers, bonding pads, common buses and conductors.
The manufacturing method of the surface acoustic wave device is characterized by heating the piezoelectric substrate to a temperature of no lower than about 250° C., forming the Al film having the film thickness of no less than about 0.25 μm and forming a desired pattern of electrodes by a reactive sputter etching process. The manufacturing method of the surface acoustic wave device is further characterized by carrying out the reactive sputter etching process under a condition of the provision of means for assuring uniform concentration of vapor phase compound which contributes to the reaction near the surface of the piezoelectric substrate and compensating for flux concentration effect and field distribution due to high dielectricity of the piezoelectric substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing a surface acoustic wave device to which the present invention is applicable.
FIG. 2 shows a sectional view taken along a line I--I shown in FIG. 1.
FIG. 3 shows a sectional view taken along a line II--II shown in FIG. 1.
FIG. 4 shows a chart of a frequency characteristic measured for a first embodiment which uses a LiNbO 3 substrate.
FIG. 5 shows a chart of a frequency characteristic measured for a comparative conventional surface acoustic wave device.
FIG. 6 shows a chart illustrating a relationship between a film thickness of the surface acoustic wave device using the LiNbO 3 substrate and an attenuation of a reflector.
FIG. 7 shows a chart of a frequency characteristic measured for a second embodiment which uses a LiTaO 3 substrate.
FIG. 8 shows a chart of a frequency characteristic measured for a comparative conventional surface acoustic wave device.
FIG. 9 shows a chart illustrating a relationship between a film thickness of the LiTaO 3 substrate and an attenuation of a reflector.
FIGS. 10 and 11 show charts illustrating relationships between the film thicknesses of the LiNbO 3 substrate and the LiTaO 3 substrate, respectively, and effective surface acoustic wave velocities at the electrodes.
FIG. 12 shows a flow chart of steps illustrating a manufacturing method of the present invention.
FIG. 13 shows a schematic sectional view of a reactive sputter etching device which is a manufacturing device in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the accompanying drawings, the preferred embodiments of the present invention will now be explained in detail. In the illustrated embodiments, the functional elements comprise input and output interdigital electrodes and a grating type reflector. FIG. 1 shows a plan view of a surface acoustic wave device to which the present invention is applied, FIG. 2 shows a sectional view taken along a line I--I shown in FIG. 1 and FIG. 3 shows a sectional view taken along a line II--II shown in FIG. 1. In those figures, portions 1a, 1b, 1c, 1d, 1e, 1f, 1g and 2a, 2b, 2f, 2g form a UHF-band filter 1 and portions 3a, 3b, 3c, 3e, 3f, 3g and 2a, 2b, 2f, 2g form a UHF-band filter 2. The portions 1a and 3a are input bonding pads of those filters, the portions 1b and 3b are r.f. bus conductors, and the portions 1c and 3c are interdigital electrodes. The portion 2a is a common grounding input bonding pad and a portion 2b is an input bus conductor for grounding the interdigital electrodes 1c and 3c. The portion 1d is a grating type reflector of the UHF-band filter 1 having a number of electrodes shorted at opposite ends. The portions 1e and 3e are output interdigital electrodes of the filters and the portions 1f and 3f are output r.f. bus conductors of the filters which are connected to the external through the output bonding pads 1g and 3g, respectively. The portion 2f is a common grounding output bus conductor for connecting the output interdigital electrodes 1e and 3e to the bonding pad 2g.
The operation of the filters 1 and 2 is now briefly explained.
An input electrical signal to the UHF-band filter 1 is applied to the interdigital electrode 1c through the bonding pad 1a and the bus conductor 1b. The electrical signal applied to the interdigital electrode 1c is transduced to a surface acoustic wave, which propagates rightward as viewed in FIG. 1. When it passes through the grating type reflector 1d, portions of frequency components are attenuated and the surface acoustic wave reaches the output interdigital electrode 1e. The surface acoustic wave having reached the output interdigital electrode 1e is transduced to an electrical signal, which is picked up as an output electrical signal through the bus conductor 1f and the bonding pad 1g. The same operation is carried out in the UHF-band filter 2 except that no absorption by the grating type electrode takes place.
An electrode wavelength of the UHF-band filter 1 is λ 01 as shown in FIG. 2 and N 1 r.f. bus conductors 1b and 1f and N 1 interdigital electrodes 1c and 1e are arranged at an interval of λ 01 /2 a length a 1 represents a width of the respective electrode. A width of the respective electrode of the grating type reflector is a G and N G electrodes are arranged at an interval of an electrode wavelength λ OG . An electrode wavelength of the UHF-band filter 2 is λ 02 as shown in FIG. 3 and the electrodes are arranged in N 2 -electrode groups at an interval of the electrode wavelength λ 02 .
In FIGS. 2 and 3, t represents a thickness of the metal films of the respective electrodes, which are formed on a piezoelectric substrate 4 by forming metal films, more particularly well-known Al films.
In a first embodiment of the present invention, a high frequency band surface acoustic wave device comprises the piezoelectric substrate 4 of Y-axis cut LiNbO 3 single crystal with a direction of propagation of surface acoustic wave device being in line with a Z-axis (or a direction of polarization of the piezo-electric substrate).
The data for the variables shown in FIGS. 1, 2 and 3 in the present embodiment are as follows. The electrode wavelength λ 01 is 7.2 μm, λ 02 is 5.6 μm, λ 0G is 7.2 μm, the electrode width a 1 is 1.8 μm, a 2 is 1.4 μm and a G is 1.8 μm. The number N 1 of electrodes is 20, N 2 is 20 and N G is 100. The electrode thickness t is 0.6 μm.
An attenuation characteristic of an electrical signal between the input and output terminals measured for the present embodiment is shown in FIG. 4, in which a point A represents a peak in a pass band characteristic of the UHF-band filter 1 and a point B represents a peak in a band elimination resonance characteristic of the grating type reflector 1d which is shown in superposition on the pass band characteristic. (A's and B's in FIGS. 5, 7 and 8 represent the similar peaks).
While the attenuation characteristic includes some ripples, a desired characteristic is attained. Particularly, a band elimination resonance characteristic of 30 dB (A-B) is attained at a center of the band of the UHF-band filter 1 (in the vicinity of 475 MHz). It is seen from the data shown in FIG. 4 that the effect to the characteristic when the film thickness of the electrode fingers increases is practically permissible. This will be discussed further hereinlater. The band elimination resonance characteristic of 30 dB at the center of the band of the UHF-band filter 1 is due to the grating type reflector 1d. In spite of the fact that the number N G of electrodes of the grating type reflector is only 100, a good band elimination characteristic is attained. This indicates the possibility of reduction of the substrate area. Because the electrode thickness is large, the break due to pinholes does not take place and hence the manufacturing yield is improved, and the loss is reduced since the electrode resistance is reduced.
In comparison to the improvement in the characteristic of the surface acoustic wave device in accordance with the present invention, FIG. 5 shows an attenuation frequency characteristic of a UHF-band filter formed by a conventional chemical etching process using the same plan structure as that of the previous embodiment except that the film thickness is changed to 0.1 μm. The attenuation (A-B) at a center of the band of the UHF-band filter 1 (in the vicinity of 475 MHz) is 16 dB in FIG. 5. Accordingly, there is a difference of attenuation of no less than 14 dB from the attenuation attained in the embodiment of the present invention. This clearly shows an advantage of the present invention.
Ripples included in the attenuation characteristic are due to a triple transit echo (TTE) and they can be reduced by using split type of input and output interdigital electrodes. They can also be reduced by reducing the number N 1 of electrodes of the input and output interdigital electrodes to approximately 10 (or 5 electrode pairs). Technically, it is not an essential problem.
In order to discuss the applicability and the limit of the present invention, the attenuation of the grating type resonator with variable film thickness of the electrode fingers is shown below. Relationships between ratios of actual film thickness to wavelength of the surface acoustic wave or normalized film thickness t/λ 01 and the resonator elimination for the representative data showing the entire trends of the experiments, that is, the Al film thicknesses t of 0.1 μm, 0.3 μm and 0.6 μm, respectively, are shown in FIG. 6. They are substantially linear as shown. It is seen from FIG. 6 that the film thickness of no less than about 0.25 μm may be used in order to attain the resonator attenuation of no less than about 20 dB. This is the first reason for selecting the lower limit of the film thickness of the surface acoustic wave device having the LiNbO 3 substrate to about 0.25 μm.
In a second embodiment of the present invention, the piezoelectric substrate is made of a Y-cut LiTaO 3 single crystal with a direction of propagation of the surface acoustic wave being in line with Y-axis. The plan structure and the plan dimensions of the electrodes are identical to those of the first embodiment with the exception that the thickness of the Al electrodes is 0.6 μm. An attenuation frequency characteristic of the second embodiment is shown in FIG. 7. The attenuation (A-B) is 32 dB, which is sufficient for practical use. FIG. 8 shows an attenuation frequency characteristic of a conventional surface acoustic wave device having the same structure as FIG. 7 with the exception that the Al film thickness is changed to 0.1 μm. The attenuation (A-B) of the resonator at the center of the band (in the vicinity of 450 MHz) is only 4 dB in FIG. 8. This indicates that the second embodiment of the present invention presents a significant effect of a high degree of elimination in the grating type reflector, and further reduction of the number N G of electrodes of the grating type reflector 1d is possible if the attenuation required is as low as about 20 dB. As a result, the substrate area can be further reduced. This is advantageous from the viewpoints of both yield and cost. The same effects as attained in the first embodiment are also presented.
In order to evaluate the applicability and the limit of the present invention which uses the LiTaO 3 substrate, relationships between the normalized film thicknesses t/λ 01 and the attenuations of the resonators similar to those shown in FIG. 6 are shown in FIG. 9 for the samples having the same plan structure and plan dimensions as those of the second embodiment with variable Al film thickness of the electrode fingers. It is seen from FIG. 9 that the Al film thickness t of approximately 0.3 μm may be used in order to attain the resonator attenuation of 20 dB. When the Al film thickness is 0.25 μm, the attenuation is approximately 10 dB, but the attenuation of approximately 20 dB may be attained by increasing the number N G of electrodes of the grating type reflector to approximately 200. In the conventional sample having the Al film thickness of 0.1 μm, the attenuation is approximately 4 dB. Accordingly, approximately 500 grating electrodes are required to attain the attenuation of 20 dB. It is thus seen that a significant advantage is presented even when the Al film thickness is about 0.25 μm.
The experimental proofs which show that the technical concept of the present invention is superior to the prior art technical concept have been described so far. The advantages of the present invention are more clearly exemplified in the following third embodiment in which low frequency surface acoustic wave devices and high frequency surface acoustic wave devices coexist on a common substrate. Although not specifically shown, it should be readily understood from the following description that when a predetermined amount (e.g. 20 dB) of attenuation is to be attained in the grating type resonator, the number of grating electrodes increases materially for the low frequency devices if the film thickness is small (e.g. 0.1 μm) as is the conventional one, and hence a large substrate area is required. On the other hand, according to the present invention, since the film thickness is large, the number of grating electrodes for the low frequency device may be very small and hence a substrate area may also be small. Various advantages result from the above.
An experimental data which implies a possibility of the technical concept of the present invention of using the thick film while the thin metal film has been used for the prior art electrode fingers is briefly shown below.
What was considered most important and risky with respect to the transfer characteristic of the surface acoustic wave device is the increase of dispersion of effective surface acoustic wave velocity at the electrodes due to large thickness of the film of the interdigital electrodes. In order to review the prior technical concept, the inventors of the present invention experimentally discussed the above phenomenon and obtained experimental data as shown in FIG. 10 for the Y-cut LiNbO 3 single crystal substrate and as shown in FIG. 11 for the Y-cut LiTaO 3 single crystal substrate, both having the Al thin film electrodes. In FIGS. 10 and 11, the abscissa represents the normalized film thickness and the ordinate represents the effective surface acoustic wave velocity at the electrode. Both the curves C and D show the same trend although the absolute values are different. When the Al film thickness is 0.6 μm, the variation of the 500 MHz filter frequency and the resonator frequency is approximately 0.6 MHz for the film thickness variation of ±5%. If a low temperature coefficient LiTaO 3 is used with a care being paid for the uniformity of the film thickness, it is practically acceptable. By improving grinding level, the dispersion of the effective surface acoustic wave velocity at the electrodes is reduced so that the Al film having the film thickness of approximately 0.6 μm is practically accepted without strict requirement for the uniformity of the film thickness so long as the film thickness is maintained within an industrial limit of uniformity. However, too thick film should be avoided because it results in the substantial increase of frequency variations (increase of gradient) due to the dispersion of the surface acoustic wave velocity and the differences (by the factor of two or three) in the resolution of the resist and the etching rates of the reactive sputter etching for the Al film and the resist. In a current technology, the limit will be approximately 1.5 μm. When the electrode finger width is 1.0 μm and the height is 1.5 μm, the electrode finger having a height-to-width ratio of no less than unit, which has not been attained heretofore, is attained.
While the interdigital electrodes have been described so far, the present invention is also applicable to a so-called comb-shape characteristic filter in which two electrodes of the same geometry are arranged in an output circuit and a number of pass band peaks are provided at a frequency interval equal to a reciprocal of a difference of delay time between those electrodes. When the operating band is wide and well defined, a desired characteristic can be attained in combination with the grating type reflector without increasing the substrate area. In any case of the above, the surface acoustic wave device of the present invention has the Al film thickness of no less than about 0.25 μm for the high frequency device so that the defect of break of the electrode fingers due to the pinholes is eliminated and the electric resistance is low and hence the resistance loss of the electrodes is low and the yield is improved. Further, the bonding of the Au wires can be readily and stably carried out and the bonded connections have long life. In addition, where the grating type resonator is included, the number of electrodes can be reduced. The Al film may be substituted by Al-Si or Al-Cu-Si alloy film.
A manufacturing method of the surface acoustic wave device according to the present invention is now explained. When a surface acoustic wave device in which the low frequency devices and the high frequency devices coexist is manufactured by a prior art technique, it is necessary in order to prevent the increase of the number of grating type reflector of the low frequency devices to vapor-deposit thin metal film on the high frequency devices and then thicken the metal film of the electrodes of the low frequency devices. As a result, separate vapor deposition steps and photo-etching processes are required. This leads to the increase of the number of steps, the reduction of yield and the increase of cost. When a chemical etching process by conventional chemical solution is used, it is difficult to manufacture the electrode having a narrow line width and a thickness of no less than about 0.25 μm, as explained above. When the conventional reactive sputter etching process is used, the Al film is peeled off at its narrow portion when pure water is sprayed under a high pressure immediately after the etching process or in a subsequent dicing process, or during an ultrasonic cleaning step, and hence a satisfactory product has not been produced. The manufacturing method of the present invention is intended to overcome the above difficulties. Firstly, since the film thickness of the high frequency devices is large (no less than about 0.25 μm), the high frequency and low frequency devices can be vapor deposited in one step and the subsequent photo-etching process is also completed in one step.
FIG. 12 shows a flow chart of steps in one embodiment of the manufacturing method of the present invention. The LiNbO 3 (or ITaO 3 ) substrate is cleaned (P 1 ). The substrate is then heated to about 300°-350° C. and Al (or Al-Si alloy or Al-Cu-Si alloy) is deposited at a deposition rate of about 100-150 Å/sec to the film thickness of no less than about 0.25 μm (P 2 ). A resist pattern of a desired electrode shape and dimension is formed (P 3 ) and vapor phase etching is carried out in low pressure reactive glow discharge, using BCl 3 as a reactive gas with a flow rate of 30-100 SccM (standard cc/min: N 2 equivalent flow rate) at a pressure of 0.1-0.3 Torr and an electric power of 150-300 watts while monitoring discharge emission by a spectrometer (P 4 ). The reactive gas may be CCl 4 or BCl 3 with some additives. The substrate is then taken out and washed in a weak alkaline solution, then in water, and the photo-resist is peeled off (P 5 ). Sound absorbing material is applied to areas corresponding to ends of chips (P 6 ). After the material has been cured, the substrate is diced by a wheel saw to divide it into chips (P 7 ). The chips are die-bonded to a TO-8 package stem by conductive epoxy resin (P 8 ). After it has been cured, ultrasonic/hot press wire bonding is carried out at a relatively low temperature by an Au wire having a diameter of 25-30 μm (P 9 ). Caps are welded in a dry nitrogen atmosphere (P 10 ). The surface acoustic wave device chips manufactured by the above process have satisfactory performance except those chips which are located at periphery of the wafer.
A first important aspect in the manufacturing method described above is that in the deposition step P 2 it is preferable to deposit Al film at the substrate temperature of about 300°-350° C. in order to enhance the adhesion of the deposited Al film to the substrate, though the high frequency surface acoustic wave devices can be manufactured at a substrate temperature of no lower than about 250° C. (deposition rate being about 50 Å/sec or lower). A second important aspect is that ih the reactive sputter etching step P 4 an SiO 2 ring 10 (see FIG. 13) having a larger rectangular sectional area then the thickness of the substrate and a larger inner diameter than the diameter of the substrate 4 is mounted on a first electrode 11 connected to an r.f. power supply, and the substrate is mounted on the first electrode in the ring 10.
Preferable range of the thickness of the SiO 2 ring is 1 mm to 7 mm (about 3 to 30 times as thick as the substrate thickness) for the substrate thickness of 0.3-0.5 mm. When the piezoelectric substrate has a high dielectric constant, a relatively thick ring e.g. 4-6 mm thick is preferable from a viewpoint of uniformity.
The use of the SiO 2 ring resolves the problem of peel-off of the thick Al film at its narrow area in the periphery of the substrate.
The inventors of the present invention found that the problem encountered at the periphery of the substrate is due to the fact that the etching rate of the reactive sputtering of the Al film on the piezoelectric substrate is faster in the periphery of the substrate than in the center of the substrate by the factor of 1.5-2. Through the discussion of the above phenomenon in detail, it has been found that (i) without the ring 10, the reaction product near the substrate surface is apt to be diffused so that the concentration in a space 15 near the periphery of the substrate is lower than the concentration in a space 14 near the center of the substrate and the etching rate in the periphery of the substrate is higher than the etching rate in the center of the substrate, and (ii) the dielectric constant of the LiNbO 3 or LiTaO 3 piezoelectric substrate used for the surface acoustic wave device is large (specific dielectric constant being 40-50) and hence the dielectic fluxes 13 concentrate to the substrate. Since a peculiar point exists in the periphery of the substrate, flux density is high at the periphery and the ions induced by the reactive sputter etching concentrate to other areas so that the etching rate is increased. In the reactive sputter etching process for the Al electrode on the piezoelectric substrate having the fine line width (no more than about 2 μm) and the thickness of no less than about 0.25 μm, it is particularly important to correct ununiform distribution of the etching rate due to the facts (i) and (ii) above. After extensive study, the inventors of the present invention found that the use of SiO 2 ring having a characteristic thickness is advantageous. By the use of the SiO 2 ring of the selected thickness, the concentration of the reaction product in the space 15 near the periphery of the substrate increases to a level comparative to the concentration in the space 14 near the center of the substrate and the fluxes otherwise concentrated to the periphery of the substrate are attracted to the corners of the SiO 2 ring which is thicker than the substrate so that the density the fluxes at the periphery of the substrate is lowered to a level of the density of the fluxes at the center. In this manner, the flux distribution is averaged. Because the piezoelectric substrate having a high dielectric constant is used, the thick SiO 2 ring is required to compensate for the concentration of the fluxes. The intended object was not attained by an SiO 2 ring almost as thick as a Si substrate.
In accordance with technical concept for resolving the above problems, a SiO 2 plate having a recess at an area in which the piezoelectric substrate is mounted, which recess has a flat bottom and a larger depth than the thickness of the substrate, may be used instead of the SiO 2 ring used in the previous embodiment to cover the entire surface of the discharging electrode of the reactive sputter etching equipment. The depth of the recess is preferably equal to the thickness of the SiO 2 ring.
In the embodiment described above, the surface acoustic wave device having a minimal line width and spacing of 0.7 μm was manufactured with ordinary ultraviolet ray lithography. When electron beam exposure or X-ray exposure is adopted in the lithography, it is possible to manufacture the surface acoustic wave device having the electrode width of 0.1 μm and hence the device is more adapted for use in high frequency band. It is apparent that the surface acoustic wave device can be manufactured in more stable manner when the manufacturing method of the present invention is applied to the manufacture of the surface acoustic wave device having a thin Al film and the surface acoustic wave device having a large line width.
As described hereinabove, according to the surface acoustic wave device and the manufacturing method thereof of the present invention, products having high performance high frequency devices and/or low frequency devices are provided and the step of locally thickening for the Au bonding is not required and the break due to the pinholes does not take place. As a result, the mass-productivity and the yield are improved.
It also provides the advantages of the reduction of the number of steps, the simplification of a test process and the availability of the monitor check in the reactive sputter etching process. Thus, the contribution of the present invention to the industry is great.
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A surface acoustic wave device, a method for manufacturing the same and a manufacturing equipment therefor are disclosed. In the surface acoustic wave device having functional elements such as input and output interdigital electrodes of Al, Al-Si alloy or Al-Cu-Si alloy thin film strips and a grating type reflector, arranged on a piezoelectric substrate and any other bus conductors arranged on the same substrate, at least a portion of the functional elements and the bus conductors having a high frequency metal strip having a line width of no more than 2 μm, at least the metal strip having the width of no more than 2 μm has a film thickness of no less than 0.25 μm at least a portion thereof but no more than an upper limit of an effective film thickness determined by a required characteristic of the surface acoustic wave device, whereby a transfer characteristic of the surface acoustic wave device is compensated and controlled, for example, a reflection efficiency of a grating type reflector is improved or a loss due to a D.C. resistance of the input and output electrodes is reduced.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a non-provisional application of an earlier U.S. provisional patent application Ser. No. 61/852,398, filed on Mar. 16, 2013.
FIELD OF INVENTION
The invention relates to a precast building system and, more specifically, relates to the latest and best aspects of precast technology and incorporate the same in the traditional cast-in-place concrete frame system to produce a reliable, trusted and economical building solution for high speed and high volume production.
BACKGROUND OF THE INVENTION
Building structures are often built on site in most parts of the world. The problems of site constructions are well documented in past journal articles. The major problems of many site building methods are their high amount of skilled labor requirements and complexity of the building structures. In cases where the building system is too foreign to the local market, system acceptance will be very low. There are certainly many different types of building systems available in the market that compete to reduce cost, provide speed construction, and provide a more energy-efficient envelope at the same time. However, no system can reduce cost sufficiently, increase construction speed, provide more energy-efficient envelope, and have more culturally acceptable features at the same time. The local market, particularly, in the developing countries is enormous because these developing countries are where the majority of the world population growth occurs in the last 35 years.
The precast building industry has been evolving slowly for the last few decades in developed countries including United States and Europe. The core concept of most precast systems is still based mainly on very heavy load-bearing wall components. Load-bearing wall panel is a panel designed to carry the load above the panel and does not rely on a column system to support the load. In contrast, the non-load bearing wall panel is designed to carry load above the panel. However, a typical load-bearing wall system inherently has limitations in application and practice in most developing markets. For example, a typical precast system requires a large amount of capital for heavy equipment to manufacture and handle its panel components, making it a very unattractive investment relative to traditional cast-in-place system which is more easily practiced and implemented without heavy machinery. As a result, traditional cast-in-place concrete system remains widely practiced everywhere, including both developed and developing countries for many generations.
An example of such a traditional cast-in-place concrete superstructure 10 is shown in FIG. 1A and FIG. 1B including widely practiced traditional concrete columns 11 and traditional concrete floor systems 12 for low rise and high rise structure. FIG. 1A shows a traditional cast-in-place concrete frame superstructure 10 including cast-in-place columns 11 and floor systems 12 for a single story or low rise structure. In contrast, FIG. 1B shows a traditional cast-in-place concrete frame superstructure 10 including cast-in-place columns 11 and floor systems 12 for multiple stories or high rise structure. In either embodiment, its cast-in-place concrete frame superstructure 10 is well understood and trusted for generations. The superstructure's columns 11 are designed to carry the structure's load. In designing and determining the load capacity of the structure, the traditional cast-in-place concrete frame superstructure 10 will be much easier to understand and be trusted by the local developing population than a load-bearing precast wall system.
Another major advantage of traditional cast-in-place concrete superstructure over traditional load-bearing precast wall systems without columns is its flexibility for future renovations. For example, partition walls can be easily knocked down or moved to accommodate new floor layout or usage of space as space usage changes in time. However, the traditional cast-in-place concrete system, as shown, for example, in FIGS. 1A-1B , also has its weaknesses. Its biggest weakness lies in the construction of walls and partitions between load-bearing columns 11 . The traditional method uses hundreds or thousands of concrete blocks or clay bricks to build the walls. Inherent major problems include slow construction speed, inconsistent quality and lack of insulation. In most cases its energy and noise performance is far lower than precast insulated walls. In today's environment and in the future, where energy consumption continues to rise as living standards increase, walls with insulation in them will save energy. In normal construction steps, the cast-in-place superstructure 10 is constructed first and is then followed with the construction of envelope walls and all partition walls. In the last few decades, another type of non-precast system using a light gauge steel frame and a thin sheathing has become an attractive alternative; however, acceptance has been very slow as most people in the developing market still prefer traditional masonry walls and do not like the flimsiness of its covering and its durability when compared to the traditional masonry walls.
Given the fact that at least 80% of 7 billion world population is living in developing countries and living mostly in traditional concrete frame housing, any precast system that does not resemble what people have been used to for generations and can offer better performance over traditional system will have little chance of acceptance and adoption. In addition to being unfamiliar in the local engineering community and end users, the high level of initial capital investment required for precast systems will make them unviable as a solution. Other non-concrete or non-masonry solutions have the same problem in their adaption as well. When people buy something as significant as their home they will want to buy something they trust and that has better value. A new building solution is desperately needed that has to be cheaper, faster construction time, higher thermal efficient performance to save energy, and has more culturally acceptable features as well.
In any market and in any innovation, end users or consumers will always accept and buy a better mouse trap because of its greater perceived value. The old mouse trap in construction technology can be referred to as traditional reinforced concrete frame with cast-in-place columns, beams, and floor. Typical load-bearing precast system from developed countries will not be perceived by the mass population in developing countries as a better mouse trap because of its lack of resemblances. This explains why most evolved precast building systems of the developed countries have failed in developing markets. The mouse trap—a home—is the most significant purchase in a person's life. As a result, not too many people are willing to buy something that does not perceive as a better mouse trap than the one they grew up in.
In recognizing all factors stated above, there is a need for a better building solution, particularly, in developing countries where developers or general contractors often do not have the excess capital for heavy equipment for traditional load-bearing precast systems.
SUMMARY OF THE INVENTION
Accordingly, it is therefore an object of the present invention to provide a new building component system that is low cost and simple for single store to high-rise structure and that has faster construction time, higher thermal performance, and more culturally acceptable features, particularly for developing countries where developers or general contractors often do not have the excess capital for heavy equipment for traditional load-bearing precast systems.
It is also an object of the present invention to provide a lightweight precast component system designed to adopt the traditional cast-in-place concrete superstructure and to reduce construction time, cost of labor and materials, while achieving higher thermal efficiency and durability and familiarity.
It is also an object of the present invention to provide a hybrid building system that integrates both elements of precast and cast-in-place technologies made possible by its precast wall panel design and specifications.
It is further an object of the present invention to provide a precast wall panel component designed to span and connect between traditional concrete columns and beams in the traditional concrete superstructure and designed to be as light as possible (no more than 5 Ton) without concern to its load-bearing capacity.
In accordance with an aspect of the present invention, the hybrid building system combines both precast panel elements and cast-in-place concrete superstructure method. The required precast elements are non-load bearing precast wall panels of certain size, type, design, and weight and any precast floor panel. The cast-in-place elements are columns, beams, and floor system resembling the traditional concrete superstructure frame that everyone recognizes and trusts. Essentially, the hybrid building system according to the present invention is designed to speed up construction speed and provide better performing wall by replacing hundreds of concrete or brick blocks with one or two precast wall panels between columns as cladding walls and partition walls. The system columns and beams in this hybrid building system are of the same traditional construction. The system floor panel can be of any ordinary precast floor panel or cast-in-place slab floor system; however, the preferred floor system disclosed in this application is of an open rib panel design and/or of cast-in-place floor system. This pre-assembled floor panel is made of a light gauge steel frame with a top sheathing. The floor panel system can be either a removable formwork or stay-in-place formwork, which is a temporary or permanent mold in which concrete or similar materials are poured. The light gauge steel frame is made of four main U or C or of both U and C steel sections assembled into a frame with a top sheathing. When the floor panels are assembled over the precast wall panels, cavities for forming floor joists are created. When compared to traditional floor slab, the floor panel system according to the present invention will reduce both concrete and steel content.
In accordance with another aspect of the present invention, the hybrid building system concept is enabled only by non-load bearing precast wall panel design and its specification. As previously discussed, the non-load bearing precast wall panel is designed to carry load above the panel. The panel basic design can be of an open rib or closed sandwich wall panel. The typical wall panel has a maximum width of 8 meter and has a height that stretches between floor beams in the superstructure, so that no more than two panels are connected between concrete columns with a cross-section area more than 7100 square millimeter (11 square inch) and floor beams in the superstructure. The construction of columns and beams of this hybrid building system is the same as traditional cast-in-place frame system. The wall panel weighs no more than 5 tons—so that lighter and cheaper class of equipment can be used in manufacturing, transporting, and erecting it at building site. Both panel types in this system use minimal concrete for their integrity and with enough reinforcement to prevent shrinkage cracks and cracks during its handling. The wall panel has a minimum panel thickness of 90 mm or 3.5 inches. The concrete layer of the open rib and closed sandwich panel has a maximum panel thickness of 2 inch or 50 mm under reveals and is made of concrete that is structural or non-structural class and has a maximum panel weight of 35 lb/ft2 or 170 kg/m2. Most load-bearing wall panels in the industry are heavier than 35 lb/ft2 or 170 kg/m2. The left and right side of each wall panel has protruding edges to reduce water penetration to the inside and help to stabilize the panel position when wet concrete is in column cavity. In this system the main joint connection is made via embedded steel rod or bolt put in place prior to casting concrete columns and floor beams. For large wall panels its side is sprayed with a releasing agent in order to prevent cold bonding between column and panel. In such case, the panel connection relies solely on connection steel bolts or rods. Since concrete panels and columns shrink, expand, or move in micro millimeters under various conditions this design joint system will allow movements and prevent crack in panels. Provision such as covering the micro joint line with a fiberglass mesh and an elastic joint compound can hide the joints completely. Thus, it now can become a joint-less precast system. Cracks and water penetrations are the common problems associated with traditional precast systems. The protruding edge of one side of the wall panel can be longer than the other side of the wall panel in order to save the formwork and reduce labor cost associated with that side. In other case, the wall panel can only have one protruding edge on its left and right side. All wall panels may have another optional extended edge on the top side of the wall panel to save the exterior formwork when casting the concrete floor and the floor beam. This wall panel design with the combination of disclosed features represents a departure from traditional precast panel design in the industry.
In accordance with another aspect of the present invention, the construction process of this hybrid building system is different from traditional building system and is described as follow for constructing a single story to a high-rise building:
Step 1—The wall and floor panels are precast at site or at factory.
Step 2—The wall and floor panels are transported to site and are then erected.
Step 3—One or more rebars are placed in column cavities and then add additional formworks.
Step 4—Place floor panels on wall panels as an option.
Step 5—Concrete is poured for columns and is then set for 24 hrs.
Step 6—Floor panels are placed over the wall panels and steel reinforcements and formworks are put in place if step 4 is not used.
Step 7—Concrete is poured for beams, joists, and top floor slab and is then allowed to set for 24 hrs.
Step 8—Repeat step 2 to step 6 until all floor panels are constructed.
In some cases, the system columns can be cast before wall panel erecting. However, such method is not efficient and would incur higher cost but it is an option.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention will become apparent from the following detailed description of example embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the following written and illustrated disclosure focuses on disclosing example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and that the invention is not limited thereto. The spirit and scope of the present invention are limited only by the terms of the appended claims. The following represents brief descriptions of the drawings, wherein:
FIGS. 1A-1B illustrate a traditional cast-in-place concrete superstructure frame 10 that is widely practiced with columns 11 designed to carry all vertical load and traditional floor systems 12 for low rise and high rise buildings.
FIG. 2 illustrates an example assembly of two precast wall panels 20 as an open rib wall panel type with protruding edges 21 on its left and right sides with embedded connectors 22 erected, and with rebar 25 for column and with formwork 24 in place.
FIG. 3 illustrates an example assembly of two wall panels 20 as an open rib wall panel type with one edge 21 extended beyond the other edge 21 on its opposite side of each wall panel, and with embedded connecting devices 22 .
FIG. 4 illustrates an example assembly of two wall panels 20 as a closed sandwich wall panel type with protruding edges 21 on left and right sides of each wall panel 20 , with optional beads of sealant 27 applied and with an optional thin coat of release agent 26 applied for large wall panels prior to casting concrete into column cavity. Examples of connecting devices include bolt like type, steel rod type, or other steel devices 22 embedded in the precast panels 20 . Additional formworks 24 are attached to the wall panels 20 temporarily and to be removed after the concrete poured in column cavities is hardened.
FIG. 5 illustrates an example floor panel 30 used for this hybrid building system including a bottom steel frame 31 made of U or C section stud and a top sheathing 32 .
FIG. 6 illustrates an example assembly 50 of both wall panels 20 and floor panels 30 in place prior to casting of columns, beams, and floor system. Details of how a rebar column 25 , a steel mesh 28 , and formworks 24 for beams and columns are in place and how joist cavities 41 are formed when the floor panels 30 are placed adjacent to each other.
FIG. 7 illustrates an example assembly with both open frame wall panels 20 and floor panels 30 assembled before concrete pouring. The precast panel 20 has an extending edge 23 at a top side that serves to eliminate the need for additional formworks for cast-in-place beams in the floor system, and a protruding edge 21 on left and right sides of each wall panel 20 .
FIG. 8 illustrates an example assembly with both open frame wall panels 20 and floor panels 30 assembled before concrete pouring. The precast panel 20 is now a composite precast panel with a back support system made of steel frame 20 C. The front concrete slab attached to frame system 20 C is extended on top and left and right side of panel 20 . The connecting devices are of bolt type or other steel devices 22 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 2 which illustrates a component precast system that is a hybrid building system designed to integrate both elements of precast and cast-in-place technologies and made possible by its precast wall panel design and specifications according to an embodiment of the present invention. As shown in FIG. 2 , the component precast system comprises mainly lightweight precast wall panel components designed to span and connect between traditional concrete columns and beams in the traditional concrete superstructure 10 as shown in FIG. 1A and FIG. 1B . The wall panel component 20 is designed to be as light as possible (no more than 5 Ton) without concern to its load-bearing capacity. The concrete layer in panel can be of regular or lightweight concrete. Essentially, the precast wall panel 20 is designed as a cladding panel to replace the hundreds of concrete block or clay bricks between columns and provide higher performance walls.
As shown in FIG. 2 though FIG. 4 , the typical precast wall panel 20 whether its design is an open rib/frame or a closed sandwich panel acts like a precast substitution for traditional masonry block or clay brick infill wall that spans between columns of the concrete superstructure 10 shown in FIGS. 1A-1B . A closed sandwich panel design is illustrated in FIG. 4 . The precast wall panel 20 is made of a foam insulation core 29 covered by front 29 a and back 29 b concrete layers. An open rib or frame panel design type is best illustrated in FIG. 2 , FIG. 7 , and FIG. 8 . For example, concrete ribs 20 B of panel 20 can be made of re-enforced concrete as shown in FIG. 2 and FIG. 7 . Alternatively, the concrete ribs 20 B frame of panel 20 can be made of steel frame 20 C as shown in FIG. 8 . The open rib/frame panel 20 is designed to be closed with gypsum boards, cement board, or other sheathing boards after utilities lines or insulation is in placed.
Because manufacturing and handling equipment used for heavy precast panels costs a lot more than for panels less than 5.1 Ton, the precast wall panel 20 has a limit weight of 5 Ton. For most high-rise buildings with a large floor area, the panels 20 are limited to 1.5 Ton due to limitations of tower cranes. Each precast wall panel 20 has a thickness equal to or greater than 75 mm or 3 inches and is made of structural concrete or non-structural concrete. The precast wall panel 20 is designed to have a weight under 35 lb/ft2 or 170 kg/m2 and to serve as non-load bearing class wall.
As illustrated in FIG. 2 to FIG. 4 , each precast wall panel 20 has two extended edges 21 on left and right sides of the wall panel 20 . The protruding edges 21 are designed to help increase resistance in path of possible water penetration and, in many cases, serve to stabilize the panel position when the pressure of wet concrete applies to the edges in opposite directions and to reduce shearing force in the steel connecting devices when wind load is applied. As shown in FIG. 4 , the wall panel 20 has embedded connection devices of steel rod or bolt or other steel connectors 22 . Bolt type devices 22 are preferred because such devices can be adapted to allow slight movement. After the precast wall panels 20 are erected, rebar is placed in column cavities having a cross-section greater than 11 square inches (7100 square millimeter). Optionally, beads of sealant 27 are applied before a thin coat of release agent 26 is applied for a larger wall panel. The release agent 26 is meant to prevent the concrete within the columns from bonding to the wall panel 20 . Concrete in columns and panels shrinks slightly under various moisture conditions and the structure frame 10 can move back and forth slightly in high-wind and seismic conditions. The bolt connector devices 22 in the hairline joint gaps will allow slight movements in the assembly without putting too much stress on the precast wall panels 20 .
FIG. 2 to FIG. 4 show how a column is to be cast right after wall panels 20 are erected, then the floor panels 30 are placed afterward on the wall panels 20 . As shown in FIG. 2 , FIG. 4 , and FIG. 7 , the rebars are constructed in the same traditional method. The protruding edge 21 of the side of wall panel 20 can extend far enough to eliminate the formwork on one side as shown in FIG. 3 and FIG. 7 . The wall panels 20 can also have an additional protruding edge 23 on a top side extended far enough to eliminate the need of formworks for forming horizontal beams above the wall panels 20 as shown in FIG. 7 . The non-load bearing precast wall 20 of an open frame design can be of steel frame system attached to a thin slab of concrete as shown in FIG. 8 .
This hybrid precast system 20 can be adopted to use as a flooring system on the market provided that a thickness of floor planks or panels is sufficient to form the required height of the floor beams. The preferred flooring system of this hybrid component system is based on a floor panel design 30 shown in FIG. 5 . As shown in FIG. 5 , the floor panel design 30 comprises a bottom frame structure 31 made out of U or C section steel frame with a top sheathing cover 32 that can be of a thin concrete layer or a concrete formwork or a cementitious board. This type of flooring system works well with Applicant's component building system as the panel's height is high enough to form the horizontal beams for the system. When floor panel boxes 30 are set in place with spacing 41 between them, the whole assembly 50 illustrated in FIG. 6 becomes a cast-in-place form work for a concrete floor with floor joists formed in the spaces 41 between the floor panel boxes 30 . The floor boxes 30 can be stay-in-place formworks or be removable formworks to save cost of materials. Leaving floor panel boxes 30 in place can certainly reduce construction time. This preferred flooring system is simple, fast to produce, and it requires low cost equipment to do the floor. With any common local flooring system, Applicant's component building system with its unique design and specifications can be adopted to create the same cast-in-place superstructure as the local traditional one. However, when implementing a concrete joist system as in the preferred flooring system shown in FIG. 6 , concrete and steel materials can be reduced at least 15% and an effective weight reduction will further reduce the materials at the foundation level also.
The construction steps or method of this hybrid building system according to an embodiment of the present invention is different from both traditional cast-in-place and precast system. The precast wall panels 20 are first erected on a floor slab, then the rebar 25 and formworks 24 are formed for columns. Concrete is then poured into column cavities and is allowed to set and harden overnight to form columns. Alternatively, concrete for columns can be postponed and poured at the same time for the floor slab. The floor panels 30 are then placed and secured over the wall panels 20 with rebar 25 and steel mesh follows. Concrete is then poured over the floor panel and inside formwork with all steel connections and re-enforcements to allow hardening and lock all components in place. The construction process or steps mention previously will repeat for each floor construction. As one can deduce, the construction of each floor can be done in a few days, typically between 3 to 4 days, which is much faster in time and less labor relatively to the traditional construction method.
While there have been illustrated and described what are considered to be example embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the present invention. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the present invention, but that the present invention includes all embodiments falling within the scope of the appended claims.
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A component building system combines both precast elements and cast-in-place elements that is cost effective, more cultural acceptance, and adaptable for constructing single story to high-rise building structures. The component building system comprises mostly open rib or closed sandwich wall panel components that are limited or non-load bearing panel connecting between main columns in the concrete frame superstructure.
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BACKGROUND OF THE INVENTION
A Luer nut is a device that is usually used in the medical field to hold two liquid carrying fittings together. The fittings have a Luer taper as described in the American National Standard ANSI/HIMA MD70.1-1983. The Luer taper is used to make quick, leak proof connections, and is comprised of two tapered pieces, one male and one female. The male and female parts are drawn together to make a tightly fitting connection. The connection is held together by a male thread on the female Luer taper part and a nut-like device with internal threads, called a Luer nut, on the male Luer taper part.
An improved Luer nut is disclosed by Thomas P. Stephens in U.S. patent application, Ser. No. 740,353, entitled "Non-Loosening Luer Nut", filed June 3, 1985. The internal cross section of the threaded section of the improved Luer nut is not round like previous Luer nuts, but is generally in the shape of a polygon that is deformable rather than stiff. The polygonal cross-section of the improved Luer nut frequently is in the general shape of a triangle with rounded sides each with a relatively large average radius and rounded corners each with a relatively small radius, which is referred to as a trilobate shape.
Unfortunately, the plastic molding of such a Luer nut having a polygonal internal cross-section is a significant problem. In general, prior molding techniques for conventional plastic nuts utilize a mold cavity with fixed dimensions to define the outside shape of the nut, and a removable, externally threaded core within the mold cavity around which the plastic nut is molded. After the plastic is injected into the mold cavity and allowed to solidify, the threaded core is simply unscrewed, and the finished nut ejected along a parting line of the mold. Such a technique will generally not work for a nut which is not internally round in section, because the threaded core for the polyognal Luer nut must also be polygonal in external cross section. Such a non-round threaded core cannot generally be unscrewed from within the solidified nut without damaging the sides of the nut due to the fixed dimensions of the mold cavity.
One solution to this problem is to extract the polygonal core from within the cavity while the nut is still attached. Then, a secondary apparatus acting like a human hand can be used to grab and hold the outside of the nut at points adjacent to the vertices of the polygonal section, so that the core can be unscrewed without stripping the threads. Naturally, such a procedure is time consuming and expensive.
A second solution to the problem of molding such a polygonal nut is to use a collapsible core. That is, the threaded core is designed so that it can be folded in on itself after the plastic has solidified. Unfortunately, Luer nuts are generally small, with an internal diameter on the order of five millimeters. In general, building a collapsible core with such small dimensions is impractical.
SUMMARY OF THE INVENTION
The present invention involves a technique for automatically molding the new Luer nut, with its polygonal internal cross-section. For ease of description, this technique will be described with respect to a plastic Luer nut with a generally trilobate internal shape. However, the technique can readily be adapted to molding of materials other than plastic, and to any nut with a non-round, polygonal internal cross-section.
For a trilobate nut, an inner threaded core having a generally trilobate external cross-section is arranged in spaced relationship to a cavity within a mold housing. In general, the cavity will have a generally trilobate internal cross-section so that the resulting Luer nuts will have a relatively constant wall thickness. After the plastic is injected within the space between the outer surface of the threaded core and the inner surface of the cavity and has been allowed to solidify sufficiently to permit part removal, the sections of the mold cavity adjacent to the large radius sides of trilobate section are permitted to move away from the nut, while the sections of the mold cavity adjacent to the small radius corners of the trilobate sections are maintained in fixed contact with the outside surface of the nut. The movable sections of the mold cavity provide areas for the molded part to expand into as the trilobate shaped threaded core is unscrewed. Since the nut and the mold core are both trilobate in sectional shape, and because sections of the cavity are movable, the portions of the part which are adjacent to the large radius portions of the core have room to expand as the three high lobes on the threaded core rotate within the nut.
In addition to having movable sections into which the nut can expand as the core is unscrewed, it is also necessary that the cavity hold the nut around its perimeter to prevent the nut from turning with the core as the core is rotated. This can be accomplished by having longitudinal slots in the inner wall of the cavity to form ribs on the outside of the nut which prevent the nut from rotating as the core is rotated. The ribs can be made significantly shorter in height, while still providing sufficient resistance to rotation especially when the threaded core initially begins to unscrew, by spacing several slots and the resulting ribs around the nut and thereby extending into both the fixed and movable sections of the mold cavity. If desired, additional resistance to rotation of the nut can be provided through the use of radially inwardly acting springs connected to the movable sections of the mold cavity.
The mold can be readily adapted to form a plurality of Luer nuts at one time by providing an equal number of cavities and threaded cores within the mold housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A-1D show an outside side view, left side view, sectional view and right side view, respectively, of a trilobial Luer nut.
FIG. 2 shows a side sectional view along the central longitudinal axis of a plastic mold according to a preferred embodiment of the present invention.
FIGS. 3A and 3B show sectional views taken along the parting line of the mold as shown in FIG. 2 in an as molded position and in an unscrewing position of the core, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1A-1D show the shape of a trilobate Luer nut, which is the result of the molding technique of the present invention. FIG. 1A shows an outside view of the Luer nut 1, including a plurality of ribs 2. In the finished part, the ribs 2 serve to provide means by which a user can easily grip and turn the nut 1 for screwing it onto a mating female part (not shown). Because the ribs 2 are intended to be manually gripped it is desirable that the ribs 2 not be so high as to irritate the user. As shown in FIG. 1B, it is also desirable that the ribs 2 be relatively evenly spaced around the circumference 3 of the nut 1. FIG. 1C, which is a sectional view of the nut 1 taken along the axis A--A as shown in FIG. 1B, shows the internal Luer Threads 4. As shown in both FIGS. 1B and 1D, the illustrated nut has both an inner and outer trilobate shpae, so that the mean thickness of the wall 5 is essentially constant around the circumference of the nut 1 at any plane along the length of the nut. If desired, the wall thickness can be varied to provide an outer shape which is any desired shape, including round.
FIG. 2 shows a side sectional view of the plastic mold 6 according to a preferred embodiment. The nut 1 is formed within a cavity 7 by injecting a thermoplastic such as polyester (e.g., Valox 325 available from the General Electric Company) via a sprew 8 and a runner 9 and a gate 10 into the cavity 7. The radial sides of the cavity 7 are formed, in the case of a trilobate nut, by three fixed sectors 11 and three movable sectors 12 in a cavity retainer plate 13. Added strength is provided by a cavity backup plate 14 to the outside of the cavity retainer plate 13. A knock-out pin 15 extends through the cavity retainer plate 13 and the cavity backup plate 14, and is mounted so that the pin 15 can slidably move along the central axis 16 of the cavity 7. The knock-out pin 15 serves two purposes: first, when in the position shown in FIG. 2, its end 17 provides one end of the cavity 7; and, second, when the nut 1 is ready to ejected from the mold 6, it can be moved longitudinally in direction L to push the nut 1 out of the mold 6 via a parting line 18 between the cavity retainer plate 13 and a stripper plate 19. A movable pin 20 is also provided within the cavity retainer plate 13, which in the position shown locks the movable sectors 12 relative to the fixed sectors 11. When the pin 20 is moved longitudinally in direction R, the movable sectors 12 are free to move with respect to the fixed sectors 11 with respect to the central axis 16. A threaded core 21 is provided extending through a core retainer plate 22, the stripper plate 19, into the cavity 7. The threaded core 21 has an end 23 with external Luer threads 24, with a trilobate external cross-section, and serves to provide the internal shape of the nut 1. The threaded core 21 can be rotated within a bearing 25 by an external rotating mechanism (not shown), such as an oil cylinder and rack and pinion gear. In order to unscrew the threaded core 21 from within the nut 1, the core retainer plate 22 is moved in direction L at the same rate as the pitch of the Luer threads 24. The coordinated movement of the rotation of the threaded core 21 and the core retainer plate 22 can be accomplished by conventional means, such as a cam (not shown) connected to the external rotating mechanism.
FIGS. 3A and 3B show a sectional view of the mold 6 taken along the parting line 18, as indicated by axis B--B. FIG. 3A shows the mold 6 when the nut 1 is in its as molded position. For purposes of further discussion, the corners of the nut 1 will be referred to as the small radii sr, and the portions between the corners will be referred to as the large radii LR. The outermost portions 30 of the core 21 form the small radii sr, and when the core 21 is unscrewing, the portions 32 of the nut 1 initially adjacent to the portions 30 of the core 21 do not have to expand because they are the outermost portions of the nut 1. Therefore, the portions 32 of the nut 1 can be in an area of the mold 6 that does not expand, that is, the fixed sectors 11. Further, since the fixed sectors 11 do not have to expand, they can serve to hold the nut 1 from rotating while the core 21 is unscrewing. The large radii portions LR of the nut 1 must, however, expand while the core 21 is unscrewing as shown in FIG. 3B. Thus the movable sectors 13 must move radially outward so that the large radii portions LR of the nut 1 can expand as the high points 30 of the core 21 rotate within the nut and push the large radii portions LR radially outward. In general, the force of the unscrewing core 21 is sufficient to expand the movable sectors 13, but active means, such as a cam (not shown) coupled between the core and the moveable sectors 13 could be used as well.
The core 21 applies considerable torque to the nut 1 while being unscrewed because the molded nut 1 is continually being distorted as the core 1 is removed. In addition, when the core unscrewing just begins, there is a very large amount of torque applied to the nut 1 until the initial part/core break away takes place. The torque applied to the nut 1 after initial break away is considerably less. This high initial torque could cause the nut 1 to turn and strip off the outside texture of the nut 1 unless the nut 1 is held firmly within the cavity 7. Such stripping is prevented by the use of slots 34 and 36, which form the ribs 2 on the nut 1. At least one of the sets of slots 34 or 36 are therefore required to prevent rotation of the nut 1. However, it is preferable that slots 36 and 34 be provided in both the fixed sectors 11 and the movable sectors 13, respectively, to provide sufficient holding, so that the ribs 2 need not be too high and/or thick. If added holding force is required, inwardly acting springs (not shown) can be then coupled to the moveable sectors 13 to maintain the even higher resistance to rotation of the nut 1. Once the initial break away of the core 21 has occurred, the moveable sectors 13 can stay in their radially expanded position, and can be retained there either by friction or by a detent device (not shown).
The use of the fixed sectors 11 also permits the sprew 8, the runner 9 and the gate 10 to be machined therein. This is generally very desireable, so that the mold can easily be run with automatic gate and runner removal.
Overall operation of the molding process occurs as follows:
1. The pin 20 is inserted to fix the movable sectors 12 relative to the fixed sectors 11, and the core retainer plate 22 is moved inward to close the mold along the parting line 18;
2. Plastic is injected through the sprew 8, runner 9 and gate 10 to fill the space between the threaded end 23 of the core 21 and the cavity 7;
3. After the plastic solidifies, the pin 20 is released to release the movable sectors 12;
4. The core 21 is rotated and core retainer plate 22 is retracted simultaneously at the rate of the pitch of the Luer threads 24 on the end 23 of the core 21;
5. After the core 21 is fully unscrewed from within the nut 1, the mold 6 is opened along the parting line 18;
6. The knock-out pin 15 pushes the finished nut 1 out of the cavity 7 and out of the mold 6 along the parting line;
7. The waste plastic within the sprew 8, runner 9 and gate 10 are pushed out of the mold 6 by conventional means. The molding cycle is now ready to begin again.
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A novel plastic mold and method is disclosed for forming a Luer nut which has a polygonal internal cross-section. The mold includes both movable and fixed cavity sections, so that a non-round threaded core can be unscrewed from within the Luer nut.
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BACKGROUND OF THE INVENTION
This invention relates to the stacking of materials, and, more particularly, to the stacking of relatively large volumes of material.
There are many situations where it is desirable to deal with large volumes of material. One example is in the operation of high speed processing machinery. Unless the materials to be processed are available in sufficient quantities, the machinery will not be able to operate at full capacity.
Another example is the movement of materials over long distances. It is apparent that the subsequent handling of the materials will be expedited if they are pre-stacked.
It is common practice to form stacks of materials on support structures such as pallets. The entire stack can then be moved by lifting the pallet.
Of course, if the materials are not arranged properly, the stack will not be able to provide the maximum quantity per unit volume. In addition, the stack may be unstable, particularly if it is large.
In order to provide stability and stack efficiency, it is common practice to form the stacks in tiers or layers, with each tier having a particular pattern. The patterns can then be alternated or varied in successive tiers in order to strengthen the average stack.
It is apparent that such a stack can be formed manually, but that is labor intensive. It is fatiguing to the stackers and relatively slow.
Numerous attempts have been made to reduce the fatigue factor and the number of persons needed for stacking. In various semi-automatic systems now in use, takes place by an operator at the top of an inclined conveyor to which the items to be stacked are fed.
In one such arrangement, the stacker machine makes use of an open top elevator. Initially the elevator platform is fully elevated. An operator receives items to be stacked at the top of an inclined feed conveyor and places them at the top opening in a desired pattern on the elevated platform to form a base tier. The elevator platform is then lowered by one tier level and a new tier is formed on the prior tier. This procedure is repeated until the entire stack is formed and the platform is in its base position. The completed stack is then removed from the machine and sent on its way.
While an improvement over purely manual stacking, the elevator stacker has a number of disadvantages. The movable platform has to support the full weight of the overall stack and therefore must be mechanically rugged and complex. More importantly, the operator is positioned at the top of the elevator. Not only is there limited space for movement, the operator must remain in position throughout the stacking operation. Consequently he is not available for ground level activities that are inevitably required. Finally, the items to be stacked must be transported to the top of the elevator by a relatively large inclined conveyor. The result is that a lot of space is need for the stacking operation.
In a variant of the elevator stacker, the platform is made to carry each tier to the appropriate stack level and return to the top of the elevator to receive a subsequent tier. While this arrangement allows the platform to operate with a reduced load, the principal disadvantages of the ordinary elevator stacker remain, namely the need for an operator at the top of the elevator, so that he is unavailable for ground level duties, and the need for a relatively long, inclined conveyor to carry the materials to the stacking position, so that a significant amount of equipment space is required.
Accordingly, it is an object of the invention to expedite the stacking of materials. A related object is to expedite the stacking of large volumes of material.
Another object of the invention is to enhance the effectiveness of stacking with mechanical equipment. A related objective is to enhance the effectiveness of stacking with semi-automatic equipment.
A further object of the invention is to achieve automated stacking using a limited amount of equipment space. A related object is to eliminate the need for relatively long, inclined power conveyors in semi-automatic stacking.
Yet another object of the invention is to enhance operator effectiveness in semi-automatic stacking. A related object is to make the operator in semi-automatic stacking available for other ground level duties, as well as the control of stacking. Another related object is to eliminate the need for stationing an operator at relatively high levels (as much as eight feet) above ground level in semi-automatic stacking.
SUMMARY OF THE INVENTION
In accomplishing the foregoing and related objects, the invention makes use of a translatable and laterally displaceable platen. Materials at a receiving position are arranged on the platen in a single tier or layer at a time in a prescribed pattern. The platen is then moved to overlie a loading position and the tier deposited. Subsequent tiers are formed and deposited in the same way to produce a multi-tier stack at the loading position.
In accordance with one aspect of the invention, each tier can be formed on the platen by or under the control of a ground level operator. As a result the operator is free to pursue other ground level duties. In addition there is no need to use a relatively long, inclined conveyor to carry materials to the receiving position. The result is a considerable saving in the space that would otherwise be used by the inclined conveyor.
In accordance with another aspect of the invention, the receiving position and the loading position are at the same operational level. This permits a ground level operator to attend to both loading and stacking operation.
In accordance with a further aspect of the invention, the platen is elevatable. This permits the stack to be formed by building successive tiers on prior tiers at the loading position.
In accordance with a still further aspect of the invention, the platen can be lowered from its initial position. This permits an extension in the range of the stacking equipment.
In accordance with yet another aspect of the invention a guide member, which can take the form of a stripper, can be employed to facilitate the deposit of each tier in the proper position at the loading position.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become apparent after considering several illustrative embodiments, taken in conjunction with the drawings in which:
FIG. 1 is a partial perspective view of a system being used to form stacks in accordance with the invention;
FIG. 2 is a partial perspective view showing details of the system of FIG. 1;
FIG. 3 is a partial perspective view showing a platen of a stacking assemblage in accordance with the invention being moved to overlie a loading position; and
FIG. 4 is a partial perspective view showing the platen of FIG. 3 in an elevated position prior to being moved to overlie the loading position.
DETAILED DESCRIPTION
Turning to the drawings, a stacking assemblage 10 in accordance with the invention is positioned between a receiving or staging position P1 and an outbound or loading position P2.
Items to be stacked, such as individual bundles B, reach the receiving position P1 over an infeed conveyor 20, which terminates in staging platform 21. To facilitate the movement of the bundles B on the platform 21, its surface 22 has a set of raised spheroids 23. In some cases, it is advantageous to further facilitate the movement of bundles across the surface 22 by substituting ball bearings for the spheroids 23.
Once a bundle arrives at the staging area, it is moved by an operator O to a platen 11 of the stacking assemblage 10, where it forms a part of a prescribed pattern of bundles in a single tier or layer. The surface 11s of the platen 11 may be may be similar to the surface 22 of the staging platform 21 to facilitate movement of the bundles, or it may be formed by rotatable cylinders of the kind commonly employed in conveyors.
After each tier is completed by the operator O on the platen 11, the stacking assemblage 10 is operated to deposit the tier at the loading position P2 on an outbound conveyor 30.
As can be seen from FIG. 1, a prior tier T1 is already located at the loading position P2; and a prior stack S1 that has been formed by the stacking assemblage 10 is farther down the outbound conveyor 30. The stack S1 is made up of various tiers, of which tiers T'1 and T'2, and parts of tiers T'3 and T'4 are visible. The stack S1 and the tier T1 are formed on a support sheet 41 which is taken from a stack 40. In some cases pallets are substituted for the support sheets 41. In other cases, no support sheet is needed.
It will be noted that the tiers T'1 through T'4 of the stack S1 have alternative configurations in order to increase the the stability of the overall stack. Each bundle B is illustratively rectangular, being formed by a substack of collapsed boxes which are to be imprinted and filled with merchandise. In the stack S1, the bundles are lapped for increased stability by having each short side adjoining a long side in an adjoining tier.
In addition, an automatic device may be substituted for the staging platform 21 in order to arrange the incoming bundles in a prescribed pattern on the platen 11.
Details of the stacking assemblage 10 are shown in FIG. 2. The platen 11 is vertically and horizontally movable by being mounted with respect to a platen support 12 in a channel 13 of stacker support 14. Gear head motors (not shown) of conventional design may be used with drive cables to move the support 12, and in turn the platen 11, upwardly or downwardly on command.
Horizontal movement of the platen 11 is provided by appropriate gearing (not shown) in the support 12 which acts on gear teeth 11g to move the platen until it overlies the loading position P2.
To further facilitate the operation of the stacking assemblage 10, guide members 15-1 and 15-2 are included. The first guide member 15-1 is attached to the platen support 12, so that movement of the platen 11 is relative to it, in a guide groove 11a.
The second guide member 15-2 is retractable with respect to a mount 16 that moves with the platen support 12. The mount 16 not only includes gearing (not shown) that meshes with the guide teeth 15g; in addition, the mount 16 desirably includes a yoke and plunger arrangement, for example (not shown) to displace the second guide 15-2 in the direction of the lateral movement of the platen 11 by a prescribed amount d.
An illustrative displacement of the platen 11 is pictured in FIG. 3. As shown, the platen 11 had previously been lowered below the level of the staging platform 21 after the formulation of the tier T1 shown in phantom by downward movement of the platen support 12. This is because the outbound conveyor 30 is located below the level of the inbound conveyor 20. Since multi-tier stacks are to be formed on the outbound conveyor 30, it is advantageous for the conveyor to be below the level at which operator force will be applied to move the resultant stacks along the conveyor. In addition, even if the outbound conveyor 30 is at the level of the inbound conveyor 20, it is advantageous for the platen 11 to go below that level in order to extend the stacking capability.
Thus, if the platen can be lowered by one or more tier levels, an operator can form two or more tiers on the platen while working at customary ground level. The multiple tier is then deposited at the loading position in the usual way.
Before the platen in FIG. 3 begins its movement towards the loading position, the second guide 15-2, which acts as a stripper, is retracted. This is to prevent interference with the tier T1. Once the platen is fully displaced, the stripper is returned to its original position. When the platen 11 is moved towards the staging member 21, the tier T1 engages the outward side of the stripper and is prevented from further movement, so that it drops at the loading position on the support sheet 41.
As noted earlier, the stripper 15-2 is desirably displaceable in the direction of outward movement of the platen 11. This displacement prevents the tiers of the stack formed at the loading position from interfering with the stacking assemblage 10 by providing for example, a clearance on the order of several inches depending on the extent of the lateral displacement of the stripper.
In FIG. 4, the platen 11 is shown in an elevated position preparatory to the deposit of a second tier T2 on the prior tier T1 at the loading position P2. The operation of the stacking assemblage is otherwise the same as that illustrated in FIG. 3.
While various aspects of the invention have been set forth by the drawings and the specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
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A stacking assemblage fed from a conveyor which transports materials to a staging area. The materials are formed into a tier on a movable platen of the assemblage in accordance with a prescribed pattern. The platen can be raised or lowered to a desired level and then shifted to deposit each tier on an outboard conveyor until a desired multi-tier stack is formed.
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BACKGROUND
From time to time, railroad cars derail and must be lifted and placed back upon the rails. The modern technique for rerailing cars is to lift them with a large crane having a lifting cable that terminates in a hook, generally a foundry (or factory) hook. The Association of American Railroads has recommended a provision for lifting a freight car comprising an opening in the horizontal structure such as a horizontal flange of the side sill or an opening in the bottom plate of the body bolster. This provision has the definite disadvantage of weakening the railroad car understructure at the side sill and/or the bolster. Thus, the understructure is weakened at the very location where strength is most needed during the lifting and rerailing of the railroad car. Consider that the same recommendation requires that the provision be designed to withstand a force of 40% of the gross weight applied at 15° of the vertical axis of the upright car. (AAR Standard S-234-78). The load must be supported without exceeding the yield strength of the material comprising the understructure except for very local deformation permitted to achieve bearing area.
Roping staples are longitudinal and vertical openings that serve the function of "cabling" cars. Cabling is a technique for towing railroad cars from a vehicle travelling substantially parallel to the track upon which the railroad car rides. The Association of American Railroads recommends that the roping staple be designed to pull 6 fully-loaded cars equipped with roller bearings on tangent track with a 1% grade (AAR Standards).
Typically, the railroad cars are cabled or pulled by a car puller located adjacent the track upon which the car is loaded. For design purposes, the cable load is considered 22,000 pounds and the cable is considered to be at an angle of 10° horizontally and 10° vertically from the roping staple. The roping staple must withstand the forces applied by the pulling cable and facilitate direct access.
U.S. Pat. Nos. 728,212 and 1,341,787 are directed to roping staples and lifting lugs for securing to the side sill of a railroad car near the side bolster. Each of these patents discloses a device that does not require holes be placed in the side sill and/or bolster except for the fasteners.
The earlier patent merely discloses a roping hook which is not arranged to accommodate a lifting hook except a very large angle be formed between the plane of symmetry of the hook and the vertical cable to which the hook is attached. The latter patent discloses a very complex shape which probably can only be formed by casting. The casting has an opening for receiving a hook which will form a large angle between the plane thereof and the vertical cable. In each case, the lifting hook is supported by the tensile strength of the annular portion of the device surrounding the opening in which a hook may be placed much the same as a chain length supports a tensile load of the chain.
It is an object of this invention to provide a simple, rugged device which can be bolted or welded to the side sill near the bolster to provide a location at which a lifting hook can be inserted and/or cables for cabling can be secured. The load is transferred from the lifting hook to the underframe through the device substantially entirely by compressive forces. Moreover, aside from bolt or rivet holes, there is no need to place holes in the elements comprising the understructure of the railroad car thus preventing an undesirable weaking of the understructure where strength is especially required. The hook of the type currently used for rerailing cars (for example a 504 factory hook) can directly engage the device eliminating any requirements for auxiliary chains and hooks.
SUMMARY OF THE INVENTION
Briefly according to this invention, there is provided a roping staple for attachment to the underface of a side sill of a railroad car comprising a ring shaped portion having an inverted stirrup shape. The ring shaped portion further comprises a generally horizontal portion having a cylindrical surface and a U-shaped portion having a generally toroidal surface. According to a preferred embodiment, the ring shaped portion is forged. According to yet another embodiment, the roping staple is provided with a bracket having an upwardly extending flange and a horizontally extending flange. The ring shaped portion is then attached to the underface of the horizontal flange and the bracket is secured as by bolting or riveting to the side sills of a railroad car. Where no bracket is used but merely the ring shaped portion, the ring shaped portion has an upper surface that is flat and which may be welded along the edges thereof to the underface of the side sill. It is preferred according to this invention that the radius of curvature of the cylindrical surface of the horizontal part of the ring shaped portion is greater than the radius of curvature of the curves generating the toroidal surface of the generally U-shaped portion. It is further preferred that if the ring shaped portion is secured to a bracket, that the approximate plane of symmetry of the ring shaped portion be offset from the planes defined by the faces of the vertical flange comprising the bracket. The offset is preferably toward the outside of the railroad car to which the bracket is secured, thus enabling the contact between the roping staple and the lifting hook to be substantially beneath the lifting cable.
THE DRAWINGS
FIGS. 1 and 2 relate to an embodiment of this invention which device is made by casting and machining, for example, and can be riveted or bolted to the side sill of a railroad car;
FIGS. 3 and 4 relates to an embodiment of this invention which is a forged device and can be welded directly to the underface of a side sill of a railroad car.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Throughout this application, the applicant's invention has been referred to as a "roping staple". However, only one of its functions is that of a roping staple. It is also a lifting lug.
The underframe of a railroad freight car typically comprises a center sill which is an elongate horizontal beam along the center line of the railroad car. At two locations near each end of the center sill, center plate assemblies are secured to center sill. The wheel trucks are pivotally secured to the center plates for rotation around generally vertical axes. Extending transverse of the center sill, usually at least outward of the center plates are tranverse bolsters which are simply cross beams forming the beam surfaces for the floor and/or body of the railroad car. Side sills are beams parallel to the center sill near the outer edge of the car secured to the ends of the transverse bolsters. Typically the couplers between the cars are secured directly to the center sills. The side sills are variously channeled beams or angle beams. The lower horizontal flange of the beams comprising the side sill may point inwardly or outwardly.
When a car is lifted by crane for rerailing, it is engaged at the side sill near the bolsters or at the trucks themselves (see, for example, U.S. Pat. No. 3,752,083). Occasionally it is desirable to chain the trucks to the underframe prior to lifting the freight car because the suspension system will expand as the weight of the railroad car is lifted off of the truck.
Referring now to FIG. 1, there is illustrated a roping staple 10 and shown in dashed lines a section of a side sill 20 and a factory hook 30. The particular side sill shown is of the type having a horizontal web 21 and a vertical web 22 formed together along abutting edges. The section of the side sill illustrated is taken to just one side or the other of the location at which the transverse bolster joins the side sill. Thus the end of the hook 31 will not be obstructed and the hook can engage the roping staple near its cradle 32. The particular side sill illustrated has an outwardly directed horizontal flange. The roping staple comprises an angle beam or bracket portion 11 and a D-shaped ring portion 12. The ring portion may be variously shaped but preferably resembles an inverted stirrup having a horizontal upper portion 13 and having a cylindrical surface and a U-shaped portion 14 depending therefrom. It is cylindrical in that it is a surface generated by a line (the generatrix) which moves so that it intersects a plane curve (the directrix) and always remains parallel to a fixed line that lies outside of the plane curve. Preferably, all or at least a portion of the directrix comprises a portion of a circle. The cylindrical horizontal portion 13 of the ring portion is essential as will be explained. The bracket portion 11 and ring portion 12 are either a unitary structure or are fastened together by welding. The inner surface of the U-shaped portion 14 has a portion that is generally toroidal. It is toroidal in that it is a surface shaped somewhat like a donut generated by the spacial rotation of a circle or a portion thereof about an axis which is in its plane, but does not intersect it. This insures that the hook will not wedge. The D-shaped ring portion of the roping staple 12 is generally symmetrical about a plane passing through all parts of the ring. This plane is, of necessity, offset from the plane of the faces of the horizontal web of the bracket portion 11 of the roping staple. However, the offset may be beneficial if it moves the ring portion outwardly from the center of the car body. In this instance it permits the cable from which the hook is supported to move more or less directly vertically upward of the location where the cable engages the hook and the hook engages the roping staple. As mentioned above, the horizontal portion 13 of the ring portion of the staple is essential. It has a cylindrical surface for bearing upon the cradle portion of the hook to thus provide a seat for the hook substantially aligned with the cable to which the hook is attached. The forces from the hook are directed upward to the angle portion of the staple and thus to the side sill. In a preferred embodiment illustrated in FIGS. 1 and 2, the radius of curvature of the cylindrical horizontal portion of the ring is just less than that of the hooks that might be used therewith. Thus the hook will seat over a larger area.
The horizontal and vertical webs or flanges of the bracket portion are provided with openings 15 through which fasteners (rivets or bolts, for example) may be passed to secure the staple to the side sill. The most severe load the staple will encounter are those when a lifting hook is inserted therein and the railroad car to which it is attached is being rerailed. Note that the fasteners are not load carrying in this instance. The upper surface of the horizontal web of the staple is simply pressed tightly against the lower face of the horizontal web or flange of the side sill. When the roping staple is to secure a cable for towing the railroad car from a vehicle on a path generally parallel to the track, the forces on the staple are much smaller and are easily handled by the fasteners.
The roping stable described with reference to FIGS. 1 and 2 may be made as unitary pieces by casting and subsequent machining. On the other hand, the ring portion may be forged and the bracket portion rolled and the two portions welded together.
FIGS. 3 and 4 illustrate another embodiment of this invention which is less expensive and lighter weight than that described with reference to FIGS. 1 and 2. In FIGS. 3 and 4, elements corresponding to those described for FIGS. 1 and 2 bear like identifying numerals. An inverted stirrup shaped ring is forged with a very flat upper horizontal surface 16. The forged ring is then welded directly to the underface of the side sill of a freight car. Because of the overall design, the welded attachment 17 provides sufficient strength. As with other embodiments, the greatest loads are encountered when the roping staple is being used for rerailing. In this instance, most of the load from the crane hook is transferred to the side sill by compression of the horizontal portion of the ring to the side sill and the welds are not strained beyond their strength.
Having thus defined my invention in detail and with particularity required by the Patent Laws, what is desired protected by Letters Patent is set forth in the following claims.
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A roping staple (and lifting lug) especially for securing to the side sill of a railroad car. The roping staple is uniquely provided with the strength and accessibility required for modern day railroading and yet is suitable for economical construction.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a slack adjuster. A slack adjuster is an integral part of actuating linkage for a vehicle air brake system on heavy duty vehicles, such as buses and trucks. The slack adjuster transmits braking force to a brake shaft, which applies the braking force to a cam and thereby to the brake shoes and drum associated with a road wheel of the vehicle.
[0002] One common type of slack adjuster includes a worm and a worm gear that are in meshing engagement within a housing or body. The worm gear is a metal gear that rotates within a cylindrical opening in a metal body. Annular shoulders on the worm gear engage the cylindrical surface of the body, to support the worm gear for rotation within the body. The brake shaft extends through the adjuster and is fixed for rotation with the worm gear by a splined connection. The worm and the worm gear are relatively rotatable to effect adjustment of the linkage to accommodate clearance that develops in the system with extended usage of the brake.
[0003] In this type of slack adjuster, the braking force is applied to the body of the slack adjuster through an actuator. The body transmits the braking force, through the worm and the worm gear, to the splined connection with the brake shaft. The brake shaft is thus rotated to actuate the brake.
[0004] The worm gear is subjected to the entire braking force passing through the brake adjuster. The resulting force presses the worm gear against the body which causes a substantial amount of friction. This friction in turn causes galling of the body material and worm gear as they interface. When the damage from galling becomes severe the performance of the slack adjuster can be greatly reduced.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a slack adjuster for a vehicle brake. The adjuster includes a slack adjuster body having a cylindrical inner surface at least partially defining a chamber in the body. A worm gear is received in the chamber in the body. At least one low friction ring is interposed between the worm gear and the body and supports the worm gear for rotation in the chamber in the body.
[0006] The present invention also relates to a method of remanufacturing a slack adjuster including the steps of removing q worm gear and at least one low friction ring from a body of the slack adjuster; setting aside the removed low friction ring; and putting the worm gear and at least one new low friction ring into the body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, in which:
[0008] FIG. 1 is a perspective view of a slack adjuster in accordance with a first embodiment of the invention;
[0009] FIG. 2 is a front elevational view of the slack adjuster of FIG. 1 ;
[0010] FIG. 3 is a side elevational view of the slack adjuster of FIG. 1 ;
[0011] FIG. 4 is a radial sectional view of the slack adjuster of FIG. 1 ;
[0012] FIG. 5 is an exploded sectional view of the slack adjuster of FIG. 1 ;
[0013] FIG. 6 is an axial sectional view of the slack adjuster of FIG. 1 ;
[0014] FIG. 7 is an axial sectional view of a slack adjuster in accordance with a second embodiment of the invention;
[0015] FIG. 8 is an exploded sectional view of the slack adjuster of FIG. 7 ; and
[0016] FIG. 9 illustrates graphically a method of remanufacturing a slack adjuster in accordance with the invention.
DESCRIPTION OF THE INVENTION
[0017] The present invention relates to a slack adjuster and is applicable to various slack adjuster constructions. As representative of the present invention, FIGS. 1-6 illustrate a slack adjuster 10 in accordance with a first embodiment of the invention
[0018] The slack adjuster 10 ( FIGS. 1-3 ) is connected between brake linkage 12 that forms a part of an actuator, and a brake shaft 14 . The application of an actuating (braking) force to the linkage 12 will operate through the adjuster 10 to rotate the brake shaft 14 and apply the brakes by engaging brake shoes with the brake drum 16 . The slack adjuster 10 is adjustable, in a known manner, to take up the slack in the brake system which occurs after prolonged use.
[0019] The slack adjuster 10 ( FIGS. 4 and 5 ) includes a body 20 having a cylindrical inner surface 22 . The surface 22 defines a circular central opening or chamber 24 centered on an axis 26 .
[0020] A worm gear 30 is received in the chamber 24 and is rotatable in the chamber about the axis 26 . The worm gear 30 has a generally cylindrical configuration including an intermediate gear tooth portion 32 and first and second end portions 34 and 36 . The intermediate portion 32 of the worm gear 30 includes a set of spiral gear teeth 42 . The worm gear 30 has a central opening 38 that receives the brake shaft 14 in a splined connection 40 .
[0021] The intermediate portion 32 of the worm gear 30 has an annular, radially extending surface 46 that forms an edge of the gear tooth portion of the worm gear. The surface 46 faces axially outward of the worm gear 40 . The first end portion 34 of the worm gear 30 has a cylindrical surface 48 that extends axially outward from the radially extending surface 46 . The two surfaces 46 and 48 form a first shoulder 50 , on the worm gear 30 , facing away from the central gear tooth portion 32 of the worm gear.
[0022] The central portion 22 of the worm gear 30 has an annular, radially extending surface 52 that forms an edge of the gear tooth portion of the worm gear. The surface 52 faces axially outward of the worm gear 30 . The second end portion 36 of the worm gear 30 has a cylindrical surface 54 that extends axially outward from the radially extending surface 52 . The two surfaces 52 and 54 form a second shoulder 56 , on the worm gear 30 , facing away from the central gear tooth portion 32 of the worm gear.
[0023] The slack adjuster 10 includes one or more bearings or low friction rings for reducing friction between the worm gear 30 and the body 20 . In the embodiment illustrated in FIGS. 1-6 , the slack adjuster 10 includes two low friction rings 60 and 62 . In the embodiment illustrated in FIGS. 7-8 and described below, the slack adjuster 10 a includes one low friction ring 80 . In other embodiments of a slack adjuster in accordance with the invention, more than two low friction rings may be included, and the low friction rings may be of a different type than as illustrated herein.
[0024] The two low friction rings 60 and 62 shown in FIGS. 5 and 6 are identical to each other. In other embodiments they may be different, for example, of differing axial widths to fit a particular slack adjuster. Each low friction ring 60 or 62 is an annulus or ring having a cylindrical inner side surface 64 , a cylindrical outer side surface 66 , and parallel, radially extending inner and outer edge surfaces 68 and 69 . A low friction ring of the present invention may be split as illustrated at 71 ( FIG. 4 ), or may be solid (unbroken around its circumference).
[0025] The low friction rings of the present invention are made from a material having a lower coefficient of friction than the worm gear itself on metal. One suitable material is nylon. Another suitable material is bronze. Other materials may be used.
[0026] Each low friction ring 60 or 62 is located in one of the shoulders 50 or 56 of the worm gear 30 . The inner side surface 64 of the first low friction ring 60 engages the cylindrical surface 48 of the first shoulder 50 of the worm gear 30 . The inner edge surface 68 of the ring 60 engages the annular side surface 46 of the first shoulder 50 .
[0027] The inner side surface 64 of the second low friction ring 62 engages the cylindrical surface 54 of the second shoulder 56 of the worm gear 30 . The inner edge surface 68 of the ring 62 engages the annular side surface 52 of the second shoulder. The outer edge surfaces 69 of the rings 60 and 62 engage the inner wall of the body 20 and the cover 74 . The rings 60 and 62 thus provide a low-friction fit between the worm gear 30 and the body 20 in an axial direction as well.
[0028] The outer diameter of the low friction rings 60 and 62 is greater than the outer diameter of any portion of the worm gear 30 including the first and second end portions 34 and 36 and the central gear tooth portion 32 . As a result, the gear teeth 42 on the worm gear 30 have a smaller diameter than the low friction rings 60 and 62 .
[0029] The slack adjuster 10 also includes a worm 70 located in the body 20 and in meshing engagement with the worm gear 30 . The worm 70 projects through a cutout 72 in the inner surface 22 of the body 20 to enable the worm to mesh with the worm gear 30 . The slack adjuster 10 also includes a cover 74 that closes the open end of the chamber 24 and helps to retain the worm gear 30 and the low friction rings 60 and 62 .
[0030] When the low friction rings 60 and 62 and the worm gear 30 are in the body 20 , the low friction rings support the worm gear for rotation relative to the body, about the axis 26 . The outer side surfaces 66 of the low friction rings 60 and 62 engage the cylindrical inner surface 22 of the body 20 . No portion of the worm gear including the first and second end portions 34 and 36 and the central gear tooth portion 32 engages the inner surface 22 of the body 20 . As a result, the worm gear 30 can rotate within the body 20 without engaging the body. When a load is applied to the worm gear 30 that tends to urge the worm gear in a direction radially toward the body 20 , the low friction rings 60 and 62 transmit that load to the body without engagement of the worm gear with the body.
[0031] The low friction rings 60 and 62 thus reduce wear on the worm gear 30 and on the body 20 . Specifically, slack adjusters 10 including the low friction rings 60 and 62 , in repeated testing, show 5 times as much useful life as those without the low friction rings. This 400% increase in useful life is attained with minimal increase in cost or manufacturing complexity compared to the overall cost of the slack adjuster. Also, a less forceful actuator can be used, and still maintain proper slack adjuster operation.
[0032] In addition, the amount of wear experienced by the worm gear 30 and the body 20 is so low that a slack adjuster 10 including the low friction rings 60 and 62 is remanufacturable. The slack adjuster can be remanufactured (rebuilt) in the following manner, as illustrated graphically in FIG. 9 .
[0033] The cover 74 on the end of the body 20 is removed. The worm gear 30 and the low friction rings 60 and 62 are removed. The used low friction rings 60 and 62 are set aside. New low friction rings 60 and 62 are placed on the same worm gear 30 or in the same body 20 . The worm gear and the new low friction rings are placed again in the chamber in the body. The removed cover 74 is replaced. At this point, a fully functional slack adjuster 10 is available for reuse or sale, using the previous body and worm gear.
[0034] FIGS. 7 and 8 illustrate a slack adjuster 10 a constructed in accordance with a second embodiment of the invention. The slack adjuster 10 a is generally similar in construction to the slack adjuster 10 ( FIGS. 1-6 ), and parts that are the same or similar are given the same reference numeral with the suffix “a” added.
[0035] In the slack adjuster 10 a , a single low friction ring in the form of a wear sleeve 80 is supported on the body 20 a , in place of the two low friction rings 50 and 62 that are on the worm gear. The sleeve 80 is preferably made from nylon, but may alternatively be made from another low friction material, such as oil-impregnated bronze.
[0036] The sleeve 80 has a cylindrical configuration including parallel inner and outer side surfaces 82 and 84 . The sleeve 80 is fitted in the chamber 24 a in the body 20 a . The chamber 24 a may be made larger in diameter that the chamber 24 , to accommodate the sleeve 80 . The sleeve 80 is fixed in the body 20 a in a manner not shown. The sleeve 80 has a cutout 86 that aligns with the cutout in the body 20 a to enable the worm to mesh with the worm gear.
[0037] The end portions of the worm gear 30 are formed as lands 88 that are larger in diameter than the central gear tooth portion 32 a . The lands 88 have cylindrical outer side surfaces that engage the cylindrical inner surface 22 a of the sleeve 80 .
[0038] When the worm gear 30 a rotates in the body 20 a , the metal of the lands 88 of the worm gear rides against the low friction material of the sleeve 80 . The friction between these parts is substantially less than the friction between a metal worm gear and a metal body. Test results show a reduction in wear and an increase in product life similar to that experienced with the first embodiment ( FIGS. 1-6 ). In addition, the adjuster 10 a is remanufacturable in the manner shown in FIG. 9 and described above with reference to the adjuster 10 .
[0039] From the above description of the invention, those skilled in the art will perceive improvements, changes, and modifications in the invention. Such improvements, changes, and modifications within the skill of the art are intended to be included within the scope of the appended claims.
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A slack adjuster for a vehicle brake includes a slack adjuster body having a cylindrical inner surface at least partially defining a chamber in the body. A worm gear is received in the chamber in the body. At least one low friction ring is interposed between the worm gear and the body and supports the worm gear for rotation in the chamber in the body. A method of remanufacturing a slack adjuster includes the steps of removing a worm gear and at least one low friction ring from a body of the slack adjuster; setting aside the removed low friction ring; and putting the worm gear and at least one new low friction ring into the body.
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Cross Reference to Related Applications
[0001] This application is a continuation of U.S. patent application Ser. No. 12/510,714, filed Jul. 28, 2009, now U.S. Pat. No. 8,160,573; which is a continuation of U.S. patent application Ser. No. 11/613,231, filed Dec. 20, 2006, now U.S. Pat. No. 7,567,801; which is a continuation of U.S. patent application Ser. No. 11/027,233, filed Dec. 30, 2004, now U.S. Pat. No. 7,209,738; which is a continuation of U.S. patent application Ser. No. 09/473,604, filed Dec. 29, 1999, now U.S. Pat. No. 6,898,427; all of which are incorporated by reference herein in their entirety into this disclosure.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and apparatus for extending coverage for a portable communications device such as an interactive (two-way) communications device. In particular, the present invention relates to extending coverage for a two-way pager in areas where the pager cannot transmit to a receiving station and/or receive from a transmitting station.
BACKGROUND OF THE INVENTION
[0003] Portable Interactive two-way pagers and a pager network system in support thereof are known. Examples of such two-way pagers include the RESEARCH IN MOTION (RIM) “BLACKBERRY” two-way pager designed and/or marketed by RESEARCH IN MOTION Limited of Waterloo, Ontario, Canada and the MOTOROLA two-way pager designed and/or marketed by MOTOROLA Corporation of Schaumberg, Ill., USA. Such pagers typically include a battery compartment for receiving a battery, a processor, memory, a data screen for displaying alpha-numeric data, a micro-size keyboard for entering alpha-numeric data, a radio receiver for receiving data over air, and a radio transmitter for transmitting data over air. Accordingly, data may be transmitted from one pager and received by another by way of the network system. Likewise, data from a source external to the network system may be received by a pager, and such pager may transmit data to a destination external to the network system. In addition, such pagers typically include a serial port or the like by which data may be uploaded and/or downloaded, for example during pager initialization, set-up, and upgrade at a pager sales and/or service center.
[0004] Examples of pager network systems include the MOBITEX network designed and/or marketed by ERICSSON MOBILE COMMUNICATIONS AB of Sweden and the REFLEX network designed and/or marketed by MOTOROLA Corporation of Schaumberg, Ill., USA. Such network systems (“networks”) typically include one or more base stations, where each base station has associated with it a plurality of geographically spaced base transmitters, each of which can potentially transmit the data received by the radio receiver of the pager, and a plurality of geographically spaced base receivers, each of which can potentially receive the data transmitted by the radio transmitter of the pager. The base transmitters and the base receivers are spread out over a network coverage area, and each is assigned particular transmitting or receiving frequencies by its respective base station.
[0005] As should be appreciated, each base station is responsible for directing pager data to its ultimate destination or from its ultimate source. Such base station also assigns the frequencies to the base transmitters and base receivers, keeps track of the locations of pagers with respect to base transmitters and base receivers, assigns each pager to a particular base transmitter and to a particular base receiver as the pager is moved through the network coverage area, or at least through the portion thereof that the base station is responsible for, and transmits information to each pager regarding the assigned base transmitter and assigned base receiver and/or frequencies thereof, among other things. Since the pager must acknowledge receipt for data verification purposes and the like, among other things, the pager must always be in two-way communication with the network, even if only receiving data from such network.
[0006] Typically, the base transmitters operate at a relatively high power, owing to the fact that each pager is battery-operated and the receiver therein operates at a relatively low power. Also owing to the fact that each pager is battery-powered and the transmitter therein likewise operates at a relatively low power, the base receivers are typically concentrated at a higher number per geographical area than the transmitter base stations in the network coverage area. Accordingly, it is statistically more likely that a pager is closer to a base receiver than to a base transmitter. Correspondingly, it is also more likely that a pager in a fringe (i.e., area on the edge) or marginal (i.e., an area with poor transmission quality) portion of the network coverage area can receive data from a base transmitter, but that a base receiver cannot receive data from such pager, owing to the relatively low transmitting power of such pager.
[0007] The network coverage area for a pager network is typically finite. For example, such network coverage area may roughly correspond to a state or region, a portion of a state or region, a metropolitan area, a metropolitan area extending over portions of several states or regions, or the like. Accordingly, through cooperative service agreements between networks, ‘roaming’ pager coverage may be provided for a pager outside the network coverage area of its ‘home’ network. With such cooperative service agreements, the over-all pager coverage area encompasses a large portion of urban areas in the United States, and many rural areas too. Inevitably, though, there are significant portions of the United States where pager coverage is not available. As should be appreciated, coverage for a pager is not available anywhere the pager cannot communicate with both a base receiver and a base transmitter to achieve the aforementioned two-way communications link. For example, coverage is not available in fringe or marginal portions of the network coverage area or the over-all pager coverage areas (if roaming coverage is provided), as was pointed out above, and in areas external to the network coverage area or the over-all pager coverage areas (if roaming coverage is provided). This is true even if the pager can communicate with a base transmitter. Of course, coverage will also not be available anywhere the pager cannot communicate with a base transmitter, but for the reasons specified above, it is more likely that loss of communication with any base receiver will occur first, or at least concurrently.
[0008] Equally inevitably, individuals with two-way pagers or the like visit areas where coverage is not available, both in and out of the United States, and such individuals would like some sort of continued two-way paging service even though in such areas without coverage. Accordingly, a need exists for a method and apparatus to provide coverage for a two-way pager or the like, especially when the pager is outside the aforementioned coverage area.
SUMMARY OF THE INVENTION
[0009] In the present invention, a portable communications device (PCD) such as a pager is coupled to a first network by way of a second network when the PCD is out of radio communication with the first network. The PCD leaves a first network mode and enters a second network mode. The PCD then establishes a network connection with the first network by way of the second network, and enters into communication with the first network by way of the second network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. As should be understood, however, the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
[0011] FIG. 1 is a block diagram showing a two-way pager or the like and a base station in accordance with one embodiment of the present invention;
[0012] FIG. 2 is a block diagram showing the two-way pager or the like and the base station of FIG. 1 in accordance with another embodiment of the present invention; and
[0013] FIG. 3 is a flow chart depicting steps employed with the two-way pager and the base station of FIGS. 1 and 2 in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] Certain terminology may be used in the following description for convenience only and is not considered to be limiting. The words “left”, “right”, “upper”, and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” are further directions toward and away from, respectively, the geometric center of the referenced object. The words “vertical” and “horizontal” in the present application designate orientations with respect to an object when such object is positioned in a particular and/or customary manner, but do not restrict the present invention to the object in such position. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.
[0015] Referring now to FIG. 1 , a pager 10 or the like and a base station 12 or the like are shown in accordance with one embodiment of the present invention. As was discussed above, and as shown, a typical two-way pager 10 is intended to be in communication with a pager network 13 and may include a battery compartment for receiving a battery 14 , a processor 16 , memory 18 , an output device such as a data screen 20 for displaying alpha-numeric data, an input device such as a micro-size keyboard 22 for entering alpha-numeric data, a radio receiver 24 for receiving data over air, and a radio transmitter 26 for transmitting data over air. Notably, any particular two-way pager 10 may be employed without departing from the spirit and scope of the present invention, and such pager 10 need not necessarily include all of the aforementioned elements 14 - 26 , again without departing from the spirit and scope of the present invention. For example, such pager 10 need not necessarily have the keyboard 22 or the data screen 20 , and could instead or in addition have a speaker and/or a microphone, a video and/or still camera and/or a video screen, and/or the like.
[0016] Importantly for purposes of the present invention, the pager 10 also includes an externally accessible serial port 28 or the like by which data may be uploaded and/or downloaded. As was discussed above, such serial port 28 has heretofore been employed for services such as pager initialization, set-up, and upgrade at a pager sales and/or service center. Nevertheless, the pager 10 is capable of interacting with a device in the field by way of such serial port 28 .
[0017] In one embodiment of the present invention, and as seen in FIG. 1 , when the pager 10 is in an area where coverage is not available, such pager 10 may be placed in a cradle 30 or the like and thereby establish contact with the base station 12 by way of a network 32 such as a public switched (i.e., land line) telephone network, a mobile switching (i.e., mobile or cellular) network, an external computing network such as the Internet, an internal computing network, and the like. The public switched telephone network or the mobile switching network are most likely preferred due to their availability even in many remote and even wilderness locations. Such public switched telephone network or the mobile switching network may also be employed to dial into the aforementioned internal or external computing networks.
[0018] Preferably, the cradle 30 includes a serial port connector 34 for coupling with the serial port 28 of the pager 10 . As may be appreciated, the cradle 30 and the pager 10 may be constructed such that a positive connection between the serial port connector 34 and the serial port 28 is achieved merely by inserting such pager 10 into such cradle 30 . For example, the cradle 30 and the pager 10 may include keying features for guiding and aligning such pager 10 and such cradle 30 during coupling to achieve such positive connection. Such keying features (not shown) may include but are not limited to complementary grooves and ridges, protrusions and recesses, and the like.
[0019] Also preferably, the cradle 30 includes a network connector 36 or the like for coupling the cradle 30 and by extension the pager 10 to the network 32 . Of course, depending on the network 32 , the network connector 36 will vary. For example, for the public switched telephone network, the network connector 36 is merely a telephone connector that receives a connector on one end of a telephone cord, where the other end is appropriately coupled to such network. For the mobile switching network, the network connector 36 may be a port that couples via an appropriate cable to a corresponding port on a mobile phone which in turn is registered on such network. Alternatively, the functional components of such mobile phone are integrated within such network connector 36 . Other appropriate network connectors 36 may be employed based on the network 32 employed without departing from the spirit and scope of the present invention.
[0020] The cradle 30 further preferably includes a network communications device 38 for interfacing between the serial port connector 34 and the network connector 36 . Of course, depending on the network 32 , the network communications device 38 will vary. For example, for the public switched telephone network and the mobile switching network, the device 38 is an appropriately configured modem of a type that is typically employed for such purpose. For the internal or external computing network, the device 38 is an appropriately configured network interface such as a network interface card. Other appropriate network communications devices 38 may be employed based on the network 32 employed without departing from the spirit and scope of the present invention. In any instance, the device 38 receives data from the pager 10 by way of the serial port 28 thereof and sends such data to the network 32 , and also receives data from the network 32 and sends such data to the pager 10 by way of the serial port 28 thereof.
[0021] The cradle 30 may have its own power source, such as a battery or an AC power converter, and/or may derive its power from the received pager 10 . Of course, if power use is more than minimal, it may be preferable that the cradle 30 have its own power source so as not to excessively draw down the battery of such pager 10 . If the cradle 30 has its own power source, such cradle 30 may supply additional power to the pager 10 so as to conserve the battery of such pager 10 and/or provide a power boost to the pager 10 .
[0022] The base station 12 is a traditional base station in the sense that it performs all the normal base station functions with regard to directing data to and from the pager 10 . However, in one embodiment of the present invention, such base station 12 is a non-traditional base station in that it does not have any associated base transmitters or base receivers, and therefore need not concern itself with frequency assignment, pager tracking, pager assignment, and the like. Instead, such base station 12 is a dedicated base station solely for servicing pagers 10 through the network 32 . Accordingly, the base station 12 is coupled to and is a portal between the network 32 and the pager network 13 or the like. In such an instance, the base station 12 may include a server 40 coupled to the network 32 and to the pager network 13 and programmed to emulate all necessary two-way base station functions. Of course, to couple to the network 32 , the base station 12 may also have a network communications device 38 similar to the network communications device 38 in the cradle 30 (e.g., a modem). Moreover, to couple to multiple cradled pagers 10 by way of the network 32 , multiple network communications devices 38 may be employed if necessary. To couple to the pager network 13 , an appropriate network connection 42 may be employed. The details of the couplings, the connections, and the emulation are generally known and therefore need not be described herein in further detail. Of course, the base station 12 may in fact be a non-dedicated base station that directs data from both the network 32 and traditional base transmitters and base receivers without departing from the spirit and scope of the present invention.
[0023] In operation, and referring now to FIG. 3 , when two-way operation of the pager 10 is disrupted because such pager 10 is out of range or is otherwise unable to contact its pager network 13 , the user thereof appropriately places such pager 10 into the cradle 30 (step 301 ) so that the serial port 28 of the pager 10 is coupled with the serial port connector 34 of the cradle 30 . In addition, such user appropriately couples the cradle 30 to the network 32 by way of the network connector 36 (step 303 ) and whatever appropriate coupling is necessary (a telephone cable, for example, in the case of a public switched telephone network).
[0024] Preferably, the pager 10 and the processor 16 therein are programmed to sense the connection to the cradle 30 , and thereby enter a ‘cradled’ mode (step 305 ) where the radio transmitter 26 and radio receiver 24 therein are not employed. Instead, in such ‘cradled’ mode, the pager 10 and the processor 16 therein preferably gain the attention of and establish control over the network communications device 38 (e.g., the modem) (step 307 ) within the cradle. Alternatively, the user may desire or be required to positively command the pager 10 to enter the cradled mode. Thereafter, the pager 10 and the processor 16 therein employ the network communications device 38 to establish a network connection with the base station 12 by way of the network 32 (step 309 ), and then the pager 10 and processor 16 therein enter into two-way communication with the base station 12 by way of the network 32 (step 311 ) to send and receive pager information.
[0025] Preferably, during the time when two-way operation of the pager 10 is disrupted because such pager 10 is out of range or is otherwise unable to contact its pager network 13 , and before the pager 10 enters into two-way communication with the base station 12 , any outgoing data from the pager 10 (such as outgoing messages and other outgoing information) is held in the memory 18 of the pager, and any incoming data destined for the pager 10 (such as incoming messages and other incoming information) is held in an appropriate memory location of the pager network 13 . Accordingly, upon establishing two-way communication between the pager 10 and the base station 12 by way of the network 32 , such incoming and outgoing data is released and exchanged therebetween. Moreover, upon establishing two-way communication between the pager 10 and the pager network 13 by way of the base station 12 and the network 32 , additional incoming and outgoing data (such as new messages and other information) may be composed and exchanged therebetween.
[0026] When the user wishes to end the session, such user may command the pager 10 to do so (step 313 ). The pager may also automatically end the session after a pre-determined period of in-activity, among other things. The user can then remove the pager 10 from the cradle 30 (step 315 ) and de-couple the cradle 30 from the network 32 by way of the network connector 36 (step 317 ). Preferably, upon sensing removal from the cradle 30 , the pager 10 returns to a ‘normal’ mode. Alternatively, the user positively commands the pager 10 to return to normal mode. In one embodiment of the present invention, the user can leave the pager 10 in the cradle 30 and allow the pager 10 to automatically make a connection to the base station 12 by way of the network 32 on a periodic or predetermined basis.
[0027] Even if coverage is available for the pager 10 in the normal mode by way of the pager network 13 , such pager 10 may still be placed in cradled mode to establish two-way communication between the pager 10 and the base station 12 by way of the network 32 without departing from the spirit and scope of the present invention. Reasons for doing so may include anticipation of more reliable two-way communication, and availability of higher data transmission speeds, among other things, as well as user choice or preference.
[0028] In a variation on the embodiment of the present invention shown in FIG. 1 , the actual structure of the cradle 30 is dispensed with, and the pager 10 or the like is coupled directly to the network communications device 38 . Such direct coupling may for example be achieved by way of a serial port connector 34 at the end of a cable which is appropriately attached to such network communications device 38 .
[0029] In another embodiment of the present invention, and referring now to FIG. 2 , the cradle 30 of FIG. 1 is omitted, but the necessary contents and/or functionality therein are re-located to the pager 10 ′, as is shown. Thus, the serial port connector 34 of FIG. 1 is no longer necessary, as the network communications device 38 and the connection between such network communications device 38 and the serial port 28 of the pager 10 ′ are internal to such pager 10 ′. The network communications device 38 (e.g., a modem) may thus comprise a chip set within the pager 10 ′, or the processor 16 of the pager 10 ′ may be programmed with the functionality of such device 38 . The network connector 36 is still necessary but is now mounted directly to the pager 10 ′ by appropriate means. Preferably, the network connector 36 is a micro-size connector to conserve space, and may for example be of a type that ‘flips out’ from the pager 10 ′ in a known manner.
[0030] In operation, the non-cradled pager 10 ′ of FIG. 2 by definition cannot automatically sense a connection to any cradle 30 . Accordingly, such pager 10 ′ must be positively commanded to enter ‘cradled’ mode, or must automatically sense a connection to the network connector 36 to enter ‘cradled’ mode. Likewise, such pager 10 ′ must be positively commanded to enter ‘normal’ mode, or must automatically sense a disconnection from the network connector 36 to enter ‘normal’ mode. Otherwise, the steps shown in FIG. 3 are performed in substantially the same manner.
[0031] Of course, the present invention also encompasses the use of two-way networked data communications devices and portable communications devices other than the pager 10 . Similarly, the present invention encompasses the use of one-way pagers 10 and other similar devices. Likewise, the data from and to the pager 10 or the like may be directed by devices other than a base station 12 , emulated or otherwise.
[0032] The programming necessary to effectuate the present invention, such as the programming run by the processor 16 of the pager 10 and the programming run by the server 40 of the base station, is known or is readily apparent to the relevant public. Accordingly, further details as to the specifics of such programming is not believed to be necessary herein.
[0033] As should now be understood, in the present invention, a method and apparatus are provided to support coverage for a two-way pager or the like, especially when the pager is outside the coverage area of its pager network. Changes could be made to the embodiments described above without departing from the broad inventive concepts thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
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A portable communications device (PCD) is coupled to a first network by way of a second network. The PCD is normally in radio communication with the first network, and is coupled to the first network by way of the second network when the PCD is out of radio communication with the first network. In particular, the PCD is coupled to the second network, and is caused to leave a first network mode and enter a second network mode. A network connection is established with the first network by way of the second network, and communication with the first network is entered into by way of the second network.
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This is a division of application Ser. No. 475,395 filed Mar. 15, 1983.
BACKGROUND OF THE INVENTION
The invention is directed to a new process for the production of 3-oxonitriles by condensation of carboxylic acid esters with carboxylic acid nitriles as well as new 3-oxonitriles. It is known to produce 3-oxonitriles by dimerization of carboxylic acid nitriles in the presence of strong bases after saponification of the intermediately formed iminonitrile in yields of a maximum of 80% (Houben-Weyl, vol. VII/2a, page 515). However, this process is only useful for the production of those compounds of general formula I below in which the group R 1 connected to the ##STR1## and the --CH--P 2 group are the same. If different nitriles are employed there are obtained mixtures of products.
It is further known that the 3-oxonitriles can be obtained directly by condensation of carboxylic acid esters with carboxylic acid nitriles in the presence of strong bases. Strong CH-acid carboxylic acid nitriles, such as benzyl cyanide can be condensed with alcoholates. The yields are between 65 and 70%, based on the carboxylic acid ester employed.
The acylation of slightly acid aliphatic nitriles is accomplished only at elevated temperatures. Thus the yield deteriorates to 53% in the production of 2-benzoylpropionitrile because of undesired side reactions (Houben-Weyl VIII, page 573).
Furthermore, it is known that the condensation of aliphatic nitriles with carboxylic acid esters can only be carried out with finely divided sodium amide in liquid ammonia in preparative satisfactory yields (Houben-Weyl Vol. VIII, page 574, Levine J. Amer. Chem. Soc., Vol. 68, pages 706-761).
In agreement with this data the condensation of 2-methoxybenzoic acid methyl ester with acetonitrile using sodamide/liquid ammonia gives 2-methoxybenzoylacetonitrile in 84% yield, in contrast this same reaction using sodium hydride in benzene only leads to a 27.4% reaction yield. (Kawase, Bull, Chem. Soc. Japan, Vol. 35 (1962), pages 1869-1871.)
Furthermore, the reaction of ethyl propionate with acetonitrile using only 50 weight % sodium hydride is known. Thereby the sodium hydride in benzene at the boiling temperature is first treated with the acetonitrile and then the carboxylic acid ester dropped in. In this procedure there is the danger of self-condensation of the nitrile. Therefore the 3-oxonitrile is obtained in only 52% yield (Brown, Bull. Soc. Chem. France (1971), pages 2195-2203).
These yields are completely insufficient and permit no industrial scale synthesis of the 3-oxonitriles.
Further processes for the production of 3-oxonitriles are the reaction of chlorosulfonyl isocyanate with ketones and subsequent treatment of the N-chlorosulfonyl-3-oxoamide with dimethyl formamide with the setting free of the 3-oxonitrile (Synthesis) 1973, page 682), as well as the reaction of enamines with cyanogen chloride (Kuehne, J. Amer. Chem. Soc. Vol. 81 (1959), pages 5400-5404).
Both methods are very expensive preparatively and require considerable security precautions because of the dangerous nature of the materials employed. Besides the reaction yields at a maximum are 50%, so that there cannot be carried out on industrial syntheses.
There are also known special syntheses for individual 3-oxonitriles. Thus for example, pivaloylacetonitrile is obtained from pinacolone by chlorination and reaction of the monochloropinacolone with an alkali metal cyanide (German OS No. 2819264, the entire disclosure of which is hereby incorporated by reference including U.S. Pat. No. 4,062,861 mentioned therein).
This process is multistep and requires dealing with extremely toxic cyanides. Besides it is known that α-chloroketones, as represented by α-chloropinacolone are dangerous irritant materials.
SUMMARY OF THE INVENTION
It has now been found that there can be produced 3-oxonitriles of the general formula (I) ##STR2## in which R 1 is a tertiary alkyl, cycloalkyl, aromatic or heteroaromatic group which in a given case can be substituted (e.g. the tertiary alkyl can have 4 to 7 or even up to 12 carbon atoms, the cycloalkyl can have 3 to 6 carbon atoms and can be substituted with one or more lower alkyl groups and/or one or more halogen atoms such as Cl, F, or Br, the aryl can be phenyl and can be substituted with at least one lower alkyl group and/or halogen atoms, e.g. Cl, Br or F and/or lower alkoxy group and/or trihalomethyl and/or alkylmercapto group and the heteroaromatic group can be the furan group or the thienyl group and can be substituted with at least one lower alkyl group and/or halogen atom, e.g. Cl, Br, or F), and R 2 is a straight or branched alkyl group, an aryl group which in a given case can be substituted (e.g. the substituent can be e.g. where the halogen is Cl, Br, or F, or lower alkyl) furan, thienyl, or halogen substituted thienyl or furan, e.g. where the halogen is Cl, Br, or F or R 2 is hydrogen by reaction of a carboxylic acid of general formula (II)
R.sub.1 --COOR.sub.3 (II)
in which R 3 is a methyl or ethyl group with a carboxylic acid nitrile of the general formula (III)
R.sub.2 --CH.sub.2 --CN (III)
where R 1 and R 2 are as defined above, in an inert solvent in the presence of sodium hydride if the sodium hydride is employed in the form of a 70-80% suspension in white oil, and this is present together with the ester of general formula (II).
The process of the invention can be carried out without the above-noted disadvantages and for the first time opens up a generally usable method for the production of 3-oxonitriles. It is one step, results in high yields and furnishes products of high purity.
The compounds of general formula I, a few of which are new are valuable intermediate products for the production of 3-ketocarboxylic acid-amides or -esters, heteroacyclics and pesticides. An example is pivaloyl acetonitrile, an important intermediate product for an isoazole herbicide (German OS No. 2,436,179, German OS No. 2,819,264 and U.S. Pat. No. 4,062,861, the entire disclosure of these publications and patents are hereby incorporated by reference and relied upon). The new compounds can be used in the same manner as the compounds prepared in the two German OS and the United States patent and the same procedures can be used.
Under the carboxylic acid esters of general formula (II) those preferred are not enolizable. Under the mentioned meanings for the symbol R 1 the term tert. alkyl groups stands for those groups in which the C-atom in the a-position contains no hydrogen atom. They can contain 4 to 12 carbon atoms, e.g. derived from the 2,2-dimethyl undecanoic acid and likewise the aromatic group can be substituted by groups which are inert to sodium hydride. There particularly belong thereto halogen atoms, alkoxy and alkymercapto groups.
The cycloalkyl group can be substituted in the same manner and preferably has 3 to 6 members.
The heteroaromatic groups which can be present for R 1 and R 2 especially have 5 or 6 members and preferably have O--, S, or N--atoms in the ring they can be uncondensed or condensed. Thus there can be present rings such as the pyridine ring, piperidine ring, thiazole ring, furan ring, thiophene ring, pyrane ring, morpholine ring, benzothiazole ring, pyrrole ring, benzopyrrole ring, quinoline ring, oxazole ring or the like.
Suitable carboxylic acid esters for example are the methyl or ethyl esters of pivalic acid, 2,2-dimethylbutyric acid, 2,2-dimethyl hexanoic acid, 2,2-dimethyl decanoic acid, 2,2-dimethyl undecanoic acid, 1-methylcyclopropanecarboxylic acid, 1-methylcyclobutanecarboxylic acid, 1-methylcyclopentanecarboxylic acid, 1-methylcyclohexanecarboxylic acid, cyclopropanecarboxylic acid, cyclohexanecarboxylic acid, 2,2-dichloro-1-methylcyclopropanecarboxylic acid, benzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid, 4-emthylbenzoic acid, 2-ethylbenzoic acid, 4-butylbenzoic acid, 2,4-dimethylbenzoic acid, 2-fluorobenzoic acid, 3-fluorobenzoic acid, 4-fluorobenzoic acid, 2-chlorobenzoic acid, 3-chlorobenzoic acid, 4-chlorobenzoic acid, 2-bromobenzoic acid, 2,4-dichlorobenzoic acid, 3,4-dichlorobenzoic acid, 3,5-dichlorobenzoic acid, 2,4,6-trichlorobenzoic acid, 2-methyl-4-chlorobenzoic acid, 2-methoxybenzoic acid, 3-methoxybenzoic acid, 4-methoxybenzoic acid, 2-ethoxybenzoic acid, 3,4-dimethoxybenzoic acid, 3,4,5-trimethoxybenzoic acid, 2-trifluoromethylbenzoic acid, furan-2-carboxylic acid, furan-3-carboxylic acid, 5-bromo-2-methylfuran-3-carboxylic acid, thiophene-2-carboxylic acid, thiophene-3-carboxylic acid, 5-methylthiophene-2-carboxylic acid, 2-methylmercaptobenzoic acid, 2-pyridinecarboxylic acid, thiazole-4-carboxylic acid, oxazole-4-carboxylic acid, pyrrole-2-carboxylic acid.
Per mole of carboxylic acid ester employed advantageously there are used 1.5 to 2.1 moles, preferably 2 moles of the sodium hydride.
As inert solvent there are suitable used esters, e.g. dioxane, dibutyl ether or aliphatic, cycloaliphatic or aromatic hydrocarbons such as hexane, decane, cyclohexane, benzene, toluene, or xylene.
The sodium hydride and the carboxylic acid ester are dissolved or suspended in the solvent and heated. Thereby it can be suitable to operate in an inert gas atmosphere, e.g. under nitrogen or argon. Then the carboxylic acid nitrile of general formula (II) is dropped into this heated, strongly stirred suspension.
In general formula (II) R 2 can have the above given meaning whereby in the case of the aromatic group, the heterocyclic group and the alkyl group there are possible the same substitutions as are given under R 1 .
As carboxylic acid nitriles there can be used for example acetonitrile, propionitrile, butyronitrile, valeronitrile, benzyl cyanide, 2-chlorobenzyl cyanide, 4-chlorobenzyl cyanide, 4-fluorobenzyl cyanide, 2-bromobenzyl cyanide, 2-methylbenzyl cyanide, 4-methylbenzyl cyanide, thiophene-2-acetonitrile, thiophene-3-acetonitrile, furan-3-acetonitrile, 5-chlorothiophene-2-acetonitrile.
The amount of the carboxylic acid nitrile of general formula (III) employed in the reaction advantageously is between 1.0 and 2.1 moles per mole of carboxylic acid ester employed. Preferred is an amount between 1.5 and 2.0 moles of nitrile per mole of ester.
The reaction can be carried out in a temperature range between 50° and 110° C. Advantageously there is maintained a range between 60° and 100° C., preferably between 80° and 95° C. The initiation of the reaction can be made easier by the addition of a catalytic amount of an alcohol (methanol, ethanol, isopropanol, etc.). It is indicated by the escape of hydrogen. In the course of the reaction, the reaction speed (indicated through the amount of escaping H 2 per unit of time) can be controlled readily through the addition of nitrile.
The end of the reaction is indicated by the end of the development of hydrogen and through the complete reaction of the NaH in the reaction solution.
The working up is carried out in known manner for example, through stirring the reaction mixture (suspension) with a sufficiently large amount of water that the solids in the reaction mixture dissolve with the formation of two clear phases. The aqueous phase is separated off, the organic phase in a given case stirred with a further amount of water, the water phases combined, cooled and adjusted to a pH between 1 and 5 with aqueous mineral acid, e.g. hydrochloric acid or sulfuric acid, under cooling. Thereby the 3-oxonitrile separates out in solid form or as an oil.
The isolation of the product is carried out by filtering off the solids with suction or separating off the oil.
The product, in a given case, after a subsequent washing with water, is dried and, if necessary, further purified by recrystallization of fractionation.
If the precipitate only dissolved with difficulty in the reaction solution with the addition of water than it can be suitable to filter off this precipitate with suction, post wash with the solvent used, and introduce the product with very strong stirring into an aqueous mineral acid, e.g. hydrochloric acid, for neutralization. The amount of acid is suitably selected so that after complete reaction there is present a pH between 1 and 5 in the aqueous solution obtained. The preferred mineral acid is hydrochloric acid.
In a given case, it can be favorable in this procedure to even employ acetic acid or a mixture of acetic acid-mineral acid. There is then obtained the 3-oxonitrile in solid or liquid form, which, as described above, can be purified. Suitably in the working up the treatment with the acid should be carried out at a temperature which does not exceed 10° C., preferably 0° C.
The white oil used as suspension agent for the sodium hydride in the examples is the commercial product Shell Oudina 15® of the Shell Company. It consists of 65% paraffins and 35% naphthenes in a quality of DAB-8. It has a boiling point of 337° to 370° C./760 Torr.
Unless otherwise indicated all parts and percentages are by weight.
The process can comprise, consist essentially of, or consist of the stated steps with the materials recited.
The invention is explained further in the following examples.
DETAILED DESCRIPTION
Example 1
Pivaloylacetonitrile
55 grams of sodium hydride (as an 80 weight % suspension in white oil) were suspended in 500 ml of dry toluene, 106 grams (0.914 mole) of methyl pivalate added and the mixture heated to 85° C. Then under vigorous stirring there was dropped in 77 grams (1.87 moles) of acetonitrile within 4 hours. Stirring was continued subsequently at 85° C. until the end of the development of hydrogen. The thickly liquid reaction mass was cooled to room temperature, treated with 700 ml of water, stirred vigorously for 30 minutes and the two phases separated in a separatory funnel. The aqueous phase was acidified with 31 weight % of hydrochloric acid at a pH 1-2 and 0° C. The precipitated pivaloylacetonitrile was filtered off with suction, washed until neutral with ice water and dried to constant weight at 25 Torr and 40° C. There were obtained 106 grams (93% of theory) of analytically pure pivaloylacetonitrile having a melting point of 65°-68° C.
Analysis: C 7 H 1 lNO (125.0): Calculated: C, 67.29; H, 8.93; N, 11.0. Found: C, 67.17; H, 8.86; N, 11.9.
Example 2
Pivaloylacetonitrile
There were added in succession under a nitrogen atmosphere into 480 liters of toluene which had been dehydrated by azeotropic distillation 67.76 kg (584 moles) of methyl pivalate and 35 kg of an 80 weight % of sodium hydride in white oil. The suspension was heated to 85° C. and treated with 48.88 kg (1192 moles) of acetonitrile within 6 hours. The reaction mixture was stirred until the end of the development of hydrogen and stirred for a further 1.5 hours at 85° C., cooled to 25° C. and stirred with 500 ml of water. The aqueous phase was separated off, cooled to 0° C. and acidified to a pH 2 with 130 liters of concentrated hydrochloric acid under cooling and stirring. The precipitated produce was separated off, washed neutral with water and dried in a vacuum at 50 Torr and 40° C.
There were obtained 68.6 kg (94% of theory) of pivaloylacetonitrile having a melting point of 65°-68° C.
Example 3
1-Methylcyclopropanoylacetonitrile
128.2 grams (1 mole) of 1-methylcyclopropanecarboxylic acid methyl ester and 60 grams (1 mole) of sodium hydride, 80 weight % in white oil were heated in 750 ml of dry toluene to 80° C. and 82.1 grams (2 moles) of acetonitrile dropped in with vigorous stirring within 1 hour. Stirring was continued at this temperature until the end of the development of hydrogen. After cooling to room temperature the reaction was treated with, in all, 1 liter of water, stirred and after phase separation the aqueous phase adjusted to pH 1.5 with hydrochloric acid. Thereby the temperature was held in a range between 0° and +5° C.
The oil which deposited was separated off, the water phase extracted with 500 ml of methylene chloride, the organic phases combined, dried over sodium sulfate and the solvent distilled off.
The oily residue was fractionated in a vacuum. 104.9 grams (85% of theory) of 1-methylcyclopropanoylacetonitrile came over at 130°-132° C./20 mm.
Analysis: C 7 H 9 NO (123.16): Calculated: C, 68.30; H, 7.40; N, 11.40. Found: C, 68.31; H, 7.44; N, 11.52.
1 H--NMR (CDCl 3 ): δ=3.70 (s, 2H) CH 2 --CH; 1.45 (s, 3H) CH 3 ; 1.4-0.65 ppm (m, 5H); Cyclopropyl
Example 4
(2',2'-Dichloro-1'-methyl)cyclopropanoylacetonitrile
183 grams (1 mole) of 2,2-dichloro-1-methylcyclopropanecarboxylic acid methyl ester and 60 grams (2 moles) of 80 weight % sodium hydride were reacted with 82.1 grams (2 moles) of acetonitrile in 750 ml of dry toluene as described in Example 3.
After the distillation there were obtained 117.6 grams (61.2% of theory) of (2,2-dichloro-1-methyl)cyclopropanoylacetonitrile having a boiling point of 102°-103° C. at 0.5 Torr.
Analysis: C 7 H 7 Cl 2 NO (192.05): Calculated: C, 43.77; H, 3.67; N, 7.29; Cl, 36.92. Found: C, 44.18; H, 4.21; N, 7.63; Cl, 36.91.
1 H--NMR (CDCl 3 ) δw=4.95, 4.90 (S, 2H) CH 2 --CH; 1.95 (AB, 2H) C (Cl 2 )--CH 2 ; 1.70 ppm (S, 3H) C--CH 3 .
Example 5
2-Thiophenoylacetonitrile
78.1 grams (0.5 mole) of thiophene-2-carboxylic acid ethyl ester and 30 grams (1 mole) of sodium hydride (80% suspension in white oil) were reacted with 41.5 grams (1 mole) of acetonitrile in 500 ml of dry toluene. There were obtained 70.0 grams (92.6% of theory) of 2-thiophenoylacetonitrile having a melting point of 110° C.
Analysis: C 7 H 5 NOS (151.18): Calculated: C, 55.61; H, 3.33; N, 9.27; S, 21.21. Found: C, 55.49; H, 3.46; N, 9.11; S, 21.05.
1 H--NMR (DMSO/ d 6 ): δ=8.1-7.0 (m, 3H) H Thiophene, 4.33 ppm (S, 2H) CH 2 CN.
Example 6
2-Furanoylacetonitrile
63.05 grams (0.5 mole) of furan-2-carboxylic acid ethyl ester and 30.0 grams (1 mole) of sodium hydride (80 weight % suspension in white oil) were reacted with 41 grams (1 mole) of acetonitrile in 500 ml of toluene with the addition of 1 ml of methanol at 90° C. After 3 hours reaction time the toluene was distilled off, the residue stirred with 500 ml of water, acidified with hydrochloric acid to pH 1.5 and the precipitated product filtered off with suction and recrystallized from methanol. There were obtained 51.3 grams (76% of theory) of 2-furanoylacetonitrile having a melting point of 74°-75° C.
Analysis: C 7 H 5 NO 2 (135.12): Calculated: C, 62.33; H, 3,73; N, 10.36. Found: C, 61.86; H, 3.48; N, 10.11.
1 H--NMR (CDCl 3 ): δ=7.69 (S, 1H), 7.38 (d, 1H); 6.63 (m, 1H) H Furan ; 4.0 ppm (S, 2H) CH 2 --CN.
Example 7
Benzoylacetonitrile
70 grams (0.5 mole) of ethyl benzoate were heated with 30 grams (1 mole) of sodium hydride (80 weight % suspension in white oil) in 500 ml of dry toluene to 75°-80° C. Within 2 hours there were dropped in 41 grams (1 mole) of acetonitrile and the mixture stirred at 85° C. until the end of the development of hydrogen. The reaction mixture was cooled to room temperature, filtered with suction and the solid material stirred in a mixture of 9 parts of glacial acetic acid and 1 part of 31 weight % hydrochloric acid at 0° C. and this reaction mixture subsequently poured on 700 ml of ice.
The precipitated solids were filtered off with suction, washed neutral with water and dried at 50 Torr 65° C. until constant weight.
There were obtained 64.5 grams (89% of theory) of benzoylacetonitrile having a melting point of 80°-82° C.
Example 8
4'-Methoxybenzoylacetonitrile
166.2 grams (1 mole) of 4-methoxybenzoic acid methyl ester and 60 grams (2 moles) of sodium hydride (80 weight % suspension in white oil) were heated to 65° C. in 750 ml of dry toluene. Within 2 hours there were dropped in 82.1 grams (2 moles) of acetonitrile at 85° C. and then stirring was continued for a further 20 hours at 90° C. The precipitate was filtered off with suction, 200 ml of glacial acetic acid slowly stirred in with cooling and subsequently the mixture was added to 1 liter of ice water. The precipitated crystal mass was filtered off with suction, post washed with water and recrystallized from acetone. There were thus obtained 149 grams (85% of theory) or 4-methoxybenzoylacetonitrile having a melting point of 127°-129° C.
Example 9
2,4,4-Trimethyl-3-oxopentanenitrile
234.6 grams (2 moles) of methyl pivalate and 120 grams (2 moles) of sodium hydride (80 weight % suspension in white oil) were heated to 90° C. in 1500 ml of dry toluene. There were dropped in at this temperature after addition of 1 ml of methanol 233.3 grams (2 moles) of propionitrile within 2.5 hours. After the end of the development of hydrogen the suspension was extracted with a total of 1200 ml of water and after phase separation the aqueous phase was acidified with concentrated HCl to a pH of 2. The deposited oil was separated off, the water phase extracted with chloroform, the organic extracts combined, dried and concentrated. The residue was fractionated in a water jet vacuum. 2,4,4-trimethyl-3-oxopentanenitrile came over at 87° C./11 Torr in an amount of 226.1 grams (81.2% of theory).
Example 10
4,4-Dimethyl-2-ethyl-3-oxopentanenitrile
58 grams (0.5 mole) of methyl pivalate, 30 grams (1 mole) of 80 weight % NaH in white oil, and 69 grams (1 mole) of n-butyronitrile in toluene were reacted in the manner described in Example 9. After working up the crude product obtained was fractionated in the water jet vacuum. 50 grams (65% of theory) of 4,4-dimethyl-2-ethyl-3-oxopentanenitrile came over at a boiling point of 98°-99° C./15 Torr.
Analysis: C 9 H 15 NO (153.2): Calculated: C, 70.5; H, 9.9; N, 9.14. Found: C, 70.48; H, 10.12; N, 9.18.
1 H--NMR (CDCl 3 ): δ=3.83 (t, 1H) CO--CH; 1.91 (q, 2H) CH 2 --CH 3 ; 1.23 (S, 9H) C (CH 3 ) 3 ; 1.06 ppm (t, 3H) CH 2 --CH 3
Example 11
4,4-Dimethyl-2-phenyl-3-oxopentanenitrile
116 grams (1 mole) of methyl pivalate, 60 grams (2 moles) of sodium hydride (80 weight % suspension in white oil) and 234.3 grams (2 moles) of benzyl cyanide were reacted in 750 ml of dry toluene at 60° C. until the end of the evolution of hydrogen. There were added 500 ml of water to the cooled reaction solution, the mixture stirred and the aqueous phase acidified with HCl to pH 3 after the separation and then extracted with chloroform. After concentrating the chloroform the oil residue was fractionated at 0.6 Torr. 110.6 grams (55% of theory) of 4,4-dimethyl-2-phenyl-3-oxopentanenitrile came over at 111° C.
The spectroscopic and analytical data agreed with those of theory.
Example 12
4,4-Dimethyl-2-(3'-thienyl)-3-oxopentanenitrile
116 grams (1 mole) of methyl pivalate, 60 grams (2 moles) of sodium hydride (80 weight % in white oil) and 184.7 grams (1.5 moles) of thiophene-3-acetonitrile were reacted as described in Examples 8 in 750 ml of dry toluene. The reaction time was 24 hours. The crystalline crude product was distilled for purification.
There were obtained 109 grams (53% of theory) of 4,4-dimethyl-2-(3'-thienyl)-3-oxopentanenitrile at a boiling point of 112° C./0.4 Torr and the product had a melting point of 45°-47° C.
Analysis: C 11 H 13 NOS (207.3): Calculated: C, 63.73; H, 6.32; N, 6.76; S, 15.47. Found: C, 63.60; H, 6.34; H, 6.64; S, 14.90.
1 H--NMR (CDCl 3 ): δ=7.4-7.0 (m, 3H) H Thiophene ; 5.33 (S, 1H) CH--CN; 1.22 ppm (S, 9H) C (CH 3 ) 3 .
Example 13
2-Benzoylpropionitrile
137 grams (1 mole) of methyl benzoate and 60 grams (2 moles) of 80 weight % sodium hydride in white oil were heated to 75° C. in 750 ml of toluene and treated at this temperature within 1.5 hours with 110.2 grams (2 moles) of propionitrile. The mixture was stirred at 85°-90° C. until the end of the development of hydrogen. The reaction mixture was filtered off with suction and the precipitate suspended in 1000 ml of water and acidified with hydrochloric acid to pH 2 with vigorous stirring. The precipitated oil was separated off, the aqueous phase extracted with a total of 300 ml of toluene. The combined organic phases were dried over sodium sulfate, concentrated and the oil fractionated in a vacuum.
There were obtained 97 grams (61% of theory) of 2-benzoylpropionitrile of boiling point 110° C./0.6 Torr in the distillation
Analysis: C 10 H 9 NO (159.1): Calculated: C, 75.45; H, 5.70; N, 8.80. Found: C, 75.41; H, 5.89; N, 8.91.
Example 14
4,4-Dimethyl-2-(4'-chlorophenyl)-3-oxopentanenitrile
116 grams (1 mole) of methyl pivalate, 60 grams (2 moles) of 80 weight % sodium hydride in white oil and 151.5 grams (1.5 moles) of 4-chlorobenzyl cyanide were reacted as described in Example 8.
After working up there were obtained 147.4 grams (62.2% of theory) of 4,4-dimethyl-2-(4'-chlorophenyl)-3-oxopentanenitrile as a viscous oil.
Analysis: C 13 H 14 ClNO (235.45): Calculated: C, 66.24; H, 5.97; N, 5.94; Cl, 15.05. Found: C, 66.44; H, 6.06; N, 6.26; Cl, 15.74.
1 H--NMR (CDCl 3 ): δ=7.37 (S, 4H) H Ar ; 5.20 (S, 1H) CH--CN; 1.20 ppm (S, 9H) C (CH 3 ) 3 .
The entire disclosure of German priority application No. P3209472.8 is hereby incorporated by reference.
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3-oxonitriles are produced by reaction of carboxylic acid esters with carboxylic acid nitriles in the presence of 70 to 80% suspension of sodium hydride in white oil. The oxonitrile are intermediate products for the production of 3-oxocarboxylic acid amides or esters and pesticides.
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RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S. patent application Ser. No. 10/005,625 filed on Dec. 5, 2001 and relates to co-pending U.S. patent application Ser. No. 10/004,979 filed on Dec. 5, 2001 and entitled “Coaxial Cable Displacement Contact”. The co-pending application names Michael F. Laub; Richard J. Perko; John P. Huss, Jr.; and Charles R. Malstrom as joint inventors and is assigned to the same assignee as the present application and is incorporated by reference herein in its entirety including the specification, drawings, claims, abstract and the like.
BACKGROUND OF THE INVENTION
[0002] Certain embodiments of the present invention generally relate to a connector for interconnecting coaxial cables and more particularly to a connector having contacts arranged in a strip line geometry. Certain embodiments of the present invention generally relate to a ground shield and center contact arrangement for a connector.
[0003] In the past, connectors have been proposed for interconnecting coaxial cables. Generally, coaxial cables have a circular geometry formed with a central conductor (of one or more conductive wires) surrounded by a cable dielectric material. The dielectric material is surrounded by a cable braid (of one or more conductive wires), and the cable braid is surrounded by a cable jacket. In most coaxial cable applications, it is preferable to match the impedance between source and destination electrical components located at opposite ends of the coaxial cable. Consequently, when sections of coaxial cable are interconnected, it is preferable that the impedance remain matched through the interconnection.
[0004] Conventional coaxial connectors are formed from generally circular components partly to conform to the circular geometry of the coaxial cable. Circular components are typically manufactured using screw machining and diecast processes that may be difficult to implement. As the difficulty of the manufacturing process increases, the cost to manufacture each individual component similarly increases. Accordingly, conventional coaxial connectors have proven to be somewhat expensive to manufacture. Many of the circular geometries for coaxial connectors were developed based on interface standards derived from military requirements. The more costly manufacturing processes for these circular geometries were satisfactory for low volume, high priced applications, as in military systems and the like.
[0005] Today, however, coaxial cables are becoming more widely used. The wider applicability of coaxial cables demands a high-volume, low-cost manufacturing process for coaxial cable connectors. Recently, demand has arisen for radio frequency (RF) coaxial cables in applications such as the automotive industry. The demand for RF coaxial cables in the automotive industry is due in part to the increased electrical content within automobiles, such as AM/FM radios, cellular phones, GPS, satellite radios, Blue Tooth™ compatibility systems and the like. Also, conventional techniques for assembling coaxial cables and connectors are not suitable for automation, and thus are time consuming and expensive. Conventional assembly techniques involve the following general procedure:
[0006] a) after sliding a ferrule over the cable, stripping the jacket to expose the outer conductive braid,
[0007] b) folding the outer conductive braid back over the ferrule to expose a portion of the dielectric layer,
[0008] c) stripping the exposed portion of the dielectric layer to expose a portion of the inner conductor,
[0009] d) connecting a contact to the inner conductor, and
[0010] e) connecting a contact to the outer conductive braid.
[0011] The above-noted procedure for assembling a connector and coaxial cable is not easily automated and requires several manual steps that render the procedure time consuming and expensive.
[0012] Today's increased demand for coaxial cables has caused a need to improve the design for coaxial connectors and the methods of manufacture and assembly thereof.
BRIEF SUMMARY OF THE INVENTION
[0013] In accordance with an aspect of the present invention, a coaxial cable connector is provided for interconnecting coaxial cables having center and outer conductors. The connector includes first and second insulated housings matably joined with one another and configured to receive first and second coaxial cables. The insulated housings include cavities that receive first and second center contacts configured to securely attach to center conductors of the respective coaxial cables. First and second outer ground contacts are configured to securely attach to outer conductors of the respective coaxial cables and are securable to the first and second insulated housings, respectively. At least one of the first and second center contacts has a planar body section arranged between planar sides of the first and second outer ground contacts.
[0014] In accordance with another aspect of the present invention, the first and second insulated housings include top, bottom and side walls formed in a rectangular shape. The first and second outer ground contacts include a rear wall formed with opposed side walls in a rectangular U-shape and having an open front face inserted over the corresponding insulated housing. The first and second insulated housings, when combined, may define flat opposed walls joining the planar sides of the first and second outer ground contacts. Optionally, the insulated housings may include staggered mating faces.
[0015] In accordance with another aspect of the present invention, the center contacts are formed with a blade contact and a receptacle contact. The blade contact is arranged in a contact plane extending parallel to the planar sides of the first and second outer ground contacts. The first and second outer ground contacts and the center contacts cooperate to form a strip line geometry. Optionally, the planar sides of at least one of the first and second center contacts are sandwiched between planar sides of the first and second outer ground contacts. The center and outer ground contacts produce electric fields concentrated in regions on opposite sides of the planar sides of the blade contact. The electric fields extend along an axis perpendicular to the planar sides of the center and outer ground contacts.
[0016] In accordance with another aspect of the present invention, a connector is provided comprising matable connector housings connectable to coaxial cables having center and outer conductors. The connector includes center and outer contacts securable to the center and outer conductors of the coaxial cable, respectively. The center and outer contacts are securely retained by the connector housings and are arranged in parallel planes with the center contact being sandwiched between the outer contacts.
[0017] Optionally, the outer contacts may be formed with U-shaped rectangular shells joining one another to surround the center contact. The center and outer contacts may cooperate to form a strip line geometry. The electric fields are focused on opposite sides of the center contact and extend in a direction transverse to the parallel planes in which the contacts are arranged.
[0018] In accordance with an alternative aspect of the present invention, a coaxial cable connector is provided that comprises a housing having opposite ends configured to be connectable to a pair of coaxial cables. The connector includes a center contact having a planar body. The center contact is configured to be connected to conductors and the pair of coaxial cables. The connector further includes ground contacts configured to be connected to ground conductors in the pair of coaxial cables. The ground and center contacts are retained by the housing and are arranged parallel to one another.
[0019] Optionally, the ground contacts may have planar bodies and be located on opposite sides of the planar body of the center contact. The planar bodies of the ground contacts are arranged parallel to the planar body of the center contact.
[0020] The pair of coaxial cables each form an electric field that is circumferentially symmetrical about the coaxial cables. The center and ground contacts of the coaxial cable connector form an electric field having an asymmetric distribution about center contact with respect to ground contacts, such that the electric field distribution is transferred from a circumferentially symmetric distribution (about the first coaxial cable) to an asymmetric distribution (about center contact with respect to ground contacts) and back to circumferentially symmetric distribution (about the second coaxial cable). The electric field formed by the ground and center contacts may comprise several shapes, but generally is focused or concentrated in areas extending outward perpendicular to the blade contacts in the coaxial cable connector.
[0021] The ground contacts may include body sections arranged parallel to the planar body of the center contact and further include sidewalls arranged perpendicular to the planar body of the center contact, thereby entirely surrounding the center contacts to further control and afford a desirable electric field distribution.
[0022] The housing of the connector may be formed with a rectangular body having a recessed slot therein that receives the center contact. The body portion may also include flat opposed sidewalls engaging the ground contacts. The body portion forms a dielectric layer between the center and ground contacts. More generally, the housing may be formed of the dielectric material and shaped with flat exterior walls engaging the ground contacts and an interior cavity receiving the center contact. The exterior walls and interior cavity of the housing are dimensioned relative to one another in order to space the center and ground contacts apart from one another by a predetermined distance. The interior cavity in the housing may represent a slot extending parallel to the exterior walls of the housing. The slot and walls cooperate to hold the ground and center contacts, respectively, in parallel planes.
[0023] In accordance with another aspect of the present invention, a ground shield is provided for a coaxial cable connector. The ground shield includes contact shells matable with one another to define a shielded chamber extending along a longitudinal axis of the contact shells. Contact shells include walls entirely surrounding a perimeter of the shielded chamber when the contact shells join one another. At least one contact shell is provided with an open end and a cable retention end located at opposite ends of the shielded chamber. The cable retention end is configured to receive and to be connected to a coaxial cable. The contact shell includes at least one wall and at least one adjacent open side extending between the open end and the cable retention end. The open side is subsequently shielded by a wall on the mating contact shell when the contact shells are joined with one another.
[0024] The contact shells may be U-shaped, L-shaped, J-shaped and the like. When formed with a U-shape, each contact shell includes opposed side walls and a connecting wall, with the open side opposing the connecting wall. When the contact shells are joined, the side and connecting walls provide 360° of shielding around a perimeter of the shielded chamber along the length of the shielded chamber from the open end to the cable retention end. The side walls of a single contact shell are located and extend along opposite sides of the shielded chamber and are lined parallel to one another.
[0025] Optionally, a coaxial cable displacement contact may be provided at the cable retention end of at least one contact shell. The coaxial cable displacement contact is configured to engage a conductor of a coaxial cable along a plane extending transverse to, and intersecting, the cable retention end of the corresponding contact shell.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0026] [0026]FIG. 1 illustrates an exploded isometric view of a connector formed in accordance with at least one embodiment of the present invention.
[0027] [0027]FIG. 2 illustrates an isometric view of an assembled connector formed in accordance with at least one embodiment of the present invention.
[0028] [0028]FIG. 3 illustrates an isometric view of an insulated housing formed in accordance with at least one embodiment of the present invention.
[0029] [0029]FIG. 4 illustrates an isometric view of a contact blade formed in accordance with at least one embodiment of the present invention.
[0030] [0030]FIG. 5 illustrates an isometric view of a receptacle contact formed in accordance with at least one embodiment of the present invention.
[0031] [0031]FIG. 6 illustrates a side view of a contact shell formed in accordance with at least one embodiment of the present invention.
[0032] [0032]FIG. 7 illustrates an end view of a contact shell formed in accordance with at least one embodiment of the present invention.
[0033] [0033]FIG. 8 illustrates a sectional view of a contact shell taken along line 8 - 8 in FIG. 6 in accordance with at least one embodiment of the present invention.
[0034] [0034]FIG. 9 illustrates a coaxial cable displacement contact mounted to a coaxial cable in accordance with at least one embodiment of the present invention.
[0035] [0035]FIG. 10 a illustrates a coaxial cable geometry for a coaxial cable suited for connection to a connector formed in accordance with at least one embodiment of the present invention.
[0036] [0036]FIG. 10 b illustrates a strip line geometry for a connector formed in accordance with at least one embodiment of the present invention.
[0037] [0037]FIG. 11 illustrates electric field distributions surrounding a coaxial cable and a connector attached thereto in accordance with at least one embodiment of the present invention.
[0038] [0038]FIG. 12 illustrates an exploded isometric view of a connector formed in accordance with an alternative embodiment of the present invention.
[0039] [0039]FIG. 13 illustrates a receptacle contact formed in accordance with an alternative embodiment of the present invention.
[0040] [0040]FIG. 14 illustrates a connector partially assembled in accordance with an alternative embodiment of the present invention.
[0041] [0041]FIG. 15 illustrates a center contact formed in accordance with at least one embodiment of the present invention.
[0042] [0042]FIG. 16 illustrates at least one center contact formed in accordance with an embodiment of the present invention.
[0043] [0043]FIG. 17 illustrates an isometric view of a shell formed in accordance with at least one embodiment of the present invention.
[0044] [0044]FIG. 18 illustrates an isometric view of a shell formed in accordance with at least one embodiment of the present invention.
[0045] [0045]FIG. 19 illustrates an end view of a shell formed in accordance with at least one embodiment of the present invention.
[0046] [0046]FIG. 20 illustrates an isometric view of an insulated housing formed in accordance with at least one embodiment of the present invention.
[0047] [0047]FIG. 21 illustrates an isometric view of an insulated housing formed in accordance with at least one embodiment of the present invention.
[0048] [0048]FIG. 22 illustrates a partially assembled connector in accordance with one embodiment of the present invention.
[0049] [0049]FIG. 23 illustrates an outer housing and coaxial cable joined in accordance with at least one embodiment of the present invention.
[0050] [0050]FIG. 24 illustrates an outer housing and coaxial cable joined in accordance with at least one embodiment of the present invention.
[0051] [0051]FIG. 25 illustrates an outer housing and coaxial cable joined in accordance with at least one embodiment of the present invention.
[0052] [0052]FIG. 26 illustrates an outer housing and coaxial cable joined in accordance with at least one embodiment of the present invention.
[0053] [0053]FIG. 27 illustrates a coaxial cable displacement contact formed in accordance with an alternative embodiment of the present invention.
[0054] [0054]FIG. 28 illustrates a side view of a contact shell formed in accordance with an alternative embodiment of the present invention.
[0055] [0055]FIG. 29 illustrates a top plan view of a contact shell formed in accordance with an alternative embodiment of the present invention.
[0056] The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, embodiments which are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentality shown in the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0057] [0057]FIG. 1 illustrates a coaxial cable connector 10 formed in accordance with an embodiment of the present invention. The coaxial cable connector 10 includes insulated housings 12 and 14 that are matable with one another when the coaxial cable connector 10 is fully assembled. Optionally, the insulated housings 12 and 14 may be assembled from more than two pieces, or formed together as one unitary structure. The coaxial cable connector 10 further includes a blade contact 16 and a receptacle contact 18 that are separately securable to center conductors of coaxial cables (not shown in FIG. 1) and engage one another both frictionally and electrically when the coaxial cable connector 10 is fully assembled to form an electrical path between the center conductors. Optionally, only one of the blade contact 16 and the receptacle contact 18 may be securable to a coaxial cable. In this alternative embodiment, the other of the blade contact 16 and the receptacle contact 18 may be connected to a circuit board, an electrical component, a non-coaxial cable and the like. First and second contact shells 20 and 22 , when electrically joined, form a shielded chamber extending along a longitudinal axis of the contact shells 20 and 22 . The contact shells 20 and 22 substantially surround a perimeter of the insulated housings 12 and 14 . The contact shells 20 and 22 are configured to electrically engage outer conductors of the coaxial cable to form an electrical path there between. FIG. 2 illustrates the coaxial cable connector 10 fully assembled, but without the coaxial cables.
[0058] The insulated housings 12 and 14 include mating faces 24 and 26 , respectively, that abut against one another when the coaxial cable connector 10 is fully assembled. In the embodiment of FIG. 1, the mating faces 24 and 26 are formed with notched portions 23 and 25 defining shelves 28 and 30 , respectively, that join one another to ensure proper vertical alignment between the insulated housings 12 and 14 . The insulated housings 12 and 14 include rectangular body sections 32 and 34 , respectively, defined by top walls 36 and 38 , bottom walls 40 and 42 , and side walls 44 and 46 , respectively. The body sections 32 and 34 are surrounded by the contact shells 20 and 22 . The insulated housings 12 and 14 are formed of a dielectric material of a predetermined thickness to afford a desired impedance through the coaxial cable connector 10 .
[0059] The insulated housing 12 includes a slot 48 extending from the mating face 24 rearward along a length of the body section 32 . The slot 48 has an upper edge opening onto the top wall 36 . The slot 48 includes a rear section that flares into a chamber 50 having an upper edge that also opens onto the top wall 36 . The chamber 50 opens into an even wider cavity 52 at a rear end 53 of the body section 32 . The body section 32 is formed integrally with a shroud 54 that is shaped in a rectangular U-shape with bottom and side walls 56 and 58 , respectively. The bottom and side walls 56 and 58 cooperate to define a portion of the cavity 52 .
[0060] The body section 32 and shroud 54 join at an interface that is shaped to accept corresponding features on the contact shell 20 (discussed below in more detail). At the interface, vertical channels 55 are provided between interior surfaces of the leading edges 57 of the side walls 58 and exterior surfaces of the rear ends 53 of the side walls 44 . The channels 55 receive end portions of the contact shell 20 .
[0061] Upper portions of the channels 55 communicate with transverse arm relief slots 59 that are directed toward one another. The arm relief slots 59 are positioned between the rear ends 53 of side walls 44 and the main body portion of the side walls 58 of the shroud 54 . The arm relief slots 59 receive coaxial cable displacement members, such as coaxial cable displacement contacts 138 on the contact shells 20 and 22 to permit the coaxial cable displacement contacts 138 to be inserted and pierce the coaxial cable.
[0062] The blade contact 16 is mounted on an end of the coaxial cable. The cavity 52 , chamber 50 , and slot 48 collectively receive the end of the coaxial cable and the blade contact 16 . The cavity 52 , chamber 50 , and slot 48 have open upper edges to facilitate automated assembly of the coaxial cable connector 10 by permitting the coaxial cable and blade contact 16 mounted thereto to be easily and automatically inserted downward in a transverse direction into the insulated housing 12 . Optionally, the coaxial cable and blade contact 16 may be inserted into the insulated housing 12 through the rear end 60 .
[0063] [0063]FIG. 3 illustrates the insulated housing 14 in more detail. The insulated housing 14 also includes a shroud 62 formed on the rear end of the body section 34 . The shroud 62 includes top and side walls 64 and 66 , respectively, that cooperate to define a U-shaped channel or cavity 68 opening to the rear end 70 of the insulated housing 14 . The cavity 68 receives a coaxial cable with the receptacle contact 18 mounted thereon. The body section 34 includes a chamber 72 having a front end 74 opening onto the mating face 26 . The front end 74 includes beveled edges. The rear end of the chamber 72 communicates with the cavity 68 defined by the shroud 62 and a rear end 63 of the body section 34 .
[0064] The insulated housing 14 also includes vertical channels 65 extending along a rear end 63 of the body section 34 between exterior surfaces of the side walls 46 and interior surfaces of the leading edges 67 of the side walls 66 . The channels 65 are sufficient in depth to receive end portions of the contact shell 22 . The channels 65 communicate with transverse arm relief slots 69 directed toward one another. The arm relief slots 69 are located between rear ends 63 of the side walls 46 and shelves 71 on the side walls 66 . The arm relief slots 69 define guideways that receive coaxial cable displacement contacts 138 on the contact shell 22 .
[0065] [0065]FIG. 4 illustrates a blade contact 16 in more detail. The blade contact 16 includes a flat planar body section 90 having a lead edge 92 that is beveled. The body section 90 includes upper and lower sides 94 and 96 aligned substantially parallel to one another and parallel to a plane of the blade contact. Side edges 98 extend along a length of the body section 90 . A rear end 100 of the body section 90 is formed with a wire crimp 102 having an opening 104 therethrough. The opening 104 receives the center conductor(s) of the coaxial cable. The wire crimp 102 may be compressed to securely, frictionally engage the center conductor(s) of the coaxial cable to mount the blade contact 16 on an end of the coaxial cable.
[0066] [0066]FIG. 5 illustrates the receptacle contact 18 in more detail. The receptacle contact 18 includes a forked body section 106 having a pair of fingers 108 formed in a C-shape. Outer tips of the fingers 108 have contact surfaces 110 spaced apart from one another a distance that is slightly less than a width of the body section 90 of the blade contact 16 . The contact surfaces 110 electrically engage the upper and lower sides 94 and 96 of the blade contact 16 when connected thereto. A rear end of the forked body section 106 is formed with a wire crimp 112 having an opening 114 therethrough. The opening 114 receives the center conductor(s) of a coaxial cable. The center conductors may be securely fixed to the receptacle contact 18 by compressing the wire crimp 112 .
[0067] FIGS. 6 - 8 illustrate the contact shells 20 and 22 in more detail. The contact shells 20 and 22 are similarly constructed; thus, the following discussion is only in connection with the contact shell 20 . The contact shells 20 and 22 may be stamped and formed from sheets of conductive material into a U-shape. The contact shell 20 includes side walls 130 formed parallel to one another and extending along planes parallel to a longitudinal axis of the contact shell 20 . A connecting wall 132 interconnects the side walls 130 . The connecting wall 132 is also planar in design and aligned in a plane extending parallel to the longitudinal axis of the contact shell 20 , but transverse to the planes containing the side walls 130 . An open face 134 (better shown in FIG. 1) extends along the side walls 130 opposite the connecting wall 132 . An open end 136 is provided at one end and a cable retention end 131 is provided at an opposite end of the side and connecting walls 130 and 132 .
[0068] The open face 134 of the contact shell 20 extends along the entire length of the side walls 130 from the cable retention end 131 to the open end 136 to facilitate manufacturability of the contact shell and assembly of the connector. More specifically, the contact shell 20 is easily manufactured, such as by stamping the side and connecting walls 130 and 132 from a common piece of material and then forming/bending the side walls 130 at a right angle to the connecting wall 132 . By leaving the open face 134 , the stamping or forming operations are simplified. During assembly, the open face 134 on each contact shell 20 and 22 permits the coaxial cables, as well as the corresponding blade and receptacle contacts 16 and 18 , to be side loaded. Side loading involves inserting the coaxial cable and corresponding blade or receptacle contact 16 or 18 along a path denoted by arrow A in FIG. 6 in a direction transverse to a longitudinal axis of the contact shell 20 .
[0069] The U-shaped configuration formed by the side and connecting walls 130 and 132 enables the contact shells 20 and 22 to be joined in a manner that provides 360 degrees of shielding around the perimeter of the blade and receptacle contacts 16 and 18 . When joined, the contact shells 20 and 22 also provide 360 degrees of shielding in a plane transverse to a longitudinal axis of the coaxial cable. The 360 degrees of shielding substantially surrounds the portions of the inner conductors of the coaxial cables that are not covered by the outer conductors of the coaxial cables. When the contact shells 20 and 22 are joined, the connecting wall 132 of contact shell 20 covers the open face 134 of contact shell 22 . Similarly, the connecting wall 132 of contact shell 22 covers the open face 134 of contact shell 20 . The side walls 130 of opposite contact shells 20 and 22 overlap one another.
[0070] The coaxial cable displacement contacts 138 are formed on the cable retention ends 131 of the side walls 130 . The coaxial cable displacement contacts 138 are bent inward to face one another. Each pair of coaxial cable displacement contacts 138 lie in a plane perpendicular to the longitudinal axis of the contact shells 20 and 22 . The plane containing the pair of coaxial cable displacement contacts 138 joins the corresponding cable retention end 131 . The coaxial cable displacement contacts 138 are spaced apart by a gap 140 . The gap 140 between the inner edges of the coaxial cable displacement contacts 138 is provided with a width based on the dimensions of the coaxial cable to be joined with the contact shell 20 . The coaxial cable displacement contacts 138 are shorter in height than the side walls 130 to form a shelf 142 that is slidable along rear ends of the side walls 44 of the insulated housing 12 . Optionally, the coaxial cable displacement members, such as coaxial cable displacement contacts 138 may be formed separate from, or stamped integral with, any other portion of the contact shell 20 , 22 proximate thereto.
[0071] The coaxial cable displacement contacts 138 include bases 139 having support projections 144 that are loosely received in holes 146 formed in the front section of the connecting wall 132 . An assembly tool (not shown) presses against the support projections 144 to mount the coaxial cable displacement contacts 138 onto the cable. Each coaxial cable displacement contact 138 includes a forked section that extends upward from the base 139 .
[0072] The side and connecting walls 130 and 132 extend up to the plane in which the coaxial cable displacement contacts 138 engage the coaxial cable. Hence, the entire length of the coaxial cables outside of the contact shells 20 and 22 shields the inner conductor with outer conductor. The portion of the coaxial cable outside, but leading up to the contact shell is self shielded. The only portion of the inner conductor exposed (e.g., not covered by the outer conductor) is inside the shielded chamber formed by mating contact shells 20 and 22 . The shelves 142 (FIG. 9) join the braid receiving slots 156 at a beveled edge that serves as a lead-in portion to direct the cable onto the displacement beams 154 . The shelves 142 and coaxial cable displacement contacts 138 are received in the transverse arm relief slots 59 and 69 in respective insulated housings 12 and 14 . The displacement beams 154 and the walls 159 induce lateral retention forces on a section of an outer conductor wedged in the braid-receiving slots 156 . The cavity 68 in the shroud 62 and the vertical channels 65 are spaced relative to each other to center the coaxial cable (not shown) between the coaxial cable displacement contacts 138 , thereby properly aligning the displacement beams 154 with respect to the outer conductor of the coaxial cable.
[0073] The connecting wall 132 includes a lip section 148 extending forward of the holes 146 . The lip section 148 is tapered inward toward its center and formed with a wire crimp 150 on a distal end thereof. The wire crimp 150 includes step-shaped tips 152 that join one another when folded inward to be clamped onto a coaxial cable. The wire crimp 150 also serves as a strain relief to prevent motion between the coaxial cable and the coaxial cable displacement contacts 138 .
[0074] As shown in FIGS. 7 and 8, the coaxial cable displacement contacts 138 include, proximate inner edges thereof, displacement beams 154 separated from the wall 159 of the coaxial cable displacement contacts 138 by braid-receiving slots 156 . Beam tips 158 of the displacement beams 154 are tapered to facilitate insertion into the coaxial cable when the contact shells 20 and 22 are mounted on the coaxial cables.
[0075] [0075]FIG. 9 illustrates the operation of the coaxial cable displacement contacts 138 when assembled to a coaxial cable 160 . This embodiment includes a pair of coaxial cable displacement contacts 138 . When the contact shells 20 and 22 are mounted to the coaxial cables 160 , the beam tips 158 pierce the cable jacket 162 and outer cable braid 164 and extend into the cable dielectric 166 . The braid-receiving slots 156 securely receive and engage the outer cable braid 164 , through a retention or normal force, to form an electrical connection between the contact shells 20 and 22 and the outer conductors (namely the outer cable braids 164 ) of the coaxial cable 160 . The retention or normal force constitutes a friction force of a magnitude sufficient to provide a long term reliable contact interface.
[0076] The displacement beams 154 are spaced apart by a beam-to-beam distance 170 that is greater than the outer diameter of the center conductor 168 , but less than the inner diameter of the outer cable braid 164 to ensure that the displacement beams 154 do not electrically contact the center conductor 168 , but do pierce the outer cable braids 164 . The displacement beams 154 are formed with a predefined outer beam width 172 and the braid-receiving slots 156 are formed with a predefined slot width 174 based on the inner and outer diameters of the outer cable braid 164 to ensure that the displacement beams 154 pierce the outer cable braid 164 , while the braid-receiving slots 156 have a width sufficient to firmly receive the outer cable braid 164 and form a reliable electrical connection therewith. The cable braid 164 has a radial width defined by the difference between inner and outer diameters of the cable braid 164 , or in other words, a width of the cable braid 164 that is measured in a direction parallel to the radius of the cable braid 164 .
[0077] As illustrated in FIG. 6, at least one side wall 130 may include a protrusion 176 therein to frictionally mate with the interior of the side wall 130 of the opposite contact shell 20 and 22 to ensure adequate normal force between the contacts shells 20 and 22 to ensure a reliable electrical interface.
[0078] Optionally, both coaxial cable displacement contacts 138 may be formed integrally with one another and attached (integrally or otherwise) to only one of the side walls 130 and/or connecting wall 132 . When formed integrally with one another, the coaxial cable displacement contacts 138 would still include a partial notch (resembling the upper end of gap 140 ) between the upper ends of the displacement beams 154 to form an area to accept the portion of the coaxial cable that is not pierced by the displacement beams 154 . Hence, the gap 140 need not extend along the entire length of the displacement beams 154 , but instead may only be provided near the upper ends thereof.
[0079] [0079]FIG. 10 a illustrates a graphical representation of a coaxial cable geometry 180 including a center conductor 181 . The center conductor 181 is centered within an intermediate dielectric material 183 that is surrounded by a cylindrical outer conductor 182 , thereby centering the inner conductor 181 in the outer conductor 182 . The outer conductor 182 may be formed as a braid type conductor and the like. The center conductor 181 has a radius r i , while the outer conductor 182 has an inner radius r 0 0 . The dielectric material 183 has a relative dielectric constant of ε r . The general formula defining the impedance produced by the coaxial cable geometry 180 is represented by the following equation:
Z o = 60 ɛ r ln ( r o r i ) Ohms Equation ( 1 )
[0080] [0080]FIG. 10 b illustrates a graphical representation of a cross-section of a strip line geometry 186 that is formed by the coaxial cable connector 10 . In the strip line geometry 186 , a center conductor 187 is sandwiched between two wider ground conductors 188 . The center and ground conductors 187 and 188 are planar in shape and aligned in planes extending parallel to one another. The center conductor 187 is formed with a width (W) and a thickness (T). The ground conductors 188 are spaced from the center conductor 187 by spacings H and H 1 . The center conductor 187 is surrounded by a dielectric material 189 filling the void between the ground conductors 188 . The dielectric material 189 has a relative dielectric constant of ε r . The general formula defining the impedance produced by the strip line geometry 186 is represented by the following equation:
Z o = 80 ɛ r ln ( 1.9 ( 2 H + T ) 0.8 W + T ) ( 1 - H 4 × H1 ) Ohms Equation ( 2 )
[0081] The strip line geometry 186 is more easily manufactured and the design parameters are more readily controlled during production as compared to connectors maintaining circular geometries or other geometries that produce symmetric electric field distribution. By way of example, during the manufacture of the coaxial cable connector 10 having the strip line geometry 186 , the manufacturing process more easily controls the spacings H and H 1 , thickness (T), width (W) and relative dielectric ε r The structures forming the strip line geometry 186 enables the impedance of the coaxial cable connector 10 to be easily controlled. This ability translates to reduced manufacturing costs.
[0082] [0082]FIG. 11 illustrates electric field distributions formed about a coaxial cable and about a coaxial cable connector 10 connected to the coaxial cable. A series of parallel lines 190 denote the geometry of the coaxial cable. A large rectangular box 192 denotes a general geometry for the coaxial cable connector 10 . A smaller shadow box 193 denotes the general geometry of a contact blade, such as contact blades 16 and 216 . The shadow box 193 may also represent a receptacle contact, such as formed by receptacle contact 18 or 218 .
[0083] An electric field distribution 191 is produced by the coaxial cable. The electric field distribution 191 is distributed symmetrically about a circumference of the coaxial cable and decreases in intensity at greater radial distances from the center conductor of the coaxial cable. A representative magnitude distribution for the electric field distribution 191 is illustrated as a series of concentric shaded rings that are aligned in one plane traversing the coaxial cable (e.g., perpendicular to the cable axis). A feature of electric fields formed about a coaxial cable geometry is that the magnitude/intensity distribution of the electric fields are circumferentially uniform and vary only in the radial direction.
[0084] An electric field 195 is formed by the coaxial cable connector 10 . The electric field 195 is distributed asymmetrically about the coaxial cable connector 10 and is oriented with a particular relation to the strip line geometry 186 created between the blade contacts 16 and 216 and the corresponding side walls 130 , 237 and 239 (as discussed above with FIG. 10 b ). The distribution of the magnitude or intensity for the electric field 195 is denoted by asymmetric shaded areas surrounding the shadow box 193 . The electric field 195 is oriented proximate opposite sides of the shadow box 193 along a transverse axis 197 extending perpendicularly to the plane of the shadow box 193 . As shown by the shaded areas in the electric field 195 , the magnitude or flux density is primarily concentrated in major areas 198 centered about the transverse axis 197 and extending in opposite directions. The magnitude or flux density of the electric field 195 is secondarily concentrated to a much lesser extent in lateral areas 199 near side edges of the shadow box 193 (representing the side edges of the blade contacts 16 and 216 ). Stated another way, the magnitude or flux density of the electric field 195 is focused primarily in major areas 198 , while being focused in lateral areas 199 to a lesser degree.
[0085] In the embodiment of FIG. 1, the blade contact 16 represents the center conductor 187 . The thickness and width of the blade contact 16 is easily controlled when stamping the blade contact 16 from a flat planar metal sheet of known thickness. The side walls 130 of the contact shells 20 and 22 represent ground conductors 188 . The width of the top walls 36 define the spacings H and H 1 between blade contact 16 and side walls 130 . The distances between the blade contact 16 and the connecting walls 132 in each contact shell 20 and 22 may be formed sufficiently wide such that the connecting walls 132 have a minimal impact on the impedance of the coaxial cable connector 10 .
[0086] In accordance with at least one embodiment, the contact shells 20 and 22 afford a one-piece contact system that utilizes the insulated housings 12 and 14 as “stuffers” to retain the coaxial cables (e.g., cable 160 ) intact during a crimping process. The insulated housings 12 and 14 also assist in locating the coaxial cables 160 . The width of the braid-receiving slot is dependent upon the diameter of the conductive braid. By way of example only, the braid-receiving slot width may be slightly larger (e.g., a few thousandths of an inch) than the diameter of the conductive braid with multiple conductors of the braid in each braid-receiving slot. This permits a significant amount of plastic deformation during the assembly process. Deformation of the conductive braid along with the wiping action that occurs during assembly ensures that clean metallic surfaces on the multiple conductors of the conductive braid come into contact with the coaxial cable displacement contacts 138 while retaining a desired amount of residual spring force between the multiple conductors and the coaxial cable displacement contacts 138 . Retaining a desired residual spring force between the braid conductors and the coaxial cable displacement contacts 138 provides a stable long term, low resistance contact interface.
[0087] Optionally, the shape of the displacement beams and displacement beam tips may be varied. The displacement beam tip may be provided with a double edge used to ensure that when the displacement beam is inserted into the dielectric material of the coaxial cable, the displacement beams travel along a straight line. Tapering the displacement beam provides added strength, while reducing unwanted deflection of the displacement beam during installation.
[0088] During assembly of the coaxial cable connector and two cables, the following steps may be carried out. Initially, the ends of the two coaxial cables to be interconnected are stripped to expose an end portion of their respective center conductors. The exposed end portion of the center conductors are then inserted into the openings 104 and 114 in the blade contact 16 and receptacle contact 18 , respectively. The wire crimps 102 and 112 are compressed to securely retain the exposed end portions of the center conductors. Next, the coaxial cables and the blade and receptacle contacts 16 and 18 are inserted into respective insulated housings 12 and 14 . With reference to FIG. 1, the body section 90 of the blade contact 16 is inserted (laterally or longitudinally) into the slot 48 , and the wire crimp 102 is inserted into the chamber 50 . An unstripped portion of the coaxial cable behind the exposed center conductor is inserted into the cavity 52 until leading edges of the dielectric material, cable braid and cable jacket abut against shelves 51 near the rear ends 53 of the side walls 44 . Once inserted, a leading tip portion of the body section 90 of the blade contact 16 projects forward from the notched portion 23 of the mating face 24 . The blade contact 16 and receptacle contact 18 are joined when the insulated housing 12 and 14 are combined.
[0089] Each of the contact shells 20 and 22 are separately mounted on a corresponding one of the insulated housings 12 and 14 . During mounting, the contact shells 20 and 22 are separately inserted along an axis 11 (FIG. 1) aligned perpendicularly to the longitudinal axis 13 of the coaxial cable connector 10 . As the contact shells 20 and 22 are inserted, the coaxial cable displacement contacts 138 pierce the corresponding coaxial cables 160 and the displacement beams 154 engage the outer cable braids 164 (as illustrated in FIG. 9). Next, an outer housing is assembled to the coaxial cable connector 10 .
[0090] Once assembled, the insulated housings 12 and 14 , blade and receptacle contacts 16 and 18 , and contact shells 20 and 22 cooperate (as illustrated in FIG. 2) to define a strip line contact configuration as discussed above in connection with FIG. 10 b to afford a desired impedance for signals carried through the coaxial cable connector 10 . The process of assembling the coaxial cable connector 10 is easily automated, reliable and cost effective.
[0091] [0091]FIG. 12 illustrates a coaxial cable connector 200 formed in accordance with an alternative embodiment. The coaxial cable connector 200 includes insulated housing 212 and 214 , a blade contact 216 , a receptacle contact 218 , and contact shells 220 and 222 . The contact shells 220 and 222 include side walls 237 and 239 , respectively, and connecting walls 233 and 235 , respectively. The blade contact 216 functionally replaces blade contact 16 , while the receptacle contact 218 functionally replaces receptacle contact 18 . The first and second insulated housings 212 and 214 include mating faces 224 and 226 , respectively, that have even more pronounced notched portions 223 and 225 and shelves 228 and 230 , respectively. The shelf 228 includes a notch 229 that accepts a body section 290 of the receptacle contact 218 . The shelf 228 also includes a slot 231 that accepts a finger 219 of the blade contact 216 .
[0092] The side walls 237 and 239 , and corresponding connecting walls 233 and 235 , are formed in U-shapes and have open faces 201 and 207 , respectively. The side walls 237 and 239 include contact retention ends 203 and 209 , and open ends 205 and 211 , respectively, opposite one another. The open faces 201 and 207 extend from the contact retention ends 203 and 209 to the open ends 205 and 211 , respectively, to afford the advantages discussed above in connection with contact shells 20 and 22 .
[0093] The blade contact 216 is illustrated in more detail in FIG. 13. The blade contact 216 includes a body section 215 with fingers 217 and 219 extending therefrom. The fingers 217 and 219 are separated by a slot 221 extending partially along a length of the body section 215 rearward from a leading edge 213 . A rear end of the body section 215 is secured to a wire crimp 223 having an opening 225 therethrough to receive the center conductor of a coaxial cable connected thereto.
[0094] The blade contact 216 and receptacle contact 218 , when joined, are aligned in perpendicular planes. The plane containing the fingers 217 , 219 of the blade contact 216 is aligned parallel to the side walls 237 and 239 of the contact shells 220 and 222 , respectively. The plane containing the body section of the receptacle contact 218 is aligned parallel to the connecting walls 233 and 235 of the contact shells 220 and 222 , respectively. As shown in FIGS. 12 and 13, the body section 290 of the contact 218 is formed with a width that is greater than a width of an adjoining crimp 291 .
[0095] Optionally, the body section 290 may be different than shown in FIG. 12. The body section 290 may be dimensioned to cooperate with the connecting walls 233 and 235 to produce a second strip line geometry. The second strip line geometry is perpendicular to the strip line geometry formed by the blade contact 216 and the side walls 237 and 239 to form a dual strip line geometry. In this dual strip line geometry, the blade and receptacle contacts 216 and 218 form a cross arrangement. Optionally, one or more of the blade contacts 16 , 216 and receptacle contacts 18 , 218 may include multiple contacts that are similarly shaped and oriented parallel or perpendicular to one another. By way of example, two contacts may be stacked parallel to one another or two contacts may be oriented perpendicular to one another.
[0096] The connecting walls 132 , 233 and 235 and side walls 130 , 237 and 239 , individually and collectively, constitute ground contacts. In other words, each connecting wall 132 , 233 and 235 constitutes an individual ground contact. The combination of opposed connecting walls 132 , 233 and 235 may be considered to constitute a ground contact. The combination of opposed side walls 130 , 237 and 237 may be considered to constitute a ground contact. As a further example, each connecting wall 132 , 233 and 235 in combination with one or more adjoining side walls 130 , 237 and 239 may be considered a ground contact.
[0097] The insulated housing 214 includes a latch 241 projecting upward from the top wall 264 . The latch 241 enables the coaxial cable connector 200 to be mounted to another structure. Channels 243 are also provided in the top wall 264 on either side of the latch 241 to provide an even wall thickness to improve moldability and to reduce the amount of material used.
[0098] [0098]FIG. 14 illustrates the contact shells 220 and 222 assembled with corresponding housings 212 and 214 . As illustrated in FIG. 14, during assembly, the contact shells 220 and 222 may be connected with corresponding coaxial cables and insulated housings 212 and 214 before the insulated housings 212 and 214 are mated with one another.
[0099] [0099]FIGS. 15 and 16 illustrate blade and receptacle contacts 316 and 318 , respectively. In FIG. 15, the blade contact 316 is illustrated having a planar body section 317 with a slot 319 cut in an outer end thereof to form a fork having fingers 321 and 322 . At the outer ends of the fingers 321 and 322 , rounded projections 323 are provided in the opening to the slot 319 and are oriented to face one another. The projections 323 ensure a secure frictional and electrical interconnection between the blade contact 316 and a joining receptacle contact 318 when the receptacle contact 318 is inserted into the slot 319 . An opposite end of the body section 317 includes a crimp 324 having an opening 325 that receives a center conductor of a coaxial cable. The crimp 324 is securely clasped to the center conductor of the coaxial cable.
[0100] [0100]FIG. 16 illustrates a receptacle contact 318 having a planar body section 326 with a beveled outer end 328 for insertion between the projections 323 on the blade contact 316 . An opposite end of the body section 326 includes a crimp 330 having an opening 332 that receives a center conductor of the corresponding coaxial cable. The crimp 330 is formed to securely attach to the center conductor of the coaxial cable.
[0101] [0101]FIGS. 17 and 18 illustrate opposite views of an alternative configuration for a contact shell. Each contact shell 340 includes side walls 344 and a connecting wall 348 . A projection 352 is provided on at least one side wall 344 to ensure a proper electrical connection between mating contact shells 340 .
[0102] The connecting walls 348 includes a transition region 356 at a rear end thereof that is formed integrally with a laterally extending separation plate 360 . The separation plate 360 includes a slot 363 to facilitate cutting of the separation plate 360 during assembly. The separation plate 360 is in turn formed integrally with a strain relief crimp 364 . During assembly, the strain relief crimp 364 is physically separated from the transition region 356 , such as through a stamping operation, and then secured to the coaxial cable.
[0103] The strain relief crimp 364 is U-shaped and includes a laterally extending body portion 361 joining the separation plate 360 . The body portion 361 is secured at opposite ends to arms 365 that extend parallel to one another and in a direction perpendicular to the body portion 361 . The arms 365 include ribs 367 along both side edges thereof. The body portion 361 includes a cable grip 369 centered between the arms 365 . The cable grip 369 includes teeth 371 directed inward to face the coaxial cable. The teeth 371 pierce the jacket of the coaxial cable and engage the outer conductor when the strain relief crimp 364 is secured to the coaxial cable. The cable grip 369 may be formed in a punched star pattern with a plurality of teeth 371 being stamped, and bent to face inward. Alternatively, the teeth 371 may be replaced with a single tooth or, with one or more barbs. Optionally, the cable grip 369 need not engage the outer conductor, but instead may only pierce a surface of the jacket sufficiently to resist any anticipated cable stresses.
[0104] [0104]FIG. 19 illustrates an end view of contact shell 340 . The coaxial cable displacement contacts 368 include support projections 370 formed on lower ends thereof to be loosely received in openings in the connecting wall 348 . The displacement beams 372 extend upward and are separated from one another by a gap 374 . The displacement beams 372 include pointed tips 376 that facilitate penetration of the jacket and outer conductor of the corresponding coaxial cable. Braid receiving slots 378 extend downward and are flared outward away from the gap 374 at base wells 373 to form a hooked shape.
[0105] The contact walls 375 include tapered undercut edges 377 extending along the top of the coaxial cable displacement contacts 368 . The undercut edges 377 end at lead tips 379 which face one another and are located at mouths 381 of the braid receiving slots 378 . The contact walls 375 shear the cable jacket away from the outer conductor as the coaxial cable displacement contacts 368 engage and pierce the coaxial cable. The undercut edges 377 form an acute angle with the central longitudinal axis of the displacement beams 372 . The undercut edges 377 are tapered downward and away from the lead tips 379 at an acute angle 383 to horizontal (denoted by a dashed line) to form a collection area for the excess cable jacket material displaced as the outer conductor is wedged into the braid receiving slots 378 , as well as to facilitate shearing. By shearing the cable jacket away from the outer conductor before entering the mouth 381 , the coaxial cable displacement contacts 368 prevent the cable jacket from becoming wedged in the braid receiving slots 378 . If the cable jacket becomes wedged in the braid receiving slots 378 , it may interfere with the electrical connection between the outer conductor and the braid receiving slots 378 .
[0106] [0106]FIGS. 20 and 21 illustrate opposite views of an alternative embodiment for an insulated housing that may be used in one or both halves of a connector. The insulated housing 400 includes a mating face 402 on a front end of a rectangular body section 404 . A rear end of the body section 404 is formed with a shroud 406 through a joining section 408 . The shroud 406 includes opposed side walls 410 and 412 cooperating to define a U-shaped chamber 414 therebetween that receives the coaxial cable. Interior surfaces of the side walls 410 and 412 include notches 416 and 418 facing one another and extending vertically in a direction transverse to a length of the insulated housing 400 . At least one of the notches 416 and 418 includes a pair of parallel ribs 420 that extend along the length of the corresponding notch 416 or 418 .
[0107] The body section 404 includes a chamber 405 adapted to receive a leading end of the coaxial cable and a crimp on a blade or receptacle contact 316 or 318 attached thereto. A front end of the body section 402 includes a slot 407 that accepts an associated one of the blade and receptacle contacts 316 and 318 .
[0108] A rear end 424 of the shroud 406 is joined with a strain relief member 426 having a base 419 with a U-shaped notch 428 therein. The notch 428 in the strain relief member 426 includes an inner surface 421 having transverse arcuate grooves 423 . Opposite ends of the notch 428 form ledges 425 . Side walls 427 extend upward from the ledges 425 along opposite sides of the notch 428 . Channels 430 are formed in each ledge 425 and extend through the strain relief member 426 to a rear side 431 . The channels 430 are spaced apart to align with and receive the arms 365 when the contact shell 340 is laterally joined with insulated housing 400 in the direction of arrow 434 (FIG. 21). The length of each channel 430 is slightly less than an outer dimension of the ribs 367 such that, as the arms 365 are pressed into channels 430 , the ribs 367 engage ledge 425 to hold the strain relief crimp 364 and strain relief member 426 .
[0109] As the strain relief crimp 364 and strain relief member 426 are pressed together, the teeth 371 of the cable grip 369 pierce the jacket and engages the outer conductor of the coaxial cable. The cable grip 369 secures the strain relief crimp 364 to the coaxial cable and prevents relative axial motion therebetween.
[0110] The cable grip 369 resists axial movement between the coaxial cable and the insulated housing 400 without deforming the circular cross-section of the coaxial cable. The strain relief crimp 364 and member 426 minimize compression of the coaxial cable into a compressed geometry which may otherwise interfere with the impedance and signal performance. The channels 430 and arms 365 need not have a rectangular cross-section, but instead may be circular, square, arcuate, triangular and the like. Optionally, the number of channels 430 and arms 365 may be fewer or greater than two.
[0111] [0111]FIG. 22 illustrates the shell 340 mated to a corresponding insulated housing 400 .
[0112] [0112]FIGS. 23 and 24 illustrate an outer housing 450 provided over one of the shells 340 once mounted to an insulated housing 400 . The outer housing 450 is formed of an insulated material. The outer housing 450 includes a latch beam 452 on one exterior surface thereof. The latch beam 452 includes a latch projection 451 . A secondary lock member 454 is provided on one end of the outer housing 450 .
[0113] [0113]FIGS. 25 and 26 illustrate an outer housing 460 provided over another of the shells 340 once mounted to an insulated housing 400 . The outer housing 460 is configured to mate with the outer housing 450 . The outer housing 460 includes a mating end 462 adapted to receive the end 453 of the outer housing 450 . A slot 464 is provided in one side of the outer housing 460 to accept the latch projection 451 on the latch beam 452 of the outer housing 450 . FIG. 26 illustrates an interior chamber 466 within the outer housing 460 , in which is viewable a shell 340 securely retained therein. An opposite end 468 of the outer housing 460 is formed with a secondary lock member 470 .
[0114] [0114]FIG. 27 illustrates an alternative embodiment of a coaxial cable displacement contact. The coaxial cable displacement contact 538 may be formed on either one of the side walls or a connecting wall, such as one of side walls 130 or connecting wall 132 (FIG. 1). The coaxial cable displacement contact 538 is aligned in a plane perpendicular to the longitudinal axis of a corresponding contact shell, such as contact shell 20 (FIG. 1). In the example of FIG. 27, the coaxial cable displacement contact 538 is joined with the connecting wall, such as connecting wall 132 , along edge 539 .
[0115] The coaxial cable displacement contact 538 includes a gap 540 defining a channel between forked displacement sections 541 and 543 . Each displacement section 541 and 543 includes a displacement beam 544 and a contact wall 546 separated by a slot 548 . Upper ends of the contact walls 546 include lead-in edges 550 formed to slope inward and downward from outer edges 552 of the coaxial cable displacement contact 538 . The lead-in edges 550 slope inward and downward to join mouths 554 of the slots 548 proximate tips 556 on upper ends of the displacement beams 544 . The lead-in edges 550 direct the cable jacket onto the displacement beams 544 . Lower ends of the slots 548 include wells 558 configured to receive an outer conductor of the coaxial cable when the displacement beams 544 pierce the outer jacket and the outer cable. The spacing between the displacement beams 544 and the slots 548 is determined based upon the dimensions of a coaxial cable to be secured therein.
[0116] [0116]FIGS. 28 and 29 illustrate an alternative embodiment for a contact shell. The contact shell 560 includes side walls 562 and a connecting wall 564 . A contact retention end 566 of the side walls 562 includes coaxial cable displacement contacts 568 . The connecting wall 564 is joined with a separation plate 570 through a transition region 572 . The separation plate 570 is in turn connected to a strain relief crimp 574 through a transition region 590 . The separation plate 570 includes a slot 576 to facilitate cutting of the separation plate 570 .
[0117] The strain relief crimp 574 is U-shaped and includes a body portion 577 having arms 578 on opposite sides thereof and extending upward therefrom. The arms 578 include ribs 580 on opposite sides thereof. The strain relief crimp 574 operates in the same manner as the strain relief crimps 364 (discussed above in connection with FIGS. 17 and 18) to frictionally engage channels in a mating strain relief member (such as channels 430 in strain relief member 426 in FIGS. 20 and 21).
[0118] The strain relief crimp 574 includes multiple cable gripping features, such as cable grips 582 and 584 and barbs 586 - 588 . Cable grips 582 and 584 are provided along the length of the body portion 577 and are formed by punching a star pattern in the body portion 577 and bending the star pattern to provide a circular ring of teeth extending upward from the body portion 577 . The barbs 586 - 588 are provided on opposite ends of the body portion 577 . In the example of FIGS. 28 and 29, a single barb 586 is stamped in, and bent upward proximate, the lead edge of the body portion 577 within the transition region 590 connecting the strain relief crimp 574 to the separation plate 570 . A pair of barbs 587 and 588 are provided proximate the rear edge of the body portion 577 next to one another. The cable grips 582 and 584 , and barbs 586 - 588 pierce the coaxial cable when the strain relief crimp 574 is securely joined with a corresponding strain relief member. The cable grips 582 and 584 , and barbs 586 - 588 may extend so far into the coaxial cable as to completely pierce the outer jacket and engage and/or also pierce the outer conductor to afford a secure connection between the strain relief crimp 574 and the coaxial cable.
[0119] Optionally, the coaxial cable connector 10 may only be connected to a coaxial cable at one end, while being connected at the opposite end to a structure other than a coaxial cable. For example, the coaxial cable connector may have one end adapted to be connected to discrete components, a printed circuit board, a circuit board, a flex circuit, a differential pair, a twisted pair of wires, two wires, a back plane, and the like. Accordingly, the end of the coaxial cable connector 10 connected to the non-coaxial structure need not include a shell or coaxial cable displacement crimp as discussed above.
[0120] Optionally, the contact shells 20 , 22 , 220 and 222 may be formed in configurations other than a U-shape. Instead, both contact shells in a pair (e.g., contact shells 20 and 22 ) may be L-shaped and configured such that, when joined the two L-shaped contact shells form a shielding box that surrounds and provides 360 degrees of shielding in a plane transverse to the axis of the cable axis. The 360 degrees of shielding substantially surrounds the inner contacts (including the crimps attaching the inner coaxial cable conductor to the inner contacts). When L-shaped, each contact shell includes two walls that may be different or equal length. Alternatively, the contact shells may have a modified J-shape, namely an L-shape with a flange bent on the outer end of the lower wall of the L-shape. The flange on the lower wall of each contact shell overlaps an adjoining upper a wall on the mating contact shell.
[0121] Optionally, both contact shells in a pair need not have the same cross-sectional shape, so long as the two contact shells, when mated, surround and provide 360 degrees of shielding in a plane transverse to the axis of the cable axis. The 360 degrees of shielding substantially surrounds the perimeter of the inner contacts and over the exposed inner conductors. Instead, one contact shell may provide shielding for three sides of the inner contacts/conductors, while the other contact shell may provide shielding for less than three sides. For example, one contact shell may be U-shaped while the other contact shell may be L-shaped, a modified J-shape or simply a flat wall covering the open face in the U-shaped contact shell mated thereto. The contact shells each may be formed with up to three walls.
[0122] While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is therefore contemplated by the appended claims to cover such modifications that incorporate those features which come within the spirit and scope of the invention.
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A coaxial cable connector is provided for interconnecting coaxial cables having center and outer conductors. The coaxial cable connector utilizes a contact and shell arrangement defining a strip line geometry for the electric fields generated by signals passing through the coaxial cable connector. The contacts and shells may be formed with planar conductors aligned parallel to one another with a center conductive strip sandwiched between planar ground strips, all of which are separated by dielectric materials. The widths and thicknesses of the contact and ground planes, the spacing there between and the dielectric materials are manufacturable in an easy, reliable, and cost effective method.
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BACKGROUND OF THE INVENTION
The present invention relates to heat reservoir devices and, in particular, such devices as are used in the food service industry and commonly called "pellets".
Pellets have long been used in the food service industry as a means for maintaining the desired temperature of comestibles on a plate or other container until such time as it is to be consumed. Originally pellets were a "donut" shaped piece of metal which was heated, placed in a stainless steel shell and the plate placed on the top. Both the plate and the pellet were contained by the metal shell. A cover was then placed over the plate. The pellets were previously heated in a heater which would heat the pellets to the desired temperature and allow them to be placed into the stainless steel metal shell as noted. Such pellets would then maintain the temperature of the food in the dish at a desirable heated temperature until it was consumed. Such pellets were commonly used in hospitals, nursing homes, and the like where food is prepared and placed on plates in a central kitchen and then placed in carts to be dispensed to the consumers throughout the particular hospital, nursing home, and the like. This is now a standard means of maintaining the food at a proper temperature until such time as it is placed before the patient or consumer. These metal pellets were not only expensive, but heavy and difficult to handle.
Consequently, improvements were needed, one of which was a unitized base which consisted of two stainless steel shells with an iron disc sandwiched in between. Some of these new style pellets also had insulation between the bottom outer layer and the disc. Further, single piece bases were also used made of either aluminum or stainless steel, some coated and some of the aluminum bases were anodized.
All of the foregoing pellets worked on the principle of heating a mass of metal so as to act as a heat radiator to keep the food hot for a period of time.
These again were unsuitable because of the cost and weight of the metal, and their inefficient radiation properties.
Another style of pellet that came on the market was a wax-filled pellet which consisted of two steel shells welded together with wax, similar to paraffin wax, sealed inside. These pellets worked on the principle of phase change. The wax, when heated, absorbs the heat energy as it is transformed from a solid to a liquid and as it slowly goes back from a liquid to a solid it gives up that heat energy, which energy is absorbed by a plate and food therein sitting in the pellet. A variation of this type of pellet was one made of two plastic shells sealed together with dead air space therebetween.
Again, the cost of making such plates was excessive, and the amount of wax that could be included was limited so again there was not the desired degree of heat transfer available.
In an attempt to cut costs by making products which were easily manufactured and with less weight, efforts were made to use plastic pellets made of plastics having a slow rate of heat PG,4 transfer. An example of such is melamine which has a slow degree of heat transfer. Once heated it gives up its heat very slowly so when the heated plate with food and its cover is placed on the pellet it helps to maintain the food temperature at the desired temperature for a longer period of time. However, melamine pellets are undesirable in that when repeatedly heated in the devices commonly used to heat pellets they tend to shrink and become brittle. As a consequence, special heating devices are required which add steam to the heat source as a means of preventing the shrinking and drying of the melamine. Such special heating device adds to the cost.
SUMMARY OF THE INVENTION
The instant invention overcomes the problems of the prior art and provides a unique plastic pellet which does not require heating in a moist atmosphere in order to avoid any shrinking or brittleness and which has a slow rate of heat transfer.
Briefly stated, the present invention comprises a heat reservoir device comprising a shaped reinforced thermoset polyester resin.
The invention also comprises the method of maintaining the temperature of comestibles as hereinafter set forth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the preferred pellet of the subject invention, and
FIG. 2 is a sectional view taken along 2--2 of FIG. 1.
DETAILED DESCRIPTION
The essential element of the instant invention is the utilization of a thermoset polyester resin. It has been found that uniquely pellets made from such resins can be heated to a temperature suitable for use in the food industry and which will give up their heat slowly, so that when a heated plate laden with comestibles and a cover are placed thereover, it will maintain the proper food temperature. Most importantly, the heating of the pellet made of the thermoset polyester resin can be accomplished without the need to heat the same in a moisture-laden atmosphere. The pellets can be heated in conventional convected air pellet heaters. This lowers the cost of heating the same and avoids the need to have special heaters. Any conventional heating device used to heat metal pellets can be utilized.
As used herein, the term "heat reservoir device" is synonymous with pellets and, as with prior pellets they can be of any of a wide variety of shapes, although it is preferred that the pellets have means permitting thermal air flow about the entire pellet as hereinafter described.
With respect to the thermoset polyester resin used, any conventional thermoset polyester resin can be utilized, although it is preferred to use reinforced resins, particularly those reinforced with fibers such as glass fibers and which also contain fillers such as alumina, clay and the like.
The term "thermoset polyester resin" as used herein is intended to cover alkyd resins as well as polyester resins. Such resins are formed by the interaction of various known unsaturated acids or anhydrides and polyhydric alcohols. When these polymers are dissolved in a cross-linking vinyl monomer, most usually styrene, or a mixture of styrene and a mono- or polyfunctional methacrylate, the solutions of these polymers in the vinyl monomer are usually called polyester resins. They are cured with the aid of free-radical initiators such as the hydroperoxides to yield thermoset articles.
It has been found that for optimum desired properties in the pellets such as resistance to scratching, surface hardness, resistance to breakage, temperature retention, resistance to chemicals, washability, and long service life that the resin used be one formed by the reaction of isophthalic acid, propylene glycol, and fumaric acid and as the dilute monomer either styrene alone or a combination of styrene and methyl methacrylate. It is preferred that the degree of unsaturation of the cured polyester resin, as represented by mol % fumarate be 50-70%.
As noted, the resins can be compounded with fillers and/or fibers in the liquid stage and then are cured with the aid of the free radical initiators to polymerize the resin and form the thermoset articles. The unsaturated polyesters can be mass cast, laminated, molded, and pultruded into a wide variety of shapes and, of course, coloring added to give the desired color.
Once the components are admixed, the pellet is formed by preferably molding it to the particular shape desired, which shape can vary widely, depending upon the size and shape of the plates or other food container in which the food to be heated is placed. The pellet is shaped to conform to such plate or container for purposes of having the heat from the pellets dispensed into the plate or other container and the food to maintain the temperature of the food.
The pellets are usually disc-shaped by virtue of the fact that most tableware is of such a shape, and the thickness thereof can vary widely and is that required to store the degree of heat that it is desired to be dispensed into the comestible(s) placed thereon for a given period of time. The particular thickness and temperature to which the pellets are heated can be readily determined for any given set of conditions by routine experimentation.
It is preferred, however, to use pellets that have means permitting thermal air flow about the entire pellet. This is preferred since the pellets are stacked when placed in heaters to be brought to the required temperature. Such heaters are conventionally convected air heaters and if the plates are tightly nested the heated air cannot circulate about the entire surface of each plate to rapidly and more uniformly heat the same.
A preferred pellet 10 is depicted in FIG. 1 and shows legs 11 spaced about the bottom 12 of pellet 10 and having an upwardly sloping sidewall 13. When a number of pellets 10 are stacked in a heater to be brought to the proper temperature, legs 11 of each space the pellets from the adjoining pellets thereby permitting thermal air flow about the top and bottom surfaces of each pellet.
The invention will be further described in connection with the following example which is set forth for purposes of illustration only.
EXAMPLE 1
Pellets having the shape of the pellet of FIG. 1 were formed by molding a polyester resin composition that was approximately 66 wt. % solids and the balance organic resin.
The resin was a polyester resin formed by reacting isophthalic acid, polypropylene glycol, and fumaric acid and utilizing styrene as a cross-linker. Such a resin is commercially available as CORELYN®. Glass fibers and alumina were the solids added. The curing catalyst was dimethylethyl hydroperoxide.
The pellets were approximately 9.5 inches in diameter and 0.32 inches thick. Upon testing it was found that these pellets could be heated to temperatures as high as 400° F. in the absence of moisture without being distorted. Melamine can only be heated to 220° F.; at higher temperatures it will thermally degrade. Also, they can maintain comestibles on a plate placed thereon at a temperature of 140° F. for 60 minutes. Most importantly, the pellets can be used in microwave ovens without adverse effect, which is not possible with pellets made of melamine.
This is of importance in the food service industry, since often when food is to be served to a patient at an unusual time, the pellet and food-containing plate assembly can be placed in a microwave oven and heated to proper temperature.
If desired, any conventional material known to absorb microwave energy can be included as part of the resin composition used to form the pellets. Uniform distribution of such distribution in the composition and in the pellets formed therefrom will enable the pellets themselves to be heated to the desired temperature in a microwave oven.
It is contemplated that thermoset epoxy resins may also be suitable to form pellets having the required properties discussed herein.
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
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A heat reservoir device for maintaining a comestible at a desired consumption temperature consisting essentially of a shaped reinforced thermoset polyester resin, preferably one made by reacting isophthalic acid, propylene glycol, and fumaric acid to form the unsaturated polyester and then forming a solution thereof in a vinyl monomer. The invention also include the method of maintaining a comestible at a desired temperature using such device.
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CROSS-RELATED APPLICATIONS
[0001] This application claims priority from Japanese Patent Application No. 2010-102901; filed Apr. 28, 2010, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a laser lap welding method for a galvanized steel sheet. More specifically, the present invention relates to a method for processing an end portion of a welding section in a laser welding method for galvanized steel sheets lapped one over the other with no gap.
[0003] In a wide variety of industries such as the automobile industry, galvanized steel sheets are commonly used because they are high in specific strength and low in cost as well as excellent in corrosion resistance. In particular, in the automobile industry, etc., where steel sheets having large areas are used, there have been attempts to introduce laser beam welding capable of higher speed processing than spot welding and the like in order to weld together a number of galvanized steel sheets lapped one over another.
[0004] However, the melting point (approximately 420° C.) and boiling point (907° C.) of zinc are much lower than the melting point (approximately 1535° C.) of iron. Accordingly, merely lapping galvanized steel sheets followed by laser irradiation results in the formation of weld defects such as pits, porosities, and worm holes due to a phenomenon in which zinc evaporated from each galvanized layer blows away molten metal therearound or remains in the molten metal as bubbles. For this reason, as described in JP 60-210386 A, JP 61-74793 A, or JP2007-38269A, countermeasures have been developed such as providing a gap for venting zinc vapor between galvanized steel sheets to be welded together by laser lap welding, using a spacer, a difference in level, or the like. However, such a method requires much time and effort, impairing the merits of introducing laser beam welding.
[0005] Then, WO 2010/005025 A1 discloses a laser lap welding method in which a laser beam is emitted with higher power density and at higher speed than usual to thereby temporarily form an elongated hole 20 (keyhole) in a molten pool 2 behind a laser irradiation position ( 10 ) as shown in FIGS. 1( a ) and 1 ( b ), and welding ( 3 ) is performed while venting metal vapor 23 through the hole 20 toward a laser irradiation source. This method eliminates the need for an additional preparing process as described above, and enables laser beam welding immediately after galvanized steel sheets are directly lapped one over the other. Thus, a large number of galvanized steel sheets having large areas can be efficiently welded together.
SUMMARY OF THE INVENTION
[0006] On the other hand, due to the feature that metal vapor is vented through the elongated keyhole, the above method also has other problems. Specifically, as shown in FIGS. 2( a ) and 2 ( b ), a trace 30 of the elongated hole ( 20 ) remains at a terminal end portion 32 of the welding section 3 , while a swell 33 of molten metal is created at the starting end portion 31 of the welding section 3 because a plume ( 23 ) blows out in a direction opposite to a welding direction F. The trace at the welding spot is observed in welding methods other than the laser beam welding. Hence, welding is performed at portions other than a design surface, or the trace is covered with another component. Regardless of such an appearance problem, such a hole trace ( 30 ) is unacceptable in many cases in automotive components and the like due to problems in functions such as liquid tightness and air tightness. Moreover, the swell ( 33 ) at the welding area is also unacceptable in many cases due to a problem in matching with, for example, assembling components mounted thereon.
[0007] Such a trace as described above is not formed at the end portion of the welding section when laser irradiation is started from one end portion of lapped galvanized steel sheets and is terminated after passing another end portion thereof. However, it is not a rare case that at least one of a starting end and a terminal end of the welding section is set within a lap region of galvanized steel sheets. In a method for conventional general laser beam welding, laser output is faded down at a terminal end portion of a welding section. In a laser beam welding method in which galvanized steel sheets are directly lapped one over the other, however, the welding conditions such as the foregoing power density and speed cannot be maintained during the process of fading down the laser output as shown in FIG. 3 , and weld defects are formed due to metal vapor. For this reason, this method is not directly applicable.
[0008] The present invention has been made in view of the aforementioned circumstances, and an object of the invention is to provide a laser lap welding method for a galvanized steel sheet which requires no additional process for avoiding welding defects due to zinc vapor, and is capable of high speed and high quality weldbonding with galvanized steel sheets being in intimate contact with one another while avoiding a swell at a starting end portion of a welding section and a hole trace at a terminal end portion thereof.
[0009] In order to achieve the above object, a laser lap welding method for a galvanized steel sheet according to the present invention includes the steps of: preparing two steel sheets ( 11 , 12 ), at least one of which is a galvanized steel sheet, in such a manner that the steel sheets are directly lapped one over the other with a galvanized layer of the galvanized steel sheet located as an interface of the steel sheets; and irradiating an outer surface of any one steel sheet in the lap region of the two steel sheets with a laser beam under predetermined power and speed conditions, so that an elongated hole ( 20 ) is formed in a molten pool ( 2 ) extending backward from a laser irradiation position ( 10 ) at least in the steel sheet on the outer surface side, whereby welding of the two steel sheets is performed while venting metal vapor produced by the laser irradiation through the elongated hole ( 20 ) backwards in a laser travelling direction and towards a laser irradiation source, wherein at a starting end portion ( 131 , 231 , 331 ) of a welding section ( 103 , 203 , 303 ) in the direct lap region, welding of any one of the welding section ( 103 ) and another welding section ( 204 , 304 ) is terminated (at 132 , 242 , 342 ) with the conditions to form the elongated hole maintained.
[0010] According to the laser lap welding method for galvanized steel sheet of the present invention, no additional process for avoiding weld defects due to zinc vapor is necessary. High speed and high quality weldbonding is performed with the galvanized steel sheets being directly in intimate contact with one another. Metal shortage at a terminal end portion of a welding section is compensated by an extra amount of molten metal built up at a starting end portion of the welding section. Furthermore, a hole trace at the terminal end portion of the welding section can be avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1( a ) is a plan view conceptually showing laser lap welding for a galvanized steel sheet, and FIG. 1( b ) is a B-B cross-sectional view thereof.
[0012] FIG. 2( a ) is a plan view conceptually showing a laser lap welding section of galvanized steel sheets, and FIG. 2( b ) is a B-B cross-sectional view thereof.
[0013] FIG. 3 is a graph showing a relationship between a laser output and a defect in the laser lap welding for a galvanized steel sheet.
[0014] FIG. 4 is a plan view conceptually showing a welding section by a laser lap welding method for a galvanized steel sheet according to a first embodiment of the present invention.
[0015] FIG. 5 is a plan view conceptually showing a welding section by a laser lap welding method for a galvanized steel sheet according to a second embodiment of the present invention.
[0016] FIG. 6 is a plan view conceptually showing a welding section by a laser lap welding method for a galvanized steel sheet according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention now will be described more fully hereinafter in which embodiments of the invention are provided with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0018] The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
[0020] A laser lap welding method for a galvanized steel sheet, which is a premise of the present invention is performed as shown in FIGS. 1( a ) and 1 ( b ) with two galvanized steel sheets 11 and 12 being lapped one over the other with no gap. With respect to the thicknesses of these galvanized steel sheets 11 and 12 , a laser beam having a significantly higher power (for example, 7 kW or more for a galvanized steel sheet having a thickness of 0.7 mm) than that of generally-adopted laser lap welding is irradiated while the laser beam travels at a significantly higher speed (for example, 9 m/min or more for a galvanized steel sheet having a thickness of 0.7 mm) than general travelling speed.
[0021] With laser welding, bonding is provided by solidification of molten metal which is fused by being heated and melted by laser irradiation energy. Thus, merely increasing a movement speed of laser irradiation results in shortage of power to be supplied per unit time, which causes poor welding. On the other hand, if a power density is too high, a melted portion cannot be fused and will burn out.
[0022] However, when laser irradiation is performed with high power and high speed, and when the power per volume in unit time, i.e., power density, is within a predetermined range as described later, an elongated keyhole 20 is formed in a molten pool 2 behind a laser irradiation position ( 10 ). The evaporation of metal concentrates on the front end side of the elongated keyhole 20 in a traveling direction F of laser irradiation. Metal vapor 23 (laser-induced plume) is vented backward R from the front end of the keyhole 20 along the traveling direction of laser irradiation toward a laser irradiation source side, so that the keyhole 20 is made elongated. Furthermore, zinc vapor is vented from or near the front end of the elongated hole 20 thus formed, so that the zinc vapor does not blow away molten metal in the molten pool 2 and the molten metal does not remain in the molten pool 2 .
[0023] In order to perform favorable laser welding with the galvanized steel sheets 11 and 12 being lapped one over the other with no gap, in case of, for example, a thin steel sheet, it is preferable to select a travelling speed v (mm/sec) such that a power per volume in unit time “P/øtv” of a laser beam is 0.07 to 0.11 (kW·sec/mm 3 ) with a laser beam having a power “P” of not less than 7 (kW) and a laser irradiation spot diameter “ø” of not less than 0.4 (mm) when a galvanized steel sheet has a thickness “t” (mm).
[0024] The matter that a power per volume in unit time P/øtv of the laser beam is within the foregoing range represents that the power P of the laser beam to be radiated is determined according to an irradiation width (irradiation spot diameter) ø, a sheet thickness t, and a travelling speed v (a movement distance per unit time of the irradiation spot). This was approximately and empirically determined from an applicable sheet thickness of a galvanized steel sheet to be subjected to laser lap welding. Assuming that there is a region having a uniform shape in the laser travelling direction and a cross-section shape thereof is an inverted triangle in which the height thereof (interpenetrated depth) is 2t (a thickness of two sheets), it is thought that the “øtv” is determined by multiplying the cross-sectional area (ø×2t/2) of the triangle by the travelling speed v. If two galvanized steel sheets to be lap-welded are different in sheet thickness t, the sheet thickness t of the galvanized metal sheet disposed on the laser irradiation source side is used as a reference. When three or more galvanized steel sheets are lap-welded, half of a total sheet thickness should be applied.
[0025] Note that a laser oscillator used for welding, a processing head for laser scanning, and the like are not particularly limited, and known laser welding devices can be used. However, since it is necessary to move a high output laser beam at high speed as described above, a preferable laser welding device is one including a galvano scan-type processing head composed of a pair of galvano mirrors and an fθ lens.
[0026] Next, the laser lap welding method for a galvanized steel sheet according to the present invention (method for processing an end portion of a welding section) will be described.
First Embodiment
[0027] As has been described above, in laser lap welding in which laser irradiation is performed with high power and high speed with the galvanized steel sheets 11 and 12 being lapped one over the other with no gap, metal vapor is vented through an elongated keyhole, and thereby weld defects due to zinc vapor can be avoided. On the other hand, when a starting end or a terminal end of a welding section is set within a region where galvanized steel sheets are lapped one over the other, as shown in FIGS. 2( a ) and 2 ( b ), a trace 30 of the elongated hole ( 20 ) remains at a terminal end portion 32 of the welding section 3 while the plume ( 23 ) blows out in the direction opposite to the welding direction F at a starting end portion 31 of the welding section 3 , creating a swell 33 of molten metal.
[0028] Thus, on a welding area 100 in a first embodiment shown in FIG. 4 , laser irradiation with predetermined high power and high speed is started from a starting end portion 131 of a welding section 103 located within a region where the galvanized steel sheets 11 and 12 are directly lapped one over the other. The laser irradiation is performed circularly (along a closed curve) as indicated by a broken arrow. While the welding conditions are being maintained, the laser irradiation is terminated at the starting end portion 131 of the welding section 103 . In other words, a terminal end portion 132 of the welding section 103 overlaps the starting end portion 131 of the welding section 103 .
[0029] Thereby, metal shortage that occurs in the hole trace 30 at the terminal end portion 32 of the welding section shown in FIGS. 2( a ) and 2 ( b ) is compensated by an extra amount of metal of the swell 33 at the starting end portion 31 of the welding section. Thus, neither the hole trace 30 nor the swell 33 remains at the connection portion ( 131 , 132 ) of the welding section 103 having a shape of such a closed curve. Otherwise, at least the bulging trend or the recessing trend is dramatically reduced. In other words, although the welding conditions of high power and high speed are maintained until the terminal end portion 132 , it can also be understood in the following way that the conditions required to form the elongated keyhole 20 are increased at a small section by the amount of the swell 33 having existed at the starting end portion 131 of the welding section; consequently, fading down is achieved (relatively).
[0030] The metal shortage in the hole trace 30 at the terminal end portion 32 of the welding section has a correlation with the extra amount of metal of the swell 33 at the starting end portion 31 of the welding section. Thus, the method of this embodiment can be performed similarly in case in which the galvanized steel sheets 11 and 12 have different thicknesses or other welding conditions are different.
Second Embodiment
[0031] On a welding area 200 in a second embodiment shown in FIG. 5 , first laser irradiation is started, for example, from a first starting end portion 231 located within a region where the galvanized steel sheets 11 and 12 are directly lapped one over the other. A first welding section 203 is laser welded. While the welding conditions are being maintained, the first laser irradiation is continuously performed on an end portion 232 of the lap region of the galvanized steel sheets 11 and 12 and terminated outside the lap region. Then, second laser irradiation is started, for example, from the outside of another end portion 241 of the lap region of the galvanized steel sheets 11 and 12 . A second welding section 204 is laser welded. The second laser irradiation is terminated at the starting end portion 231 of the first welding section 203 . In other words, a terminal end portion 242 of the second welding section 204 overlaps the starting end portion 231 of the first welding section 203 , which is different therefrom.
[0032] In this case also, as similarly to the first embodiment, metal shortage at the terminal end portion ( 242 ) of the welding section is compensated by an extra amount of metal at the starting end portion ( 231 ) of the welding section. Thus, neither a hole trace nor a swell remains at such a connection portion ( 231 , 242 ) of the first or second welding section 203 or 204 . Otherwise, at least the bulging trend or the recessing trend is dramatically reduced.
Third Embodiment
[0033] In any of the welding areas 100 and 200 respectively described in the first and second embodiments, illustrated is the case in which the terminal end portion ( 132 , 242 ) of the welding section ( 103 , 204 ) overlaps the starting end portion ( 131 , 231 ) of the welding section ( 103 , 203 ) in the same direction. Nevertheless, the terminal end portion may overlap the staring end portion from another direction. For example, in a welding area 300 in a third embodiment shown in FIG. 6 (modified example of the second embodiment), the laser irradiation is terminated with a terminal end portion 342 of a second welding section 304 perpendicularly overlapping a starting end portion 331 of a first welding section 303 irradiated with the laser in advance. The other configurations are the same as those of the second embodiment.
[0034] Any direction can be set for overlapping the terminal end portion with the starting end portion, and the overlap can be performed at any angle other than the same direction (0°) and the perpendicular direction (90°). The overlap can also be performed in an opposite direction (180°) with respect to the starting end portion. Additionally, in the welding section 100 having a shape of the closed curve as in the first embodiment, the terminal end portion ( 132 ) can overlap the starting end portion 131 in any direction.
[0035] Furthermore, in completing the laser irradiation on the welding section ( 103 , 204 , 304 ) where the terminal end portion ( 132 , 242 , 342 ) overlaps the starting end portion ( 131 , 231 , 331 ), it is possible to fade down the laser output in the already-welded portion of the region ( 103 , 203 , 303 ).
Examples
[0036] After that, to verify the effect of processing the end portions of the welding section in the laser lap welding method for a galvanized steel sheet according to the present invention, the overlapping amount of the starting point and the terminal point at the position of the terminal end portion 132 relative to the starting end portion 131 , i.e., on the control coordinates of laser scanning, was intentionally changed in the laser welding of the welding area 100 in the first embodiment. The comparison experiment was conducted as follows.
[0037] In the experiment, a fiber laser oscillator manufactured by IPG Photonics Corporation (a maximum output 7 kW and a transmission fiber diameter ø=0.2 mm) and a scanner head (just focused processing diameter ø=0.6 mm) were used. Galvanized steel sheets with a thickness of t=0.7 mm were lapped one over the other with no gap so that each galvanized layer was an interface therebetween. Laser irradiation was performed with a spot diameter of ø=0.67 mm, a laser output of 7 kW, a power density of 19.9 kW/mm 2 , and a travelling speed of 11 in/min. The condition of welding and the condition of the terminal end portion (connection portion) of the welding section were examined for each overlapping amount of the starting end portion and the terminal end portion:
[0038] (a) 2.5 mm (optimum value);
[0039] (b) 0 mm (no overlap); and
[0040] (c) 4.4 mm (excessive overlap, i.e., overrun).
[0041] Moreover, as a comparative example (d), laser irradiation was performed with an overlapping amount of 0 mm under the welding condition to form no elongated keyhole: a laser output of 4.5 kW, a power density of 12.8 (kW/mm 2 ), and a travelling speed of 8 (m/min). Comparison was made with each case of the above overlapping amounts. The results of each case and the comparative example were as follows.
(1) Condition of Welding
[0042] In any case of (a) to (c) above, an elongated hole (keyhole) having a length of approximately 1.5 mm was observed behind the welding spot during the welding; in addition, no weld defects were observed in an intermediate portion of the welding section (bead). Meanwhile, in (d) above, no hole was observed behind the welding spot during the welding; in addition, nine weld defects (blow holes) were observed on the front surface side of the welding section (bead), and four weld defects were observed on the back surface side thereof.
(2) Condition of Terminal End Portion (Connection Portion) of Welding Section
[0043] In the case of the (a) overlapping amount of 2.5 mm (optimum value), a swell was observed at the starting end portion immediately after the welding was started. Nevertheless, by overlapping the terminal end with the starting end portion 131 by an appropriate length, no hole trace such as a recessed portion was observed at the terminal end portion (connection portion) after the completion of the welding. It was confirmed that metal shortage at the terminal end portion of the welding section was compensated by an extra amount of metal of the swell at the starting end portion of the welding section.
[0044] Meanwhile, in the case of the (b) overlapping amount of 0 mm (no overlap), a swell remained at the starting end portion of the welding section, and a hole trace remained at the terminal end portion of the welding section adjacent to and immediately in front of the starting end portion.
[0045] Moreover, in the case of the (c) overlapping amount of 4.4 mm (overrun), most of a swell at the starting end portion of the welding section was eliminated, but a hole trace remained at the terminal end portion of the welding section adjacent to the starting end portion.
[0046] Note that in (d) above, although the welding was terminated without overlapping, no swell was formed at the starting end portion and no hole trace was formed at the terminal end portion. However, as described above, a number of defects were formed on the front and back sides of the welding section (bead), and the state of the overall welding section was a problem to be solved before the problem of the terminal end portion (connection portion) and thus was not at an acceptable level.
[0047] For example, in the first embodiment, illustrated was the case in which the welding area 100 is formed of the single circular welding section 103 . The welding area 100 nevertheless may have another shape of closed curve such as ellipse or water droplet. Moreover, such a welding section 103 may be saved as a welding unit in a controller of a laser welding device so that the welding unit can be realized only by designating the reference position such as the center of a circle. Further, it is possible to set a flange around an opening of galvanized steel sheets lapped one over the other, or the welding section 103 that turns along an attachment portion of an article, or the like.
[0048] Having thus described certain embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope thereof as hereinafter claimed. The following claims are provided to ensure that the present application meets all statutory requirements as a priority application in all jurisdictions and shall not be construed as setting forth the full scope of the present invention.
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Provided is a laser lap welding method for a galvanized steel sheet, comprising the steps of: preparing two steel sheets ( 11, 12 ), at least one of which is a galvanized steel sheet, in such a manner that the steel sheets are directly lapped one over the other with a galvanized layer of the galvanized steel sheet located as an interface of the steel sheets; and irradiating an outer surface of any one steel sheet in the lap region of the two steel sheets with a laser beam under predetermined power and speed conditions, so that an elongated hole ( 20 ) is formed in a molten pool ( 2 ) extending backward from a laser irradiation position ( 10 ) at least in the steel sheet on the outer surface side, whereby welding ( 3 ) of the two steel sheets is performed while venting metal vapor ( 23 ) produced by the laser irradiation through the elongated hole ( 20 ) backwards (R) in a laser travelling direction and towards a laser irradiation source, wherein at a starting end portion ( 131, 231, 331 ) of a welding section ( 103, 203, 303 ) in the direct lap region, welding of any one of the welding section ( 103 ) and another welding section ( 204, 304 ) is terminated (at 132, 242, 342 ) with the conditions to form the elongated hole maintained.
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BACKGROUND OF THE INVENTION
This invention relates to heat exchangers, particularly to heat exchangers of the spiral plate type which typically form spiral passages for the fluid media from strip material.
Although practical designs for many heat exchanger applications were developed years ago, fouling, which is the deposition and accumulation of undissolved material in the passages or channels and chambers of a heat exchanger, poses special problems. Fouling is undesirable because it insulates the heat transfer surfaces from the fluid flowing through the passage or channel, causing a decrease in heat transfer, and because it restricts the flow of fluid through the affected passages of the heat exchanger by reducing the cross sectional area of the fluid passage and by increasing the friction between the fluid and the passage walls. The presence of undissolved materials suspended in fluid passing through a heat exchanger raises the likelihood of fouling. Because of fouling problems, no practical design to the applicant's knowledge has yet been widely accepted for many heat transfer applications.
Once a heat exchanger has become fouled, cleaning procedures are necessary to remove the accumulated material. These cleaning and maintenance procedures often add so much to the operating cost that many heat exchanger applications go unfilled. For example, in dish washer applications, each dish washing machine discharges several gallons per minute of waste water at approximately one hundred and fifty degrees Fahrenheit (150° F.) to the drain. Theoretically, the heat from this waste water could be recycled by a heat exchanger which cools the waste water and heats the incoming clean water. Because of fouling by materials washed off the dirty dishes, no heat exchanger has yet been recognized as offering an acceptable combination of resistance to fouling, low operating cost, and low manufacturing cost.
Many design parameters affect fouling tendencies. They include fluid velocity, availability of multiple parallel fluid passages, and obstructions in the fluid passages. High fluid velocities and the shear forces associated therewith tend to impede suspended matter from settling onto the wetted perimeter of fluid passages, and material which has settled tends to be loosened and carried away by these shear forces and by impacts with solids suspended in fast moving fluid. On the other hand, fouling is promoted by low fluid velocities, which may be caused within heat exchanger passages by channel shapes which distribute flow unevenly across the available cross section, such as on the shell side of a shell and tube heat exchanger.
Also, fouling is promoted in heat exchangers having multiple parallel fluid passages. Fluids carrying undissolved fouling material (such a fluid being referred to herein as a "fouling fluid") tend to distribute material deposits unevenly inside available parallel passages. A deposit of fouling material which partially obstructs one passage in a multiple parallel passage heat exchanger, causes the velocity through that one passage to drop while causing the fluid velocity in other passages to increase. This decrease in velocity promotes additional accumulation of fouling material in the obstructed passage. This mechanism for fouling explains why fouled passages of shell and tube bundles have the inside of some tubes completely blocked by accumulations, while other passages contain almost no deposits.
Fluid passages which are completely blocked tend not to be responsive to chemical cleaning procedures such as circulating a bleach, caustic, or acid solution through the passage. Instead, expensive disassembly and mechanical cleaning is usually required.
As mentioned above, fouling is promoted by obstructions in the fluid passage where solids such as fibers can be caught, and which create areas of low velocity in their proximity where undissolved material accumulates. The spiral heat exchangers described in U.S. Pat. Nos. 2,360,739 to Strom (1944) and 3,921,713 to Schnitzer et al. (1975) have structure extending between the coiled heat transfer surfaces to set the spacing between the heat transfer surfaces. This structure partially obstruct the fluid passage into which it protrudes, limiting the application of those heat exchangers. The spiral heat exchanger described in U.S. Pat. No. 3,762,467 to Poon et al. (1973) also has structure between the heat exchange surfaces, and incorporates a filter for removing fibers and other solids before the fouling fluid enters the heat transfer fluid passage. The need to frequently clean the filter in applications involving large quantities of undissolved materials makes this heat exchanger impractical for such applications.
Many unfilled heat exchanger applications, such as the aforementioned dish washer application or recycling heat from wash water in laundromats, involve only a few thousand dollars worth of energy recovery per year per installation. For a new heat exchanger design to be practical for a wide range of applications, both the initial cost and the operating cost of the exchanger must be low.
To achieve low production cost, the exchanger design should minimize material costs and the total cost of all fabrication procedures such as casting, cutting, shaping, welding, machining, and final assembly.
Spiral heat exchangers such as the one described in U.S. Pat. No. 2,360,739 to Strom require much welding and milling, which increases manufacturing costs. U.S. Pat. No. 4,577,683(1986) to Kelch suggests forming a heat transfer duct member, which defines the heat transfer fluid passages, in a mold. An expensive mold, machined to tight tolerances appears to be required for each desired channel configuration, and production appears to be limited to factories equipped with furnaces for melting metal, or equipped with injection molding equipment used to form ducts of plastic.
SUMMARY AND OBJECTS OF THE INVENTION
Several objects of the present invention are:
(a) to provide a simple, compact, efficient heat exchanger;
(b) to provide a heat exchanger fabricated by means of a simple and inexpensive procedure;
(c) to provide a heat exchanger for which the design and the fabrication procedures are easily and inexpensively adapted for a wide variety of applications;
(d) To provide a sturdy and durable heat exchanger, which is tolerant of abuse during installation, operation, and maintenance;
(e) to provide a heat exchanger which is resistant to the deposition and accumulation of undissolved materials;
(f) to provide a heat exchanger which is easy and inexpensive to clean;
(g) to provide a heat exchanger which is safe to manufacture, install, operate, and maintain;
(h) to provide a heat exchanger to which a manufacturer can easily and inexpensively give any of a variety of distinctive appearances.
Further objects are: to provide a heat exchanger which is suitable for recovering thermal energy from waste water, especially waste water containing undissolved solids; to provide a heat exchanger which offers savings of utility costs far in excess of the installed cost of the heat exchanger for a large number of end users; to provide a heat exchanger which requires a low start up cost of production, making it feasible to manufacture on a small scale, and to provide a heat exchanger which can be produced in a wide variety of distinct models by one manufacturer who benefits from economies of scale. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
The invention achieves the above and other objects by providing a heat exchanger for indirect heat transfer between fluid media in accordance with one or more of the following.
A transition chamber is provided between the inlet for the fouling fluid and a heat exchanging passage for the fouling fluid (where substantial heat exchange between the fouling fluid and the other fluid medium takes place). The fouling fluid flows through the transition chamber before entering the fouling fluid heat exchanging passage. The transition chamber is configured to collect undissolved material that may otherwise flow into the fouling fluid heat exchange passage. For example, the cross section of the transition chamber may be substantially larger than the cross section of the fouling fluid passage and preferably includes a throat section in which the chamber transitions to the cross section of the fluid passage. This arrangement allows undissolved material to collect without completely blocking the fouling fluid passage. Should undissolved material collect in the transition chamber so as to slow the throughput of fouling fluid in the fouling fluid passage, that can easily be detected and remedial action taken such as introducing a chemical cleaning agent or removing the undissolved material before a complete blockage can occur. Preferably, easy access is provided to the transition chamber to remove collected undissolved material. A transition chamber may also be provided for the other fluid used in the heat exchanger, which may be either a clean fluid (one without substantial amounts of undissolved material) or another fouling fluid. Use of a transition chamber avoids the need for a filter and the problems associated therewith. Preferably, the transition chamber feeds a single heat exchanging fluid passage, although it may feed multiple heat exchanging fluid passages and still realize at least some of the benefits described above.
A single fluid passage is provided for the fouling fluid. This avoids the problem associated with parallel flow passages where one or more flow passages can become blocked without a decrease in throughput, which could reduce the heat exchanging characteristics of the heat exchanger. Preferably, the single fluid passage extends helically in the heat exchanger, and the heat exchanger is a spiral heat exchanger. Preferably, the heat exchanger is a spiral heat exchanger which includes a single, helically extending flow passage for the fouling fluid and the transition chamber described above.
A spiral heat exchanger according to the invention has two heat exchanging fluid passages defined by a heat-conducting strip spirally wound within a shell or casing with opposite edges of the strip sealed to the casing to define two adjacent, spirally extending fluid passages of substantial length in a heat exchanging relationship with each other for substantial lengths thereof. The strip is supported and sealed at opposite edges thereof without obstructing at least a fluid passage which conducts a fouling fluid, and preferably without obstructing either fluid passage, i.e., no spacing or supporting structure extends into at least the fouling fluid passage and preferably both fluid passages. The seal is preferably accomplished by a sealant that may be applied in liquid form and which thereafter hardens or cures, as described below.
The sealing and spacing of the helically wound strip may be accomplished in accordance with the invention by a sealant that is introduced to one or both edges of the strip in liquid form and held there for a sufficient time for the sealant to harden. In addition to sealing one or both edges of the strip, the sealant preferably also engages the strip to space adjacent runs thereof. The sealant thus need not protrude into the fluid passages defined by the helically wound strip, and yet can maintain the spacing between adjacent runs of the strip.
A spiral heat exchanger having a helically wound coil may be supported in accordance with the invention by a rigid support element or stanchion to which the coil is affixed and which extends from the coil so that the coil may be supported by means of the support element. For example, the support element may have a mounting portion extending from the coil which may be bolted to a support structure. Preferably, the coil is the helically wound strip described above, which is affixed to the support element by the sealant described above. In that embodiment, one edge of the strip is adjacent the support element when the sealant is introduced, which when it hardens bonds the strip to the support element. The support element may also include structure adapted to receive or engage the coil. Also, the support element may be used to affix and/or support the shell of the heat exchanger, and/or a removable or permanently affixed end plate thereof, and/or a removable cover which provides access to the interior of the heat exchanger for service or maintenance purposes. Fluid inlets and outlets may also be affixed to and supported by the support element.
A heat exchanger according to one embodiment of the invention comprises a first fluid inlet, a first chamber in communication with the first fluid inlet, a first fluid outlet, a first fluid passage of substantial length communicating the first fluid inlet and the first fluid outlet, with the first fluid chamber defining a fluid passage between the first fluid inlet and the first fluid channel which is substantially larger in cross section than the first fluid passage. The heat exchanger also includes a second fluid inlet, a second fluid outlet, and a second fluid passage of substantial length communicating the second fluid inlet and the second fluid outlet and being in a heat-exchanging relationship with the first fluid passage for substantial lengths thereof
The heat exchanger according to this embodiment:
may include a second fluid chamber communicating the second fluid inlet with the second fluid passage, where the second fluid chamber defines a fluid passage between the second fluid inlet and the second fluid channel which is substantially larger in cross section than the second fluid passage;
may be provided with an opening to the first fluid chamber accessible from the exterior of the heat exchanger and means for selectively closing the opening, and where a second fluid chamber is provided, an opening thereto accessible from the exterior of the heat exchanger and means for selectively closing the opening;
may be a spiral heat exchanger comprising a single first fluid passage and a single second fluid passage each extending spirally within the heat exchanger, and may comprise a spirally wound, heat-conducting strip and means for closing off and/or sealing opposed edges of the strip and/or spacing adjacent runs of the strip as described herein;
may also comprise a support element as described herein.
A spiral heat exchanger according to an embodiment of the invention comprises a shell, a heat-conducting strip spirally wound within the shell with opposite edges thereof sealed to the shell to define adjacent, spirally extending first and second fluid passages of substantial length in a heat exchanging relationship with each other for substantial lengths thereof, with at least the first fluid passage being unobstructed in-between the shell. The heat exchanger also includes a first fluid inlet communicating with the first fluid passage, a first fluid outlet communicating with the first fluid passage spaced a substantial distance from the first fluid inlet, a second fluid inlet communicating with the second fluid passage, and a second fluid outlet communicating with the second fluid passage spaced a substantial distance from the second fluid inlet.
A spiral heat exchanger according to an embodiment of the invention comprises a rigid support element, a spirally wound heat-conducting strip supported by the support element with opposite edges thereof sealed to define adjacent, spirally extending first and second fluid passages of substantial length in a heat exchanging relationship with each other for substantial lengths thereof, a first fluid inlet supported by the support element communicating with the first fluid passage, a first fluid outlet supported by the support element communicating with the first fluid passage spaced a substantial distance from the first fluid inlet, a second fluid inlet supported by the support element communicating with the second fluid passage, and a second fluid outlet supported by the support element communicating with the second fluid passage spaced a substantial distance from the second fluid inlet.
The spiral heat exchanger according this embodiment:
may have a first fluid chamber defined by the strip communicating the first fluid inlet with the first fluid passage, where the first fluid chamber defines a fluid passage between the first fluid inlet and the first fluid channel which is substantially larger in cross section than the first fluid passage;
may have a second fluid chamber defined by the strip communicating the second fluid inlet with the second fluid passage, where the second fluid chamber defines a fluid passage between the second fluid inlet and the second fluid channel which is substantially larger in cross section than the second fluid passage;
may have an opening to the first fluid chamber accessible from the exterior of the heat exchanger and means for selectively closing the opening;
may have an opening to the second fluid chamber accessible from the exterior of the heat exchanger and means for selectively closing the opening;
may have a shell which includes a sealant sealing one edge of the strip at least where the strip defines the first and second fluid passages and engaging the strip to space adjacent runs of the strip;
may have a shell which includes a gasket adjacent one edge of the strip at least where the strip defines the first and second passages, and a plate urging the gasket against the one edge of the strip effective to seal the one edge of the strip, where the plate may be removably mounted to the heat exchanger; and
may have a rigid support element as described herein.
In any of the above embodiments, the heights of the fluid passages may vary over the length thereof within a predetermined range of heights and a predetermined frequency of variation, forming numerous convergences and divergences and frequently changing the direction of the fluid flow as a means of imparting turbulence into the fluid. Also, the heights of the fluid passages may vary over different predetermined ranges of heights for each fluid passage, as a means of establishing different fluid flow characteristics such as velocity, pressure drop, and Reynolds Number for each of the fluids flowing through the two fluid channels.
In achieving some of the above objects, the invention also provides a method for fabricating a spiral heat exchanger, comprising the steps of: holding a thermally conductive strip in a configuration which forms two adjacent helically extending fluid channels, installing an inlet port and an outlet port in communication with each of the two fluid channels, introducing a liquid sealant in contact with one edge of the strip until the sealant hardens to engage and maintain the wound strip and to seal the strip along the edge, and sealing the opposite edge of the strip.
The steps of holding the strip and introducing sealant may be carried out by holding the strip in a mold which maintains the configuration of the strip and introducing the sealant into the mold. The step of installing the inlet and outlet ports may be carried out by attaching them to a rigid support element and positioning the support element adjacent the strip while the sealant is introduced to attach the support to the strip by means of the sealant. The mold may be bonded to the strip by the sealant and become part or all of a shell of the heat exchanger.
In a specific embodiment, the heat exchanger comprises a coil which includes two separate and adjacent inner flow transition chambers, two separate peripheral flow transition chambers, and two separate and adjacent fluid channels all formed by a thin thermally conductive strip and sealant such that two fluid passage are provided which are unobstructed by protrusions from any wetted internal surface. Each passage is formed to connect one inner flow transition chamber, dedicated to that passage, and one peripheral flow transition chamber, dedicated to that passage, and is configured such that the fluid passages are helically wound around the inner flow transition chambers to form the coil with peripheral flow transition chambers at the outer surface. The heat exchanger includes a rigid support element or stanchion formed of rigid structurally strong material, such as metal plate, attached to the side of the coil, such that the stanchion is adjacent to all of the flow transition chambers. Inlets and outlets are arranged such that each flow transition chamber is accessed by an inlet or outlet extending through the exterior of the coil, through the stanchion, through the sealant, and through any other layers of material between the exterior of the coil and the flow transition chamber. The thin thermally conductive strip may be closed by sealant on only the edge which is adjacent to the stanchion, the other edge being closed by a removable cover fabricated of a structurally strong material such as metal plate and a gasket made of a resilient material such as nitrile rubber or other elastomer sheet. The cover is attached to the coil by a suitable arrangement of fasteners extending from the stanchion across the width of the coil, outside of the flow channels.
The stanchion may be increased in size such that it extends beyond the perimeter of the coil sufficiently to anchor the fasteners. The heat exchanger may be provided with an inspection port or opening of adequate size to at least one flow transition chamber to facilitate removal of undissolved solids. An inspection port cover and gasket is fastened to each inspection port. The number of the flow transition chambers are of a predetermined size, and are shaped and oriented approximately as the lower part of a cylinder with a horizontal axis, the cylinder having been divided by a plane parallel to the axis of the cylinder; and joined to the corresponding fluid channel along one edge formed by the intersection of the surface of the cylinder and the plane which divides the two parts of the cylinder. Each flow transition chamber is joined to the corresponding fluid channel at a throat region which is fabricated such that at no place throughout the length of the fluid channel is the channel height less than the channel height in the throat region, whereby undissolved material too large to pass through the fluid passage is contained within the flow transition chamber until it is removed through the maintenance port. The heights of the two fluid passages may be different for the two fluid passages, as a means of establishing different fluid flow characteristics (e.g., for introducing turbulence into the fluid) such as velocity, pressure drop, and Reynolds Number for each of the fluids flowing through the two fluid channels. The heights of the fluid channels may vary over the length of the fluid channels within a predetermined range of heights and a predetermined frequency of variation, forming numerous convergences and divergences and frequently changing the direction of the fluid flow as a means of imparting turbulence into the fluid. The thin thermally conductive strip used to form the heat transfer passages may have a protruding pattern such as a corrugated or ribbed pattern which includes irregularities across the direction of fluid flow, such that the distance between adjacent wraps varies repeatedly within a predetermined range of distances to serve as a means to impart turbulence to the fluid flowing through the passages.
A containment ring fabricated of a structurally strong material such as metal may surround the coil axially and be attached to the coil by sealant between the outer wrap of the coil and the containment ring. The heat exchanger includes a shell which encloses both sides of the coil including both edges of the inner flow transition chambers, both edges of the flow channels, and both edges of the peripheral flow transition chambers. The shell is fabricated of a material which gives an appropriate aesthetically attractive appearance to the heat exchanger such as corrosion resistant metal such as stainless steel, or plastic, and is attached to the coil by sealant on both sides of the coil. The shell may overlay a layer of filler material, and encases both sides of the coil, thereby serving to structurally support the sealant closing the edges of the coil, serving to insulate the coil from radiative heat transfer with its surroundings, and serving to give the heat exchanger the appearance of having been manufactured to high quality standards. In one embodiment, the shell is held firmly to the side of the coil opposite the stanchion by the cover over each maintenance port, and the shell is fabricated with appropriately sized holes which align with the maintenance port, and with each fluid passage.
The thin thermally conductive strip may be made of material such as stainless steel, aluminum, galvanized steel, or similar thermally conductive material, and the sealant may be an epoxy, urethane, silicone rubber or similar material which adheres to the strip, which hardens as the sealant cures, and which contacts a predetermined portion of the width of the strip as a means of maintaining the distance between adjacent wraps and as a means of closing the edge of the coil. Sealants satisfactory to perform these functions are readily commercially available from sources known to those of skill in the art.
The stanchion may have a 90° bend at one end which protrudes a predetermined distance from the main part to define amount portion for the coil. A suitable arrangement of bolt holes through the main portion enables the mount part to serve as a means to fasten the heat exchanger to a structure. The inlets and outlets through the stanchion are defined by a structurally strong material such as metal tubing or pipe which firmly attached to the stanchion, preferably by welding.
A specific embodiment of the method for fabricating the heat exchanger comprises the steps of: shaping a thermally conductive strip to form two center flow transition chambers, two helical fluid channels, and two peripheral flow transition chambers; joining each of the two ends of the strip to the adjacent inner wrap of strip by a means which results in a strong leakproofjoint; fabricating a stanchion subassembly which includes a brace, four fluid passages, and fasteners; bringing together the coiled strip, the stanchion, and liquid sealant in a mold such that each of the four fluid passages through the stanchion aligns with one of the four flow transition chambers formed by the strip, the fasteners extend across the width of the coil without obstructing any of the fluid channels or any of the throats where the fluid channels join the chambers; and the liquid sealant extends across the thickness of the brace and partially across the width of the coil such that when the sealant cures, the brace becomes attached to the coil, one edge of each of the four flow transition chambers and one edge of the helical fluid passages becomes closed in a mechanically strong and leakproof manner, and the distances between adjacent wraps forming the two center flow transition chambers, the two helically wound fluid passages and the two peripheral flow transition chambers becomes fixed; and closing the remaining open edge of the two center flow transition chambers, the two helically wound fluid passages and the two peripheral flow transition chambers by a means which results in a leakproof seal.
The thermally conductive strip may be shaped to form the two center flow transition chambers by locating a point near the center of the length of strip between blocks which in profile have the desired shape of the center flow transition chambers, and which do not extend across the width of the strip such that the blocks hold the strip in the desired shape and leave room for sealant to flow between adjacent wraps of strip without the blocks becoming bonded to the strip during the molding procedure; and winding the strip around the blocks. The thermally conductive strip is shaped to form the two helically wound fluid channels by placing flexible belts which do not extend across the width of the strip such that the belts hold the strip in the desired shape and leave room for sealant to flow between adjacent wraps of strip without the belts becoming bonded to the strip during the molding procedure. The strip and the belts are then wound around the center flow transition chambers and the thermally conductive strip is shaped to form the two peripheral flow transition chambers by placing blocks, which in profile have the desired shape of the peripheral flow transition chambers, against the adjacent inner wrap of strip at the desired locations such that the blocks hold the strip in the desired shape and leave room for sealant to flow between adjacent wraps of strip without the blocks becoming bonded to the strip during the molding procedure; and winding the strip over the blocks. After bonding the stanchion to the coil, the blocks and belts are removed through the remaining open edge of the two center chambers, the two helically wound fluid channels, and the two peripheral channels.
After bonding the stanchion to the coil to close the remaining open edge of the two center flow transition chambers, the two helically wound fluid channels and the two peripheral flow transition chambers, in another molding procedure the coil is positioned in a mold and liquid sealant is introduced such that the liquid sealant extends partially across the width of the coil, leaving an open space of approximately uniform width between the two layers of sealant deposited during the two molding procedures. A maintenance port is created into one or more flow transition chambers through the sealant which closes the edge of the chambers which is opposite the stanchion, and a removable maintenance port cover with a removable maintenance port cover gasket are provided to close the port before operation. The maintenance port cover and the gasket are positioned and attached to the side of the coil by fasteners in a tight leakproof manner.
The molds used in the procedures which combine sealant and strip, may be bonded by the sealant, and become part of all of the shell of the heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, closely related figures have the same figure number, but have different alphabetic suffixes. Also, the same reference numeral or the same reference numeral with different alphabetical suffixes in different figures indicates the same or a similar or related part.
FIG. 1 is a rear perspective view, particularly in section and party broken away, of a heat exchanger according to the present invention.
FIG. 2 is a radial section view of a heat exchanger according to the invention, but showing a reduced number of fluid passages enlarged for clarity.
FIGS. 3A and 3B are front and rear perspective views aspects of a stanchion subassembly of the heat exchanger depicted in FIG. 1.
FIG. 4A is a schematic rear perspective view, partly in section and partly broken away, of the heat exchanger depicted in FIG. 2.
FIG. 4B is a front perspective view, partially exploded, of the heat exchanger depicted in FIG. 2.
FIG. 5A is a rear perspective view, partly broken away, of another embodiment of a heat exchanger according to the invention for high pressure applications, but showing a reduced number of fluid passages enlarged for clarity.
FIG. 5B is a front perspective view, partially exploded, of the heat exchanger depicted in FIG. 5A.
FIG. 6 is a rear perspective view, partly broken away, of another embodiment of a heat exchanger according to the invention having a removable channel maintenance cover to provide easy access to the fluid passages within the heat exchanger, but showing a reduced number of fluid passages enlarged for clarity.
FIG. 7A is a front perspective view, partially exploded, of a heat exchanger according to another embodiment of the invention for use in applications in which both fluids carry fouling material.
FIG. 7B is a radial axial section view of the heat exchanger depicted in FIG. 7A, but showing the heat exchanger with a reduced number of enlarged fluid passages for clarity.
FIG. 8 illustrates a molding procedure for bonding the shell of the heat exchanger and the stanchion which supports the heat exchanger to a coiled strip which forms the fluid passages of the heat exchanger.
REFERENCE NUMERALS IN DRAWINGS
10 heat exchanger
10A heat exchanger
10B heat exchanger
10C heat exchanger
12 heat transfer coil
13 strip
14 heat exchanger main part or body
16 stanchion
16A brace or central portion
16B mount or base portion
16C positioning guide portion
16D bolt holes
17 inlet port for fluid A
18 outlet port for fluid A
19 inlet port for fluid B
20 outlet port for fluid B
22 fluid passage for fluid A
24 fluid passage for fluid B
25 fastener
25A shank
25B washer
25C lock washer
25D nut
26 inspection port
28 raised ridge
30 coil center
31 tubular spacers
32 inspection port gasket
34 inspection port cover
40 center flow transition chamber for fluid A
40A throat
40B constriction at throat
42 peripheral flow transition chamber for fluid A
42A throat
44 center flow transition chamber for fluid B
44A throat
46 peripheral flow transition chamber for fluid B
46A throat
46B constriction at throat
50 channel terminal
51 sealant
52 casing
53 containment ring
54 containment plate
55 channel maintenance cover gasket
56 channel maintenance cover
58 fasteners at the periphery
60 hole in containment plate
62 washer
63 lock washer
64 nut
70 block shaped as center flow transition chamber for fluid A
72 block shaped as peripheral flow transition chamber for fluid A
74 block shaped as center flow transition chamber for fluid B
76 block shaped as peripheral flow transition chamber for fluid B
82 belt for fluid passage 22
84 belt for fluid passage 24
85 mold for first bonding procedure
85A cut away side section of the mold
87 opening in the mold for port 17
88 opening in the mold for port 18
89 opening in the mold for port 19
90 opening in the mold for port 20
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1, 2, 3A, 3B, 4A, 4B
A typical embodiment of a heat exchanger incorporating the present invention is illustrated in FIGS. 1 and 2. The heat exchanger 10 comprises a heat transfer coil 12 (shown in simplified profile in FIG. 2) attached to a rigid support element in the form of a stanchion 16. In the preferred embodiment, the shape of the main part or body 14 of the heat exchanger 10 is a cylindroid. The stanchion 16 includes a central or brace portion 16A within the body portion 14 of the heat exchanger and a base or mount portion 16B which protrudes from the body 14. Fluid ports 17-20, anchored to the stanchion central portion 16A, also protrude from the body 14. The coil 12 is formed of a single thin thermally conductive strip 13 helically wrapped or wound a number of times to define two spiral flow passages or channels 22, 24 within heat exchanger body 14. Fluid passage 22 conducts the fouling fluid, fluid A, and the fluid passage 24 conducts fluid B. To achieve adequate length, the strip 13 may be formed by joining two or more pieces of thin thermally conductive strip in a manner which results in a mechanically strong non-porous joint, for example, by welding. Stainless steel, galvanized carbon steel, and aluminum are typical materials suitable for use as thin thermally conductive strip 13. Ports 17 and 18 are in communication with fluid passage 22 and are inlet and outlet ports, respectively, for fluid A, and ports 19 and 20 are in communication with fluid passage 22 and are inlet and outlet ports, respectively, for fluid B. As mentioned, the fluid ports 17-20 are anchored to the central portion 16A of the stanchion 16.
However, ports may be formed and attached to the heat exchanger in other ways. For example, a hole may be bored through the shell of the heat exchanger to communicate with the desired passage or chamber. The hole may also be bored through the stanchion and threaded at the stanchion for receiving a threaded tube or pipe. Or bolts may be used to affix flanged tubes or pipes to the heat exchanger.
In the center of the coil 12, the strip 13, is shaped to form two distinct flow transition chambers 40 and 44. Chamber 40 serves to redirect fluid flow between fluid inlet port 17 and the corresponding fluid passage 22, and chamber 44 redirects fluid flow between passage 24 and the corresponding fluid outlet port 20. The center flow transition chambers 40 and 44 also serve as appropriate sites for the fasteners 25 at the coil center 30 to pass through the coil 12 such that the fasteners do not interfere with fluid flow through the fluid passages 22 and 24. In the preferred embodiment, when viewed radially, the center of the coil 12 appears shaped like the letter S with the lower loop of the S larger than the upper loop. The center flow transition chamber 40 for the fouling fluid, fluid A, is the larger chamber, which serves as the inlet for the fouling fluid. In the throat 40A where the fouling fluid exits the large center flow transition chamber 40 and enters the helical fluid passage 22, the strip 13 may be shaped to form a constriction 40B. The constriction 40B need not be severe. For a short length, the distance between adjacent wraps or runs of the strip 13 may be reduced to a distance which is slightly less than the distance between adjacent wraps forming any other part of the fluid passage 22.
A sufficient length of strip 13 is helically wound around the flow transition chambers 40, 44 to form the two separate helical fluid passages 22 and 24 of the desired length. The strip 13 forming the helical fluid passages 22, 24 may be shaped with a three dimensional pattern of alternating peaks and troughs oriented perpendicular to the length of the strip, or embossed with a different pattern. The minimum distance between adjacent wraps of the strip 13 forming one fluid passage may be different than the minimum distance between adjacent wraps of the strip 13 forming the other fluid passage, thereby creating fluid passages which may have different heights and different cross sectional areas for fluid flow.
The two peripheral flow transition chambers 42 and 46 are formed by increasing, then decreasing the distance between adjacent wraps of the strip 13 forming the two fluid passages 22 and 24. In the preferred embodiment these peripheral flow transition chambers are crescent shaped and diametrically opposed on the periphery of the coil 12, as illustrated by FIG. 2. The exterior wrap of the strip 13 is wound in contact with the adjacent inner wrap of the strip 13 which forms the peripheral flow transition chambers 42 and 46. A channel terminal 50 is formed where the exterior wrap of the strip 13 is fastened to the adjacent inner wrap of the strip 13 by a method which results in a strong non-porous joint, for example, by welding.
A sealant 51 adhering to the thin thermally conductive strip 13 closes off the edges, i.e., one side, of the spiral channels 22 and 24 and flow transition chambers 40, 42, 44, and 46 and bonds the strip 13 to the stanchion central or brace portion 16A. The sealant is a substance which adheres or bonds to metal and hardens from a fluid state as it sets. Epoxy is a suitable sealant for closing the edges of the spiral channels and flow transition chambers. Urethane, silicone rubber, fiberglass resin, or similar substances may also be used. The sealant 51 not only performs the sealing function but also a mechanical function of fixing adjacent wraps of the strip 13 at the desired spacing. The central portion 16A of the stanchion 16 functions as a brace for the wrapped strip 13.
FIG. 3A (front view) and 3B (rear view) show the stanchion 16 subassembly. The stanchion 16 is fabricated of a structurally strong material, typically metal such as stainless steel, galvanized carbon steel, or aluminum. The stanchion includes the brace and mount portions 16A, 16B, and provides structural strength to the heat exchanger 10 by serving as a brace for the coil 13, as a secure frame for anchoring fasteners 25 and the fluid ports 17-20, and as the mount for the heat exchanger 10.
The mount portion 16B functions as a base of the heat exchanger 10 which is secured to a support structure. To serve this purpose, the mount portion 16B is typically oriented perpendicular to the plane of the brace portion 16A, and positioned beneath the coil 12, although other configurations adopted for the particular mounting structure involved may be used. The mount portion 16B typically has a number of bolt holes 16D therethrough. The brace portion 16A extends from the mount portion 16B for a distance greater than the largest diameter of the elliptical edge of the coil 12. At the end of the brace portion 16B opposite the mount portion 16A, a positioning guide portion 16C may be formed. The positioning guide portion 16C extends perpendicular to the brace portion 16A, above the coil 12. The length of the positioning guide portion 16C need not exceed the width of the coil 12. The positioning guide portion 16C serves to assist assembly of the heat exchanger 10 by facilitating alignment of the coil 12 onto the brace portion 16A. The four ports 17-20 which are anchored to the brace portion 16A (preferably are tubes made of the same material as the stanchion 16). They pass through and are securely anchored to the stanchion 16, preferably by welding. Two fluid ports 17 and 20 pass through the stanchion 16 near the center of the brace portion 16A. One fluid port 19 passes through the brace portion 16A near the positioning guide portion 16C; and one fluid port 18 passes through the brace portion 16A between the mount portion 16B and the center of the brace portion 16A.
Near the center of the stanchion brace portion 16A, a number of fasteners 25 extend from the stanchion 16. If nuts and bolts are used as fasteners, each bolt is securely anchored to the stanchion 16, preferably by welding. The shank 25A of each bolt extends through the coil 12 axially. The threaded portion of the shank 25A protrudes from the coil a distance adequate to facilitate installation of an inspection port gasket 32 and an inspection port cover 34, with a washer 25B, lock washer 25C, and nut 25D which are parts of the fastener 25. Tubular spacers 31 may be installed on the shanks 25A of some or all of the fasteners 25. Each tubular spacer extends from the coil side of the stanchion, across the width of the coil, to the outer surface of the coil. The tubular spacers 31 prevent the coil from damage if the fasteners 25 are over tightened. The fasteners 25 are arranged such that when the stanchion subassembly and the coil 12 are joined, the fasteners are positioned out of the fluid passages 22 and 24 and out of the throats 40A and 44A. In the preferred embodiment, the fasteners 25 pass through the center flow transition chambers 40 and 44, and are arranged near the perimeter of the center flow transition chamber 40A for fluid A.
FIG. 4A shows that on the coil side of the stanchion, the fluid ports 17-20 extend through the sealant 51 used to seal the edge of the coil 12 adjacent to the stanchion. Each of the four fluid ports 17-20 align with and enter one of the four flow transition chambers 40, 42, 44, and 46, respectively.
A casing or shell 52 fabricated of plastic or metal overlaying a layer of sealant 51 or other filler material may encase the sealant 51 closing the edges of the coil 12. A shell 52 fabricated of metal or plastic overlaying a layer of insulating material (not shown) slows heat losses during operation, and makes the exchanger safer to touch. To serve this purpose, the shell may be shaped to facilitate placement of a layer of insulation against the coil 12 and brace portion 16A. Since the shell 52 serves no purpose in the basic operation of the heat exchanger, it may be omitted without adversely affecting thermal performance. However, a shell is preferred for the reasons stated above and because it gives the heat exchanger 10 a sturdy appearance and an attractive finish.
In accordance with the invention, the edges or ends of the strip 13 forming the passages 22, 24 are closed with the sealant material 51 in a mold. In the preferred embodiment, the mold comprises sections of the shell 52, typically, formed of plastic or metal such as thin stainless steel. In those embodiments, the mold becomes part of the heat exchanger. However, in other embodiments, a shell is formed around the heat exchanger in a reusable mold which does not become part of the heat exchanger. The shell may be given an appearance characteristic of the company supplying the heat exchanger to the market.
FIGS. 4A and 4B show opening or inspection port 26 which extends axially through the shell 52 and sealant 51 into the center flow transition chamber 40 for fluid A. The inspection port 26 is located near the center 30 of the coil 12 on the side opposite the brace portion 16A of the stanchion 16. The cross sectional area of the inspection port 26 is sufficient to permit removal of solids which are small enough to enter the flow transition chamber through the fouling fluid inlet port 17, but too large to pass through the constriction 40B in the throat 40A. The cross sectional area of the inspection port 26 is larger than the cross sectional area of the inlet port 17 into the center flow transition chamber 40 for fluid A, and is larger than the cross sectional area of the fluid passage 22 for fluid A. A small raised ridge 28, or a number of small ridges, may encircle the inspection port 26. The ridge or ridges 28 are located on the shell 52, or on the edge of the coil 12 when no shell is used. The inspection port 26 is closed and sealed by an inspection port cover 34 and an inspection port gasket 32.
The ridge or ridges 28 are usually located between the inspection port 26 and the fasteners 25 at the coil center 30, which attach the inspection port cover 34 to the heat exchanger. The ridge or ridges serve to assure a better seal by the inspection port gasket 32 between the inspection port cover 34 and the shell 52, or the coil 12 when no shell is used. The inspection port cover 34 is fabricated of a structurally strong and rigid material, preferably metal such as stainless steel, galvanized carbon steel, or aluminum. The inspection port cover 34 is located over both the center flow transition chamber 40 for fluid A, and over the center flow transition chamber 44 for fluid B. This placement of the inspection port cover 34 uses the structural strength of the inspection port cover 34, the fasteners 25 at the coil center, and the brace portion 16A to support the sealant 51 which close the edges of the two center flow transition chambers 40 and 44. The inspection port cover 34 has a number of holes therethrough corresponding to the fasteners 25 extending from the stanchion 16 and protruding from the coil 12. The inspection port gasket 32 is placed between the inspection port cover 34 and the shell 52, or between the inspection port cover 34 and the edge of the coil 12 when no shell is used. The surface area of the inspection port gasket 32 is greater than or equal to the surface area of the inspection port cover 34. The inspection port gasket 32 is suitable for reuse after removal and replacement of the inspection port cover 34 many times over a number of years. The inspection port gasket 32 is preferably formed of a resilient elastomer material such as nitrile rubber.
Method of Manufacture--Figure 8
To prepare the strip 13 for coiling, it is checked for defects and cut to a length corresponding to the total length to be coiled. A pattern may be imprinted on the portion of the strip which will form the helical fluid passages 22 and 24, if desired, to improve stiffness across the width of the strip and to induce turbulence in the fluid flowing through the fluid passages.
Blocks or inserts 70, 72, 74 and 76 shaped in profile as the desired flow transition chambers 40, 42, 44, and 46, and flexible spacer belts 82 and 84 of canvas, rubber or similar material of thicknesses corresponding to the minimum heights of the two fluid passages 22 and 24 may be used to fabricate the coil 12. The blocks 70, 72, 74 and 76 and the belts 82, 84 should not cover the entire width of the strip 13, such that a vacant space is provided between the wraps of strip which will be filled by the sealant 51 that bonds the coil 10 to the stanchion 16, and closes the edge of channels 22 and 24 adjacent to the stanchion. The dotted line on the coil 12 in FIG. 8 represents the maximum depth of insertion of the blocks 70, 72, 74 and 76 and the belts 82, 84 into the coil 12. The approximate midpoint of the width of strip 13 may be placed between the blocks 70 and 74 that are shaped as the center flow transition chambers 40 and 44. The strip 13 and the spacer belts 80 may be tightly wound around the blocks 70 and 74 shaped as center flow transition chambers until the desired channel length is attained. Spacer blocks 72 and 76 in the desired shape of the peripheral flow transition chambers 42 and 46 may then be placed in the appropriate positions, and the strip 13 wrapped over them. Excess length of belts 82 and 84 may pass through holes in the blocks 72 and 76 shaped as the peripheral flow transition chambers 42 and 46. The outer wrap of the strip 13 may then be attached to the adjacent inner wrap of the strip 13 to form the channel terminal 50.
In the preferred embodiment, the stanchion 16 (see FIGS. 3A and 3B) is fabricated from metal plate sufficiently wide and thick to provide the desired strength to the heat exchanger. The plate is cut and formed into the desired shape of the brace portion 16A, the mount portion 16B, and the positioning guide portion 16C. Holes are made through the plate for fasteners 25 and fluid ports 17-20. The fasteners 25 are securely attached to the stanchion. The ports 17-20 are securely attached to the stanchion for example by welding or a threaded connection, or by attaching the ports to the stanchion with fasteners. The combination of stanchion 16, fasteners 25, and fluid ports 17-20 comprises the stanchion subassembly.
The first molding procedure illustrated in FIG. 8 bonds the stanchion 16 to the coil 12 in a horizontal mold 85. The mold 85 has openings 87-90 to allow the ports 17-90 to pass through and to allow the central portion 16A of the stanchion to avoid interference with the side of the mold. A cut away section 85A of the mold 85 provides clearance for the stanchion 16. The cut away side section 85A is replaced after the stanchion 16 is inserted horizontally into the bottom of the mold 85. A caulking or seal is used to contain the liquid sealant 51 at each of these openings.
After the mold 85 is caulked, liquid sealant 51 is poured into the mold 85 to approximately the depth shown by the dotted line on the mold in FIG. 8. The depth of sealant 51 immerses the central portion 16A of the stanchion, and when the coil is placed into the mold containing the stanchion 16 and sealant 51, the sealant extends up to the coiled strip 13 a distance adequate to provide a strong leakproof seal on the edge of coil 12. The depth of sealant 51 is not enough to contact the spacer blocks 70, 72, 74 and 76 or the belts 82, 84 holding the position of the wrapped strip 13.
The coil 12 is bonded to the stanchion subassembly by bringing together the stanchion subassembly, the coiled strip 13, and sealant 51 in a horizontal mold as described above. The positioning guide portion 16C of the stanchion is used to speed assembly by facilitating alignment of the coil 12 and the stanchion 16. After the sealant 51 has hardened, the spacer belts and blocks are removed through the open side of the coil 12. The remaining open edges of the fluid passages 22 and 24 may be closed by bringing together the coil 12 and sealant 51 in another horizontal mold.
Additional embodiments are shown in FIGS. 5A, 5B, 6, 7A and 7B. Each of these figures is a simplified sketch intended to emphasize details discussed in the text.
FIGS. 5A and 5B
FIGS. 5A (rear view), and 5B (front view) show a heat exchanger 10A reinforced for applications involving high design pressure. Compared to the stanchion 16 of the heat exchanger 10, the brace portion 16A of the stanchion 16 in the heat exchanger 10A has been increased in width, such that the brace portion approximates the perimeter of the coil 12. Also, the positioning guide portion 16C of the stanchion 16 of heat exchanger 10 has been eliminated in the stanchion 16 of heat exchanger 10A. On the edge of the coil 12 opposite the brace portion a containment plate 54 has been added. The containment plate 54 is fabricated of structurally strong material, preferably metal. The containment plate 54 is attached to the brace portion 16A by a number of fasteners 58 at the periphery, and by the fasteners 25 at the center 30 of the coil. Tubular spacers 31 may be used on the shanks of the fasteners 25 and 58. All fasteners lie outside the fluid passages 22 and 24 and throats 40A, 42A, 44A, and 46A. The containment plate 54 is fabricated with a hole 60 near its center which aligns with the inspection port 26. The hole approximates the size and shape of the inspection port. The inspection port 26 is closed and sealed by an inspection port cover 34 and an inspection port gasket 32.
Heat exchanger 10A also has a containment ring 53 which encircles the coil 12. The containment ring 53 may be fabricated of a strip of heavy gauge metal, which is the same width as the strip 13 used to fabricate the coil 12. The metal strip may be formed into a ring by securely fastening the ends together, preferably by welding. When viewed axially, the containment ring 53 has an elliptical shape slightly larger than the coil 13, such that the coil can fit snugly in the containment ring 53.
The thickness of the strip 13, the thickness of the inspection port cover 34, and the load capacity of the fasteners 25 at the coil center 30 are all increased. The depth of sealant 51 used to close the edges of the fluid passages 22 and 24 may be increased, and the strip 13 will be increased in width by an amount equal to the increased depth of sealant 51 closing the edges of the fluid passages 22 and 24. Both the brace portion 16A and the containment plate 54 may be stiffened by reinforcements. The mount portion 16B of the stanchion may be reinforced by a gusset.
FIG. 6
FIG. 6 shows a heat exchanger 10B fabricated to allow inspection and thorough mechanical cleaning of both fluid passages 22 and 24. In comparison to the heat exchanger 10, only the edge of the fluid passages which is bonded to the stanchion 16 is closed by sealant 51. The other edge of the fluid passages is closed and sealed by a channel maintenance cover 56 with a channel maintenance cover gasket 55. The channel maintenance cover 56 and the channel maintenance cover gasket 55 are removable.
Compared to the stanchion 16 of the heat exchanger 10 described above, the positioning guide portion 16C of the stanchion 16 of heat exchanger 10 is eliminated. The width of the brace portion 16A is increased such that the brace portion approximates the perimeter of the coil 12. This enlargement of the brace portion is adequate to permit the placement of a number of fasteners 58 at the periphery extending between the brace portion 16A and the channel maintenance cover 56. The fasteners 58 are located outside the throats 42A and 44A and outside the fluid passages 22 and 24. With bolts used as fasteners, the bolts extend axially across the width of the coil 12, between the brace portion 16A and the channel maintenance cover 56. The bolts extend beyond the cover a sufficient distance to permit installation of a washer 62, lock washer 63, and a nut 64. Tubular spacers 31 may be installed on the shanks of the fasteners.
The strip 13 used to fabricate the coil 12 of heat exchanger 10B is narrower than the strip used in the heat exchanger 10 by a distance equivalent to the depth of sealant 51 which would have been used in the heat exchanger 10 to close the edges of the fluid passages 22 and 24 on the side of the coil opposite the brace portion 16A of the stanchion. The channel maintenance cover 56 is fabricated of structurally strong material, preferably metal plate, and is sufficiently sized to overlap the perimeter of the coil 12 and to be secured by the fasteners 25 and 58 extending from the brace portion 16A.
The channel maintenance cover 56 and the channel maintenance cover gasket 55 are pressed against the coil 12 by the ring of fasteners 58 at the periphery of the coil and by the fasteners 25 at the coil center 30. The channel maintenance cover 56 may also be attached to the brace portion 16A by a hinge. The channel maintenance cover gasket 55 may be formed from a sheet of elastomer which is compatible with the fluids circulating through the heat exchanger at the design conditions.
FIGS. 7A and 7B
FIG. 7A provides an exterior view of a heat exchanger 10C for use with two fouling fluids. FIG. 7B shows the profile of the coil 12 fabricated for this application. In comparison with the heat exchanger 10, this variation features a large peripheral flow transition chamber 46 for fluid B in addition to the large center flow transition chamber 40 for fluid A. The large center flow transition chamber 40 for fluid A serves as the inlet into the fluid passage 22 for fluid A, and the large peripheral flow transition chamber 46 for fluid B serves as the inlet into the fluid passage 24 for fluid B.
The coil 12 is fabricated with an inspection port 26 into the center flow transition chamber 40 for fluid A and into the peripheral flow transition chamber 46 for fluid B. Each of the two inspection ports 26 penetrate through the side of the coil 12 opposite the brace portion 16A of the stanchion. Each inspection port is covered and sealed by an inspection port cover 34 and an inspection port cover gasket 32. At both inspection ports 26, fasteners 25 and 58 extend axially through the coil 12 between the brace portion 16A and the inspection port cover 34. These fasteners attach the inspection port gaskets 32 and the inspection port covers 34 to the side of the coil 12 opposite the brace portion 16A.
A slight constriction at the throat 40B may be formed between the center flow transition chamber 40 for fluid A and the fluid passage 22 for fluid A. Another slight constriction at the throat 46B may be formed between the peripheral flow transition chamber 46 for fluid B and the fluid passage 24 for fluid B. For a short length, the distance between adjacent wraps of strip 13 may be reduced to a distance which is slightly less than the distance between adjacent wraps of strip forming any other part of that fluid passage.
Operation
The spiral heat exchangers 10-10C are constructed to be mounted such that the inspection port cover 34 is assigned the most accessible orientation. The mount portion 16B of the respective stanchion is used to securely fasten the respective exchanger to an appropriate structure.
The inlet port 17 which enters the large center flow transition chamber 40 for fluid A serves as the inlet for fluid A (the fluid containing undissolved material). This potentially fouling fluid must flow upward from the center flow transition chamber 40 for fluid A to enter the fluid passage 22 for fluid A. Oversized material, unable to pass through the constriction at the throat 40B, remains in the center flow transition chamber 40 for fluid A, which is designed to hold a quantity of large undissolved material pending removal of that material during maintenance.
After entering the respective heat exchanger, undissolved materials suspended in fluid A will leave the heat exchanger by one of two ways. Either the undissolved materials are carried by fluid A through the helical fluid passage 22 for fluid A and exit through the outlet port 18 used to discharge that fluid, or the undissolved materials collect in the large center flow transition chamber 40 and are removed through the inspection port 26. In an effort to enable most of the undissolved materials to pass through the respective heat exchanger, a minimum distance is established between the adjacent wraps of strip 13 which form the fluid passage 22. For each application, the minimum spacing for adjacent wraps of strip 13 which form the fluid passage 22 will depend on the size distribution and fouling characteristics of the undissolved materials. Minimum spacing for common applications typically ranges from 1/4 inch to 3/4 inch. For each application a minimum velocity for fluid A will also be established. Minimum velocity for most common applications typically ranges from 1.8 to 3.0 feet per second.
The outlet port 18 through which the fouling fluid discharges is near the perimeter of the coil 12. This outlet port 18 may be near the top of the coil 12 or near the bottom, depending on the orientation of the strip 13 when formation of the desired length of the fluid passage for fluid A is completed.
Fluid B, the clean fluid, enters through the other inlet port 19 on the perimeter of the coil 12, and exits through the outlet port 20 which extends into the smaller center flow transition chamber 44 for fluid B. Clean fluids require neither a minimum velocity nor a minimum distance between adjacent wraps which form the fluid passage 24 for fluid B. Typically a small distance between adjacent wraps and a corresponding high fluid velocity are used, within the limits of available pressure drop.
The two fluids typically move through the respective spiral heat exchanger in counter current flow. A rippled pattern embossed into the strip 13 induces turbulence in the fluids for more efficient forced convective heat transfer.
To service heat exchanger 10 shown in FIGS. 4A&B, or heat exchanger 10A shown in FIGS. 5A&B, and to remove oversized material from the center flow transition chamber 40 for fluid A, the fasteners 25 at the coil center 30 are loosened. The inspection port cover 34 and the inspection port gasket 32 are removed, leaving the inspection port 26 open. Debris can be removed from the center flow transition chamber 40 through the inspection port 26. To place the respective heat exchanger back into service, the inspection port cover 34 and the inspection port gasket 32 are replaced, and the fasteners 25 are tightened. Tubular spacers 31 on the shanks of the fasteners protect the coil 12 from damage caused by over tightening the fasteners.
To service the heat exchanger 10B shown in FIG. 6, the fasteners 25 at the coil center 30 and the fasteners 58 at the periphery are all loosened. The channel maintenance cover 56 and the channel maintenance cover gasket 55 are removed, exposing the fluid passage 22 for fluid A, the fluid passage 24 for fluid B, and the flow transition chambers 40, 42, 44 and 46 at each end of each fluid passage. Unwanted material may be removed from the fluid passages and from the flow transition chambers by means of a brush. The heat exchanger may be closed by reinstalling the channel maintenance cover gasket 55 and the channel maintenance cover 56. The fasteners 25 at the coil center 30 and the fasteners 58 at the periphery are then tightened to complete the reassembly of the heat exchanger.
To service the heat exchanger 10C shown in FIG. 7A, the fasteners 25 at the coil center 30 and the fasteners 58 at the periphery are loosened. The two inspection port covers 34 and the two inspection port gaskets 32 are removed, thereby giving access to the two inspection ports 26. Debris may be removed from the center flow transition chamber 40 for fluid A and from the peripheral flow transition chamber 46 for fluid B through the two inspection ports 26. The heat exchanger may be made ready to be returned to service by reinstalling the two inspection port gaskets 32 and the two inspection port covers 34 over the two corresponding inspection ports 26. The fasteners 25 and 58 are then tightened.
Advantages
The heat exchanger of the present invention was developed with the goal of making energy recovery practical for applications which presently waste heat because no effective means of heat recovery is available. To be practical, the heat exchanger must offer better performance at lower cost than has ever been available before. To that end, the advantages of the inventive spiral heat exchanger over prior heat exchangers relate to lowering production costs, improving heat transfer performance, and lowering operating costs. From the description above, a number of advantages of my spiral heat exchanger become evident:
(a) The cost of fabrication of the heat exchanger is greatly reduced by substitution of inexpensive molding procedures for the expensive welding and machining procedures extensively required to fabricate other spiral heat exchangers.
(b) The innovative structure and method for sealing the edges of the fluid passages facilitates forming fluid channels of rippled thermally conductive strip, which is one of the distinguishing features of the invention. Rippled or embossed heat transfer surfaces generate higher shear forces and higher heat transfer coefficients than are generated in flow channels formed by the smooth strip typically used to fabricate other spiral heat exchangers. Less heat transfer surface is required, thereby lowering the material and labor production costs.
(c) The spiral heat exchanger of the present invention uses only two fluid channels, one for each of the two fluids flowing through the heat exchanger. Each fluid channel is designed and constructed to induce turbulence in the fluids flowing through the heat exchanger. This makes the heat exchanger resistant to accumulation of fouling materials on the wetted perimeter of the fluid passages.
(d) The spiral heat exchanger of the present invention resists fouling by stringy suspended solids because the passages are free of obstructions. The present invention does not depend on studs welded onto the strip or other contact points to maintain channel spacing. The unobstructed fluid passages permit long stringy solids to pass unhindered through the entire length of the fluid passage and to pass out of the heat exchanger.
(e) The constriction at the throat between the flow transition chamber and the fluid passage is designed to prevent suspended solids, which may be too large to pass freely through the fluid passage, from ever entering the fluid passage. These large suspended solids are accumulated in the large flow transition chamber. This facilitates removal of these oversized solids through an inspection port equipped with a removable cover.
Two Applications
In a typical food service industry application, one spiral heat exchanger would be used per dish washing machine, regardless of the capacity of the dish washing machine. The heat exchanger may be mounted beneath the dish washing machine, which usually stands at counter height. If space is limited in a particular application, two or more smaller spiral heat exchangers can be connected in series to obtain the desired heat transfer surface. The heat exchanger would typically be designed and fabricated to recover 60% to 80% of the temperature difference between the incoming fluid streams.
In a typical laundromat application, one spiral heat exchanger would serve a large number of washing machines. All heated wash water and rinse water would be discharged from the washing machines through the spiral heat exchanger. Clean water would be preheated in the spiral heat exchanger before flowing to the water heater for the washing machines.
The heat exchanger causes a pressure drop in each of the fluids flowing through it. The fouling fluid flows through a fluid passage formed by adjacent wraps of strip with relatively wide spacing. The wide spacing allows solids to pass through the heat exchanger with less likelihood of the solids bridging the fluid passage, causing fouling. The pressure drop through that passage is relatively low, usually 2 to 5 pounds per square inch. To optimize heat transfer, the clean fluid typically flows through a narrower passage. The pressure drop through that passage is usually 4 to 8 pounds per square inch. Adequate pressure to each fluid is needed to push the fluids through the heat exchanger.
The heat exchanger 10C shown in FIG. 7A would be favored by a commercial laundry, where cold used rinse water is heated and reused as wash water. Used hot wash water flows through one fluid passage 22 or 24, and used cold rinse water flows through the other. Both fluids contain fibers and probably other undissolved materials. Therefore both fluid passages 22 and 24 are provided with a constriction at throat 40B and 46B to prevent large objects from becoming lodged midway through a passage, and both transition chambers which serve as fluid inlets are provided with an inspection port 26 near the constriction, through which the debris may be easily removed.
Summary, Ramifications, and Scope
Accordingly, one will see that the spiral heat exchanger of this invention can be used to recover and recycle heat from liquids containing undissolved solids, and do so with very little maintenance.
The spiral heat exchangers according to the invention operate in recognition of the difference between undissolved materials which are small enough to pass through the heat exchanger, and large debris which may become lodged in the fluid passage. Small particles are allowed to flow through the fluid passage, but large particles are collected in the large flow transition chamber, from where they can be easily removed.
The invention provides:
a simple, compact, and efficient heat exchanger, capable of recovering a major portion of the temperature difference between the two fluids passing through the heat exchanger;
a heat exchanger which can be fabricated by simple and inexpensive procedures;
a heat exchanger for which the design and fabrication procedure can be easily and inexpensively changed to produce heat exchangers to meet a wide variety of operating conditions and performance requirements;
a strong heat exchanger designed and constructed to give a long service life, despite possible over tightening of pipes and fasteners during installation and maintenance procedures;
a heat exchanger which reduces maintenance requirements by resisting the deposition and accumulation of undissolved materials;
a heat exchanger which is responsive to chemical cleaning procedures;
a heat exchanger encased in an attractive shell upon which company trademarks, and installation, operation, and maintenance instructions may be displayed;
a means to recover energy, for which the value of the energy recovered far exceeds the combined installed and operating costs of the heat exchanger.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the flow transition chambers can have other shapes; spacer belts composed of open cell foam, and saturated with sealant can be introduced to the sheet during coiling to hold the passage height and to close the passage ends; large particles may be removed from the fluid by a different method, such as a cylindrical screen attached to the inside of the inspection port cover, or by a device in the path of the fluid between the source of the fouling fluid and the fluid passage of the heat exchanger. Also, in some embodiments, the fluid passages need not extend spirally but may extend in other configurations such as sinuously, back and forth, or in other dense or spread out configurations. Further, the inlets and outlets may be formed and or attached to the heat exchanger in ways other than those described herein. Many other variations within the spirit and scope of the invention disclosed herein will be apparent to those of skill in the art from the disclosure herein, and it is intended that the claims cover such variations to the extent that the prior art allows. Additionally, the invention has application to heat transfer between many fluid mediums, both liquid and gaseous, and including but not limited to waste water
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by specific embodiments described herein.
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A spiral heat exchanger is disclosed for indirect heat transfer between fluid media, primarily in heat recovery applications characterized by undissolved materials suspended in one or both fluid media. The heat exchanger has a transition chamber between the inlet for a fouling fluid (one which carries undissolved materials) and a heat exchanging passage for the fouling fluid. The transition chamber is has an enlarged cross section compared to the fouling fluid passage to collect undissolved material that may otherwise flow into the fouling fluid passage. This arrangement allows undissolved material to collect without completely blocking the fouling fluid passage. Easy access is provided to the transition chamber to remove collected undissolved material. A heat-conducting strip spirally wound within a shell or casing with opposite edges of the strip sealed to the casing defines two adjacent, spirally extending fluid passages. The strip is supported and sealed at opposite edges thereof without obstructing at least the fouling fluid passage. The seal may be accomplished by a sealant applied in liquid form which then hardens or cures. The heat exchanger is supported by a rigid support element or stanchion to which the strip is affixed and which extends as a mounting from the coiled strip so that the coiled strip may be supported thereby. Fluid inlet and outlet ports may also be affixed to and supported by the support element.
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TECHNICAL FIELD
The present invention relates to a device for locking means, particularly an alarm device, or an alarm system.
The invention relates in general to door locks, but particularly to door locks which operate with a code written on cards, e.g., in the form of a pattern of holes, magnetic spots, or similar, i.e., so-called card operated locks. The system or the device is not restricted thereto, it also being applicable for conventional mechanical locks if they additionally are equipped with an electrical power source and a signal transmitter means.
BACKGROUND OF THE INVENTION
For the time being, it is common to provide card operated locks with an emergency opening mechanism. This is a demand from some users and often from the fire department. The fire authorities will in some cases and in some fields of applications, e.g., hotels, often demand a mechanical opening possibility which is simple and well known, and which overrides card readers and electronics.
This emergency opening is often made as a lock cylinder of a known conventional type. In hotels, this lock cylinder is often a type which is relatively difficult to pick, but which can be opened with a main key, a so-called master key or floor key.
Such a system has weak points which are hard to avoid. Because no chain is stronger than the weakest joint, it follows that the possibility to pick the lock, which is very low for the card reader, is put back to "old fashion" level for the emergency opening mechanism. Several picking methods are experienced. In some cases the burglar has had success in picking the lock cylinder, or at least in attempting to pick it. However, in several cases the following method is used: a burglar rents a room in the hotel in a legal manner. During the night he removes the lock cylinder and replaces it with another with the same appearance. The staff will not notice this, because this emergency opening is never or very rarely used. The burglar can then bring the lock cylinder to his home and undisturbed analyse it and determine the shape of the master key. He may then visit the hotel, and by use of this key he is able to make to lot of damage by stealing from the rooms. The hotel will be forced to replace all compromised lock cylinders.
RELATED ART
Several attempts to avoid this problem have been made. There is referred to U.S. Pat. No. 5,577,408 or the corresponding Norwegian patent 178 639, which illustrates a mechanical way to confine the possibilities for removal of the lock cylinder. There are two major disadvantages related to this solution, firstly, a locksmith who has access to the room must be able to remove the lock cylinder, and secondly, it will always be possible to pick mechanical lock cylinders, and by means of the so-called "impression" method it is possible to determine the code for the key without dismantling the lock cylinder.
Further, from GB 1316973, CH 625590 and CB 2286423 it is known to provide lock cylinders with sensing means which detect attempts to pick the lock according to different picking methods.
Still further, from U.S. Pat. No. 5,041,814, it is known to provide lock cylinders with sensing means which detect unauthorized removal or swapping of the lock cylinder, which would cause trigging of the alarm.
When an alarm is triggered in one of these known designs, it is assumed that the system has to be reset by means of a device which is separated from the lock, or by a difficult and time consuming procedure on the lock alarm itself. This is not described in detail in the above mentioned patent publications, but it is common to provide such systems with a centrally placed, key operated device, for resetting of the alarm. Such systems demand however cabling from the movable door to a means which is placed outside the lock and door.
The above known, described methods and designs have all different deficiencies associated with the reset of the alarm, either by cabling from the door leaf to the fixed wall, or by a complicated device in the door itself.
SUMMARY OF THE INVENTION
The aim for present invention is to remedy the above mentioned weaknesses by means of a simple system which may be designated as a lock alarm system.
Mainly, a device according to the invention will comprise means which sense unauthorized movement of one or several elements in the lock, which are disposed to cause an alarm signal which may only be suspended by authorized operation of the lock.
More particular, the invention relates to that the sensing means are disposed for sensing movement of one or several elements which are included in an emergency opening mechanism.
In one particular embodiment, the device is characterized in that the sensing means are disposed for sensing movement of a lock cylinder.
Further features and advantages of the present invention will be apparent from the following description, taken in consideration together with the attached Figures, as well as from the attached patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the front of an embodiment of a lock, where the device according to the invention may be applicable.
FIG. 2 is a side view, partially in section, of the lock shown in FIG. 1, mounted in a door leaf or similar.
DETAILED DESCRIPTION OF EMBODIMENTS
The present invention disclosures a system to solve the problems mentioned in the description of prior art. In connection with card operated locks, it is preferable to avoid cable routing from the lock to places outside the door leaf. The lock should preferably exist as an autonomous unit with its own built in power supply.
Further it is preferred that the alarm from the lock may be reset by means of an especial reset card, which may be used in the normal card insert gap. An alarm card which only few, authorized persons have access to, an more specific a card with a code which can be altered periodical if desired.
The present invention generally relates to a device for a lock, in particular an alarm device, which is characterized in that the device comprises means which sense unauthorized movement of one or several elements in the lock, which are disposed to cause an alarm signal which may only be reset by authorized operation of the lock.
Further features for the invention may be listed as in the following:
the sensing means are disposed for sensing movement of one or several elements which is/are included in an emergency opening mechanism,
the sensing means are disposed for sensing movement of a lock cylinder
the sensing means are connected to an electronic circuit which when receiving an alarm signal transmits this further to a visual indicator and/or a central in the building in which the lock is mounted,
the sensing means are disposed for being reset, respectively have their alarm signal stopped by means of a communication means being specific for an authorized person, which may be used by authorized operation of said lock elements, and
the communication means has the form of a special reset card, particularly a punch card or a magnetic card, alternatively have the shape of a keyboard belonging to the lock, alternatively have the shape of a preferably portable computer with associated light detector/light transmitter, for communication with the electronic circuits in the lock.
Related to one embodiment of a lock comprising an emergency lock in the form of a lock cylinder, one example of application of the invention is as follows.
The lock cylinder is inside the lock case connected to an electronic indicator which will register all turning movements of the lock cylinder, as well as other movements which displaces its vital parts or elements in the space. When such an indication occurs e.g. a flashing red light will, by means of electronic circuits which are not described herein, become visible on the front of the lock facing towards the corridor. Most card operated locks are today provided with a light emitting diode (LED) which will display a green light when a card is used correctly, and a red signal when a card is used in a wrong way. They are also provided with electronic circuits which would be capable to handle this extra function without large extra costs.
When an emergency opening cylinder has been touched or shifted in one way or another, special means in the lock will display this by means of a flashing red light which will operate as long as the electrical power source functions, and this light will be easily seen by the staff upon ordinary walking in the corridor. The signal may of course be supervised from a central in another way, e.g., by means of cabling, video or similar.
When authorized use of the alarm system occurs, the alarm system can be stopped by, e.g. a special reset card, i.e. an off-position card, which is available only for authorized staff. This reset card must of course be kept in a secure place, and in another place than the emergency keys.
In this way the authorized staff will be able to use the emergency key without triggering a permanent alarm. This is an alarm which although it is recorded, will be terminated at once. Unauthorized persons, which use the emergency key, or make attempts to pick the lock or emergency opening mechanism will trip the alarm. The system demands secure storage of the reset card.
An example of an embodiment of the system described is shown in the FIGS. 1 and 2.
FIG. 1 shows the outside of the door lock faced against the corridor, with a sign 1, a card reader gap 2 and a light emitting diode 3.
An emergency opening mechanism 4 is here shown as a standard lock cylinder, but it could be formed in another way, e.g. as a window which must be smashed or similar.
FIG. 2 shows a sectional view, vertically through lock case and sign where an indicator 5 may be a magnetic sensor, micro switch, optical eye or something else. The indicator 5 is connected with control electronics 6, which further is connected with a card reader 7 and the light emitting diode 3. Resetting of the alarm is done via the card reader gap 2.
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An alarm device for a lock which provides a security system which displays unauthorized tampering with the lock. The device senses unauthorized movement of one or several elements in the lock and causes an alarm signal which may only be terminated by resetting the device by authorized operation of the lock.
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BACKGROUND
[0001] Vehicles, such as automobiles, may include equipment for mitigating the impact of collisions, such as, e.g., passenger and side-curtain air bags in the occupant cabin. Optimal deployment of such collision mitigation equipment, however, may be dependent on the impact mode. For example, in an oblique impact mode, one vehicle may contact another vehicle at an approximately 15° oblique angle and with an approximately 35% overlap of the widths of the vehicles and generate relatively large rotational forces, as compared to other impact events. In another example, for mitigation of collisions with pedestrians, vehicles may include equipment such as bumper- or hood-mounted airbags and/or hood-lifting systems on the exterior of the vehicle. To control and employ such equipment, the vehicle is required to detect a corresponding collision—e.g. discriminate an oblique impact or a pedestrian impact from other impact events, and from each other. Current mechanisms for detecting vehicle collisions may be unable to sufficiently discriminate between impact events and/or may also suffer from drawbacks such as relatively high complexity and cost.
DRAWINGS
[0002] FIG. 1 is a partially exploded perspective view of an exemplary front end of a vehicle, including an exemplary sensing apparatus.
[0003] FIG. 2 is a partially schematic top view of the exemplary front end of the vehicle of FIG. 1 , including the exemplary sensing apparatus.
[0004] FIG. 3 is a block diagram of an exemplary vehicle system.
[0005] FIG. 4 illustrates an exemplary process for utilizing an exemplary sensing apparatus in collision detection and evaluation.
DETAILED DESCRIPTION
[0006] FIG. 1 is an exemplary illustration of a vehicle 10 with a front end 12 . The vehicle 10 includes a front bumper assembly 14 , illustrated in FIG. 1 in exploded view. The front bumper assembly 14 includes a bumper beam 22 , an energy-absorbing component or energy absorber 24 , and a front fascia component 26 , as well as a multi-cavity sensing apparatus 28 disposed between the energy absorber 24 and the front fascia 26 .
[0007] The bumper beam 22 includes a front face 30 with a curved shape that substantially spans the width of the front end 12 of the vehicle 10 . The bumper beam 22 may further include rearward-extending portions 32 and 34 configured to couple to a frame assembly of the vehicle 10 . The bumper beam 22 is a relatively rigid component of a material such as, for example, steel.
[0008] The energy-absorbing component 24 includes a rear face 36 sized and shaped to correspond with the front face 30 of the bumper beam 22 , and it is fixed to the bumper beam 22 . The energy-absorbing component 24 further includes a forward face 38 with a plurality of protrusions 40 . The energy-absorbing component 24 is relatively elastic as compared to the bumper beam 22 . For example, the energy absorbing component 24 be a plastic or foam component and the protrusions 40 may be adapted to deform, crush, or flatten in order to absorb kinetic energy in the event of a collision or impact with the front end 12 of the vehicle 10 .
[0009] The front fascia component 26 overlaps and engages the assembly of the bumper beam 22 , the energy-absorbing component 24 , and the sensing apparatus 28 and attaches to the front end 12 of the vehicle 10 . The sensing apparatus 28 has an overall width corresponding to the size of the forward face 38 of the energy absorber 24 . The sensing apparatus 28 extends across the forward face 38 of the energy absorber 24 and is fixed in engagement therewith. The sensing apparatus 28 is shaped complementary to the forward face 38 of the energy absorber 24 and the interior of the front fascia component 26 .
[0010] The front fascia component 26 is relatively thin as compared to the energy-absorbing component 24 and the sensing apparatus 28 , and the front fascia component 26 is elastic as compared to the bumper beam 22 . The front fascia component 26 may include material such as, for example, plastic. The sensing apparatus 28 is shaped complementary to, and in mechanical engagement with, the interior of the front fascia component 26 . Therefore, a force applied to the exterior of the relatively thin front fascia component 26 in a location overlapping or otherwise mechanically engaged with the sensing apparatus 28 is translated to the sensing apparatus 28 .
[0011] With further reference to FIG. 2 , the sensing apparatus 28 includes a left cavity or chamber 50 , a center cavity or chamber 52 and a right cavity or chamber 54 . The left cavity 50 and the center cavity 52 are coupled with a left channel portion 56 extending therebetween. The center cavity 52 and the right cavity 54 are coupled with a right channel portion 58 extending therebetween. In one exemplary implementation, the length of the left and right chambers 50 and 54 are each approximately 25˜35% of the length of the bumper beam 22 , and the length of the center chamber 52 is approximately 30˜50% of the length of the bumper beam 22 .
[0012] The left, center and right cavities 50 , 52 , 54 each substantially enclose fluid volumes 60 , 62 , 64 , respectively. The left and right channel portions 56 , 58 fluidly couple the volumes 60 , 62 , 64 , and, therefore, enable the pressures in the volumes 60 , 62 , 64 to substantially equalize over time. In some implementations, the sensing apparatus 28 may be pressurized to a higher pressure than the volume outside thereof. The left, center and right cavities 50 , 52 , 54 each include a front surface, respectively denoted at reference numerals 66 , 68 , 70 , and a rear surface, respectively denoted at reference numerals 72 , 74 , 76 . The sensing apparatus 28 may be formed of any suitable materials, including, e.g., automotive grade pipe and blow-molded plastic, and may be formed as a unitary body of such suitable materials, such as blow-molded plastic.
[0013] The sensing apparatus 28 further includes left, center and right pressure sensors 80 , 82 , 84 respectively coupled to the left, center and right cavities 50 , 52 , 54 and in communication with the volumes 60 , 62 , 64 , respectively. The pressure sensors 80 , 82 , 84 may be any suitable pressure sensor for automotive applications. As illustrated in FIGS. 1-2 , the pressure sensors of the sensing apparatus 28 may be outside of the respective chambers thereof, such as the left and right pressure sensors 80 and 84 , or integrated in to the shape of a chamber, such as the center pressure chamber 82 . In other implementations, the pressure sensors of a sensing apparatus of the present disclosure may be disposed within the volumes of the chambers.
[0014] The bumper beam 22 is coupled to left and right frame rails 90 , 92 , and the pressure sensors 80 , 82 , 84 are in communication with a vehicle computing device or computer 105 of the vehicle 10 . It should be understood that a sensing apparatus according to the present disclosure may vary in configuration with variations in shape and/or material composition across the width thereof, alone or in combination with variations in configuration, size or thickness as discussed herein. For example, a sensing apparatus according to the present disclosure may have a variety of cross-sectional shapes, including, for example, circular, elliptical, and rectangular.
[0015] Referring to FIG. 3 , the vehicle computing device or computer 105 in communication with the pressure sensors 80 , 82 , 84 of the sensing apparatus 28 generally includes a processor and a memory, the memory including one or more forms of computer-readable media, and storing instructions executable by the processor for performing various operations, including as disclosed herein. The computer 105 of the vehicle 10 receives information, e.g., collected data, from one or more data collectors 110 related to various components or conditions of the vehicle 10 , e.g., components such as a braking system, a steering system, a powertrain, etc., and/or conditions such as vehicle 10 speed, acceleration, pitch, yaw, roll, etc. The computer 105 generally includes restraint control module 106 that comprises instructions for operating collision mitigation systems or equipment 120 . Further, the computer 105 may include more than one computing device, e.g., controllers or the like included in the vehicle 10 for monitoring and/or controlling various vehicle components, e.g., a restraint control module 106 , an engine control unit (ECU), transmission control unit (TCU), etc. The computer is generally configured for communications on a controller area network (CAN) bus or the like. The computer may also have a connection to an onboard diagnostics connector (OBD-II). Via the CAN bus, OBD-II, and/or other wired or wireless mechanisms, the computer may transmit messages to various devices in a vehicle and/or receive messages from the various devices, e.g., controllers, actuators, sensors, etc., including the pressure sensors 80 , 82 , 84 of the sensing apparatus 28 and collision mitigation systems or equipment 120 . Alternatively or additionally, in cases where the computer actually comprises multiple devices, the CAN bus or the like may be used for communications between the multiple devices that comprise the vehicle computer. In addition, the computer may be configured for communicating with a network, which may include various wired and/or wireless networking technologies, e.g., cellular, Bluetooth, wired and/or wireless packet networks, etc.
[0016] Generally included in instructions stored in and executed by the computer 105 is a restraint control module 106 . Using data received in the computer 105 , e.g., from data collectors 110 , including the pressure sensors 80 , 82 , 84 , and data included as stored parameters 116 , etc., the module 106 may control various vehicle 10 collision mitigation systems or equipment 120 . For example, the module 106 may be used to deploy equipment responsive to an oblique impact event, such as side curtain air bags, or a pedestrian impact event, such as bumper- or hood-mounted airbags and/or hood-lifting systems. Further, the module 106 may include instructions for evaluating information received in the computer 105 relating to vehicle 10 operator characteristics, e.g., from pressure sensors 80 , 82 , 84 and/or other data collectors 110 .
[0017] Data collectors 110 may include a variety of devices. For example, various controllers in a vehicle may operate as data collectors 110 to provide data 115 via the CAN bus, e.g., data 115 relating to vehicle speed, acceleration, etc. Data collectors 110 may include conventional crash or impact detectors, such as accelerometers. Yet other sensor data collectors 110 could include impact sensors such as pressure sensors 80 , 82 , 84 . In addition, data collectors 110 may include sensors to detect a position, change in position, rate of change in position, etc., of vehicle 10 components such as a steering wheel, brake pedal, accelerator, gearshift lever, etc.
[0018] A memory of the computer 105 generally stores collected data 115 . Collected data 115 may include a variety of data collected in a vehicle 10 . Examples of collected data 115 are provided above, and moreover, data 115 is generally collected using one or more data collectors 110 , and may additionally include data calculated therefrom in the computer 105 , and/or at a server (not shown). In general, collected data 115 may include any data that may be gathered by a collection device 110 and/or computed from such data. Accordingly, collected data 115 could include a variety of data related to vehicle 10 operations and/or performance, data received from another vehicle, as well as data related to environmental conditions, road conditions, etc. relating to the vehicle 10 . For example, collected data 115 could include data concerning a vehicle 10 speed, acceleration, pitch, yaw, roll, braking, presence or absence of precipitation, tire pressure, tire condition, etc.
[0019] A memory of the computer 105 may further store parameters 116 . A parameter 116 generally governs control of a system or component of vehicle 10 . These parameters may vary due to an environmental condition, road condition, vehicle 10 condition, or the like. In one example, parameters 116 may specify thresholds for determining frontal impacts, generally, and for identifying oblique frontal impacts from other frontal impacts and, thus, conditions for deployment of impact mitigation systems, such as passenger airbags and seat belt pre-tensioning systems, particularly tailored for the type of impact. In another example, parameters 116 may specify predetermined impact thresholds for identifying impacts with pedestrians and, thus, conditions for deployment of pedestrian impact mitigation systems such as bumper- or hood-mounted airbags and/or hood-lifting systems.
[0020] The sensing apparatus 28 provides a range of responses to impact forces applied to the front end 12 of the vehicle 10 , toward sensing and identifying a collision or impact with the front end 12 of the vehicle 10 . The left, center and right cavities 50 , 52 , 54 may be elastically deformable in response to relatively low impact forces, such as a collision of the vehicle 10 with a pedestrian, so as to generate a change in the pressure of one or more of the volumes 60 , 62 , 64 , depending on the impact location and magnitude, which may be detected by pressure sensors 80 , 82 , 84 , respectively. The pressure sensors 80 , 82 , 84 generate pressure signals from which the vehicle computer 105 may discriminate between the impact location and magnitude, so as to further control the operation of collision mitigation equipment and systems. For example, at the time immediately after the vehicle 10 experiences an oblique impact on the left side of the front end 12 , the left pressure sensor 80 of the left chamber 50 senses a stronger pressure change than the center pressure sensor 82 of the center chamber 52 , and the right pressure sensor 84 of the right chamber 54 senses little or no pressure change. By comparing the pressure differences between the three sensors various frontal impact modes, such as full frontal impact mode can be differentiated from the oblique impact. In some implementations, this discrimination between the pressure signals may be executed by the sensing apparatus 28 and the computer 105 in 20 milli-seconds or less. Over a longer period of time, in the absence of permanent deformation to the sensing apparatus 28 , the pressure equalizes through the channels 56 , 58 .
[0021] Additionally, in an implementation in which the sensing apparatus 28 is pressurized relative to a volume outside thereof, the computer 105 may use signals from the pressure sensors 80 , 82 , 84 for failure mode prevention, e.g. to identify a leak in the sensing apparatus 28 . For example, if the pressure of the volumes 60 , 62 , 64 drops over time, as opposed to equalizes as described herein, the computer 105 may generate a communication or signal identifying the leak.
[0022] FIG. 4 is a diagram of an exemplary process 400 for utilizing an exemplary sensing apparatus of the present disclosure, e.g. sensing apparatus 28 , to identify an oblique frontal impact with the vehicle 10 . It should be understood that an exemplary sensing apparatus of the present disclosure, e.g. sensing apparatus 28 , may be utilized in a variety of sensing applications in addition to or as an alternative to the exemplary process 400 , e.g., to identify an impact with a pedestrian and to identify a head-on impact with another vehicle.
[0023] The process 400 begins in a block 405 , in which the computer 105 of the vehicle 10 receives signals from the left, center and right pressure sensors 80 , 82 , 84 . Next, in a block 410 , the computer 105 respectively compares the signals from the left, center and right pressure sensors 80 , 82 , 84 to a frontal impact threshold value among the stored parameters 116 . For example, the frontal impact threshold value may correspond to a minimum value that would be experienced by any part of the sensing apparatus 28 in the event of a collision of the front end 12 of the vehicle 10 with another vehicle or rigid object and which may necessitate the activation of occupant protection measures. Accordingly, next, in a block 415 , if none of the pressure signals from pressure sensors 80 , 82 , 84 meets or exceeds the frontal impact threshold, the process 400 returns to the block 405 . On the other hand, if any of the pressure signals from pressure sensors 80 , 82 , 84 meets or exceeds the frontal impact threshold, the process 400 continues to a block 420 .
[0024] In the block 420 , the computer 105 compares the signals from the left and right pressure sensors 80 and 84 with a processing threshold value among the stored parameters 116 . For example, if the impact at either the left or right side of the sensing apparatus 28 meets or exceeds a certain severity, as set by the processing threshold value, the frontal impact identified relative to the frontal impact threshold may be further identified as at least involving the side corresponding with the one of the pressure sensors 80 and 84 providing a signal exceeding the processing threshold.
[0025] If, as determined at a block 425 , one or both of the pressure sensors 80 and 84 does provide a signal exceeding the processing threshold, next, in a block 430 , the computer 105 subtracts the signal from the center pressure sensor 82 from the one or both of the pressure sensors 80 and 84 providing a signal exceeding the processing threshold. Next, in blocks 435 and 440 , the computer 105 compares the resultant difference to an oblique impact threshold value among the stored parameters 116 . For example, in an at least offset frontal impact as identified by comparison of the signals of the pressure sensors 80 , 82 , 84 to the frontal impact threshold and/or the processing threshold, the difference calculated at the block 430 may meet or exceed the oblique impact threshold when the impact force is sufficiently concentrated to one of the sides of the vehicle 10 , and thus at the sensing apparatus 28 , as may be with an oblique impact between vehicles.
[0026] If, in the block 440 , the oblique impact threshold has been determined to have been met or exceeded, then, at block 442 , based on the output from blocks 435 and 440 , the computer 105 determines if oblique impact is a left or right oblique impact. At block 445 , the computer 105 selects operational parameters from the stored parameters 116 for the collision mitigation systems 120 for identified left or right oblique impact and applies those parameters, e.g. through the restraint control module 106 . For example, oblique impact specific impact countermeasures, such as side curtain airbags, may be deployed, in the event an oblique impact is identified. Upon application of those parameters, the process 400 ends.
[0027] If, at the block 425 , neither of the signals from the left or right pressure sensors are at or above the processing threshold, or, if, at the block 440 , the difference calculated at the block 435 is not at or above the oblique impact threshold, the process 400 continues to the block 450 , where other impact modes, and corresponding parameters for the collision mitigation systems 120 , may be identified. Following the block 450 , the process 400 ends.
[0028] Computer-executable instructions may be compiled or interpreted from computer programs created using a variety of programming languages and/or technologies, including, without limitation, and either alone or in combination, Java™, C, C++, Visual Basic, Java Script, Perl, HTML, etc. In general, a processor (e.g., a microprocessor) receives instructions, e.g., from a memory, a computer-readable medium, etc., and executes these instructions, thereby performing one or more processes, including one or more of the processes described herein. Such instructions and other data may be stored and transmitted using a variety of computer-readable media. A file in a computing device is generally a collection of data stored on a computer readable medium, such as a storage medium, a random access memory, etc.
[0029] A computer-readable medium includes any medium that participates in providing data (e.g., instructions), which may be read by a computer. Such a medium may take many forms, including, but not limited to, non-volatile media, volatile media, etc. Non-volatile media include, for example, optical or magnetic disks and other persistent memory. Volatile media include dynamic random access memory (DRAM), which typically constitutes a main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, any other memory chip or cartridge, or any other medium from which a computer can read.
[0030] In the drawings, the same reference numbers indicate the same elements. Further, some or all of these elements could be changed. Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It should be understood that, as used herein, exemplary refers to serving as an illustration or specimen, illustrative, or typical. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.
[0031] All terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary in made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.
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An apparatus includes a center component defining a center chamber therein and first and second side components defining first and second chambers therein, respectively. The first and second side components are coupled to opposing ends of the center component with the first and second chambers in fluid communication with the center chamber. The center, first side and second side components are configured to extend substantially across a width of a vehicle. The apparatus further includes first, second and third pressure sensors in communication with the first, second and center chambers, respectively.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to an electromagnetic valve, in particular for safety-related pneumatic systems in motor vehicles, with an armature, which, by means of current supplied to an electrical winding, can be displaced axially relative to a core and relative to a first valve seat, inside an inner channel of a coil carrier carrying the winding on a winding section. Furthermore, the invention concerns a safety-related pneumatic system, in particular a pneumatic braking system for motor vehicle applications, in particular for commercial vehicle applications, preferably an ABS or an EBS system.
[0002] From DE 93 000 39 U1 an electromagnetic valve is of known art, whose displaceable armature is guided in the course of its axial displacement on the inner periphery of a coil carrier. DE 41 39 670 C2 shows an alternative electromagnetic valve in which such an armature guide is similarly implemented. In addition, the document shows the integral formation of the valve seat with the coil carrier. What is disadvantageous in the electromagnetic valve of known art, however, is the necessarily massive armature, which is responsible for a high weight and high production costs. Moreover, the damping with respect to the core is implemented in a complex manner via a spring pin positioned in the armature. The sealing function with respect to the valve seat is achieved by means of a sealing element that is axially spaced apart from the spring pin.
[0003] Preceding designs of electromagnetic valves have not been successfully implemented for safety-related applications, for example for ABS or EBS brake valves in commercial vehicle compressed air brakes, since their functional efficiency is not guaranteed under all conditions of deployment. Thus, in the extreme case, for example as a result of unintentional excess current, the result can be overheating of the winding (coil), as a result of which the coil carrier can reduce its inner diameter, which in forms of embodiment of known art defines the guide clearance for the armature, which brings with it the risk of armature seizure. This can be ascribed to the fact that the winding, which is fitted with an appropriate winding tension, is responsible for the fact that in the event of heating the plastic of the coil carrier does not expand outwards, or only to a limited extent, but rather is forced radially inwards, which leads to the above-referred to problematic reduction of the coil carrier inner diameter.
[0004] From DE 10 2005 039 640 A1 an electromagnetic valve for pneumatic systems in motor vehicles is of known art, which has an armature, which, by means of current supplied to an electrical winding, can be displaced axially relative to a core and relative to a first valve seat, inside an inner channel of a coil carrier carrying the winding.
[0005] Cited with reference to other prior art that is concerned with electrical valves, are DE 10 2008 042 731 A1, US 2010/0252761 A1, DE 10 2008 060 483 A1, DE 10 2006 055 833 A1, DE 10 2004 001 565 A1, DE 102 53 769 A1, and U.S. Pat. No. 4,341,241 A.
SUMMARY OF THE INVENTION
[0006] Based on the above-cited prior art, the object underlying the invention is therefore that of specifying an electromagnetic valve with an armature that can be displaced inside an internal channel of a coil carrier for purposes of limiting the axial build length, in which the risk of armature seizure is minimised, in particular so as to be able to deploy the electromagnetic valve for safety-related pneumatic systems in motor vehicles, in particular in commercial vehicles. The task furthermore consists in specifying a safety-related pneumatic system, in particular a braking system, with at least one such electromagnetic valve.
[0007] With regard to the electromagnetic valve this task is achieved with the features disclosed herein, i.e. by means of a generic electromagnetic valve, in that a guide channel is provided in the armature, into which projects a guide pin formed integrally with the coil carrier so as to guide the armature in the course of its axial displacement. With regard to the safety-related pneumatic system the task is achieved with the features disclosed herein.
[0008] Advantageous further developments of the invention are specified in the subsidiary claims. Within the framework of the invention all combinations originate from at least two of the features disclosed in the description, the claims, and/or the figures.
[0009] For purposes of avoiding armature seizure and at the same time for purposes of accommodation of the armature, formed as a stub sleeve, or as a sleeve, at least in some sections inside an internal channel of the coil carrier, the concept underlying the invention is that of not guiding, or not exclusively guiding, the armature on its outer periphery, as in the prior art, but rather instead to implement an armature inner guide, and in particular by means of an axial guide pin, on whose outer periphery the armature is guided, with the inner periphery having a guide diameter of a guide channel provided in the armature, wherein the guide pin, for purposes of ensuring optimal axial parallellism and for purposes of minimising assembly complexity, is formed integrally with the coil carrier (winding carrier) and projects axially into a winding section of the coil carrier carrying the winding. Expressed in other words, the coil carrier extends in the axial direction beyond its winding section provided with a winding, so as then in a region radially further inwards to project axially back into the winding section, and to guide the armature in a region inside the winding section in the course of its axial displacement. By this means it is possible to increase the radial clearance (air gap) between the armature outer diameter, and the coil carrier inner diameter, more precisely the inner channel inner diameter, so that even in the event of a reduction of the inner channel inner diameter as a consequence of overheating there is no longer any risk of armature seizure. The guide pin itself is thereby located sufficiently radially spaced apart from the critical hot region of the winding, in particular it is also spaced apart via the armature itself, so that any possible expansion caused by temperature of the outer diameter of the guide pin turns out to be comparatively small, with the consequence that the guide clearance between the outer diameter of the guide pin and the inner periphery of the armature can be designed to be significantly smaller. This in turn advantageously influences the tribological wear and thus ensures, at the same time with a minimised risk of armature seizure, the service life of the electromagnetic valve designed in accordance with the concept of the invention, which predestines the latter for deployment in safety-related motor vehicle pneumatic systems.
[0010] The armature is preferably guided on the guide pin over at least half the axial extent of the armature. If required, the armature, in the course of an axial displacement, in addition to the armature inner guide that has been implemented, can be guided on its outer periphery on the coil carrier, preferably at least in some sections, more preferably completely outside the winding section in axial terms.
[0011] The electromagnetic valve designed in accordance with the concept of the invention can be designed solely with one, namely the first, valve seat, and then preferably in the form of a 2/2-way valve, wherein the single (first) valve seat can then alternatively be provided on the guide pin, particular on the end face of the latter, by means of integral formation with the guide pin, which is preferred, or it can be located opposite in the region of the core, either formed directly on the core, or on a valve seat component accommodated in the core, preferably passing through the latter. The form of embodiment with a first valve seat provided on the guide pin is particularly suitable for a form of embodiment that is closed in the unpowered state, in particular by means of return springs arranged axially between the armature and the core, while the form of embodiment with a single valve seat arranged in the region of the core is particularly suitable for a form of embodiment that is open in the unpowered state, similarly by means of return springs arranged axially between the armature and the core. In a form of embodiment as a valve that is closed in the unpowered state, it is preferable if a supply channel, assigned directly to the first valve seat, leading to a supply port, preferably runs as a central channel inside the armature, and if the compressed air is subsequently led away, or is led to a working port, via channels provided on the outer periphery of the guide pin, or via at least one such channel.
[0012] Alternatively, as referred to, the embodiment with two valve seats can be implemented, namely with a first valve seat and a second valve seat that is axially spaced apart from the latter, wherein one of the valve seats is provided on the guide pin, while the other valve seat is provided in the core region, either directly on the core, or in a valve seat component or element arranged in the core. The form of embodiment with a first and second valve seat is particularly suitable for the design of the electromagnetic valve as a 3/2-way valve, preferably with a first valve seat that is closed in the unpowered state.
[0013] A further important advantage of the inventive electromagnetic valve consists in the fact that the armature is significantly reduced in weight compared with a solution of solid material. In principle it is possible to design the sleeve-form or stub sleeve-form armature, at least in some sections, as a turned part, wherein cost-effective production by means of sintering, or cold flow pressing, in any event as a mould-dependent component, is preferred. The resulting weight reduction is also advantageous for the magnetic design, amongst other features, for the copper content of the winding, since with the same level of vibration resistance a preferably provided return spring, against whose spring force the armature can be axially displaced when current is supplied to the winding, can be designed to be weaker than is the case in a comparable armature of solid material.
[0014] In a further development of the invention provision is advantageously made for the guide pin to project into the internal channel to the extent that it is located radially inside the winding, as is also preferably a first valve seat provided on the guide pin. It is particularly preferable if the guide pin projects axially into the winding section over at least a quarter of the axial extent of the winding, that is to say of the winding section, very particularly preferably over at least a third of the axial extent of the winding section, even more preferably over at least approximately half the axial extent of the winding section, so that a minimum axial build length is possible with good functionality and mounting of the core optimised in terms of build space, preferably inside the coil carrier.
[0015] It is particularly appropriate if the radial guide clearance between the outer periphery of the guide pin and the inner periphery of the armature is smaller than a radial clearance between the outer periphery of the armature and the inner periphery of the inner channel of the coil carrier, in order in this respect to obtain a valve that is optimised in terms of a minimised tendency for armature seizure.
[0016] It is particularly appropriate if the core is arranged at least in some sections inside the coil carrier, wherein the guide pin then projects into the latter from an end of the winding section facing away from the core. Here a form of embodiment is very particularly preferred in which the core is sealed relative to the coil carrier in the radial direction, in particular via a ring seal provided on the outer periphery of the core, and/or via a ring seal provided on the inner periphery of the coil carrier, so as to prevent any exit of compressed air in the axial direction in a region between the coil carrier and the core.
[0017] In principle it is possible for the armature to interact directly with the first and, as appropriate, a second valve seat—however, particularly preferred is a form of embodiment in which the sealing function is implemented by means of a sealing element, more preferably by means of an elastomer part, wherein even more preferably, the sealing element is fitted on the armature in a form fit, in that the sealing element preferably passes through an axial passage opening in the armature, in particular on the end face, and overlaps the edge of the passage opening at both axial sides in the radial direction, which can be implemented, for example, by means of an outer peripheral groove on the sealing element. In particular for the preferred case in which the sealing element passes through a passage opening of the armature to both axial sides and—as a function of the switching position—interacts both with the guide pin, in particular with a valve seat there provided, and with the core, or with a valve seat component optionally provided in the core, the sealing element serves a dual function.
[0018] Thus the sealing element operates, in particular, if it is formed as an elastomer part, at both axial sides, as a preferably single damping element, so that the complex spring pin design shown in the prior art can be omitted, and in addition it has a sealing function for purposes of sealing the first valve seat and, if present, for sealing the second valve seat that is then located opposite. This advantageous embodiment of the electromagnetic valve can then in particular, be simply implemented, if the guide pin formed integrally with the coil carrier projects axially into the armature up to radially inside the winding section, as a result of which the respective interactive surfaces come together more closely, for purposes of interaction with the valve seat and the core, than in the prior art. By this means it is advantageously possible in design terms to implement the above-stated dual function of a sealing element.
[0019] If one wished to implement an integration of the sealing and damping functions in the case of the valve of known art from DE 41 39 670 C2, this would only be possible in an extremely complex manner by means of elastomer vulcanisation through the armature, or by the installation of a very long elastomer component in the armature. In this case the length of this integral elastomer part would be of the same order as the armature length, and with expansion coefficients of between approximately 130 and 185×10 −6 mm/K typical of elastomer would show typically several tenths of a millimetre temperature expansion, in particular in the typical range of temperature deployment for motor vehicles of between approximately −40° C. and 125° C., in addition to self heating. This expansion would have to be accommodated in the armature stroke, wherein, however, a greater armature stroke design with the same closing force requires over-dimensioning of the magnet with a larger iron and copper content in the flux circuit, and thus in addition to an increased build space requirement, would lead to increases in production costs.
[0020] It is particularly preferable if the axial extent of the sealing element, then interacting both with the core side, and also with the pin, is significantly less than the axial extent of the armature. The axial extent of the sealing element is preferably less than 50%, yet more preferably less than 40% , very particularly preferably less than 30%, of the axial extent of the armature. Very particularly preferably the axial extent of the sealing element fulfilling a dual function is selected from a range of values between approximately 10% and 20%, yet more preferably between approximately 15% and 25%, of the axial armature length.
[0021] Alternatively it is also conceivable to assign a separate sealing element to each of the valve seats, or to dispense with a sealing element that is separate from the armature completely.
[0022] By means of an advantageous form fit connection between the sealing element and the armature, in accordance with a further development, the otherwise usual bonding agent can be omitted. In particular if the function of stop damping is at the same time assigned to the sealing element, preferably at the core end, this serves to provide for a minimising of switching noise, together with a minimising of wear, by avoiding metallic hard stops, and thereby an increase in service life.
[0023] As already indicated in the introduction, a form of embodiment of the electromagnetic valve is particularly preferred in which the first valve seat is arranged on the guide pin, in particular on its end face, in particular by forming the valve seat integrally with the guide pin. Alternatively, as referred to, it is possible to arrange the first valve seat on the core, or on a valve seat component arranged in the core, wherein in the last-cited case, the valve seat component at the same time preferably bounds a compressed air channel to the valve seat.
[0024] For the case of the arrangement, preferably the formation, of the first valve seat on the guide pin it is preferable if a first fluid channel, in particular a compressed air channel, is formed inside the guide pin, preferably formed as a central channel, which very particularly preferably forms a supply channel, which is supplied from a supply port. When the first valve seat is open, the compressed air can preferably be led away via at least one fluid channel provided on the outer periphery of the guide pin, in particular a working channel leading to a working port. In the case of provision of the first valve seat on the core, or a valve seat element provided on the core, the inflow or outflow of compressed air, to or from the first valve seat respectively, takes place through a channel provided inside the core, or inside a valve seat component.
[0025] Above-cited working channels on the outer periphery of the guide pin are preferably formed by axial grooves between guide sections or guide segments spaced apart in the peripheral direction, which bound a, preferably cylindrical, envelope contour for purposes of guiding the then preferred hollow cylindrical armature on its inner periphery.
[0026] In the case of a form of embodiment with two axially opposed valve seats, it is preferable if an air-conducting connection is implemented between an armature interior, preferably between at least one channel provided on the outer periphery of the guide pin, and one channel in the core, or in a valve seat component provided in the core, in particular through at least one axial passage opening in the region of an armature end face, so that in the case of an armature sitting against the first valve seat an exchange of air is enabled between the then open core region-side second valve seat and the armature interior, preferably the peripheral-side air channel on the guide pin there emerging.
[0027] In production engineering terms it is particularly preferable if the coil carrier and the guide are formed as a common injection-moulded plastic part, preferably with an integral first valve seat, although the latter is not essential if the first valve seat is provided in the region of the core.
[0028] In the case of formation of the coil carrier and the guide pin as a common injection-moulded plastic part, it is preferable if the material of the injection-moulded plastic part contains friction-minimising admixtures, in particular PTFE, in order then preferably to be able to dispense with a sliding coating on the outer periphery of the guide pin for purposes of improving the tribological properties. By this means a cost-intensive armature sliding coating can also be omitted.
[0029] It is particularly appropriate if the working stroke of the armature can be adjusted, or is adjusted, by the axial displacement and subsequent securing of the core, in particular by crimping of a core section axially projecting from the coil carrier together with a metallic flux guide plate, conducting the magnetic flux, and preferably formed as a valve housing. By this means, an optimised energy efficiency of the electromagnetic drive can be implemented. In addition, such an installation can be well controlled with given tolerances.
[0030] The invention also leads onto a safety-related pneumatic system, in particular a (pneumatic) braking system for motor vehicle applications, in particular commercial vehicle applications. In a very particularly preferred manner the safety-related system takes the form of an ABS or EBS braking system, in which an electromagnetic valve designed in accordance with the concept of the invention is deployed, which particularly preferably takes on the function of an ABS brake valve or an EBS brake valve. By virtue of the robust principle of the design the suitability of such safety-related electromagnetic valves for safety-related pneumatic systems is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Further advantages, features and details of the invention ensue from the following description of preferred examples of embodiment, and with the aid of the figures.
[0032] Here:
[0033] FIG. 1 : shows a cross-sectional representation of a closed 2/2-way valve in the unpowered state,
[0034] FIG. 2 : shows a cross-sectional view through the armature guide of the valve in FIG. 1 ,
[0035] FIG. 3 : shows a representation of a 2/2-way valve in a variant of embodiment that is open in the unpowered state, and
[0036] FIG. 4 : shows a possible form of embodiment of an electromagnetic valve designed in accordance with the concept of the invention as a 3/2-way valve with two valve seats axially spaced apart.
DETAILED DESCRIPTION
[0037] In the figures the same elements, and elements with the same function, are identified with the same reference symbol.
[0038] FIG. 1 shows a design of an electromagnetic valve formed in accordance with the concept of the invention as a 2/2-way valve in an embodiment that is closed when current is supplied. A coil carrier 1 formed in plastic can be discerned, which in an axial winding section carries a winding 6 , to which current can be supplied. The supply of current to the winding 6 takes place via a contact pin 5 . The coil carrier 1 is formed integrally with a guide pin 3 , which projects from a side facing away from a core 13 into the winding section, and which, on its outer periphery implements an armature guide 18 , for purposes of guiding an armature 9 on its inner periphery when current is supplied to the winding 6 . In accordance with a preferred variant the armature 9 is additionally guided on its outer periphery, and in fact on the inner periphery of an inner channel of the armature, into which the guide pin 3 projects axially. When the winding 6 is unpowered, the armature 9 , or more precisely, a sealing element 10 , here an elastomer, fitted in a form fit on the armature 9 , which projects beyond a passage opening in the armature in the direction of an armature interior, interacts with a first valve seat 2 formed on the end face of the guide pin 3 . Force is applied onto the armature 9 in the direction onto this valve seat by means of a spring 11 , which is supported on the one hand axially on the core 13 , and on the other hand, axially opposite on the armature 9 .
[0039] When current is supplied to the winding 6 the magnetic flux runs inside the core, then in the radial direction outwards into a flux guide plate 12 , which at the same time exercises a yoke plate function, and then in the opposite axial direction inside the flux guide plate 12 up to a lower flux guide plate section in the plane of the figure, which is accommodated in a peripheral groove of the coil carrier 1 . There the radial clearance to the armature 9 is bridged; inside the armature the flux runs further axially across an axial air gap between armature and core in the direction of the core.
[0040] A section of the core 13 is arranged inside the inner channel of the coil carrier 1 , and is sealed with respect to the latter by means of a ring seal 14 . Axially further outward the core is axially secured by means of crimping 15 it together with a metallic flux guide plate 12 , which has a flux-conducting function.
[0041] When current is supplied to the winding 6 the armature 9 is displaced axially in the direction of the core 13 , on which it is then supported by means of the sealing element 10 , to which is assigned not only a sealing function, but also a stop damping function.
[0042] The radial guide clearance in the region of the armature guide 17 is less than a radial clearance 16 (air gap) between the outer periphery of the armature 9 and the inner periphery of the inner channel of the coil carrier in the region of the axial winding section.
[0043] When the first valve seat is open, i.e. when current is supplied to the winding 6 , compressed air can flow via a first fluid channel, formed as a central channel, here a supply channel (P) axially into the armature interior, and out of the latter in the opposite axial direction via second fluid channels 4 formed on the outer periphery of the guide pin 3 to a working port A. Needless to say, the flow through the electromagnetic valve can also be in the opposite direction (the port figures then alter accordingly).
[0044] In the installation position the supply port is sealed with respect to the working port via an O-ring seal 8 , and the working port is sealed with respect to the environment via an O-ring seal 7 arranged radially further outward.
[0045] FIG. 2 shows a detail view in the context of a cross-sectional view of the guide pin 3 . Three radially projecting guide segments 19 can be discerned, wherein two of the guide segments 19 , spaced apart in the peripheral direction, which bound a cylindrical envelope contour, between them bound a channel 4 , which in the example of embodiment shown preferably serves as a working air channel.
[0046] In what follows the example of embodiment in FIG. 3 is now described, wherein for purposes of avoiding repetition it is essentially the differences from the example of embodiment in the previous figures that are entered into. With regard to the common features, reference is made to the previous example of embodiment, together with the description of the figures.
[0047] FIG. 3 shows a design of an electromagnetic valve formed in accordance with the concept of the invention as a 2/2-way valve in an embodiment (normally open) that is closed when current is supplied. It can be discerned that the first valve seat 2 is not implemented on the guide pin 3 as in the previous example of embodiment, but instead opposite the guide pin 3 on a valve seat component 20 accommodated in the core 13 , which at same time contains a compressed air channel, here a supply channel P, while further channels 4 , via which the compressed air can flow out when the first valve seat is open, are implemented on the outer periphery of the valve seat component 20 .
[0048] In the example of embodiment shown the spring 19 is also located axially between the armature 9 and the core 13 . As in the example of embodiment in FIG. 1 , here too the coil carrier 1 encompasses the armature 3 axially outwards in the radial direction, in order then to project axially up into the winding section in the shape of the guide pin 3 .
[0049] The example of embodiment of an electromagnetic valve in accordance with FIG. 4 comprises, in addition to the first valve seat 2 , formed on the guide pin 3 , a second valve seat 21 , which is formed axially opposite, here, for example, directly on the core 13 , wherein, however, an arrangement on a valve seat element, which is accommodated in the core 13 , is alternatively possible.
[0050] In the example of embodiment shown the armature 9 interacts via the sealing element 10 with the second valve seat when current is supplied to the winding 6 and when no current is supplied it sits, via the sealing element 10 , against the first valve seat 2 .
[0051] The channels 4 on the outer periphery of the guide pin 3 , and/or an armature interior, are permanently connected in an air-conducting manner with a radially adjacent region of the second valve seat 21 , so that when the second valve seat 21 is open, and the first valve seat 2 is accordingly closed, a fluid-conducting connection exists between the fluid channel 23 in the core 13 , or alternatively in a valve seat element, and the channels 4 , while when the first valve seat is open this connection is interrupted and instead a fluid-conducting connection exists between the fluid channel inside the guide pin and the channels 4 .
[0052] From FIG. 4 it can be discerned that an O-ring seal 22 is assigned to the channel R for purposes of sealing with respect to the environment.
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An electromagnetic valve for safety-related pneumatic systems in motor vehicles, with an armature ( 9 ), which, by means of current supplied to an electrical winding ( 6 ), can be displaced axially relative to a core ( 13 ) and relative to a first valve seat ( 2 ), inside an inner channel of a coil carrier carrying the winding ( 6 ) on a winding section, wherein, in the armature ( 9 ) is arranged a guide channel, into which projects axially a guide pin ( 3 ) formed integrally with the coil carrier ( 1 ), so as to guide the armature ( 9 ) in the course of its axial displacement.
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BACKGROUND OF INVENTION
[0001] Polycarbonate resins are useful materials valued for their physical and optical properties. Methods for the preparation of polycarbonate resins include interfacial processes and melt processes. In interfacial processes, as described, for example, in U.S. Pat. No. 4,360,659 to Sikdar, a bisphenol is reacted with phosgene in the presence of solvents. In melt processes, as described, for example, in U.S. Pat. No. 3,153,008 to Fox, a bisphenol is reacted with a diary carbonate. Melt processes are presently preferred because they avoid the use of phosgene and solvents.
[0002] Use of a melt process for polycarbonate synthesis requires an industrially efficient process for producing diaryl carbonates. There are several known processes for producing diaryl carbonates. One example of such a process is described by U.S. Pat. No. 4,182,726 to Illuminati et al. In this process, diaryl carbonates are produced by reacting dialkyl carbonates with aryl hydroxides (see Scheme I, below).
[0003] U.S. Pat. No. 4,182,726 also demonstrates that diary carbonates can be reacted together with dihydric phenols to produce polycarbonates (see Scheme II, below).
[0004] A preferred process for making dialkyl carbonates is illustrated in Scheme III, below, and described, for example, in U.S. Pat. No. 5,527,943 to Rivetti et al.; and U.S. Pat. Nos. 4,218,391 and 4,318,862 to Romano et al.
[0005] U.S. Pat. No. 5,527,943 (the '943 patent) also describes a known drawback of the dialkyl carbonate process according to Scheme (III): it produces water as a by-product. Also, hydrochloric acid (HCl) may be continuously added to the reaction mixture to maintain a desired molar ratio of chloride to copper. Therefore, HCl, CuCl catalyst, and water are typically found in the stream exiting the reactor vessel. Hydrochloric acid and copper chlorides are very corrosive in the presence of water, so equipment made from corrosion-resistant materials, such as glass-lined vessels, must be used in the reaction section of a chemical plant making dialkyl carbonates by this process. As corrosion-resistant equipment is expensive, there is a desire to use it in as little of the plant as possible.
[0006] A typical plant for performing preparing dialkyl carbonates according to Scheme Ill may contain three sections: a reaction section for converting raw materials to dialkyl carbonate, a separation section for isolating the dialkyl carbonate from unreacted monomers and by-products, and a purification section for removing water and further isolating the dialkyl carbonate. The '943 patent teaches that one can minimize the amount of corrosion-resistant equipment required by removing the HCl from the process stream immediately after the reaction section. This eliminates the necessity of using expensive corrosion-resistant materials in the separation and purification sections of the plant. The '943 patent further suggests that removal of HCl and possible copper halide salts from the stream immediately after the reaction section can be accomplished by exposing the gas-liquid mixture produced by the reaction to a liquid stream consisting of one of the process fluids. The '943 patent also states that the operating conditions employed are preferably adjusted such that the gaseous mixture from the reactor does not condense, or condenses only to a negligible extent, before the acid removal section in order to avoid the necessity of having to reheat the mixture before removing the HCl (col. 3, lines 17-30).
[0007] In view of the above, it was desirable to construct a plant wherein the HCl and any copper halide salts would be removed from the stream after the reaction section to avoid corrosion in the separation and purification sections. However, a technique similar to that described by the '943 patent—removing HCl and copper salts by treatment of a vaporized feed in a column using a counterflowing azeotrope fluid from the reaction mixture—failed to prevent corrosion in the downstream separation and purification sections.
[0008] There is therefore a need for a dialkyl carbonate process that recognizes and eliminates additional sources of corrosion.
SUMMARY OF INVENTION
[0009] The above-described and other drawbacks and disadvantages of the prior art are alleviated by a method of preparing a dialkyl carbonate, comprising: reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; and removing alkyl chloroformate from said mixture.
[0010] After considerable effort, the present inventors have discovered that dialkyl carbonate synthesis can form alkyl chloroformate by-products that lead to problematic corrosion. For example, in the reaction of methanol, carbon monoxide, and oxygen to form dimethyl carbonate (hereinafter “DMC”), methyl chloroformate (hereinafter “MCF”) may be formed as a by-product. The MCF may pass through the HCl removal column into the separator and purification sections, where it reacts slowly with methanol and/or water to form corrosive HCl. Therefore, it was determined that steps were needed to remove MCF prior to the separation and purification sections.
[0011] Other embodiments, including an apparatus for preparing dialkyl carbonates, are described below.
BRIEF DESCRIPTION OF DRAWINGS
[0012] [0012]FIG. 1 is a diagrammatic view of a first embodiment of the apparatus.
[0013] [0013]FIG. 2 is a simplified diagrammatic view of a comparative apparatus that is susceptible to corrosion.
[0014] [0014]FIG. 3 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 comprises two holding vessels 120 .
[0015] [0015]FIG. 4 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 comprises four holding vessels 120 .
[0016] [0016]FIG. 5 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 comprises a tubular section 130 .
[0017] [0017]FIG. 6 is a simplified diagrammatic view of an embodiment of the apparatus comprising an ion exchange resin bed 190 .
[0018] [0018]FIG. 7 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 comprises a first gas-liquid separator 90 and a second gas-liquid separator 100 .
[0019] [0019]FIG. 8 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 precedes the first gas-liquid separator 90 .
[0020] [0020]FIG. 9 is a simplified diagrammatic view of an embodiment of the apparatus in which the fluid passageway 110 follows the azeotrope column 180 .
[0021] [0021]FIG. 10 is a plot of chloride concentrations at the bottom of an azeotrope column 180 as a function of apparatus type (FIG. 2 and FIG. 3) and time.
[0022] [0022]FIG. 11 is a plot of methyl chloroformate concentrations entering and exiting the fluid passageway 110 as a function of time for an apparatus corresponding to FIG. 3.
DETAILED DESCRIPTION
[0023] One embodiment is a method, comprising: reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; and removing alkyl chloroformate from said mixture.
[0024] There is no particular limitation on the alkanol used in the method. Suitable alkanols include primary, secondary, and tertiary C 1 -C 12 alkanols, with primary C 1 -C 6 alkanols being preferred. Highly preferred alkanols include methanol.
[0025] Oxygen may be provided in any form, with gaseous forms being preferred. Suitable oxygen sources include, for example, air, and oxygen-containing gases having at least about 95 weight percent molecular oxygen, preferably at least about 99 weight percent molecular oxygen. Suitable oxygen-containing gases are commercially available from, for example, Air Products.
[0026] Carbon monoxide is preferably supplied as a gas having at least about 90 weight percent, preferably at least about 95 weight percent, more preferably at least about 99 weight percent, carbon monoxide. Suitable carbon monoxide-containing gases are commercially available from, for example, Air Products.
[0027] Suitable catalyst include those comprising iron, copper, nickel, cobalt, zinc, ruthenium, rhodium, palladium, silver, cadmium, rhenium, osmium, iridium, platinum, gold, mercury, and the like, and combinations comprising at least one of the foregoing metals. Preferred catalysts may comprise copper. A highly preferred catalyst comprises copper and chloride ion in a molar ratio of about 0.5 to about 1.5. Within this range, a molar ratio of at least about 0.8 may be preferred. Also within this range, a molar ratio of up to about 1.2 may be preferred. Highly preferred catalysts include cuprous chloride (CuCl) and cupric chloride (CuCl 2 ), with cuprous chloride being more highly preferred. During operation of the process, a suitable chloride ion concentration may be maintained by the addition of hydrochloric acid (HCl).
[0028] [0028]FIG. 1 illustrates a dialkyl carbonate plant 10 having linked reaction section 20 , separation section 30 , and purification section 40 . With reference to FIG. 1, the catalyzed reaction of alkanol, oxygen, and carbon monoxide may be performed in a single reactor 50 , or in two or more reactors 50 . The conditions for performing this step should be selected to maximize the yield of dialkyl carbonate while minimizing the degradation of dialkyl carbonate. Preferably, the reaction is performed in a single reactor 50 , at a temperature of about 50° C. to about 250° C. Within this range, the temperature may preferably be at least about 100° C. Also within this range, the temperature may preferably be up to about 150° C. The reactor 50 is preferably kept at a pressure of about 15 to about 35 bar gauge (barg). Within this range, a pressure of at least about 20 barg may be preferred. Also within this range, a pressure up to about 28 barg may be preferred. In the case of dual reactor systems, the catalyst may be recycled between tanks. The catalyst concentration should be sufficiently high to produce an acceptable yield, but should be kept below a concentration that would cause solid setting of the catalyst in the reactor 50 or clogging of the equipment. The reactants alkanol, oxygen, and carbon monoxide are preferably added in a molar ratio of (about 0.5 to about 0.7):(about 0.04 to about 0.06):(about 0.8 to about 1.2), respectively. A highly preferred molar ratio of alkanol:oxygen:carbon monoxide is (about 0.6):(about 0.05):(about 1).
[0029] The amount of catalyst used relative to the reactants will depend on the identity of the catalyst. For example, when the catalyst comprises CuCl, a highly preferred catalyst concentration is about 140 to about 180 grams per liter of reaction mixture. During operation, the catalyst may initially be added from a catalyst tank 60 . Sufficient HCl is preferably added to reactor 50 from a hydrochloric acid tank 70 during the course of the reaction to maintain a molar ratio of Cu:Cl close to 1.0. The concentration of HCl is preferably continuously determined and controlled by the addition of HCl. A typical mass ratio for HCl feed to total liquid feed is about 6×10 −4 to about 8×10 −4 .
[0030] The reaction produces a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide. The mixture may further comprise residual methanol and oxygen, as well as side-products such as alkyl chlorides and dialkyl ethers. The mixture is typically withdrawn from the reactor 50 in a gas/vapor form. The term “vapor” is meant to refer to gaseous organic components of the mixture such as, for example, evaporated dialkyl carbonates, alcohols, alkyl chloroformates, etc., and to water vapor. That is, the term “vapor” refers to fluids having a boiling point of at least −50° C. at one atmosphere. In contrast, the term “gas” is meant to refer to the gaseous oxygen, carbon dioxide, carbon monoxide, and optional nitrogen. That is, the term “gas” refers to fluids having a boiling point less than −50° C. at one atmosphere. The vapor may be at least partially condensed in condenser 80 , and fed to a first gas-liquid separator 90 . The apparatus may optionally employ a single gas-liquid separator, or a plurality of (i.e., at least 2; preferably up to about 5) gas-liquid separators. The first gas-liquid separator 90 may be kept at a pressure within about 10%, more preferably within about 1%, of the pressure of the reactor 50 . The gas effluent from the first gas-liquid separator 90 may be recycled, for example to reuse excess carbon monoxide. The mixture may be sent to a second gas-liquid separator 100 , which preferably has a pressure less than about 20% of the pressure of the reactor 50 (e.g., preferably less than 3 bar gauge, more preferably about 0.2 bar gauge) to preferably achieve separation of at least about 90%, more preferably at least 95%, by weight of the remaining gas in the mixture. In a highly preferred embodiment, substantially all of the gas is removed from the mixture. The gas effluent removed from the second gas-liquid separator 100 can also be recycled. It is preferred that the vapor in the mixture be in a partially condensed form (i.e., at least about 10% condensed), more preferably a fully condensed form (i.e., at least about 90% condensed), before entering the first gas-liquid separator 90 , and between the first gas-liquid separator 90 and the second gas-liquid separator 100 .
[0031] In the embodiment shown in FIG. 1, the mixture exiting the second gas-liquid separator 100 may be in a single liquid phase. After the second gas-liquid separator 100 , the mixture may proceed through a fluid passageway 110 that removes alkyl chloroformate from the mixture. It will be understood that the terms “remove” and “removal” in reference to a particular chemical species encompass any chemical or physical process that reduces the concentration of the species in the mixture. The alkyl chloroformate may be removed from the condensate by any method. Some preferred methods include heating, increasing pressure, increasing residence time, adding a polar solvent, adsorbing, separating with a membrane (including gas and liquid membrane separation), pervaporating, passing through an ion exchange resin, exposing to a stoichiometric reagent, exposing to a catalytic reagent, and the like, and combinations comprising at least one of the foregoing techniques. In a preferred embodiment, the alkyl chloroformate is removed from mixture by reaction with water (see Scheme IV) or alkanol (see Scheme V).
[0032] It may also be preferred to remove the alkyl chloroformate without passing the mixture through an ion exchange resin, because such resins are expensive to install and operate. It may be preferred to remove at least about 50 percent, more preferably at least about 90 percent, yet more preferably at least about 95 percent, even more preferably at least about 99 percent, of the alkyl chloroformate from the mixture. In one embodiment, it may be preferred to reduce the alkyl chloroformate concentration in the mixture to less than about 500 ppm, more preferably less than about 100 ppm, yet more preferably less than about 30 ppm. In any of these embodiments, it may be preferred to remove less than about 10%, more preferably less than about 5%, yet more preferably less than about 1%, of the dialkyl carbonate. Although the method may be described as “removing less than about 10% of said dialkyl carbonate”, it will be understood that the concentration of dialkyl carbonate need not be reduced and may even increase. For example, the concentration of dialkyl carbonate may increase if the Scheme V reaction of alkyl chloroformate with methanol forms dialkyl carbonate faster than dialkyl carbonate decomposes due to other reactions.
[0033] Through extensive kinetic studies of the dimethyl carbonate process utilizing variations in factors including temperature, residence time, water concentration, methanol concentration, and hydrochloric acid concentration, the present inventors have found that the rate of methyl chloroformate decomposition may be given by the equation (1)
−r MCF =( k 1 [H 2 O]+ k 2 [MeOH])[MCF] (1)
[0034] where r MCF is the rate of change of the moles of methyl chloroformate (MCF) per unit volume, [H 2 O], [MeOH], and [MCF] are the instantaneous concentrations of water, methanol, and methyl chloroformate, respectively, in moles per unit volume, and k 1 and k 2 are rate constants that vary with temperature according to equations (2) and (3), respectively
k 1 =k 1 0 e −6381/T (2)
k 2 =k 2 0 e −7673 /T (3)
[0035] where k 1 0 =2.09×10 9 mL/mol-min, k 2 0 =4.14×10 10 mL/mol-min, and T is the temperature in degrees kelvin.
[0036] In many cases, it is valid to assume that the concentrations of water and methanol, and the density of the solution are essentially constant. Within these general kinetic constraints, different kinetic expressions may be used for different process and apparatus types. With knowledge of the relevant chemical reactions and rate constants provided in this application, these expressions may be readily derived by those of ordinary skill in the art. For example, in a batch process, the rate of methyl chloroformate decomposition may be expressed as a function of residence time, as shown in equation (4):
− d [MCF]/ dt =( k 1 [H 2 O]+ k 2 [MeOH])[MCF] (4)
[0037] where t is residence time in minutes. The residence time t may be defined as the total time spent by an average molecule in the fluid passageway 110 . In a batch process, at least about 50% of the methyl chloroformate may be removed by maintaining the mixture under conditions comprising a water concentration ([H 2 O]), a methanol concentration ([MeOH]), a temperature (T), and a residence time (t), such that a parameter X according to the equation (5)
X=exp {−[(2.09×10 9 ) e (−6381/T) [H 2 O]+(4.14×10 10 ) e (−7673/T) [MeOH]] t } (5)
[0038] has a value less than about 0.9, wherein the water concentration and the methanol concentration are expressed in moles per milliliter, the temperature is expressed in degrees Kelvin, and the residence time is expressed in minutes. The value of X may preferably be less than about 0.5, more preferably less than about 0.2, yet more preferably be less than about 0.1, even more preferably less than about 0.05, still more preferably less than about 0.01. The water concentration may be about 0.1 to about 50 moles per liter (mol/L). Within this range, the water concentration may preferably be at least about 0.5 mol/L, more preferably at least about 1 mol/L. Also within this range, the water concentration may preferably be up to about 30 mol/L, more preferably up to about 20 mol/L, yet more preferably up to about 10 mol/L, even more preferably up to about 5 mol/L. The methanol concentration may be about 1 to about 25 mol/L. Within this range, the methanol concentration may preferably be at least about 5 mol/L, more preferably at least about 10 mol/L. Also within this range, the methanol concentration may preferably be up to about 20 mol/L, more preferably up to about 18 mol/L. The residence time may be about 0.5 hour to about 10 hours. Within this range, the residence time may preferably be at least about 1 hours, more preferably at least about 2 hours. Also within this range, the residence time may preferably be up to about 8 hours, more preferably up to about 6 hours. The temperature may be about 30 to about 130° C. Within this range, the temperature may preferably be at least about 40° C., more preferably at least about 50° C., yet more preferably at least about 60° C. Also within this range, the temperature may preferably be up to about 110° C., more preferably up to about 100° C., yet more preferably up to about 90° C.
[0039] In the limit of an ideal steady state plug flow reactor, and assuming constant density of the mixture, the rate of methyl chloroformate decomposition may be expressed according to equation (3), with t representing residence time in minutes.
[0040] For an ideal steady state continuous stirred tank reactor (CSTR), the concentration of methyl chloroformate is given by equation (6)
[MCF]=[MCF] t=0 (1/(1+ kt )) (6)
[0041] where [MCF] t=0 is the initial concentration of methyl chloroformate in moles per milliliter, t is the residence time in minutes, and k is given by equation (7)
k=k 1 [H 2 O]+ k 2 [MeOH] (7)
[0042] where k 1 , k 2 , [H 2 O], and [MeOH] are as defined above.
[0043] In another embodiment that relates to a batch reactor, removing alkyl chloroformate from the mixture comprises maintaining the mixture under conditions comprising an initial concentration of methyl chloroformate ([MCF] t=0 ), a water concentration ([H 2 O]), a methanol concentration ([MeOH]), a temperature (T), and a residence time (t), such that a parameter Z calculated according to the equation (8)
Z=[MCF] t=0 exp {−[(2.09×10 9 ) e (−6381/T) [H 2 O]+(4.14×10 10 ) e (−7673/T) [MeOH]] t} (8)
[0044] has a value less than about 5×10 −6 , preferably less than about 1×10 −6 , more preferably less than about 5×10 −7 , even more preferably less than about 5×10 −8 , wherein the initial concentration of methyl chloroformate, the water concentration, and the methanol concentration are expressed in moles per milliliter, the temperature is expressed in degrees Kelvin, and the residence time is expressed in minutes. The temperature, residence time, methanol concentration, and water concentration in this expression are as described above. The initial concentration of methyl chloroformate will depend on the reactor conditions, but it is typically about 5×10 −3 moles per liter to about 5×10 −1 moles per liter. Within this range, the initial concentration of methyl chloroformate may be at least about 1×10 −2 moles per liter. Also within this range, the initial concentration of methyl chloroformate may be up to about 1×10 −1 moles per liter.
[0045] In a preferred embodiment that relates to a batch reactor, removing alkyl chloroformate comprises subjecting the mixture to conditions comprising an initial dimethyl carbonate concentration ([DMC] t=0 ), an initial water concentration ([H2O] t=0 ), an initial methanol concentration ([MeOH] t=0 ), an initial hydrochloric acid concentration ([HCl] t=0 ), a temperature (T), and a residence time (t), such that a parameter X calculated according to the equation (9)
X=exp {−[(2.09×10 9 ) e (− 6381/ T )[H 2 O] t=0 +(4.14×10 10 ) e (−7673/T) [MeOH] t=0 ]t} (9)
[0046] has a value less than about 0.9, and a parameter Y calculated according to the equation (10)
Y = ( 1 - [ H 2 O ] t = 0 [ DMC ] t = 0 ) ( 1 - ( [ H 2 O ] t = 0 [ DMC ] t = 0 ) ( exp ( ( 6.6 × 10 10 ) ( exp ( - 6636 / T ) ) [ HCl ] t = 0 [ DMC ] t = 0 ( [ H 2 O ] t = 0 [ DMC ] t = 0 - 1 ) t ) ) ) ( 10 )
[0047] has a value of at least about 0.9, wherein the initial dimethyl carbonate concentration, the initial water concentration, the initial methanol concentration, and the initial hydrochloric acid concentration are expressed in moles per milliliter, the temperature is expressed in degrees Kelvin, and the residence time is expressed in minutes. The value of Y may preferably be at least about 0.95, more preferably at least about 0.99. Suitable analytical techniques to determine initial concentrations of water, methanol, hydrochloric acid, and dimethyl carbonate in reaction mixtures are well known in the art. The term “initial concentration” refers to the concentration of a species before intentional removal of alkyl chloroformate. The initial water and methanol concentrations are the same as the water and methanol concentrations described above (under typical reaction conditions, the water and methanol concentrations are large are essentially constant during alkyl chloroformate removal). The initial dimethyl carbonate concentration may be about 0.5 to about 10 mol/L. Within this range, the initial dimethyl carbonate concentration may preferably be at least about 1 mol/L, more preferably at least about 2 mol/L. Also within this range, the initial dimethyl carbonate concentration may preferably be up to about 8 mol/L, more preferably up to about 6 mol/L. The concentration of HCl in the mixture will depend on the type and concentration of catalyst employed. The initial hydrochloric acid concentration will depend on the type and amount of catalyst, but it is typically about 1×10 −3 to about 2×10 −1 moles per liter. Within this range, the initial hydrochloric acid concentration may preferably be at least about 5×10 −1 more preferably at least about 1×10 −2 mol/L. Also within this range, the initial hydrochloric acid concentration may preferably be up to about 1×10 −1 more preferably up to about 7×10 −2 mol/L.
[0048] The method may be operated, for example, in a batch, semi-batch, or continuous manner.
[0049] In the particular embodiment shown in FIG. 1, the mixture passes through a first heat exchanger 140 to adjust the temperature of the mixture about 30° C. to about 130° C. Within this range, the temperature may preferably be at least about 40° C., more preferably at least about 50° C. Also within this range, the temperature may preferably be up to about 80° C., more preferably up to about 70° C. The term “heat exchanger” describes a well-known device for heating chemical reaction streams, typically by exchanging heat between a thermal energy source (e.g., steam) and a cooler chemical reaction stream, but it is understood that other types of equivalent heaters (e.g., electrical heaters) are also included. The condensate may proceed into a fluid passageway 110 , which serves to increase the residence time of the mixture under conditions to maximize decomposition of alkyl chloroformate while minimizing decomposition of dialkyl carbonate. The condensate may preferably remain fully condensed within the fluid passageway 110 . It is desirable to keep the condensate fully condensed because at least some alkyl chloroformates (e.g., methyl chloroformate) are more stable in the vapor phase than the liquid phase under conditions used for this process.
[0050] The residence time and temperature in the fluid passageway 110 are preferably sufficient to remove enough alkyl chloroformate to prevent unacceptable downstream corrosion, but they should not be so excessive as to cause unnecessary reductions in the productivity and yield of the desired dialkyl carbonate product. FIG. 2 shows a simplified process diagram representative of a comparison process. In this process, the mixture flows directly from a first gas-liquid separator 90 to a first heat exchanger 140 , then to an acid removal column 160 . Three specific embodiments of the fluid passageway 110 are shown in FIGS. 3, 4, and 5 . In a preferred embodiment, at least about 50% of the alkyl chloroformate is removed, more preferably at least 80% is removed. In a highly preferred embodiment, the alkyl chloroformate concentration is reduced to less than about 500 parts per million (ppm) by weight, more preferably less than about 100 ppm by weight, yet more preferably less than about 30 ppm by weight, based on the total weight of the mixture after alkyl chloroformate removal. The fluid passageway 110 is preferably selected such that the total residence time between the reactor 50 and the acid removal column 160 is about 0.5 hour to about 10 hours. Within this range, the residence time may preferably be at least about 1 hour, more preferably at least about 2 hours. Also within this range, the residence time may preferably be up to about 8 hours, more preferably up to about 7 hours.
[0051] In one embodiment, illustrated in FIG. 3, the fluid passageway 110 comprises 2 holding vessels 120 . These holding vessels 120 may, for example, maintain the mixture at a temperature of about 55° C. for about 2 hours. Each holding vessel 120 may preferably have a length to volume ratio (L/V) less than 5, preferably less than about 2. While two holding vessels 120 are illustrated in this figure, there is no particular limitation on the number of holding vessels 120 in the fluid passageway 110 . It may be preferred to use at least 2 holding vessels 120 , and configurations comprising 3, 4, 5, 6, or more holding vessels 120 may also be preferred.
[0052] In another embodiment, illustrated in FIG. 4, the fluid passageway 110 comprises 4 holding vessels 120 . These holding vessels 120 may, for example, maintain the mixture at a temperature of about 70° C. for about 4 hours. Each holding vessel 120 may preferably have a length to volume ratio (L/V) less than 5, preferably less than about 2.
[0053] In yet another embodiment, illustrated in FIG. 5, the fluid passageway 110 may comprise a section having L/V of at least 5, preferably at least about 10. For brevity, this section may be referred to as a tubular section 130 . Such a tubular section 130 having L/V>5 may promote plug flow of the mixture through the fluid passageway 110 , thereby efficiently utilizing the residence time for removal of the alkyl chloroformate. In this embodiment, it may be preferred that the mixture reside in one or more narrow sections having L/V>5 for at least about 50% of the total residence time spent in the fluid passageway 110 , more preferably at least about 80% of the total residence time spent in the fluid passageway 110 .
[0054] Referring again to FIG. 1, after exiting the fluid passageway 110 , the mixture may, optionally, pass through a second heat exchanger 150 to at least partially vaporize the mixture. This second heat exchanger 150 may have a residence time of less than 10 minutes. This vaporization step may also be accomplished without a heat exchanger by lowering the pressure applied to the condensed mixture (e.g., by passing the condensate into an acid removal column 160 that is kept at a relatively lower pressure). The vaporized mixture may then, optionally, be treated to remove HCl, preferably by injecting it into an acid removal column 160 . The acid removal column 160 may also help remove any entrained catalyst (e.g., CuCl) that could otherwise contribute to downstream corrosion. In the acid removal column 160 , the vaporized condensate may preferably encounter a counter-flowing liquid supplied by counter-flowing liquid line 170 to a higher point in the column (e.g., the upper third). The counter-flowing liquid may trap the remaining HCl and other reactants, which may be removed from the bottom of the acid removal column 160 and recycled to the reactor 50 . The dialkyl carbonate mixture may be removed from the top of the acid column 160 , and, optionally, passed into an azeotrope column 180 . As shown in FIG. 6, an optional ion exchange resin bed 190 may be included after the acid removal column 160 , or at any other position downstream with respect to the acid removal column 160 . It may be advantageous to include an optional ion exchange resin bed 190 after water is removed from the product dialkyl carbonate stream in the purification section 40 . In a preferred embodiment, the apparatus does not include an ion exchange resin bed 190 .
[0055] In a preferred, embodiment, the method comprises reducing the concentration of hydrochloric acid in the mixture to less than about 1×10 −3 mol/L, more preferably less than about 5×10 −4 mol/L, even more preferably less than about 1×10 −4 mol/L, based on the total composition after removing hydrochloric acid.
[0056] In a preferred embodiment, the portions of the separation section 30 downstream from the azeotrope column 180 , and the purification subsection 40 are not required to be corrosion-resistant. Equipment upstream of the azeotrope column 180 is preferably corrosion-resistant; for example, it may be glass lined. The term “corrosion-resistant” is meant to describe a material capable of withstanding an HCl content of 500 ppm at a temperature of about 50° C. to about 135° C. in the reaction mixture without substantial corrosion in a relatively brief time period (e.g., six months). Glass lined vessels, precious metal (e.g., tantalum) lined vessels and special steels such as HASTELLOY® and CHROMALLOY® would be considered corrosion-resistant materials, while ordinary stainless steels not modified to enhance corrosion resistance would not be considered corrosion-resistant. The azeotrope column 180 can be made at least in part from corrosion-resistant metals. In a preferred embodiment, the bottom of the azeotrope column 180 may be made from a corrosion-resistant steel, whereas the top of the column can be ordinary stainless steel.
[0057] In one embodiment of the apparatus, illustrated in FIGS. 1 and 3- 6 , alkyl chloroformate is removed in a fluid passageway 110 .
[0058] In another embodiment of the apparatus, illustrated in FIG. 7, the mixture is present in the gas-liquid separation vessels 90 and 100 for sufficient residence time and at sufficient temperature to remove alkyl chloroformate. In other words, the fluid passageway 110 comprises the gas-liquid separation vessels 90 and 100 . For example, the mixture may remain in the condense phase in the gas-liquid separation vessels to be substantially decomposed by reactions with water and methanol. In this embodiment, the first heat exchanger 140 and the holding vessels 120 may be unnecessary.
[0059] In another embodiment of the apparatus, illustrated in FIG. 8, the alkyl chloroformate may be removed in a fluid passageway 110 that precedes the gas-liquid separation vessels 90 and 100 . In this embodiment, one of the above-mentioned techniques for removing alkyl chloroformate may be employed upstream of the gas-liquid separation vessels 90 and 100 .
[0060] In another embodiment of the apparatus, illustrated in FIG. 9, the hydrochloric acid may be removed from the mixture before removing the alkyl chloroformate. In this embodiment, the alkyl chloroformate may be removed in the vapor, rather than the liquid phase. For example, referring to FIG. 9, the fluid passageway 110 may follow the azeotrope column 180 ; for example, it may be inserted into the azeotrope column vapor exit line 210 . In this embodiment, the first heat exchanger 140 and the holding vessels 120 illustrated in FIG. 3 may be omitted. In this embodiment, the fluid passageway 110 may preferably comprise an apparatus suitable for removing alkyl chloroformate from the vapor phase (e.g., ion exchange resins, absorption beds, vapor phase membranes, etc.), and the alkyl chloroformate need not be condensed.
[0061] A preferred embodiment is a method of preparing a dialkyl carbonate, comprising: reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; and passing said mixture through a fluid passageway 110 at a temperature of about 50° C. to about 80° C. and for a residence time of about 1 hour to about 10 hours.
[0062] Another preferred embodiment is an apparatus for preparing a dialkyl carbonate, comprising: means for reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; and means for removing alkyl chloroformate from said mixture.
[0063] Another preferred embodiment is an apparatus for preparing a dialkyl carbonate, comprising: a reactor for reacting an alkanol, oxygen, carbon monoxide, and a catalyst to a produce a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, and carbon dioxide; and a fluid passageway 110 for removing alkyl chloroformate.
[0064] Dialkyl carbonates prepared according to the method are useful for the preparation of diaryl carbonates. For example, diaryl carbonates may be generated by the reaction of a dialkyl carbonate with an aryl hydroxide (see Scheme I, above). The diaryl carbonate may in turn be reacted with a dihydric phenol to form a polycarbonate (see Scheme II, above). For example, dimethyl carbonate prepared according to the method may be reacted with phenoxide to form diphenyl carbonate, which in turn may be reacted with bisphenol A to form a polycarbonate.
[0065] The invention is further illustrated by the following non-limiting examples.
EXAMPLE 1
[0066] A plant according to simplified FIG. 2 was built and operated to produce dimethyl carbonate. Corrosion damage was observed in and downstream of the azeotropic column 180 . After extensive experimentation, it was determined that the corrosion damage was caused by methyl chloroformate passing through the acid separation column. Specifically, methyl chloroformate was found to be present in the azeotrope column 180 at a concentration of 300 parts per million (ppm) by weight.
EXAMPLES 2-5
[0067] The decomposition kinetics of methyl chloroformate were studied under four different conditions. A procedure for determining methyl chloroformate in a sample was as follows. For Example 2, 32 milliliters (mL) of dimethyl carbonate, 10 mL of dimethyl carbonate containing 50 mg of a biphenyl internal standard 63 mL of methanol, and 5 ml of water were added to a 250 mL flask equipped with a thermometer, a condenser, and a port for sampling. (Toluene may be used instead of the methanol/water solution.) The resultant homogeneous solution was placed in an oil bath and the temperature of the solution was held constant at 50° C. At time zero, 81.7 microliters of pure methyl chloroformate were added to the solution (1,000 ppm on a weight basis). Samples were withdrawn at various time intervals and were quenched by reacting the methyl chloroformate in the sample with diisobutyl amine to convert the methyl chloroformate to N,N′-diisobutyl methyl carbamate. The amount of N,N′-diisobutyl methyl carbamate was then analyzed via titration with a standard silver nitrate solution to quantify the amount of ionic chloride present. The amount of methyl chloroformate could then be inferred by analyzing the original sample for ionic chloride. The difference in chloride concentration is equal to the methyl chloroformate concentration because each equivalent of methyl chloroformate liberates one equivalent of ionic chloride upon derivatization. Alternatively, gas chromatography can be used for direct analysis of the N,N′-diisobutyl methyl carbamate using an internal standard.
[0068] Table I below show the observed decomposition rate constants (k) at 50° C. for various conditions. Example 2 corresponds to the case described above. Example 3 has added hydrochloric acid that is generally present in the authentic reaction mixture. In Example 4, the effect of a small amount of sodium bicarbonate was tested. In Example 5, the ratio of dimethyl carbonate to methanol was held constant, but the amount of water was increased from 5% to 10%. The results are summarized below in Table I.
TABLE I DMC MeOH (wt %) (wt %) H 2 0 (wt %) Temp (° C.) k (min −1 ) Ex. 2 45 50 5 50 0.043 Ex. 3* 45 50 5 50 0.043 Ex. 4** 45 50 5 50 0.480 Ex. 5*** 43 47 10 50 0.055
[0069] Plots of the logarithm of methyl chloroformate concentration versus time were linear, fitting a pseudo-first-order kinetic model. This behavior was observed even in the presence of hydrochloric acid, and therefore this method can be used to determine the concentration of methyl chloroformate in a particular sample. Comparison of Examples 2 and 5 indicates that only minor variations in the rate coefficient, k, are observed when analyzing samples having water contents varying by a factor of two. Comparison of Examples 2 and 3 shows, surprisingly, that added HCl did not affect the observed rate of methyl chloroformate decomposition. Comparison of Examples 2 and 4 shows that even a small amount of base increased the reaction rate by more than ten-fold. As a practical matter, however, it may be desirable to avoid strongly basic conditions because they also may increase the decomposition rate of dimethyl carbonate.
EXAMPLE 6, COMPARATIVE EXAMPLE 1
[0070] These experiments show that the fluid passageway 110 is effective to reduce the concentration of methyl chloroformate that can react to form HCl in downstream sections of the plant. With reference to FIG. 1, two samples were obtained by sampling the process fluid at different points in a dimethyl carbonate plant having a configuration with a first heat exchanger 140 and two holding vessels 120 (i.e., a configuration corresponding to FIG. 3). The first sample (Comparative Example 1) was taken immediately before the first heat exchanger 140 . The second sample (Example 6) was taken after the second holding vessel 120 (i.e., after the fluid passageway 110 ). Each same was taken to the lab, and its chloride content was determined as a function of time elapsed from sampling. The results are presented in Table II. The Ex. 6, data show essentially constant levels of chloride ion, indicating that labile, chloride-generating species such as methyl chloroformate are not present in the sample. In contrast, the data for Comp. Ex. 1 show an increase with chloride level over time, consistent with presence of methyl chloroformate in the initial sample and its decomposition over time to form additional chloride ion. Thus, the data collectively show that in the absence of the fluid passageway 110 , substantial chloride formation may take place in downstream (post-acid removal column 160 ) sections of the plant, causing corrosion, but the presence of the fluid passageway 110 is effective to decompose alkyl chloroformate to chloride ion before the acid removal column 160 , thereby preventing downstream corrosion. [t5]
TABLE II Chloride Concentration (ppm) Time (h) Ex. 6 Comp. Ex. 1 0 374 189 2 408 312 4 374 339 8 372 368 10 372 357 25 381 368
EXAMPLE 7, COMPARATIVE EXAMPLE 2
[0071] For Comparative Example 2, a dimethyl carbonate plant according to simplified FIG. 2 was operated according to the conditions described in Table III, below. This plant was similar to that shown in more detail in FIG. 1, with the exception that the first heat exchanger 140 and the fluid passageway 110 were absent. Corrosion was observed in and downstream of the azeotrope column 180 . Next, this plant was modified to include the first heat exchanger 140 and two holding vessels 120 were added to increase residence time (i.e., FIG. 3 configuration). FIG. 10 presents measurements of residual ionic chlorides found in samples taken from the bottom of the azeotrope column 180 , comparing the FIG. 2 and FIG. 3 configurations, each over time. Residual chlorides were determined by titration using a silver nitrate solution, as described above. The data for the FIG. 2 configuration have an average of 671 ppm chloride with a standard deviation of 370 ppm chloride, whereas the data for the FIG. 3 configuration have an average of 35 ppm chloride and a standard deviation of 25 ppm chloride. The data thus show a dramatic reduction in chloride levels for the FIG. 3 configuration vs. the FIG. 2 configuration. It is predicted this reduction would be even greater for the configurations according to FIGS. 4 and 6, in which four holding vessels 120 are used to provide a residence time of four hours at 70° C. FIG. 11 presents measurements of methyl chloroformate concentration entering and exiting the fluid passageway 110 of the FIG. 3 concentration. In other words, the points signified by “+” and labeled “MCF feed to Phase 0” in FIG. 11 correspond to measurements on the mixture as it was entering the fluid passageway 110 ; these points have an average value of 930 parts per million by weight (ppmw) and a standard deviation of 412 ppmw. And the points signified by “▪” and labeled “MCF from Phase 0” correspond to measurements on the mixture as it exits the fluid passageway 110 ; these points have an average value of 45 ppmw and a standard deviation of 77 ppmw. These data clearly show that an apparatus according to FIG. 3 is effective to dramatically reduce the concentration of methyl chloroformate in the process stream.
[0072] [t1]
TABLE III Ex. 7 (FIG. 2 Control Ex. 2 (FIG. 3 Conditions Configuration) Configuration) Mass Ratio MeOH/O 2 /CO 0.7/0.06/1 0.7/0.06/1 Catalyst Content Fixed Fixed Reaction Temperature (° C.) 133 133 Reaction Pressure (barg) 23 23 Temp. of Pre-Residence Time Heater 60 — (° C.) Temp. of Acid Column Feed Vaporizer 90 90 (° C.) Residence Time between flash vessel 2 0.03 and acid column, excluding both (hours)
[0073] [t2]
TABLE IV average chloride concentration ± standard Configuration deviation (ppm) FIG. 3 (comparison) 671 ± 370 FIG. 2 (invention) 35 ± 25
[0074] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
[0075] Where not specifically defined herein, technical terms in this specification may be interpreted according to Grant and Hach's Chemical Dictionary, 5 th ed., McGraw-Hill, Inc.
[0076] All cited patents and other references are incorporated herein by reference in their entirety.
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Unexpected corrosion of downstream sections of a dialkyl carbonate manufacturing apparatus has been traced to alkyl chloroformate impurities, which slowly decompose to yield hydrochloric acid. An improved process and apparatus for dialkyl carbonate synthesis reduce corrosion by physically removing or chemically decomposing the alkyl chloroformate impurities within the corrosion-resistant upstream sections of the apparatus.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to currently pending U.S. Provisional Patent Application 60/882,330, entitled, “Stable Differentiation of Adult Stem Cells”, filed Dec. 28, 2006, the contents of which are herein incorporated by reference.
FIELD OF INVENTION
This invention relates to use of embryonic and adult stem cells for cell replacement therapy and the treatment of disease.
BACKGROUND OF THE INVENTION
An enormous amount of interest has been generated in the use of embryonic and adult stem cells for cell replacement therapy and the treatment of disease. The most interest has been generated by embryonic stem cells, whose pleuripotent potential enables them to become any tissue in the body. The mechanisms through which embryonic stem cells differentiate have partially been discovered. However, the appropriate concentration and time of delivery of known growth factors have not been adequately determined. Additionally, it is not known if all appropriate growth factors for a given stem cell have been identified.
The use of adult stem cells has also generated a great deal of interest. Adult stem cells are multipotent, rather than pleuripotent. In other words, they are capable of transforming into a variety of tissue types. They can be used in a similar manner to embryonic stem cells, such as for cell replacement therapy and treatment of disease. Interest in adult stem cells and their differentiation has also increased due to a relatively new theory hypothesizing that cancers contain abnormal adult stem cells that are less susceptible to chemotherapy than the more metabolically active progeny of these cancer stem cells. Therefore, new methods of treating cancer should target the proliferation and differentiation of cancer stem cells, as well as reducing the already differentiated cells.
One major problem in studying either the differentiation of embryonic, adult or cancer stem cells is that the differentiation of daughter cells created following division of the stem cells is not stable. These daughter cells often retain a specific cell phenotype for a few days or a few months, and then fail to show the appropriate chemical composition or morphology. This is especially true with attempts to create neurons from embryonic or adult stem cells. While there are numerous reports of the creation of cells with specific neural markers and neurotransmitter phenotypes, usually with the addition of growth factors or retinoic acid to aid differentiation, often these cells fail to maintain their original neurotransmitter phenotype after a few days in culture or following transplantation into the nervous system.
Embryonal carcinoma cells derived from teratocarcinoma contain pleuripotent stem-like cells capable of differentiating into a variety of cell types, including neural cells. Human embryonal carcinomas may be an alternative cell source of adult stem cells. One of the most promising embryonal carcinomas cell source is the Ntera2/D1 (NT2) cell line. The NT2 cell line is derived from an embryonal teratocarcinoma cell line capable of differentiating into post-mitotic dopaminergic neurons (NT2N) following treatment with retinoic acid (RA). RA differentiated NT2N neurons (i.e., hNT neurons) have been shown to engraft within the central nervous system and have been used successfully in ameliorating the behavioral deficits associated with stroke, spinal cord injury, and traumatic brain injury. Although, these cells are derived from teratocarcinoma cells, they do not form tumors in the striatal environment. However, RA differentiation results in an unstable dopaminergic phenotype, leading to the rapid loss of their dopaminergic phenotype. Additionally, RA-induced differentiation of NT2 cells leads to increased apoptosis of differentiated hNT neurons compared to undifferentiated NT2 cells.
Cell aggregation in suspension culture has a profound effect on growth and differentiation of cells. The use of embryonic stem cell suspension cultures that form embryoid bodies, has proven to be valuable method to study lineage commitment and differentiation of pleuripotent stem cells without the influence exerted by surrounding tissue. Suspension cultures of neural stem cells, which form neurospheres, also have proven to be an important method to study proliferation, multipotent differentiation of neural stem cells, and differentiation of neural progenitors. Similarly, teratocarcinomas form embryoid bodies, and have been used as in vitro models to study differentiation and stem cell development. Cell aggregation can influence differentiation and cell fate determination of embryonal carcinoma P19 cells. It was found that a neuronal phenotype was the most abundant phenotype among aggregated mouse embryonic cells, followed by astrocytes and microglia. Recent studies showed that aggregated NT2 cells form spheres that contain cells with neuronal morphology after RA treatment. Additionally, these spheres generate neurons when they are exposed to growth factors that also stimulate neural stem cells. The distinctive feature of cell aggregation is the three-dimensional arrangement of the cells that creates cell-to-cell interaction resembling a normal cell environment in vivo. It was shown that cell to cell contact can activate signaling pathways such as the protein kinase C (PKC) pathway. However, as mentioned above, these cultures required the use of RA and/or growth factors to achieve these results. Use of RA and growth factors can be undesirable due instability issues with the resulting cells, residual RA and growth factors in the cultures, apoptosis concerns and other issues surrounding the use of these compounds.
What is needed is cell that retains its differentiated phenotype for an extended period of time. It would be highly desirable for the methodology used to produce such cells to avoid the use of RA and/or growth factors for development and differentiation of the cells. It would also be desirable to have a cell line that retains the dopaminergic phenotype. The present invention solves this and other important needs as will be evident in the specification below.
SUMMARY OF THE INVENTION
In accordance with the invention, the problem of the unstable phenotype and residual RA in the resulting cells is solved by a method of differentiation using cell aggregation and subsequent substrate contact without requiring the use of RA or exogenous growth factors. By way of example, the method involves growing precursor adult stem cells, such as NT2 cells, in suspension culture for a period of around 7 days or longer in the absence of RA. The cells can then be plated on surfaces such as laminin or PLL and grown as plated cells. The inventors have discovered that, using such methodology, it is possible to develop a cell that retains its differentiated phenotype for an extended period of time.
In a first aspect the present invention provides a method for the stable differentiation of adult stem cells. The method includes the steps of expanding precursor cells in conventional culture, lifting the expanded precursor cells, growing the lifted precursor cells in suspension culture for at least about 7 days, plating the cells on laminin or PLL and growing the plated cells for about 14 days. By “stable differentiation” it is meant that the resulting cells maintain their differentiated phenotype for an extended period of time. In contrast, cells differentiated using techniques such as RA treatment lose their differentiated phenotype after a period of about 3 days. For example, these RA treated cells are initially TH+, but after about 3 days lose this TH+ phenotype. Cells differentiated according to the present invention maintain their phenotype past 3 days, 7 days, 10 days, 14 days, 21 days and out to periods of 30 days or more.
In certain embodiments the precursor cell is an embryonal carcinoma cell. The embryonal carcinoma cell can be derived from a teratocarcinoma line. Alternatively, the precursor cell can be derived from a neuroblastoma line. Furthermore, the precursor cell can be an NT2 cell. In certain embodiments the lifted adult stem cells are grown in suspension culture for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In an advantageous embodiment, the lifted adult stem cells are grown in suspension culture for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the lifted adult stem cells are grown in suspension culture for at least about 14 days. In further embodiments, the lifted adult stem cells are grown in suspension culture for up to about 21 days.
In certain embodiments the plated cells are grown for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In still further embodiments the plated cells are grown for about 14 days. In an advantageous embodiment, the plated cells are grown for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the plated cells are grown for at least about 14 days. Plating the cells provides an adherent surface upon which the cells can grow. Adherent surfaces for plating include laminin, poly-L-lysine (PLL) or DLL. Upon plating, the cells evidence migration and other characteristics of neurons. In practice, the plated cells will, in effect, actually be being “replated” following growth in suspension culture, to the extent that the cells were originally expanded in conventional cultures on plates and then lifted for growth in the suspension culture.
The cells grown in suspension culture can be grown in the absence of retinoic acid in certain embodiments. Additionally, the cells are grown in suspension culture in can be grown in the absence of growth factors. By the phrase “absence of growth factors” it is meant that no additional growth factors will be added to media in which the cells are grown, excluding factors typically found in the serum, which serum the cells require for growth. The growth factors could be further referred to as “exogenous growth factors.” Examples of such exogenous growth factors would be egh and fgh. In further embodiments the cells are grown in suspension culture in the absence of both retinoic acid and growth factors. Additionally, the cells do not require conditions of micro-gravity to achieve the desired differentiation.
In a second aspect the present invention provides a method for the stable differentiation of adult stem cells to a neuronal phenotype. The method includes the steps of growing precursor cells in suspension culture for at least about 5 days, plating the cells and growing the plated cells for at least about 7 days.
In certain embodiments the precursor cell is an embryonal carcinoma cell. The embryonal carcinoma cell is derived from a line selected from the group consisting of teratocarcinoma line and a neuroblastoma line. Furthermore, the precursor cell can be an NT2 cell.
In certain embodiments the precursor cells are grown in suspension culture for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In an advantageous embodiment, the precursor cells are grown in suspension culture for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the precursor cells are grown in suspension culture for at least about 14 days. In further embodiments, the precursor cells are grown in suspension culture for up to about 21 days.
In certain embodiments the plated cells are grown for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In still further embodiments the plated cells are grown for about 14 days. In an advantageous embodiment, the plated cells are grown for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the plated cells are grown for at least about 14 days. Plating the cells provides an adherent surface upon which the cells can grow. Adherent surfaces for plating include laminin, poly-L-lysine (PLL) or DLL.
The cells grown in suspension culture can be grown in the absence of retinoic acid in certain embodiments. Additionally, the cells are grown in suspension culture in can be grown in the absence of growth factors. In further embodiments the cells are grown in suspension culture in the absence of both retinoic acid and growth factors. Additionally, the cells do not require conditions of micro-gravity to achieve the desired differentiation.
In a third aspect the present invention provides a method for the differentiation of adult stem cells to a neuronal phenotype. The method includes the steps of culturing the precursor adult stem cells as three-dimensional spheres for at least about 5 days, plating the cells, and growing the plated cells. The phrase “culturing the precursor cells as three-dimensional spheres” refers to the conditions where the cells are able to group or cluster together much as aggregates, free of the constraints imposed by growth of cells adjacent to a fixed surface such as that found when cells are grown on plates. Cell aggregation is one such technique whereby the cells are able to grow in 3-dimensions, with an environment analogous to that which would be found in vivo, as opposed to 2-dimensional plate growth.
In certain embodiments the precursor cell is an embryonal carcinoma cell. The embryonal carcinoma cell can be derived from a line selected from the group consisting of teratocarcinoma line and a neuroblastoma line. Furthermore, the precursor cell can be an NT2 cell.
In certain embodiments the precursor cells are grown in suspension culture for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In an advantageous embodiment, the precursor cells are grown in suspension culture for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the precursor cells are grown in suspension culture for at least about 14 days. In further embodiments, the precursor cells are grown in suspension culture for up to about 21 days.
In certain embodiments the plated cells are grown for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In still further embodiments the plated cells are grown for about 14 days. In an advantageous embodiment, the plated cells are grown for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the plated cells are grown for at least about 14 days. Plating the cells provides an adherent surface upon which the cells can grow. Adherent surfaces for plating include laminin, poly-L-lysine (PLL) or DLL.
The cells grown in suspension culture can be grown in the absence of retinoic acid in certain embodiments. Additionally, the cells are grown in suspension culture in can be grown in the absence of growth factors. In further embodiments the cells are grown in suspension culture in the absence of both retinoic acid and growth factors. Additionally, the cells do not require conditions of micro-gravity to achieve the desired differentiation.
In a fourth aspect the present invention provides a method for the stable differentiation of Ntera2/D1 (NT2) cells to a neuronal phenotype. The method includes the steps of expanding NT2 cells in conventional culture, lifting the expanded NT2 cells, growing the lifted NT2 cells in suspension culture for at least about 7 days, plating/replating the cells growing the replated cells. Cells differentiated according to the present invention maintain their phenotype past 3 days, 7 days, 10 days, 14 days, 21 days and out to periods of 30 days or more.
In certain embodiments the lifted NT2 cells are grown in suspension culture for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In an advantageous embodiment, the lifted NT2 cells are grown in suspension culture for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the lifted NT2 cells are grown in suspension culture for at least about 14 days. In further embodiments, the lifted NT2 cells are grown in suspension culture for up to about 21 days.
In certain embodiments the replated cells are grown for at least about 5 days, at least about 7 days, at least about 11 days or at least about 14 days. In still further embodiments the replated cells are grown for about 14 days. In an advantageous embodiment, the replated cells are grown for at least about 7 days or at least about 11 days. In a particularly advantageous embodiment, the replated cells are grown for at least about 14 days.
The NT2 cells grown in suspension culture can be grown in the absence of retinoic acid in certain embodiments. Additionally, the cells are grown in suspension culture in can be grown in the absence of growth factors. In further embodiments the cells are grown in suspension culture in the absence of both retinoic acid and growth factors.
The present invention further provides differentiated stem cells. The differentiated stem cells can be produced according to any of the methods of the present invention.
We have developed an alternate method of differentiation using cell aggregation and subsequent substrate contact without the use of RA or exogenous growth factors. The developed a method of differentiating adult stem cells can use cells derived from a teratocarcinoma cell line, such as the Ntera2/D1 clone (NT2). NT2 line is a cell line that is available from ATCC. Using the methodology of the invention the NT2 cells or other cell line differentiates to neurons with a stable neurotransmitter phenotype without the use of growth factors or retinoic acid, which may be difficult to completely remove during commercial production. We are able to identify specific neurotransmitters in these differentiated NT2-derived neurons (NT2-N) after 30 days in culture or 30 days survival in vivo.
The resulting stably differentiated neuronal stem/precursor cells exhibit a neuronal phenotype that can be then be used in cell replacement therapy for neurodegenerative disease, stroke or spinal cord injury. At least four different types of neurons are produced from this method of differentiation: dopaminergic, cholinergic, GABAergic and glutaminergic. Additionally, since the cells are a cancer stem cell prior to differentiation, they may serve as a model system for developing anti-cancer therapies aimed at the cancer stem cell, rather than the more differentiated daughter cell.
The inventors have also discovered that it is possible to develop a stable dopaminergic neuronal cell that is tyrosine hydroxylase (TH) positive, and continues to express TH in vitro, and in vivo following transplantation. Our data evidence that NT2N neurons differentiated in NT2 spheres without RA express a stable dopaminergic phenotype. Our data also implicate the involvement of β-catenin/GSK-3β in the differentiation of NT2 cells to NT2N neurons in NT2 spheres.
The present invention provides a stable dopaminergic neuronal cell that is tyrosine hydroxylase (TH) positive, and continues to express TH in vitro, and in vivo following transplantation. The methodology has enabled an examination of the pathway or pathways involved for the differentiation of NT2 cells, and the degree to which their differentiation mimicked the differentiation process of dopaminergic neurons. A distinctive feature of cell aggregation is the three-dimensional arrangement of cells that recreates cell-to-cell interaction more closely resembling the normal cell environment in vivo in which neurons differentiate and develop. Similarly, the Wnt signaling pathway plays a critical role in neuronal differentiation of embryonic stem cells and DA precursors, and was a logical pathway to examine. Our data indicates that NT2N neurons, differentiated in NT2 spheres, express a stable dopaminergic phenotype without the use of retinoic acid. Our data also implicate the involvement of the Wnt signaling pathway, and the role of connexin 43 in the differentiation of NT2 cells to NT2N neurons within NT2 spheres.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a photomicrograph of (C) NT2 cells grown in conventional culture as a monolayer compared to (A) NT2 cells grown for 4 days in suspension culture (DISC), (B) and for 11 DISC. Cells in conventional culture spread and form a confluent monolayer. However, NT2 cells adhere to each other and form spheres in 3-dimensional suspension culture. After 4 DIV in suspension culture, all NT2 cells were aggregated as NT2 spheres. The NT2 spheres remain intact and continue to grow after 11 DIV in suspension culture. (D-F) NT2 11 DISC were re-plated for an additional 11 days.
FIG. 2 is a fluorescent photomicrograph of NT2 spheres. (A) 11 DISC NT2 sphere after re-plate for an additional 11 days show TH+ cells (red when viewed in color/lighter region when viewed in greyscale), (B) Neurite outgrowth show immunoreactivity to synaptophysin (green when viewed in color/lighter region when viewed in greyscale). (C) Double label of TH+ cells showing long, extend synaptophysin+ neurite outgrowth.
FIG. 3 shows a western blot analysis showing increased TH expression in NT2 spheres after 11 DISC.
FIG. 4 is a fluorescent photomicrograph of NT2 cells grown in conventional culture compared to NT2 spheres grown in 3-dimensional suspension culture. (A-F) Immunohistochemistry was done to detect Map-2 in these two culture conditions. There was an increase in Map-2+ cells in NT2 spheres, but not in NT2 cells in conventional culture. (G-M) Immunohistochemistry was done to detect TH in these two culture conditions. There was an increase in TH+ cells in NT2 spheres with TH+ neurite outgrowth, but not in NT2 cells in conventional culture. Scale bare=50 μm.
FIG. 5 is a fluorescent photomicrograph of NT2 spheres one month post-transplantation in the host striatum. (A) and (D) NT2 spheres engraft in the host striatum. (B) and (C) TH+ cells (white arrows) one month post-transplant. (E) double label of TH+ cells (green when viewed in color) and human mitochondria (red when viewed in color). (F) double label of TH+ cells (green when viewed in color) and human nuclei (red when viewed in color). Scale bar=100 μm.
FIG. 6 is a fluorescent photomicrograph of NT2 spheres one month post-transplantation in the host striatum. (A) to (E) TH+ cells (red when viewed in color) in the host striatum one month post-transplant. (C) and (D) extensive TH+ neurite outgrowth within the transplant site. (F) and (G) nestin+cells (red when viewed in color) within the graft. (H) and (I) NF+neurites (red when viewed in color) extend from the graft to host striatum. Scale bar=100 μm.
FIG. 7 shows a western blot analysis demonstrating decreased expression of the cell adhesion molecule N-cadherin and gap junction protein connexin Cx43 in NT2 4 DISC spheres compared to NT2 monolayer cell culture. The decrease of Cx43 expression is consistent with differentiation of NT2cells in NT2 spheres.
FIG. 8 shows a western blot analysis demonstrating an increase in unphosphorylated β-catenin expression in NT2 4 DISC spheres compared to NT2 monolayer, with almost no change in GSK-3β. These findings suggest the stabilization of β-catenin within the cytosol, and possible translocation to the nucleus.
FIG. 9 shows a western blot analysis demonstrating a decrease in TH expression in NT2 4 DISC spheres treated with sulindac sulphide, a β-catenin inhibitor, suggesting the possible involvement of the Wnt/β-catenin pathway in the differentiation of NT2 cells in NT2 spheres.
FIG. 10 shows RT-PCR analysis of NT2 cells in monolayer, 4, 11 and 14 DISC NT2 spheres. There was up regulation in LEF-1 mRNA in 4 DISC (1.1 fold), 11 DISC (1.8 fold) and 14 DISC (3.1 fold) in NT2 spheres. The up regulation in LEF-1 mRNA was associated with up regulation of TH mRNA in 4 DISC (4.5 fold), 11 DISC (11.7 fold) and 14 DISC (14.4 fold) NT2 spheres. Nurr 1 was expressed in undifferentiated NT2 monolayer and NT2 spheres. GAPDH amplification was used as control.
FIG. 11 is a series of fluorescent photomicrographs showing marked increase of β-catenin in NT2 spheres grown in 3-dimensional suspension culture compared to NT2 monolayer cell culture. The increase in the unphosphorylated (active) form of β-catenin in the cytosol with a slight increase in the nucleus suggests the involvement of the Wnt/β-catenin pathway in the differentiation of NT2 cells in NT2 spheres.
FIG. 12 shows a western blot analysis showing an increase in p27 expression in NT2 spheres after 4 and 11 DISC compared to monolayer culture, indicating withdrawal of cells in NT2 spheres from the cell cycle.
FIG. 13 is a graph illustrating dopamine release. HPLC analysis of DA concentrations in media collected from NT2 11 day spheres replated 14 days on PLL reported as percentage of baseline control. Baseline, unstimulated cell media (n=8) and media collected from replated spheres allowed to rest for 3 hours after KCl stimulation (n=8) had mean concentrations of 0.2375 nM and 0.03 nM, respectively. Media collected from replated NT2 spheres stimulated with KCl for 20 minutes (n=8) had a mean DA concentration of 1.20875 nM, a 6-fold increase from baseline (p<0.05).
FIG. 14 is a graph illustrating GABA release. CZE-LIF analysis of GABA concentrations in media collected from NT2 11 day spheres replated 14 days on PLL reported as percentage of baseline control. Baseline, unstimulated cell media (n=8) and media collected from replated spheres allowed to rest for 3 hours after KCl stimulation (n=8) had mean concentrations of 0.7625 nM and 0.9375 nM, respectively. Media collected from replated NT2 spheres stimulated with KCl for 20 minutes (n=8) had a mean GABA concentration of 7.4375 nM, a 10-fold increase from baseline (p<0.05).
FIG. 15 is a graph illustrating dopamine uptake. Cellular uptake of 3H-DA in blank wells, NT2 conventional cells, and NT2 11 day spheres replated 14 days on PLL was analyzed using liquid scintillation spectrometry and is reported as percentage of blank control. Blank wells (n=3) had a mean radioactivity level of 103.2 count per million (CPM). NT2 conventional cells did not take up significantly more 3H-DA than blank wells (n=8, M=120.1 CPM, p>0.05). NT2N neurons in replated NT2 spheres had a mean radioactivity level of 276.09 CPM, a significant increase from blank wells and NT2 conventional cells (p<0.05).
FIG. 16 is a graph illustrating glutamate release. CZE-LIF analysis of glutamate concentrations in media collected from NT2 11 day spheres replated 14 days on PLL reported as percentage of baseline control. Baseline, unstimulated cell media (n=8) and media collected from replated spheres allowed to rest for 3 hours after KCl stimulation (n=8) had mean concentrations of 0.10222 mM and 0.15 mM, respectively. Media collected from replated NT2 spheres stimulated with KCl for 20 minutes (n=8) had a mean glutamate concentration of 1.71444 mM, a 17-fold increase from baseline (p<0.05).
FIG. 17 is a photomicrograph showing formation of NT2 spheres in 3-dimensional suspension culture. (A) NT2 cells forms spheres after 4 days in suspension culture (DISC). (B) NT2 spheres after 11 DISC. (C) 11 DISC NT2 spheres were re-plated for an additional 11 days as a monolayer. (D) Undifferentiated NT2 cells were expanded as a monolayer for 1 week. Scale bar 50 μm.
FIG. 18 is a fluorescent photomicrograph of neuronal markers expression by NT2 spheres after re-plate for an additional 11 days as a monolayer. (A) 11 DISC NT2 spheres expressed mature neuronal marker MAP-2 (red), (B) DAPI nuclear stain (blue), (C) double-labeling of MAP-2 and DAPI. (D) Undifferentiated NT2 cells in monolayer did not express MAP-2, (E) DAPI nuclear stain (blue), (F) double-labeling of MAP-2 and DAPI. (G) 11 DISC NT2 sphere expressed TH (red). TH+ cells showed long, extended neurites. (H) DAPI nuclear stain (blue), (I) double-labeling of TH and DAPI. (K) Undifferentiated NT2 cells in monolayer did not show any TH+ cell, (L) DAPI nuclear stain (blue), (M) double-labeling of TH and DAPI. Scale bar 50 μm.
FIG. 19 is a graph illustrating TH expressions in 11 DISC NT2 spheres and 11 DISC re-plate together with undifferentiated NT2 cells in monolayer by western blot analysis. There was no TH expression in the undifferentiated NT2 cells in monolayer. There was 1.2 fold increase in TH expression in 11 DISC NT2 spheres. However, 11 DISC NT2 spheres re-plate showed 6.5 fold increase in the levels of TH expression. Actin was used as a loading control.
FIG. 20 is fluorescent photomicrograph of NT2 spheres. (A) 11 DISC NT2 sphere after re-plate for an additional 11 days show TH+ cells (red), (B) Neurite outgrowth show immunoreactivity to synaptophysin (green). (C) Double label of TH+ cells showing long, extend synaptophysin+ neurite outgrowth. Scale bar 50 μm.
FIG. 21 is a graph illustrating β-catenin/GSK-3β expression in 11 DISC NT2 spheres and 11 DISC re-plate together with undifferentiated NT2 cells in monolayer by western blot analysis. There was 1.2 fold decrease in the cytoplasmic β-catenin in both 11 DISC NT2 spheres and 11 DISC NT2 re-plate compared to undifferentiated NT2 monolayer. Nuclear β-catenin showed 1.2 fold decrease in the 11 DISC NT2 spheres; however in the 11 DISC NT2 re-plate there was 1.3 fold increase in the nuclear β-catenin. There was almost no change in the inactive phosphorylated GSK-3β in 11 DISC NT2 re-plate while NT2 11 DISC spheres had a 1.6 fold decrease in the phospho-GSK-3β. Actin was used as a loading control.
FIG. 22 shows RT-PCR analysis of dopaminergic transcription factors in NT2 cells in monolayer, 11 DISC NT2 spheres and 11 DISC NT2 re-plated spheres. Data in FIG. 22 B are presented as a ratio of transcription factors in 11 DISC spheres and 11 DISC NT2 re-plated spheres compared to levels present in NT2 monolayers. There was a moderate increase in Lmx1b (black bar) in both 11 DISC spheres and re-plates as compared to NT2 monolayers. EN-1 (grey bar) did not change significantly in 11DISC spheres or 11 DISC re-plates. Ptx-3 (right diagonal), which was not present in NT2 monolayers increased 5 fold in NT2 spheres and 16 fold in NT211 DISC re-plate. Nurr1 (cross-hatch) moderately increased in 11 DISC spheres and 11 DISC NT2 re-plated spheres, as compared to NT2 monolayers. Interestingly, TH mRNA (left diagonal) in 11 DISC re-plated spheres increased six fold, as compared to NT2 monolayers, but was moderately increased in 11 DISC spheres. GAPDH was used as a loading control.
FIG. 23 is a graph illustrating Ki-67 expression in undifferentiated NT2 monolayer, 11 DISC NT2 spheres an 11 DISC NT2 re-plate. There was 1.6 fold decrease in Ki-67 expression in the NT2 11 DISC spheres, while in NT2 11 DISC re-plate there was 5 fold decrease in Ki-67 expression. Actin was used as a loading control.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A method of differentiating adult stem cells, such as the teratocarcinoma cell line Ntera2/D1 clone (NT2) available from ATCC, has been developed. The method differentiates the NT2 cells to neurons with a stable neurotransmitter phenotype without the use of growth factors or retinoic acid. The growth factors and/or retinoic acid can be difficult to completely remove during commercial production, highlighting the importance of developing methods not requiring their use. Specific neurotransmitters were identified in these differentiated NT2-derived neurons (NT2-N) after 30 days in culture or 30 days survival in vivo.
The effect of 3-dimensional cell aggregation suspension culture on neuronal differentiation of the embryonal teratocarcinoma cell line NT2 cells without RA treatment is a fundamental aspect of the present invention. The first description of NT2 cell aggregation [Cheung W M, WY Fu, W S Hui and NY Ip. (1999)] showed that the aggregation technique shortened NT2 differentiation time from 5 to 3 weeks of RA treatment. More recent studies documented that the aggregation techniques allowed for decreased RA treatment, usually deemed essential for neuronal differentiation of NT2 cells. Megiorni and colleagues reported the presence of mRNA and protein of multiple neuronal markers during RA differentiation of NT2 floating aggregates [Megiorni F, B Mora, P Indovina and M C Mazzilli. (2005)]. Another study by Paquet-Durand and colleagues led those to posit that both RA and cell aggregation have a synergistic role in NT2 cell differentiation [Paquet-Durand F, S Tan and G Bicker. (2003)]. However, those authors did not conclude that cell aggregation alone is not sufficient to induce neuronal differentiation.
In the present study we show, for the first time, that teratocacinoma derived NT2 cells can differentiate to a dopaminergic phenotype by aggregation in a 3-dimensional suspension culture and re-plate without RA treatment. As described by Cheung, NT2 cell aggregation without RA was sufficient to induce low levels of phosphorylated neurofilament protein [Cheung W M, W Y Fu, W S Hui and NY Ip. (1999)]. Cell aggregation for at least 12 days with exposure to 0.1 μm RA for a brief period, followed by re-plating, was essential to induce differentiation of these cells to an observable neuronal phenotype. In our culture conditions, prolonged re-plating period of the NT2 spheres up to 11 days appears to be one factor contributing to the neuronal characteristics of the re-plated NT2 spheres that we observe. The advantage of the dopaminergic phenotype acquired by NT2N through aggregation in a 3-dimensional suspension culture alone over that induced by RA, which results in the loss of the dopminergic phenotype of NT2N within one week [Saporta S, C V Borlongan and P R Sanberg. (1999); Willing A E, T Zigova, M Milliken, S Poulos, S Saporta, M McGrogan, G Snable and P R Sanberg. (2002); Baker K A and I Mendez. (2005)], is that aggregation leads to a stable dopaminergic phenotype for at least 14 days in vitro.
In addition, we also show that the non-RA differentiated NT2N in the re-plated NT2 spheres express neuronal markers such as MAP-2 and synaptophysin. These data indicate that NT2N differentiated by aggregation and then re-plated show characteristics of mature neurons. The presence of synaptophysin, a protein present in pre-synaptic terminals, also suggests that aggregation/re-plate differentiated NT2N have functional synapses [Wiedenmann B and W W Franke. (1985)]. A previous study demonstrated that NT2N neurons form functional excitatory glutamatergic and inhibitory GABAergic synapse when co-cultured with primary astrocytes [Hartley R S, M Margulis, P S Fishman, V M Lee and C M Tang. (1999)]. Our finding also supports a recent study that showed significant transcriptional up-regulation of synapsin I, II and III in RA differentiated NT2 re-plated spheres [Leypoldt F, M Flajolet and A Methner. (2002)].
Signaling Pathway (s) Involved in NT2 Sphere Differentiation:
Differentiation of neuronal precursors has been widely sought, and RA participates in the normal differentiation of neurons during development [Bibel M, J Richter, K Schrenk, K L Tucker, V Staiger, M Korte, M Goetz and Y A Barde. (2004)]. However, a three dimensional environment also stimulates differentiation in vivo [Layer PG, A Robitzki, A Rothermel and E Willbold. (2002)] and cell fate specification [Hamazaki T, M Oka, S Yamanaka and N Terada. (2004)], as it allows tissue-like cell arrangements and cell-to-cell contact. Cellular interaction among adjacent cells is considered a key factor in initiation of signal transduction that guides differentiation. For example, it was shown that oligodendrocyte-neuronal contact activates the PKC pathway, which is involved in cell proliferation, differentiation, and apoptosis in oligodendrocytes [He M, D G Howe and K D McCarthy. (1996)]. Furthermore, transfection of embryonic carcinoma P19 cells with Sox 6 led to enhanced neuronal differentiation through activation of Wnt-1, Mash-1, N-cadherin, E-cadherin and Map-2 genes expression [Hamada-Kanazawa M, K Ishikawa, K Nomoto, T Uozumi, Y Kawai, M Narahara and M Miyake. (2004)]: up-regulated Wnt-1 and Mash-1 resulted in neurogenesis, while aggregation and cell-to-cell interaction induced E-cadherin and N-cadherin, enhancing neuronal differentiation.
The present methodology shows that aggregation plays a pivotal role in differentiation of NT2 cells. In the NT2 sphere model, there was down-regulation of unphosphorylated cytoplasmic β-catenin in both NT2 11 DISC spheres and the re-plated NT2 11 DISC spheres ( FIG. 21 ). However, nuclear β-catenin was markedly up-regulated in the re-plated NT2 11 DISC spheres indicating nuclear translocation of β-catenin where it may activate β-catenin induced transcription. Additionally, phosphorylated cytoplasmic GSK-3β, which is responsible for phosphorylation and degradation of β-catenin, was down-regulated in the NT2 11 DISC spheres, while it is found in near-normal levels in the re-plated NT2 11 DISC spheres. This finding is consistent with the subsequent increase in nuclear β-catenin seen in re-plated NT2 11 DISC spheres. Additionally, β-catenin is one of the cytoplasmic components of the Wnt pathway, which also has been shown to play a role in neuronal differentiation of embryonic stem cells and DA precursors [Otero J J, W Fu, L Kan, A E Cuadra and J A Kessler. (2004); Castelo-Branco G, N Rawal and E Arenas. (2004)]. In this NT2 re-plated sphere model the stabilization and translocation of β-catenin to the nucleus, likely leads to TCF/LEF transcription activity [Castelo-Branco G, N Rawal and E Arenas. (2004); Kikuchi A. (2000); Grimes C A and R S Jope. (2001); Katoh M. (2002); Jope R S and G V Johnson. (2004)]. Activation and stabilization of β-catenin may be occurring through participation of the Wnt differentiation pathway resulting in down-regulated GSK-3β, and stabilization and translocation of β-catenin to the nucleus, where it targets TCF/LEF transcription [Otero J J, W Fu, L Kan, A E Cuadra and J A Kessler. (2004); Willert J, M Epping, JR Pollack, P O Brown and R Nusse. (2002)]. However, other pathways may be involved, as well, such as the phosphoinositol 3-kinase protein kinase B (PI3K/Akt), protein kinase A (PKA), or protein kinase C (PKC) cell signaling pathways acting through regulation of GSK-3 [Jope R S and G V Johnson. (2004)].
Transcription Activation in the NT2 Spheres:
Induction of dopamine neurons in the midbrain is determined by a combination of many factors during development. The first up-regulated genes in the mesencephalon include Engrailed ½ (En½), Pax⅖, Wnt1 and Lmx1b in a closely regulated sequence [Smidt M P, S M Smits and J P Burbach. (2003)]. Nurr1 transcription factor is expressed just prior to TH expression, which also requires co-expression of Pitx3 [Smidt M P, S M Smits and JP Burbach. (2003); Riddle R and JD Pollock. (2003)]. Lmx1b is expressed in early development of mesencephalic dopamine neurons, promoting their proliferation and survival. Lmx1b is expressed in all mesencephalic dopamine neurons prior to Nurr1 expression [Riddle R and JD Pollock. (2003)]. Smidt and colleagues proposed that transcription activity in mesencephalic dopamine neurons can be summarized in 3 gene pathways: the dopamine synthesis pathway that requires Nurr1 expression, the Lmx1b and Pitx3 pathways that maintain the dopaminergic phenotype over time, and the En½ survival pathway [Smidt M P, S M Smits and J P Burbach. (2003); Simon H H, L Bhatt, D Gherbassi, P Sgado and L Alberi. (2003)] that is essential for the survival of dopaminergic neurons. In this study we have shown that Lmx1b, a factor that is expressed in mesencephalic dopamine neurons, is up-regulated in 11 DISC spheres and 11 DISC re-plated spheres, as is Pitx3 and TH. Importantly, Nurr1 is also up-regulated in both differentiated 11 DISC spheres and re-plated spheres, consistent with their differentiating to a dopaminergic neural phenotype. However, undifferentiated NT2 cells also express Nurr1 [Misiuta I E, L Anderson, M P McGrogan, P R Sanberg, A E Willing and T Zigova (2003)]. This suggests that undifferentiated NT2 cells are similar to dopaminergic precursors capable, under the proper circumstances, to become a dopamine-like neuron. Aggregation of these cells to form spheres, and re-plating the spheres allowing cells to re-adhere to a substrate, enhances their dopaminergic differentiation. Re-adhered cells from NT2 spheres express all essential mesencephalic dopaminergic transcription factors.
Previous work has shown that Wnt 1 and Wnt 5a increase the number of dopaminergic neurons in Nurr1+ precursors [Castelo-Branco G, J Wagner, F J Rodriguez, J Kele, K Sousa, N Rawal, H A Pasolli, E Fuchs, J Kitajewski and E Arenas. (2003)], which may lead to activation of the Wnt/β-catenin pathway. However, another study suggested that up regulated Nurr1 expression is a consequence of activation of the PKA and/or PKC pathway [Satoh J and Y Kuroda. (2002)].
Tumor Formation and NT2 Spheres:
One impetus of the present invention was the development an improved cell source for transplantation in Parkinson's disease. Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of the dopaminergic neurons in the substantia nigra pars compacta. Patients with PD present with tremor, bradykinesia, and rigidity, as well as cognitive disorders. Treatment with L-dopa to restore dopamine in the striatum is the primary pharmacological treatment, and is initially effective, though patients usually develop tolerance after long-term treatment. Therefore, the use of cell replacement therapy for PD has been considered a hopeful long-term treatment goal. Cell transplantation therapy using fetal dopaminergic neurons into the striatum ameliorates behavioral deficits in animal models of PD [Bjorklund A and O Lindvall. (2000)]. However, ethical concerns limit the use of human embryonic stem cells and fetal neural cells for transplantation. Human, double blind, placebo controlled, clinical trials that transplanted fetal dopaminergic neurons in PD patients reported controversial results. A trial to compare transplantation efficacy in younger and older patients showed that patients' pre-operative response to L-dopa, not the patients' age, predicted improvement of UPDRS motor “off” scores [Freed C R, M A Leehey, M Zawada, K Bjugstad, L Thompson and RE Breeze (2003)]. Additionally, some patients developed dyskinesia after one or two years of clinical improvement. Another clinical trial also reported mixed results with no overall clinical improvements, as more than 50% of patients develop off medication biphasic dyskinesia [Olanow C W, C G Goetz, J H Kordower, A J Stoessl, V Sossi, M F Brin, K M Shannon, G M Nauert, D P Perl, J Godbold and T B Freeman. (2003)]. However, these authors conclude that their patients' dyskinesia was likely the result of patchy release of dopamine provided by the transplant. Thus, the outcome from such clinical trials is not yet optimal due to technical issues concerning the transplantation procedure and tissue preparation. In order for a successful cell therapy procedure to be established, dopaminergic neurons of uniform quality that can be obtained in large numbers and that are free of biohazards must be used to achieve consistent results [Redmond D E, Jr. (2002)].
In view of the fact that NT2 spheres are derived from an embryonal teratocarcinoma, there is a possibility of tumor formation post-transplantation. Nevertheless, the possibility of tumor formation by transplanted undifferentiated NT2 cells that are still dividing must be ruled out. The nuclear protein Ki-67 is expressed in all proliferating cells [Gerdes J, H Lemke, H Baisch, H H Wacker, U Schwab and H Stein. (1984)]. Those cells that do not express K167 are in Go and have exited the cell cycle. Our results show that Ki-67 is markedly down-regulated in the re-plated NT2 11 DISC spheres compared to NT2 monolayer. Withdrawal from the cell cycle is necessary for terminal differentiation, and we suggest that growth arrest of the re-plated NT2 spheres may be a consequence of NT2N neuron differentiation within the NT2 spheres compared to the undifferentiated NT2 monolayer. A previous in vivo study discussed this issue, stating that NT2 cells form lethal tumors when transplanted in peripheral organs or most parts of the central nervous system. However, when transplanted in the caudate-putamen complex of nude mice, NT2 cells showed engraftment for 33 weeks post-transplantation with no tendency to form tumors [Miyazono M, P C Nowell, J L Finan, V M Lee and J Q Trojanowski. (1996)]. A more recent study by Ferrari and colleagues contradict the former study. They showed that intracortical transplantation of undifferentiated NT2 cells survive, migrate and differentiate into neuron and glia like cells in P0 normal mice with no tendency of tumor formation after 3 weeks post transplant [Ferrari A, E Ehler, R M Nitsch and J. Gotz. (2000)]. We propose that aggregation of NT2 cells in 3-dimensional suspension culture is sufficient to induce neuronal differentiation. Additionally, aggregation is able to generate a more stable dopaminergic phenotype than differentiation of NT2 with RA.
The invention is described below in examples which are intended to further describe the invention without limitation to its scope.
Example 1
Differentiated NT2N Neurons Derived from Aggregated NT2 Cells not Exposed to Retinoic Acid Survive and Engraft in the Rat Striatum
Results
FIGS. 1 through 4 show that NT2 spheres differentiate to dopaminergic neurons without retinoic acid. FIGS. 5 and 6 show that NT2 spheres survive in the host striatum and retain their dopaminergic phenotype. FIGS. 7 through 11 show possible signaling pathways for NT2 differentiation. The results demonstrate that there is an increase in the expression of TH in NT2N neurons within NT2 spheres grown in 3-dimensional suspension culture after 4 DISC without retinoic acid treatment, compared to NT2 cells grown in monolayer conventional culture. TH expression is markedly increased in re-plated 11 DISC NT2 spheres together with expression of multiple neuronal markers such as MAP-2 and synaptophysin. There is also increased unphosphorylated β-catenin in NT2 spheres, with almost no change in GSK-3β, and a marked decrease in N-cadherin, compared to NT2 cells grown in conventional culture. These findings implicate the involvement of the Wnt signaling pathway in neuronal differentiation of cells in NT2 spheres.
Additionally, the non-steroidal anti-inflammatory sulinac sulfide, a β-catenin inhibitor, decreased TH expression, further suggests the involvement of the Wnt signaling pathway. Therefore, differentiation of NT2 cells within NT2 spheres to dopaminergic NT2N neurons is dependent, at least in part, on the Wnt signaling pathway.
Transcription analysis using RT-PCR showed up-regulation of LEF-1 overtime, which coincides with up-regulated TH transcription, further implicates activation of the Wnt pathway.
Nurr-1 transcription is present in both NT2 cells and in NT2 spheres. NT2 spheres survive in the host striatum, and retain their dopaminergic phenotype, as they continue to express TH and other neuronal markers in vivo for one month post-transplant.
Materials And Methods
NTera2/D1 cells:
The NTera2/D1 (NT2; ATCC) were thawed quickly at 37° C. until just before the last ice crystals were gone. The cells were gently transferred to a 15 cc centrifuge tube filled with 10 ml of DMEM:F12 and 10% fetal bovine serum (FBS) and 0.1% gentamicin (maintenance medium). The cells were centrifuged at 700 rpm for 7 min, the supernatant discarded, and the cells resuspended in 1 ml of the DMEM:F12/FBS media. Viability and cell number were assessed using the trypan blue dye exclusion method.
Differentiation Protocol (Formation of NT2 Spheres):
The NT2 precursors were thawed at 37° C. (as described above). The cells were gently transferred to a 15 ml centrifuge tube containing 10 ml of Dulbecco's Modified Eagle's Medium (DMEM), 10% fetal bovine serum (FBS), and 0.1% gentamicin (Sigma), centrifuged resuspended in 1 ml of the DMEM/FBS media. NT2 precursors were seeded at 1×10 7 cells/50 ml in 150 mm plates in the same medium as described and sub cultured when they achieved 70-80% confluency. NT2 cells were seeded at a density of 2×10 6 cells/ml in ultra low attachment polystyrene 6 well plates (Costar) in DMEM, 10% FBS, 0.1% gentamicin. Media were supplemented daily for the duration of the experiment.
Inhibitors were used through out the experiment. The final concentration was 1 μm for AKT inhibitor (wortmannin, cell signalling) and 100 μm for β-catenin inhibitor (sulindac sulphide, sigma).
Western Blot:
Conventional cultures of NT2 cells and NT2 spheres were prepared by washing them in phosphate buffered saline (PBS), scraping the NT2 cells from the culture dish and placing the harvested cells into cold PBS and stored at −80° C. until they were analyzed. Frozen samples were thawed quickly in lysis buffer and 1 μM dithiothreitol, and sonicated. Protein samples and molecular weight markers (Amersham Bioscience) were resolved on 10% SDS-PAGE gel, and transferred to Invitrolon PVDF membranes (Invitrogen). The membranes were incubated in TBS containing 5% non-fat milk and 0.1% Tween-20 for 1 hour at room temperature to block non-specific binding, and then incubated overnight in appropriate antibody at 4° C. The membranes were washed, in TBS with 0.1% Tween-20, and incubated in peroxidase-conjugated anti-rabbit IgG (1:20,000; Jackson ImmunoResearch) for 1 hour at room temperature. Primary and secondary antibodies were diluted in TBS, 5% non-fat milk and 0.1% Tween-20. Immunoreactivity was visualized using a West Pico Chemiluminescent Kit (Pierce Biotechnology). Digitized images of the films will be analyzed using Image Pro-Plus (Media Cybernetics, Silver Springs, Md.) software.
Antibodies for Western Blot:
Tyrosine hydoroxylase (TH) 1:500, (Pelfreeze), β-actin 1:10000, (Sigma), phosphorylated AKT 1:500, (Cell Signaling Technology), N-cadherin 1:1000 (Zymed Laboratories), Cx43 1:1000, (Zymed Laboratories), β-catenin 1:5000, (BD Biosciences), Glycogen synthase kinase 3β (GSK-3β) 1:1000, (Calbiochem), TAU1:1000 (Sigma), P27 1:500 (Calbiochem), Neuro D11:1000 (Chemicon).
Immunohistochemistry:
NT2 cells and NT2 spheres were removed with their culture medium from plates and centrifuged for 5 min at 700 rpm. The pellet were briefly rinsed in cold PBS, recentrifuged and immersed fixed for 1 hr in 4% paraformaldehyde prepared in PBS. The NT2 cells and NT2 spheres were washed in PBS, embedded in HistoGel (Richard-Allen Scientific), dehydrated through an ascending ethanol series, cleared in xylene and embedded in paraffin blocks. Sections were incubated overnight at 4° C. in the appropriate antibody. The following day, sections were washed 3 times and incubated with goat anti-mouse Alexa 488 (Molecular probes) 1:200 for 1 hr at room temperature, or goat anti-rabbit conjugated to Alexa 594 dye. Slides were washed 3 times, coverslipped with Vectashield with DAPI (Vector Laboratories Inc.)
Antibodies for Immunohistochemistry:
Tyrosine hydroxylase (TH) 1:400, (Pel Freeze), Nestin 1:500, (Chemicon), Neuofilament 1:200 (Zymed), Human mitochondria 1:20 (Chemicon), Human nuclei 1:20 (Chemicon), Map-2 1:500 (Chemicon), synaptophysin 1:1500 (Chemicon).
RT-PCR:
Total RNA was isolated from NT2 cells grown in conventional culture and 4, 11, and 14 DISC NT2 spheres using TRI Reagent (Sigma) followed by cDNA synthesis from 5 μg of total RNA using SuperScript First strand synthesis (Invitrogen). The following PCR conditions were optimized as shown: GAPDH (5′ accacagtccatgccatcac 3′, 5′ tccaccaccctgttgctgta 3′, 30 cycles, 60° C.), TH (5′ tgtcagagctggacaagtgt 3′, 5′ gatattgtcttcccggtagc 3′, 33 cycles, 58° C.), LEF-1 (5′ ctaccacgacaaggccagag 3′, 5′ cagtgaggatgggtagggttg 3′, 30 cycles, 62° C.) and Nurr 1 (5′ ttctcctttaagcaatcgccc 3′, 5′ aagcctttgcagccctcacag 3′, 35 cycles, 60° C.). Digitized images of the films were analyzed using Image Pro-Plus (Media Cybernetics, Silver Springs, Md.) software. The level of mRNA was estimated by measuring the optical density of mRNA bands using Image Pro-Plus (Media Cybernetics) as mentioned above.
Transplantation:
Rats were anesthetized with Ketamine (0.35 ml/KG) and maintained with Flurothane gaseous anesthesia. Animals were placed in a stereotaxic frame, and bregma located through an incision at the vertex of the head. NT2 spheres were withdrawn up in a 10 μl microsyringe fitted with a 26 g thin-wall needle (200 μm internal diameter) and approximately 200,000 cells were deposited in the striatum. NT2 spheres were collected as described for western blot analysis, but washed in Hanks' balanced salt solution. Medium injection consisted of 2 μl of Hanks' balanced salt solution. The coordinates for the injections were 1.2 mm anterior to bregma, 2.7 mm laterally and 5 mm ventral to dura, with the toothbar set at zero. Each injection were delivered at a rate of 1 μl/min. The needle was held in place for an additional 5 minutes after the completion of the injection before being slowly withdrawn. The incision was sutured with wound clips.
Preparation of Brain Containing Transplanted SC-NT2 Tissue Constructs and NT2 Spheres:
Rats, deeply anesthetized with sodium pentobarbital (60 mg/Kg), were transcardially perfused with normal saline followed by 4% paraformaldehyde in 0.1 M phosphate buffer and the brain removed. Brains were post-fixed for 12 hours in 4% paraformaldehyde, dehydrated through an ascending series of alcohols, cleared in xylene and embedded in paraffin. Sections were cut at 5-7 μm. Every 20th section through the area of the transplant will be stained with cresyl violet to identify the location of the graft.
Example 2
Human NT2-N Neurons Differentiated by the Cell Aggregation Method have Functional Neurotransmitter Systems In Vitro
The NTera2/cloneD1 (NT2) human teratocarcinoma cell line is capable of terminal differentiation into postmitotic neurons (NT2N) upon exposure to retinoic acid (RA). These NT2N differentiated with RA (hNT) are a heterogeneous population of neurons expressing multiple neurotransmitter enzymes. hNT neurons harvested and analyzed with High Performance Liquid Chromatography (HPLC) have low but detectable levels of dopamine (DA) present, while NT2 cells do not. Further supporting the in vitro functionality of these neurons, excitatory glutamatergic and inhibitory gamma-aminobutyric acidergic (GABAergic) are formed when hNT neurons are plated on primary astrocytes. However, hNT neurons lose expression of neurotransmitter enzymes after 30 days in vitro and in vivo, indicating loss of phenotype and a probable loss of functionality.
We have developed an alternate method of differentiation using cell aggregation and subsequent substrate contact without the use of RA or exogenous growth factors. NT2 spheres contain immature neurons (NT2-N) after 4 days in suspension culture, and rapidly mature with substrate contact. These NT2-N neurons display stable neuronal phenotypes after 30 days in vitro and in vivo, unlike NT2N (hNT) differentiated using RA. Neurons expressing stable phenotypes may be considered differentiated, though not necessarily fully functional. Mature neurons in vivo are able to both release and take up neurotransmitter. The functional maturity of these neurons in vitro is assessed by examining neurotransmitter release and uptake.
Cultures were stimulated with potassium chloride and analyzed using HPLC with electrochemical detection and Capillary Zone Electrophoresis with Laser Induced Fluorescence (CZE-LIF). Levels of DA, GABA, and glutamate release were examined in NT2-N from replated NT2 spheres. Cellular uptake of 3H-DA was also examined in these cultures. Levels of 3H-DA uptake were measured by liquid scintillation spectrometry in NT2-N from replated NT2 spheres and NT2 cells grown in conventional culture.
Significantly higher levels of DA, GABA, and glutamate were found in medium collected from potassium stimulated NT2-N than unstimulated cells or cells allowed to rest for 3 hours after stimulation. In addition, significantly more radioactive DA was taken into NT2-N than NT2 conventional cultures or blank wells. NT2-N induced by cell aggregation and matured with substrate contact are able to both release and take up neurotransmitters, suggesting that these NT2-N are terminally differentiated, functional neurons after one month in vitro.
FIGS. 1-4 illustrate the results of the experiments. There was shown to be significant increases in media DA, GABA, and glutamate concentrations after KCl stimulation, which indicates that NT2-N neurons found in replated NT2 spheres synthesize and release neurotransmitter after one month in vitro. A high concentration of extracellular potassium causes NT2-N neurons in replated NT2 spheres to release neurotransmitters, which suggests that the membranes of these neurons are polarized and are able to be depolarized after one month in vitro. Since significantly more 3H-DA was found in lysed cells from replated NT2 spheres than NT2 conventional cells, this indicates NT2-N neurons in replated NT2 spheres have functional neurotransmitter uptake systems while NT2 conventional cells do not. NT2-N neurons induced by cell aggregation and matured with substrate contact are able to both release and take up neurotransmitters, which suggests they are functional neurons after one month in vitro.
Materials and Methods
Cell Culture:
The NTera2/D1 cells (NT2; ATCC) were thawed quickly at 37° C. until just before the last ice crystals were gone. The cells were gently transferred to a 15 mL centrifuge tube filled with 10 mL of DMEM with 1% antibiotic/antimycotic (Invitrogen) and 0.1% gentamicin (Sigma) (wash medium). The cells were centrifuged at 800 rpm for 3 min, the supernatant discarded, and the cells resuspended in 1 mL of DMEM:F12 media containing 10% fetal bovine serum (FBS), 1% antibiotic/antimycotic (Invitrogen) and 0.1% gentamicin (Sigma) (maintenance medium). Viability and cell number were assessed using the trypan blue dye exclusion method. NT2 precursors were seeded at 4×106 cells/50 mL in 150 mm plates in the maintenance medium described and sub cultured when they achieved 70-80% confluence. For differentiation, NT2 cells were seeded at a density of 2×106 cells/mL in ultra low attachment polystyrene 6 well plates (Costar) in DMEM:F12 maintenance medium. Media was supplemented daily for the duration of the experiment. After 11 days in suspension culture (DISC), NT2 spheres were collected and replated on 0.01% Poly-L-Lysine (PLL) coated plates. Spheres were split 1:8 onto 24 well plates for cellular uptake studies and 1:16 onto 96 well plates (Nalge Nunc) for HPLC and CZE-LIF studies and grown for 14 days.
High Performance Liquid Chromatography:
50 μl of pre-stimulation media was collected for each sample, then 30 mM KCl was applied for 20 minutes and stimulated cell media was also collected. 5 μl of 0.1M HCl per 50 μl sample was added to avoid further oxidation. Media samples were stored at −80° C. until they were analyzed. A standard curve was generated by adding known quantities of neurotransmitter. Cell culture media without cells was treated in the same manner as sample media. Samples were analyzed using a reverse phase HPLC system (PerkinElmer series 200) coupled to a dual-channel electrochemical detector (model 5100A, ESA, Inc). Detection was performed using a C18 column (4.6 mm×100 mm, 3 μm particles, ODS), and a Chrome Guard pre-column (Varian). The mobile phase was citrate-acetate containing 6.0% methanol and 0.35 mM 1-octane-sulfonic acid, pH 4.0, at a flow rate of 1 mL/minute. Detected peaks were quantified using Total Chrom Workstation software (PerkinElmer) using the standard curve for the neurotransmitter. All results are expressed as mean + or − SEM. Experiments were analyzed using repeated measures analysis of variance and post-hoc analyses were done using a Scheffe post-hoc test.
Capillary Zone Electrophoresis with Laser-Induced Fluorescence:
A capillary electrophoresis system equipped with an argon laser tuned to 488 nm was used (Model R2D2, Meridialysis Co., Merida, Venezuela). A carbonate buffer (20 mM carbonate/bicarbonate) was the running buffer to transport the sample through the capillary when detecting glutamate. Detection of GABA from the samples required a different running buffer consisting of 23 mM borate with 120 mM sodium dodecyl sulfate (SDS) and 1% methanol. The samples or standards were sucked into the anodic end by applying a negative pressure (19 psi or 1.34 kg/cm for 1 s) at the cathodic end of the capillary. Electrophoretic separation was achieved by applying a high voltage between the anode and the cathode for 12 min, 22 kV for glutamate and 26 kV for GABA. Fluorescein isothiocyanate (FITC) was conjugated with glutamate and GABA as the fluorescent chromophore. Optimal concentrations of FITC and the calibration curves for both amino acids have been reported previously. Samples and standards were derivatized with 5 μl of FITC (1 mM) and carbonate buffer (20 mM) mixture. A syringe loaded with FITC-carbonate mixture was placed in a precision pump, and 2 μl of the mixture was delivered into a tube containing sample. The samples reacted overnight (14 hr) at room temperature in a water-saturated chamber that minimizes evaporation. Homoglutamine (10-5 M) was used as an internal standard and was mixed in the carbonate buffer used to derivatize samples and standards. This amino acid was chosen because it is not produced in the mammalian brain. All results are expressed as mean + or − SEM. Experiments were analyzed using repeated measures analysis of variance and post-hoc analyses were done using a Scheffe post-hoc test.
Cellular Uptake of 3H-DA:
Media was removed and the cultures were washed three times with incubation solution (5 mM glucose, 1 mM ascorbic acid in PBS, pH 7.4). Cultures were then preincubated for 5 minutes at 37° C. with 1 mM of incubation solution containing 0.1 mM pargyline (MAO inhibitor). Cells were incubated with 100 nM 3H-Da (37 Ci/mmol) for 15 minutes at 37° C. Blanks were obtained by incubating the cells at 0° C. The uptake was stopped by removing the incubation mixture followed by three rapid washes with PBS. Cells were scraped twice with 1 mL PBS containing 1% triton X-100 and 6% perchloric acid. Radioactivity was measured by liquid scintillation spectrometry after addition of 10 mL of Quantafluor to each vial.
All results are expressed as mean + or − SEM. Experiments were analyzed using one way analysis of variance and post-hoc analyses were done using a Scheffe post-hoc test.
Example 3
Material and Methods for the Examples 4-7
NTera2/D1 cells:
The NTera2/D1 (NT2; ATCC) were thawed quickly at 37° C. until just before the last ice crystals were gone. The cells were gently transferred to a 15 cc centrifuge tube filled with 10 ml of Dulbecco's Modified Eagle's Medium (DMEM:F12), 10% fetal bovine serum (FBS) and 0.1% gentamycin (Sigma). The cells were centrifuged at 700 rpm for 7 min, the supernatant discarded, and the cells re-suspended in 1 ml of the DMEM: F12/FBS media. Viability and cell number were assessed using the trypan blue dye exclusion method.
Formation of NT2 Spheres:
The NT2 cells were gently transferred to a 15 ml centrifuge tube containing 10 ml of DMEM, 10% FBS and 0.1% gentamycin, centrifuged at 700 rpm for 7 min and re-suspended in 1 ml of the DMEM/FBS media. NT2 precursors were seeded at 1×10 7 cells/50 ml in 150 mm plates in the same medium as described and subcultured when they achieved 70-80% confluence. The cells were lifted using 0.25% trypsin, washed three times in DMEM/FBS and centrifuged at 800 rpm for 5 min. The number of NT2 was determined using a hemocytometer, and viability was assessed using trypan blue dye exclusion.
NT2 cells were seeded at a density of 2×10 6 cells/ml in ultra low attachment polystyrene 6 well plates (Costar) in DMEM, 10% FBS, and 0.1% gentamycin. Media were supplemented daily for the duration of the experiment. NT2 spheres were either collected at 11 days in suspension culture (11 DISC) or re-plated on poly-L-lysine coated plates for another 11 days (11 DISC re-plated).
Dopaminergic Differentiation of NT2 Cells:
TH is the rate limiting enzyme of dopamine synthesis. The level of TH expression in NT2 spheres and NT2 re-plated was assessed and compared to undifferentiated NT2 cells (NT2 monolayer) using western blot and immunohistochemistry (below). The level of TH mRNA transcription in NT2 spheres and NT2 re-plated was also estimated by RT-PCR and compared to the undifferentiated NT2 cells. Other transcription factors essential for dopaminergic differentiation such as Lmx1B, En-1, Ptx3 and Nurr-1 were also assessed.
β-catenin/GSK-3β Expression:
Activation of β-catenin, the cytoplasmic component of Wnt pathway, was assessed by western blot analysis in NT2 spheres after 11 DISC, NT2 11 DISC re-plated cells and undifferentiated NT2 monolayer. Similarly, levels of cadherin, glycogen synthase kinase 3β (GSK-3β), were determined using western blot analysis (below).
Proliferation of NT2 Cells:
Teratocarcinoma derived undifferentiated NT2 cells proliferate in conventional culture. In order to assess whether NT2 spheres contained proliferating NT2 cells, western blot analysis for the nuclear protein Ki-67, which is present in all cells that have not left the cell cycle [Gerdes J, H Lemke, H Baisch, H H Wacker, U Schwab and H Stein. (1984)], was used to compare continued cell division in undifferentiated NT2 cells with cells in differentiated NT2 spheres.
General Methods
Western Blot:
NT2 monolayer and NT2 11 DISC spheres and re-plated NT2 11 DISC spheres were washed once in phosphate buffered saline (PBS), the NT2 cells scraped from the culture dish and placed the harvested cells into cold PBS. Culture medium in wells containing NT2 spheres was aspirated from the culture wells and centrifuged for 5 min at 700 rpm. The supernatant was discarded and the pellet was re-suspended in cold PBS. All samples were washed once more in PBS and stored at −80° C. until they were analyzed. Frozen samples were thawed quickly in lysis buffer and 1 μM dithiothreitol, and sonicated. Cytoplasmic and nuclear protein fractions were extracted (Pierce Biotechnology). Protein samples (20 μg) and full range molecular weight markers (Amersham Bioscience) were resolved on 10% SDS-PAGE gel, and transferred to Invitrolon PVDF membranes (Invitrogen). The membranes were incubated in Tris-buffer saline (TBS) containing 5% non-fat milk and 0.1% Tween-20 for 1 hour at room temperature to block non-specific binding, and then incubated overnight in appropriate antibody at 4° C. The membranes were washed 3 times, 10 minutes each, in TBS with 0.1% Tween-20, and incubated in peroxidase-conjugated anti-rabbit IgG (1:20,000; Jackson ImmunoResearch) for 1 hour at room temperature. Primary and secondary antibodies were diluted in TBS, 5% non-fat milk and 0.1% Tween-20. Immunoreactivity was visualized using a West Pico Chemiluminescent Kit (Pierce Biotechnology). Digitized images of the films were analyzed using Image Pro-Plus (Media Cybernetics) software.
Antibodies for Western Blot:
Tyrosine hydoroxylase (TH) 1:500 (Pelfreeze), β-catenin 1:5000 (BD Biosciences), GSK-3β 1:1000 (Cell Signaling), Ki-67 1:1000 (DAKO). Protein levels were estimated by measuring the optical density of the protein bands using Image Pro-Plus (Media Cybernetics). Briefly, an area of interest (AOI) was sized to incorporate a visible band on the film and then tested against all other visible bands to ensure that each band would be incorporated by the AOI. The density of each band was determined by the Image Pro-Plus software, and a background reading taken using the same AOI. In cases where a band was not obviously visible, the probable location of the band was estimated from adjacent visible bands. Protein levels are reported as the ratio of target protein to actin protein.
Immunohistochemistry:
NT2 11 DISC re-plated spheres in 35 mm poly-1-lysine (sigma) coated plates in DMEM/F12, 10% FBS and 0.1% gentamycin, and then fixed in 4% paraformaldehyde. The re-plated NT2 11 DISC spheres and the undifferentiated NT2 cells were blocked in 10% goat serum for 1 hour at room temperature. Appropriate primary antibodies were incubated overnight at 4° C. The following day, cells were washed 3 times and incubated with goat anti-mouse Alexa 488 (Molecular probes) 1:200, or goat anti-rabbit conjugated to Alexa 594 (Molecular probes) 1:200 for 1 hr at room temperature. Cells were washed 3 times, coverslipped with Vectashield containing DAPI (Vector Laboratories Inc.) and examined under epifluorescence.
Antibodies for Immunohistochemistry:
Tyrosine hydroxylase (TH) 1:400 (Pel Freeze), MAP-2 1:500 (Chemicon), synaptophysin 1:1500 (Chemicon).
RT-PCR:
Total RNA was isolated from undifferentiated NT2 cells, NT2 spheres and re-plated NT2 using TRI Reagent (Sigma) followed by cDNA synthesis from 5 μg of total RNA using SuperScript First strand synthesis (Invitrogen). The following PCR conditions were optimized as shown: GAPDH (5′ accacagtccatgccatcac 3′,5′ tccaccaccctgttgctgta 3′; 30 cycles, 60° C.) [Megiorni F, B Mora, P Indovina and M C Mazzilli. (2005)], TH (5′ tgtcagagctggacaagtgt 3′, 5′ gatattgtcttcccggtagc 3′; 33 cycles, 58° C.) [Long X, M Olszewski, W Huang and M Kletzel. (2005)], Nurr1 (5′ ttctcctttaagcaatcgccc 3′, 5′ aagcctttgcagccctcacag 3′, 35 cycles, 60° C.), Engrailed-1 En-1 (5′gcaacccggctatcctacttatg 3′, 5′ atgtagcggtttgcctggaac 3′, 35 cycles, 60° C.), Lmx1b (5′ acgaggagtgtttgcagtgcg 3′, 5 ccctccttgagcacgaattcg 3′, 30 cycles, 60° C.) [Park C H, Y K Minn, J Y Lee, D H Choi, M Y Chang, J W Shim, J Y Ko, H C Koh, M J Kang, J S Kang, D J Rhie, YS Lee, H Son, S Y Moon, K S Kim and S H Lee. (2005)], Pitx3 (5′ actaggccctacacac 3′, 5 tttttttgacagtccgc 3′, 30 cycles, 55° C.) [Zeng X, J Cai, J Chen, Y Luo, Z B You, E Fotter, Y Wang, B Harvey, T Miura, C Backman, G J Chen, M S Rao and W J Freed. (2004)]. Digitized images of the films were analyzed using Image Pro-Plus (Media Cybernetics, Silver Springs, Md.) software. The level of mRNA was estimated by measuring the optical density of mRNA bands using Image Pro-Plus (Media Cybernetics) as mentioned above.
Methodology for Cell Production
1. Expanding the NT2 cells in conventional culture in DMEM F12 (which is used in all subsequent cultures, as well)
2. Lift and grow the NT2 cells in suspension culture for 11 days. The 3-dimensional adhesion of the cells seems to trigger the differentiation process. Previous reports have stated that the NT2 cells do not differentiate after 7 days in suspension culture. However we have noticed that, at the time periods we use, there is some differentiation.
3. Replate the cells on laminin (also works on PLL, although laminin is preferred) and grow for 14 days. This is the step where the differentiation is observed to proceed most dramatically. A 4-fold increase in dopaminergic neurons has been observed at this step, as compared to the 11 day spheres. Additionally, while there are NT2 cells that have not differentiated and are still dividing, within the replated cells, all the differentiated cells (dopaminergic, cholingergic, GABAergic and glutamatergic) are postmitotic. Sorting methods are being developed to sort the differentiated neurons from the NT2 cells that are still in the cell cycle.
The invention is based upon the unexpected observation that purported cancer stem cells within a cancer cell line would respond to this method of differentiation. This technique extends previous techniques used to differentiate neural stem cells to neurons. Some important differences include the time points and the medium used in the instant technique. The instant technique does not rely on neural basal medium. Additionally, the cells are cultured in suspension culture and the replate duration is longer than techniques used for differentiation of neural stem cells.
Example 4
Neuronal Markers Expression
Cultures of NT2 cells grown in suspension culture without RA remained in suspension with no tendency to form a monolayer ( FIG. 17D ). NT2 cells tended to adhere to each other, forming aggregates by 4 days ( FIG. 17A ) that grew larger over time ( FIG. 17B ). After 11 days in suspension culture, NT2 spheres were re-plated, and NT2N neurons migrated away from the sphere and grew as a monolayer for an additional 11 days ( FIG. 17C ).
Immunohistochemistry showed increased expression of the mature neuronal marker MAP-2 in re-plated 11 DISC NT2 spheres ( FIGS. 18A and 18C ), compared to undifferentiated NT2 monolayer ( FIGS. 18D and 18F ). Additionally, there was an increase in TH expression in 11 DISC NT2 spheres, compared to undifferentiated NT2 monolayer. When these 11 DISC NT2 spheres were re-plated as a monolayer for an additional 11 days, NT2N neurons showed extended neurites with moderate branching. Additionally, these NT2N neurons expressed TH+ immunoreactivity ( FIGS. 18G and 18I ) that was still present up to 2 weeks in vitro, unlike hNT cells that lose their TH phenotype within 1 week in vitro [Willing A E, T Zigova, M Milliken, S Poulos, S Saporta, M McGrogan, G Snable and P R Sanberg. (2002)]. Undifferentiated NT2 monolayers showed no TH expression ( FIGS. 18K and 18M ). Western blot analysis confirmed the increased TH expression in the re-plated NT2 spheres. In 11 DISC re-plated NT2 spheres ( FIG. 19 ) there was a 6.5 fold increase in TH expression ( FIG. 19 ). Furthermore, synaptophysin, a pre-synaptic vesicle protein present in neurons, was expressed in re-plated 11 DISC NT2 spheres ( FIG. 20B ). TH positive cells ( FIG. 20A ) were co-localized with synaptophysin ( FIG. 20C ) indicating possible synapse formation among dopaminergic NT2N neurons in the NT2 spheres. However, synaptophysin positive signal was also evident on some non-TH+ cells.
Example 5
β-Catenin/GSK-3β Expression
Several pathways have been investigated to determine the pathway(s) involved in the differentiation process of NT2N neurons developed in NT2 spheres, including MAPkinase, a known growth and differentiation pathway [Mansour S J, W T Matten, A S Hermann, J M Candia, S Rong, K Fukasawa, G F Vande Woude and N G Ahn. (1994)], and PI3/AKT, a pathway involved in cell proliferation and cell survival [Eves E M, W Xiong, A Bellacosa, S G Kennedy, P N Tsichlis, M R Rosner and N Hay. (1998)]. The Wnt signaling pathway, another pathway involved in cell survival, proliferation and differentiation, has also been implicated (Kikuchi A. (2000)). β-catenin, the cytoplasmic element of Wnt pathway, is involved in adhesion with cadherin and transcription through TCF/LEF transcription complex [Gottardi C J and B M Gumbiner. (2004)]. In 11 DISC re-plated spheres there was a 1.3 and 1.6 fold increase in nuclear β-catenin compared to nuclear β-catenin of undifferentiated NT2 monolayer and NT2 11 DISC, respectively ( FIG. 21 ). Cytoplasmic β-catenin decreased 0.8 fold in NT2 11 DISC and NT2 11 DISC re-plates.
Glycogen synthase kinase-3β phosphorylates β-catenin prior to lysozomal degradation. In our culture conditions, there was a 1.6 fold increase in the phosphorylated (inactive) form of GSK-3 D in 11 DISC NT2 re-plates compared to 11 DISC NT2 spheres ( FIG. 21 ). However, there was essentially no change in the GSK-3β levels between the re-plated NT2 11 DISC spheres and the undifferentiated NT2 monolayer ( FIG. 21 ).
Example 6
Dopaminergic Transcription Expression
RT-PCR analysis showed up-regulated Ptx3 and TH transcription, in the 11 DISC re-plated NT2 spheres compared to undifferentiated NT2 monolayer and 11 DISC NT2 spheres. However, Lmxb1 and Nurrr1 transcription were up-regulated in the both 11 DISC NT2 spheres and the re-plated 11 DISC NT2 spheres compared to undifferentiated NT2 monolayer. There was almost no change in En-1 transcription between all the groups ( FIG. 22 ).
Example 7
Ki-67 Expression
NT2 11 DISC spheres and NT2 11 DISC re-plate showed 1.6 and 5 fold decreases of nuclear protein Ki-67 expression, respectively, ( FIG. 23 ) compared to the undifferentiated NT2 monolayer suggesting that cell proliferation within the differentiated NT2 11 DISC re-plates has markedly slowed.
The disclosure of all publications cited above are expressly incorporated herein by reference, each in its entirety, to the same extent as if each were incorporated by reference individually.
It will be seen that the advantages set forth above, and those made apparent from the foregoing description, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. Now that the invention has been described,
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A method of differentiating adult stem cells, such as those derived from a teratocarcinoma cell line, the Ntera2/D1 clone (NT2). The developed cells exhibit a stable neurotransmitter phenotype without the required use of growth factors or retinoic acid in differentiation process, which may be difficult to completely remove during commercial production. An identification of specific neurotransmitters is possible in these differentiated NT2-derived neurons (NT2-N) after 30 days in culture or 30 days survival in vivo. The invention includes a method to stably differentiate neuronal stem/precursor cells to a neuronal phenotype for use in cell replacement therapy for neurodegenerative disease, stroke or spinal cord injury. At least four different types of neurons are produced from this method of differentiation: dopaminergic, cholinergic, GABAergic and glutaminergic. Additionally, since the cells are a cancer stem cell prior to differentiation, they may serve as a model system for developing anti-cancer therapies aimed at the cancer stem cell, rather than the more differentiated daughter cell.
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The application claims priority to U.S. Provisional Application No. 60/485,270 which was filed on Jul. 7, 2003.
BACKGROUND OF THE INVENTION
This invention is generally related to an intake manifold and a method of assembling an intake manifold. More particularly, this invention relates to an intake manifold fabricated from an inner shell inserted and welded within an outer shell utilizing a laser welding process.
Plastic intake manifolds have been developed for use in motor vehicles that provide reduced weight and cost. A plastic intake manifold is typically constructed from a plurality of parts that are molded separately and then joined to one another. Various methods are known for joining plastic parts including vibration welding. Joint configurations for these plastic parts typically include a complicated cross-section for providing sufficient melt down material as well as features for trapping flash. Such joint geometries contribute substantially to the cost of fabricating an intake manifold.
Further, vibrational welding methods lead to the design of plastic manifolds that are designed to include a series of horizontal or vertical slices. Horizontal and vertical slices result in a plurality of parts that must be joined. Further the many parts each require a separate molding tools and assembly stations that complicate assembly and increase overall cost. Additionally, if any of the joints in such a process are defective the intake manifold assembly cannot be repaired.
Laser welding has been used to join plastic parts with success. Laser welding of plastic is accomplished by directing a laser through a laser translucent material onto a laser absorbent material. Laser Transmission Contour Welding is known for use with large asymmetrical parts. Kinematics of robots has advanced to permit following a complex contour such as is typical of an intake manifold assembly. However, typically laser welding is simply applied to joints originally designed according to known conventions for producing a vibration-welded joint. There is still a plurality of parts that require many joints. Further, in some instances, parts are inaccessible once the manifold is complete. Such construction increases the likelihood that an improper joint may result in the entire intake manifold being unusable. Laser welding requires that the parts touch without substantial gaps and access to the joint for the laser-welding tool.
Accordingly, it is desirable to design a plastic intake manifold to take advantage of laser welding processes to reduce the number of parts and to reduce the number of joints.
SUMMARY OF THE INVENTION
This invention is a plastic intake manifold assembly including an inner shell and an outer shell including an improved joint interface for a laser transmission weld.
The intake manifold assembly includes an outer shell and an inner shell. The outer shell defines a cavity having an inner surface. The inner shell includes a plenum type tube and a plurality of dividers that extend radially outward from the plenum tube. The plenum tube includes a mounting flange for a throttle body. The plenum and the tube may be integrated so as to appear as one part or the tube may remain separate and appear as a throttle zip tube which has the effect of increasing the length of the column of air passing through the throttle body or discharging the air into the plenum in a nominally central location of the manifold. Air entering through the plenum tube flows into the spaces between the dividers. The dividers are jointed at an outer periphery to the outer shell to form the runners or air passages.
The outer shell includes the typical and necessary external features common to all intake manifolds for mounting to an engine. Such features include flanges for mounting to each intake opening of the engine, along with other openings for sensors and other devices that commonly are installed within an intake manifold assembly. The inner shell includes the dividers that provide for and define the runners or air passages that deliver air at a desired pressure and flow rate to each of the engine cylinders. Fully assembled, the inner shell is fully within the outer shell. The dividers are joined to the outer shell to define the separate air passages that delivers airflow to each cylinder.
The outer periphery of the divider is joined to the outer shell by a laser-welded joint. The laser welded joint forms a substantially air tight seal between each divider and the inner surface of the cavity of the outer shell. The laser weld joint is accomplished by application of laser energy along an outside surface of the outer shell. The outer shell is preferably fabricated from a plastic material that is laser translucent to the laser. The inner shell, and specifically the dividers are fabricated from a plastic material that is substantially laser opaque. This preferential material configuration provides for the laser to penetrate the outer shell and reach the inner shell, where the energy from the laser creates a molten pool of plastic within the inner shell at the interface between the inner shell and the outer shell, that cause corresponding melting of the adjacent surface in the outer shell. The plastic then intermixes and forms the desired joint.
The laser device is set a desired distance from the outer surface and moved along the path at a speed determined to provide the desired joint depth and strength. Further, a worker skilled in the art would understand the settings including beam strength, focal length, and feed rate that is required to produce the desired depth of the laser weld joint. A laser weld joint requires contact between parts to be joined and must be accessible to the laser device. The laser device is traversed about the outer surface of the outer shell, however the laser device may also be moved within the cavity to provide desired joints.
The example intake manifold assembly includes the plurality of like shaped dividers that are inserted within a substantially circular outer shell. Processing consideration for assembly of the inner shell to the outer shell requires that each successive divider be of cross-sectional area sufficiently smaller than the preceding divider to aid assembly. The example cavity is stepped such that the smallest diameter or cross-sectional area is at an end distal to initial insertion of the inner shell. Each successive joint location is larger than the preceding such that each divider is easily passed through to the desired location. Each divider abuts a tapered area of the cavity. The tapered area corresponds to a taper on the periphery of the divider. This taper provides for good contact between the two parts to be joined. The laser weld joint is best performed on two parts that are in direct contact with each other.
The intake manifold assembly of this invention provides for a clamping of the inner shell to provide the desirable contact at the joints. The clamping of the inner shell to the outer shell is accomplished by applying a clamping force that selectively collapses the inner shell against the outer shell. The inner shell includes a plurality of deformations provided at selective stages of the inner shell. Application of force compresses and collapses the inner shell at the deformations such that the tapered areas substantially abut the tapered periphery of the dividers. This contact provides a favorable joint for application of the laser.
The intake manifold assembly of this invention includes an innovative joint that provides contact between the inner shell and outer shell and access to the joint area for the laser device. The resulting intake manifold assembly provides for a reduction of component parts and a reduction in part and assembly costs.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an inner shell and an outer shell of an intake manifold according to this invention.
FIG. 2 is a schematic view of the assembled intake manifold.
FIG. 3 is a top schematic view of the assembled intake manifold.
FIG. 4 is a schematic view of a collapsible inner shell within the outer shell.
FIG. 5 is a schematic view of the outer shell collapsed onto the inner shell.
FIG. 6 is an enlarged schematic view of an interface between the inner shell and the outer shell.
FIG. 7 is another enlarged schematic view of the interface between the inner shell and the outer shell.
FIG. 8 is a top view schematically illustrating a web segment directing airflow.
FIG. 9 is a schematic sectional view illustrating blocking and directing of airflow with the web segment.
FIG. 10 is a schematic sectional view illustrating a center inlet tube of the inner shell.
FIG. 11 is a schematic view illustrating assembly of an example intake manifold according to this invention.
FIG. 12 is a cross-sectional view of an example intake manifold according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , an intake manifold assembly 10 includes an outer shell 12 and an inner shell 14 . The outer shell 12 and the inner shell 14 are disposed along a longitudinal axis 16 . The outer shell 12 defines a cavity 18 having an inner surface 20 . FIG. 1 is a schematic illustration of the intake manifold assembly 10 of this invention and does not show such features common to all manifolds. The inner shell 14 includes a plenum tube 22 that extends substantially the entire length of the inner shell 14 . A plurality of dividers 24 extend radially outward from the plenum tube 22 . The plenum tube 22 includes a mount 30 for a throttle body 38 . Air entering through the plenum tube 22 flows into the spaces between the dividers 24 . The dividers 24 include an outer periphery 36 that is joined with outer shell 12 to form air passages 26 within the manifold assembly 10 .
The inner shell 14 shown includes nine dividers 24 to form the eight air passages 26 required for an eight-cylinder engine. As appreciated, a worker with the benefit of this disclosure will recognize the applicability to other intake manifolds for other engine configurations. The intake manifold assembly 10 of this invention substantially includes only the two parts, the outer shell 12 and inner shell 14 . The outer shell 12 includes the typical and necessary external features common to all intake manifolds for mounting to an engine. Such features include flanges for mounting to each intake opening of the engine, along with other openings for sensors and other devices that commonly are installed within an intake manifold assembly. The inner shell 14 includes the dividers 24 that provide for and define the runners or air passages 26 that deliver air at a desired pressure and flow rate to each of the engine cylinders. The dividers 24 are disposed at angle 27 relative to a plane perpendicular to the longitudinal axis 16 . The angle 27 accommodates the spacing between cylinders of an engine as known.
Referring to FIG. 2 , the intake manifold assembly 10 is schematically shown in an assembled state. Fully assembled, the inner shell 14 is fully within the outer shell 12 . The dividers 24 are joined to the outer shell 12 to define the separate air passages 26 that deliver airflow to each cylinder. Further, besides defining air passages 26 , the dividers 24 provide the structure that defines a first end 23 and a second end 25 of the intake manifold assembly 10 . The dividers 24 provide the division between the air passages 26 for each of the cylinders.
In the example embodiment illustrated in FIG. 2 each of the dividers 24 provides a portion of each adjacent air passage 26 . That is, the dividers 24 provide a separation wall for two air passages 26 . As appreciated, the number of dividers 24 can be modified within the contemplation of this invention to provide for different air passage configuration. Each air passage 26 may be formed from there own set of dividers 24 such that no air passage 26 shares a divider 24 . Further, the various air passages 26 can be selectively configured through the use of more or less dividers 24 .
The dividers 24 include the outer periphery 36 that is joined to the outer shell 12 by a laser welded joint shown schematically by arrows 46 . The laser welded joint 46 forms a substantially air tight seal between each divider 24 and the inner surface 20 of the cavity 18 of the outer shell 12 . The laser weld joint 46 is accomplished by application of laser energy along an outer surface 28 of the outer shell 12 . The outer shell 12 is preferably fabricated from a plastic material that is substantially laser transparent or translucent to the laser. That is the outer shell 12 is formed from a material that provides for some transmission of the laser through to the inner shell 14 . The inner shell 14 , and specifically the dividers 24 are fabricated from a plastic material that is substantially laser opaque. This preferential material configuration provides for the laser to penetrate the outer shell 12 and reach the inner shell 14 , where the energy from the laser creates a molten pool of plastic within the inner shell 14 , that causes corresponding melting of the adjacent surface in the outer shell 12 . The laser device 40 is subsequently moved or deactivated, providing for the re-solidification of the melted plastic. The melted plastic from the inner shell 14 intermixes with the melted plastic from the outer shell 12 to form the laser weld joint 46 . The laser weld joint 46 provides both the desired structural rigidity to the intake manifold assembly 10 along with the desired air seal between adjacent air passages 26 .
Referring to FIG. 3 , a top schematic view of the intake manifold assembly 10 is shown and illustrates how the laser weld joint 46 is formed. The example intake manifold assembly 10 is illustrated as substantially circular; however, other shapes as are desired and required for each application are within the contemplation of this invention. Further, example movement of the laser device 40 along the path 42 as circular. A robot as known can be used for moving the laser device 40 along the contours of the intake manifold assembly 10 . Movement of the laser device 40 follows a path that provides the desired joint and moves along the contours of the outer surface 28 . The example intake manifold assembly 10 is shown with several joints 46 that are substantially linear about the longitudinal axis 16 , however, the path and therefore the joint 46 can be any shape as is required to join the dividers 24 to the inner surface 20 of the outer shell 12 .
The laser device 40 is set a desired distance from the outer surface 28 and moved along the path 42 at a speed determined to provide the desired joint depth and strength. The specific laser device 40 is as known. Further, a worker versed in the art would understand the settings including beam strength, focal length, and feed rate that is required to produce the desired depth of the laser weld joint. A laser weld joint requires contact between parts to be joined and must be accessible to the laser device 40 .
In the example shown in FIG. 3 , the laser device 40 is traversed about the outer surface of the outer shell 12 , however the laser device 40 may also be moved within the cavity 18 to provide desired joints.
Referring to FIG. 4 , the example intake manifold assembly 10 includes the plurality of like shaped dividers 24 that are inserted within a substantially circular outer shell 12 . The dividers 24 are shown as substantially identical, however it is not required that each divider be identical, only that the shape of the divider 24 corresponds to the cavity 18 . Processing consideration for assembly of the inner shell 14 to the outer shell 12 require that each successive divider 24 be of cross-sectional area sufficiently smaller than the preceding divider 24 to allow for ease of assembly. Assembly of the plurality of dividers 24 into a successive diameter of the same size would make assembly difficult, as each successive divider would require very precise alignment to allow the first divider 24 to be installed to the far end of the outer shell 12 .
Accordingly, the example cavity 18 is stepped such that the smallest diameter or cross-sectional area is at an end distal to initial insertion of the inner shell. Each successive joint location is just a bit larger than the preceding such that each divider 24 is easily passed through to the desired location. The difference in relative cross-sectional areas is such that to the naked eye no difference will be perceived. The difference between cross-sectional areas is greatly exaggerated in FIG. 4 to illustrate the specific example configuration.
In the example intake manifold assembly 10 shown, each divider 24 abuts a tapered area 48 of the cavity 18 . The tapered area 48 corresponds to a taper on the periphery of the divider 24 . This taper provides for good contact between the two parts to be joined. The laser weld joint 46 is best performed on two parts that are in direct contact with each other. The intake manifold assembly of this invention provides for a clamping of the inner shell 14 to provide the desirable contact at the joints 46 . The clamping of the inner shell 14 to the outer shell 12 is provide by applying a clamping force 54 that selectively collapses the inner shell 14 against the outer shell 12 .
The inner shell 14 includes a plurality of deformations 44 provided at selective stages of the inner shell 14 . Application of the force 54 compresses and collapses the inner shell 14 at the deformations 44 such that the tapered areas 48 substantially abut the tapered periphery of the dividers 24 . The number of deformations 44 for each collapsible portion along the plenum tube 22 is determined to progressively and selectively collapse the plenum tube 22 . The greater the number of deformations 44 the less force required to collapse that section of the plenum tube 22 . The deformations 44 can take different forms such as dimples or serrations within the plenum tube. Further, the deformations 44 can be a flexible portion of the plenum tube 22 .
The process can proceed by collapsing one divider 24 into the tapered area 48 , performing the weld, and then further collapsing the inner shell for the next divider. Alternatively, the entire inner shell 14 may be collapsed at once such that each divider 24 abuts the inner surface 20 of the cavity 18 . In either process, the clamping, collapsing of the inner shell 14 produces the desired abutted contact between the dividers 24 and the inner surface 20 of the outer shell 12 .
Referring to FIG. 5 , another example intake manifold assembly 10 according to this invention includes deformations 52 in the outer shell 12 such that a clamping force 54 is applied to selectively collapse the outer shell 12 into contact with the inner shell 14 . The force 54 causes the outer shell 12 to compress enough to contact the periphery 36 of each divider 24 . The contact provides the desired joint geometry for the laser weld joint 46 .
Additionally, the inner shell 14 can be formed from a plastic material that has less re-enforcing content to encourage local deformations that in turn result in improved contact for welding. The inner shell 14 and the outer shell 12 are formed from a plastic material including re-enforcing material. One of the inner shell 14 and the outer shell 12 is more compliant than the other to facilitate local deformations and improved contacts. The relative compliance between the inner shell 14 and the outer shell 12 is provided by a reduction in the amount of re-enforcing material provided in the more compliant one of the inner shell 14 and outer shell 12 . The re-enforcing material present within the inner shell 14 and the outer shell 12 is as known.
Referring to FIG. 6 , an enlarged view of the joint 46 is shown and includes the tapered area 48 in proximity to the periphery 36 of the divider. Preferably, the divider 24 contacts the tapered area 48 and the laser device 40 provides the desired energy to form the joint 46 . However, the joint 46 can also be formed with a gap 56 between the divider 24 and the outer shell 12 . Gaps 56 form due to tolerance stack ups and manufacturing deviations that inevitably are encountered in any assembly and manufacturing process.
Accordingly, it is desirable to develop a process that can accommodate such variations. The joint 46 can be formed between the divider 24 and the outer shell 12 with gaps 56 of up to approximately 0.2 mm. Preferably, the divider 24 is in direct contact with the outer shell 12 , however a joint 46 as desired can be formed over gaps 56 of approximately 0.2 mm. Although, a gap of 0.2 mm is described, the specific joint geometry and material may result in more or less of a gap 56 being allowable while still providing a joint as desired.
Referring to FIG. 7 , a schematic view of the laser device 40 forming the joint is shown. The laser device 40 transmits energy that forms a molten plastic pool 55 between the inner shell 14 and the outer shell 12 . The molten plastic pool 55 intermixes and re-solidifies, resulting in the desired joint 46 .
Referring to FIG. 8 , a schematic view of the example air passage 26 is shown and includes a web section 58 . Typically, the length and size of the air passage 26 is carefully selected to provide desired engine performance characteristics. The length of the air passage 26 is closely controlled such that all air passages 26 are of the same length to provide equal airflow to each cylinder and provide equal acoustic lengths to minimize emissions of undesirable noise through the throttle body 38 . The web section 58 calibrates the length of the air passage 26 for the example intake manifold assembly 10 as desired.
The web section 58 blocks airflow 60 entering the air passage 26 from the plenum tube 22 . Airflow 60 must circulate about the plenum tube 22 before reaching the intake opening 62 to the cylinder. The position of the web section 58 corresponds with opening 61 within the plenum tube 22 to provide the desired length of the air passage 26 .
Referring to FIG. 9 , a cross sectional view of adjacent air passages 26 includes the web sections 58 and illustrates how airflow 60 is diverted about the plenum tube 22 . The web sections 58 correspond with the openings 61 in the plenum tube 22 to provide the desired length of air passage 26 .
Referring to FIG. 10 , in another example intake manifold assembly 10 according to this invention, the mount 30 for the throttle body 38 is part of the outer shell 12 . The inner shell includes an intake tube 64 that extends transversely from the plenum tube 22 . The intake tube 64 provides a conduit for incoming airflow into the plenum tube 22 from a central location of the manifold assembly 10 . A laser weld joint 66 seals the interface between the intake tube 62 and the outer shell 12 to provide the desires air passage 26 . The mount 30 is illustrated in a central location, however other locations as would be required by application specific requirements are within the contemplation of this invention.
Referring to FIG. 11 , another example intake manifold assembly 70 is shown and includes an inner shell 72 that is inserted into an outer shell 74 . In previous example embodiments the dividers were illustrated as substantially circular members disposed about a central plenum tube. However, the inner shell 72 need not consist of circular members. The inner shell 72 includes dividers 75 that form air passages 84 through the intake manifold assembly 70 .
The dividers 75 are J-shaped channels that include the desired configuration of the air passages. Further, the dividers 75 include an enclosed portion 86 and a walled portion 88 . The enclosed portion 86 provides a tube that extends into a cavity 76 of the outer shell 74 . The enclosed portion 86 does not require a laser weld joint. The walled portion 88 includes two sides that correspond to inner surfaces 90 of the cavity 76 to form the remainder of the air passage into intake runners 78 within the outer shell 74 .
The outer shell 74 defines the cavity 76 and the runners 78 that extend and connect with the engine to communicate air to each engine cylinder. Assembly of the intake manifold assembly 70 includes molding the inner shell 72 and the outer shell 74 . The inner shell 72 is inserted into the outer shell 74 . The inner shell 72 is then clamped such that surfaces of the inner shell 72 that will form the weld joint with the outer shell 74 are in substantial contact with the inner surface 90 of the outer shell 74 . The contact between the inner shell 72 and the outer shell 74 is preferably within a desired gap range to provide the desired laser weld joint.
The laser device 40 is traversed along the outer surface 91 of the outer shell 74 along a predetermined path 82 . The predetermined path 82 corresponds with the position of the inner shell 72 such that the desired laser weld joint is formed. The predetermined path 82 is illustrated as a simple rectangular path; however, the path of the laser device 40 can be of any shape required to provide the desired air passages and intake mold configuration. Once the laser weld joint is complete, the intake manifold assembly 70 is substantially complete except for assembly of external devices such as the throttle body 38 , sensors and other hardware supporting operation.
Referring to FIG. 12 , the assembled intake manifold assembly 70 is shown as a cross-section through the mount 30 . Airflow 80 through the mount 30 enters the cavity 76 . The cavity 76 is in communication with each of the air passages formed by the dividers 75 . In this example intake manifold assembly 70 the dividers 75 include the enclosed portion 86 that extends into the cavity 76 . Airflow 80 entering the enclosed portion 86 flows through the air passage to the walled portion 88 . The walled portion 88 cooperates with the inner surface 90 to define the remainder of the air passage.
Forming of the laser weld joint along the weld path 82 provides the desired structural connection between the inner shell 72 and outer shell 74 . Further the laser weld joint provides the air sealing required to isolate airflow to each cylinder. The laser weld joint requires no special joint configuration, other than the need to provide sufficient weld area, and to provide access to the joint area.
The example intake manifolds of this invention provide a substantial reduction in the number of parts, along with a substantial simplification in the joint between manifold parts. The example intake manifolds described include substantially two components, however, additional components as be required for a specific application would also benefit from the simplified joint configuration and laser weld process. Further, the example intake manifold substantially reduces assembly and manufacture time and expense.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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Laser welding of plastic involves a laser passing through laser translucent then laser absorbent material. A technical description as envisaged here is Laser Contour Welding. Universally, laser welding is done by Quasi simultaneous techniques and rarely by Contour techniques. Regular or symmetrical parts, under 5 inches are welded by Quasi simultaneous. Asymmetric and large parts are best welded by Contour Welding.
Kinematics of robots permits a complex contour. Automotive plastic manifolds exceed 5 inches with asymmetry. The pairing of robot contour and laser welding facilitates a new Automotive manifold. It requires a new split line for laser access and manufacturing as described. Encompassing the above requirements and solutions can reduce the moldings for a V8 to 2 major operations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
In general this invention relates to portable exercise apparatus and in particular to compact exercise apparatus, which is capable of being used in a home, office, or other non-commercial or even a commercial training or exercising facility, which apparatus may in general be used in a sitting or supine body position and by which the lower and upper body portions can be individually exercised.
2. Description of the Prior Art
Indeed, there are many different and various exercise apparatus on the market today. Even more exercise apparatus have reached the prototype stage and might even have been patented; but, from a commercial standpoint they were never successful. That this is so is because for portable exercise apparatus to be commercially successful it must work repeatedly as intended, be capable of being manufactured on a mass production basis, must be inexpensive, must be convenient to use and must provide the workout said to be capable of being achieved. Notwithstanding the plethora of various exercise apparatus, both portable and nonportable, on the market today, none is truly compact, affordable, and yet provides real exercise. Furthermore, few, if any, can be used while a person doing the exercise is in a sitting position in a common and ordinary household or office chair. Thus, there exists the need for a truly portable, compact, and useful exercise apparatus as provided by the present invention which is described and claimed herein.
Accordingly, the primary goal of the present invention is to provide exercise apparatus which is compact and portable and still provides real exercise.
Another object of the present invention is to provide portable exercise apparatus which is simple in construction and operation and therefore may be repeatedly used over a long period of time.
Another object of the present invention is to provide portable exercise apparatus which may be used for primarily strengthening the lower portion of the body but also provide for strengthening the upper portion of the body.
Yet another object of the present invention is to provide portable exercise apparatus which provides for variable resistance so that people of all ages and strengths and even some people having minor disabilities may utilize the exercise apparatus.
Still another object of the present invention is to provide portable exercise apparatus which may be used by people sitting in ordinary home or office type chairs, for example, as when watching television.
SUMMARY OF THE INVENTION
The present invention provides for the above-stated objectives as well as others by providing simple but effective portable exercise apparatus which may be used by a person sitting in an ordinary chair or lying in a supine position.
The exercise apparatus provided for herein comprises a main frame having a wedged type of overall appearance made up of common I beams, channel beams, and box beams as structural components. A pair of hydraulic cylinders are rigidly attached to the frame at one end and extend along the length of the obliquely angled member of the frame. The other end of the hydraulic cylinders is attached to an axle rod which is oriented in a transverse but horizontal position and adapted to move along the length of the obliquely angled members along tracks comprising the channel formed by the I beam sections and the U channel beam sections of the structural members. Limb-engaging pedals, later referred to as foot pedals are attached to the axle rods for rotational movement about the longitudinal axis of the axle rods. Finally, the hydraulic cylinders are connected together by hydraulic tubing with a needle valve positioned within the hydraulic line. By manipulating the needle valve the force of resistance of each of the hydraulic cylinders may be increased or decreased appropriately. When one of the foot pedals is moved downward along the angled support members, the other hydraulic cylinder and the foot pedal attached thereto moves in the opposite or upward direction therealong.
In the event that the force of resistance is adjusted to a strong position, it is possible that the frame of the portable exercise apparatus will move along the surface on which it is placed. In order to avoid this undesired motion, the framing may be attached to a flexible pad which extends from the exercise apparatus to under a chair used by the person and whose weight secures the pad as well as the portable exercise apparatus in place. As an alternative to the pad, flexible straps extending from the rear of the exercise device may be hand held by the person using the exercise apparatus.
When not in use, the portable exercise apparatus may be stored in an ordinary closet, while taking up the space of only one shelf thereof.
Various other objects, advantages and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric overall view of the inventive exercising apparatus illustrating the simplicity and the operational functions thereof;
FIG. 2 is a detailed view of the pivotally attached foot pedals and guide system taken through the line 2--2 of FIG. 1;
FIG. 3 is a schematic drawing of the hydraulic circuit and flow pad used in the invention apparatus;
FIG. 4 is a detailed plan view of the hydraulic cylinder attachment means at the bottom thereof to the main frame of the exercise apparatus; and,
FIG. 5 is a schematic side view of the inventive apparatus equipped with both a strap and a flexible pad.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Reference is now made to the drawings wherein like characteristics and features of the present invention shown in the various figures are designated by the same reference numerals
Referring now to the various figures, particularly FIG. 1, there is illustrated therein, the overall appearance and functional operation of the inventive portable exercise apparatus 10. A main frame assembly 11 includes three elongated structural members which are angled approximately 30° to the horizontal. The angled members 12A and 12C each may have a U-shaped beam cross section conforming to half the cross-section of I-beam member 12B so as to provide the necessary structural support and comprise guide tracks for the movement of the foot pedals of the exercise apparatus as more fully explained hereinafter. A vertical member 13, which may have a box cross-sectional shape, is attached to each of the angled members 11. Cross box beam members 14 are attached to the vertical members 13 at the lower elevation thereof. Also, a channel beam member 15 is attached to the ground level of the angled beam members 12A, 12B and 12C at the front of the apparatus 10. All the connections between the various beam members are fixed so as to obtain a solid and strong frame assembly 11. By making each of the frame members 12, 13, 14, and 15 from aluminum, a lightweight and strong frame member is obtained. However, other suitable materials such as steel or plastic may be used for the frame members 12, 13, and 14.
Hydraulic cylinders 16A and 16B are attached at their bottom end to cross beam member 15. This connection is rigid. The rod or stem members 17 extending from hydraulic cylinder 16 is attached at one end within the hydraulic cylinder to a piston 18 and through a transversely apertured stem adapter 40 at its other end to an axle rod 19 which extends transversely across the opening between the angled support member 12. Axle rod 19 extends through a hole 21 provided in stem adapter 40 of the hydraulic cylinders 16 as shown in FIG. 2.
Still referring to FIG. 2, the ends of axle rod 19 are provided with rollers 20 which may roll about a non-rotating axle rod 19, or in the alternative roll with a rotating axle rod 19. A foot pedal 24 having mounting lugs 25 attached to a bottom surface thereof. Each lug 25 is provided with a transversely extending hole 26 within which extends axle rod 19. Accordingly, foot pedal 24 is pivotally attached to axle rod 19. Axle rod 19 is moveable lengthwise within the channels 23 formed by the cross-sectional shape of I beam member 12B and channel beam members 12A and 12C.
As shown in the drawings, hydraulic cylinders 16 are side-by-side arranged and each is associated with a foot pedal.
Refer now also to FIGS. 3, 4, and 5 which show various other details. Each of the hydraulic cylinders 16 may comprise a body 39 which may, for example, be molded from a material such as nylon. Within the body 39 of hydraulic cylinder 16, the piston 18 comprises rod 17 and by the use of bushing 41 and seal rings 42, is sealingly fitted to the interior bore of hydraulic cylinder 16. This arrangement compensates for the tendency of piston 18 from moving transverse to the axis of cylinder 16. The pushing force on the foot pedal 24 causes piston 18 of hydraulic cylinder 16A to move downward within hydraulic cylinder 16A forcing the oil or hydraulic fluid within hydraulic cylinder 16A to pass through hydraulic line 27 which couples the remote ends of hydraulic cylinders 16A and 16B. As the hydraulic fluid within hydraulic cylinder 16A moves downward in the direction of arrow 30, the piston 18 and stem assembly 17 of cylinder 16B are caused to move upward in the same direction as arrow 31. Thus, while either one of the foot pedals 24A or 24B move in one direction, the other foot pedal moves in the opposite direction. The downward motion is the only motion which experiences resistance as provided by the hydraulic circuit. A needle valve 29 attached within hydraulic line 27 may be utilized to vary the amount of resistance provided by the inventive apparatus 10. Reinforcing structure 28 is provided for hydraulic line 27 (FIG. 3). By further closing the valve 29, the force required to move the hydraulic fluid from one hydraulic cylinder assembly, for example, 16A to the other cylinder assembly 16B is increased. Conversely, by further opening needle valve 29, the resistance provided by moving the hydraulic fluid from one cylinder to the other results in a lesser foot pedal force being required.
In FIG. 4 one method of attaching the bottom end of the housing 23 of hydraulic cylinder 16 to cross frame member 15 is shown. In this embodiment, a lug 32 which may be molded integrally with housing 23, extends from the bottom thereof and through a hole 35 in frame member 15. A cotter or a split pin 33 may be mounted in a hole 34 transversely positioned through mounting lug 32 in order to removably secure the lower or remote ends of the hydraulic cylinder 16 to the cross bar 15 of frame assembly 11. Other obvious methods, such as screws or studs, may be used to provide equivalent rigid mounting.
During use of the exercise apparatus 10, a person would position himself in a chair 37 in front of the vertical portion of the inventive apparatus 10 (FIG. 5). This will orient the foot pedals 24 in front of the hydraulic cylinders 16 and in line therewith. Thus, the angled members and the hydraulic cylinders would be oriented in the position extending downward and away from the person using the exercise apparatus 10. The distance that the inventive apparatus 10 is placed away from or toward the chair determines which part of the leg muscles would be more exposed to the exercise. However, should the upper leg muscles in general be desired to be exercised, the apparatus may be placed in front of the person such that when one of his legs is substantially fully extended, the foot pedal and hydraulic assembly associated with such foot is depressed at the maximum downward position. This would cause a nominal bending at the knee at the person's other leg which is resting on the other foot pedal which is located in its maximum upward location. Then, the person simply moves the bent leg down while the other leg moves up. This is a continual repeating cycle so as to cause the legs to be moving in an upward and downward motion somewhat similar to that provided by the pedals of a moving bicycle. As described above, by adjusting needle valve 29 more or less resistance to the leg motions may be obtained. The person doing the exercise determines the amount of exercise he desires by adjusting the needle valve 29 and by adjusting the velocity of the cyclic up-and-down motion of his legs.
When using the portable exercise apparatus provided for by this invention in a moderate or medium level of exercising, the friction between the bottom feet of the exercise apparatus 10 will generally stay in fixed contact with the ground beneath the exercise apparatus. In the event that a high degree of exercising is desired, it is possible for the frame assembly 11 of the invention apparatus 10 to slide along the ground and away from the person doing the exercising. In this situation it is necessary to prevent the frame assembly 11 from so sliding by providing one or the other of the means shown in FIG. 5 to fix the movement of the exercise apparatus 10.
In one embodiment a pliable rug or mat 36 is permanently affixed to the feet or lower end of the frame members 11 which are in contact with the ground. The end of the mat or rug 36 extending away from the frame assembly 11 is to be located under the chair 37 of the person using the exercise apparatus 10. His weight will keep the mat 36 in place and its permanent attachment to the frame member will prevent the exercise apparatus 10 from sliding forward when high or excessive force is used.
In the alternative, flexible straps 38 may be attached to the vertical end of frame member 11 at one end and be hand held by the person using the exercise apparatus at the other end of the straps, or may be attached to the chair 37. In this manner, the resistance provided to prevent the frame assembly 11 from moving forward is provided by the hand held straps.
While the inventive apparatus 10 is primarily intended to be utilized by a person sitting in an ordinary chair and for the purpose of exercising his legs, it may be utilized to exercise the upper body portions also. In the latter situation, the person using the exercise apparatus 10 would position himself in a kneeling position in front of the heightened portion of the frame assembly 11 and place his hands one each on the appropriate pedal. Then, the person would move each alternative hand in a upward and downward motion to obtain the exercise desired. Similarly, the person using the exercise apparatus may lie in a supined position on his back and with his feet against the pedals then proceed to use the exercise apparatus in the manner intended. In this latter situation, it would be preferable to have the mat or rug 36 attached to the bottom of the legs of the frame assembly 11.
While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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Compact and portable exercise apparatus is disclosed. A frame assembly having a wedge type of shape comprising aluminum structural members has mounted thereto a pair of hydraulic cylinders which are interconnected by a hydraulic flow line containing an adjustable needle valve. The other end of the hydraulic cylinders is connected to a foot pedal which allows the force of a person's downward push of his legs to act upon the resistance provided within the hydraulic circuitry and which automatically causes the opposite foot pedal travel upward. The exercise apparatus is intended to primarily be used in conjunction with a person sitting in an ordinary chair.
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BACKGROUND OF THE INVENTION
The subject invention is directed to the art of headlamp adjusting systems and, more particularly, to a headlamp adjusting system using bevel gears enclosed in a hinged, folding housing.
Mechanisms and systems for vertical and horizontal adjustment of seal beam type automobile headlamps have previously been provided. Generally, such systems provided for individual lamp adjustment via independent adjusting screws by driving such screws with a suitable tool. Occasionally, the adjusting screws were difficult to access or first required time consuming removal of certain components of the headlamp assembly. Sometimes problems were encountered because the adjusting screws had became corroded or otherwise rusted and/or coated with road grime, rendering the adjustment procedure inordinately time consuming and difficult, or necessitating removal and replacement of a number of parts.
Some mechanisms are known which employ a bevel gear arrangement to adjust a headlamp. U.S. Pat. No. 4,742,435, for example, discloses a bevel gear headlamp adjustment system. However, the bevel gear system is enclosed in an intricately molded, non-hinged housing which is complicated and difficult to assemble. Furthermore, the mechanism is partially constructed of metal and is therefore susceptible to corrosion. In addition, the rotation of the adjustment shaft is prevented via a non-rotatable ball-in-socket arrangement.
U.S. Pat. No. 4,939,945 discloses a bevel gear adjustment system including a housing of which one part is formed of plastic. However, this patent fails to teach an easily assembled hinged housing comprised fully of plastic. In addition, the assembly requires the typical step in the art of attaching the adjustment member to the headlamp to prevent rotation of the adjustment member coincidentally with rotation of the adjustment bevel gear.
Accordingly, there is a need for a completely plastic and long lived adjustment device. Furthermore, it is desirable to have a simplified adjustment device which is easily assembled and installed.
BRIEF STATEMENT OF THE INVENTION
The subject invention provides a headlamp adjustment mechanism which is simple to assemble and has a long lifespan.
In accordance with the invention, the adjustment mechanism comprises a gear arrangement including a first "drive" gear which drives a second "adjustment" gear. Both gears are formed of plastic. Means are provided for selective rotation of the drive gear. The means may comprise a slot or aperture to accommodate a suitable tool, for example, an allen wrench or a phillips head screwdriver. The adjustment gear includes a threaded axial bore. The threaded bore receives an elongated threaded adjustment rod for connecting with an adjustment point on a headlamp. Rotation of the adjustment gear produces axial movement of the rod and thus of the headlamp.
In the preferred embodiment, the drive and adjustment gears are meshing bevel gears. A plastic housing surrounds the gears and at least the part of the adjustment element which is engaged with the threaded bore. The housing includes a first chamber which encompasses the drive bevel gear and a second chamber which encompasses the adjustment bevel gear. The housing is formed of two sections connected by releasable means to allow opening and closing of the housing and thus access to the chambers and the drive and adjustment gears. The first and second chambers meet in a common area wherein the drive gear meshingly engages the adjustment gear.
Preferably, the adjustment rod has a flat side and there is a surface interactive with the flat side of the adjustment rod to prevent rotation of the adjustment rod when the adjustment bevel gear is rotated. Accordingly, only axial movement of the adjustment rod through the adjustment gear bore is permitted. In the specific embodiment disclosed, the flat axial end of the drive gear abuts the flat side of the adjustment element and prevents rotation.
In accordance with a further aspect of the invention, the two housing sections are releasably joined in assembled relationship by a hinge and latch arrangement. The drive and adjustment gears are maintained in their properly engaged relationship by the formation of the first and second chambers upon closure of the housing.
As can be seen from the foregoing, a primary object of the invention is the provision of a simplified headlamp adjustment mechanism which uses a minimum number of components and can readily be formed from plastic or other corrosion-resistant materials.
A further object of the invention is the provision of an adjustment mechanism of the type described wherein the housing is a two-piece, molded plastic structure that carries and guides the gears in integral chambers.
Another object of the invention is the provision of a mechanism of the type described that is economical to manufacture and reliable.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawing wherein:
FIG. 1 is an isometric view showing the overall arrangement of the preferred embodiment of headlamp adjusting mechanism of the invention; and,
FIG. 2 is an isometric view of the headlamp adjustment mechanism of FIG. 1 but showing the housing in its open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawing wherein the showing is for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same, FIGS. 1 and 2 show the overall arrangement of a preferred form of the headlamp adjustment assembly 10. As illustrated, the assembly 10 includes a rigid housing comprised of two molded plastic housing halves 12 and 14 joined by an integral molded hinge 16.
Housing half 12 includes an internal chamber 18 formed and sized to closely and rotatably receive and guide a drive bevel gear 20. Drive bevel gear 20 is shown in this embodiment as including an integral extension shaft element 22 terminating in a hex nut 24 which also includes an allen wrench recess 26. Nut 24 and recess 26 provide means for manually driving gear 20. It is, of course, possible that extension shaft element 22 could be eliminated and gear 22 simply incorporate a recess capable of directly accepting a suitable tool such as a screwdriver or allen wrench. In either embodiment, housing 12 is formed with a semi-cylindrical recess 28 in its side wall to accommodate extension shaft 22 or an inserted tool. In the closed position of assembly 10, recess 28 cooperates with semi-circular recess 29 in housing half 14 to form a cylindrical bearing which accommodates extension shaft 22.
Housing half 14 includes recess 30 shaped and sized to closely receive and guide a rotatable adjustment bevel gear 32. In its preferred form, bevel gear 32 is comprised of two identical half portions 32a and 32b. Portion 32b includes an alignment pin 34 which fits into a recess (not shown) in bevel gear portion 32a. Each half of adjustment gear 32 includes a shoulder element 36 which operatively fits within bearing recess 38 on housing half 14. Particularly, recess 38 is sized to closely encircle shoulder element 36 to keep bevel gear portions 32a and 32b functionally joined in their operative relationship and to provide a thrust surface and rotational bearing surface for the gear.
Adjustment bevel gear 32 is also equipped with a threaded axial through-bore 40. Bore 40 is arranged to threadedly engage and drivingly interact with an adjustment rod 42 and specifically with threads 44 on the exterior of rod 42. Housing half 12 includes a smooth bore 58 which allows guided passage of rod 42 axially therethrough when the assembly is in the closed position of FIG. 1. Housing half 14 includes a similar, axially aligned smooth bore. Preferably, rod 42 includes a flat side 46 which operatively engages with surface means to prevent rotation of rod 42 when adjustment bevel gear 32 is rotated. In the illustrated embodiment, the flat axial end 51 of bevel gear 20 engages the flat side 46 to prevent axial rotation of the rod 42. Also, the smooth bores in the two housing halves will preferably include flats for anti-rotation purposes.
Preferably, rod 42 includes at least one end terminating in a ball 48 which interacts with a socket joint (not shown) on an adjustable headlamp assembly. The interaction of the ball 48 and the manner of use for assembly 10 can be readily understood by reference to U.S. Pat. No. 4,742,435, issued May 3, 1988 for Support Arrangement for a Vehicle Headlamp.
When the two halves of the housing are mated, two cantilevered catches 50 on housing half 14 snap over resilient beveled latch tabs 50a on housing half 12 (see FIG. 1) to maintain the assembly 10 in its closed position. Many types of resilient latch or lock members, as well as other selectively releasable fasteners, could be used for this purpose.
Housing half 14 preferably includes a recess 56 which receives a complementary projection (not shown) on housing half 12 to achieve and maintain alignment of halves 12 and 14 in the closed position.
In its preferred embodiment, one half of housing 12 or 14 includes tabs 54 which interact with slots or openings (not shown) on a frame or superstructure of an automobile to attach headlamp adjustment apparatus 10 in its operative position.
The adjustment assembly of this invention is compatible with a variety of adjustable headlamp units known to those skilled in the art. As stated earlier, each of the identified parts in FIGS. 1 and 2 are preferably injection molded of plastic or similar moldable resinous material to resist the corrosive elements to which automobiles are often exposed. In addition, although the preferred embodiment is comprised wholly of plastic, several features of the invention are improvements in the art even when formed of traditional materials such as metals or alloys. As is apparent from the foregoing, the subject invention provides simple, easily manufactured and operated, and long-lived headlamp adjustment mechanism.
While the invention has been described with reference to a preferred embodiment, it is apparent that variations and modifications will occur to others upon a reading and understanding of the subject specification. It is intended to include such variations and modifications as part of our invention insofar as they come within the scope of the claims.
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A headlight adjustment mechanism comprised of interactive plastic drive and adjustment bevel gears located within a two-piece plastic housing wherein a threaded adjustment rod passes through a threaded axial bore in the adjustment bevel gear. Cooperating flats on the adjustment rod and the drive gear prevent rotation of the adjustment rod during rotation of the adjustment gear.
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BACKGROUND OF THE INVENTION
This invention relates to underground boring devices they may be steered along a chosen path while boring. More specifically, but without limitation, the present invention relates to continuously rotating, steerable, waterjet drillheads located in the forwardly facing end of a hollow, pushed drillstring. The drillhead receives high pressure water from within the drill string and selectively directs, through the appropriate, forwardly facing nozzles, high pressure cutting jets of drilling fluid to cut a curved tunnel that the pushed drillstring will follow. In this way the waterjet drillhead may be continuously steered along a desired path. When installing inground cable, conduit or pipe such as power cables, telephone lines, fiber optic cable, gas lines, water lines or the like the method of trenching is commonly employed. However, when traversing urban areas containing streets, driveways, utilities, buildings and other "obstacles", continuous trenching is sometimes impossible. For military use, it is also desirable to traverse long distances without trenching; for example, when laying a fiber optic cable or pipeline under a beach. It is therefore, highly desirable to have the capability of providing a continuous, underground tunnel for installing cable, conduit, pipe or the like at distances of up to 25,000 feet or more. It is also desirable to steer the apparatus that can provide such an underground tunnel.
It is therefore desirable to provide a horizontal drilling system (HDS) that can reach out to very long distances of up to 25,000 feet and more in favorable conditions. However, when drilling at horizontal distances of up to 25,000 feet and more, frictional forces and push forces become very large and result in failure by buckling and/or joint failure of the drillstring. The long drilling distances also require steerability of the drillstring to accomplish both reasonable accuracy and to navigate down and under an obstacle and then up again, for example. To provide such a system, it is necessary to minimize the friction resulting from the drillstring and drillhead. Accordingly, a hollow, continuously rotating drillstring (to reduce torsion and push forces) with constant inside diameter (for pigging capability) and constant outside diameter (for reducing friction between the drillstring and the bored tunnel) is preferred. Water jet cutting (to minimize push forces and add tension to overcome buckling) and using the drillstring as a conduit for supplying pressurized drilling fluid are also preferred.
Previous systems for steering (deviating) a drillstring are inadequate to operate under these parameters and are themeselves unable to accomplish these objectives.
One jetting technique for deviating a well from vertical includes orientating a large jet at the downhole end and towards the desired direction of deviation, initiating pumping to erode the hole in that direction, applying a high bit weight and then reciprocating the drillstring. After making a few feet, the hole is conventionaly drilled for about 20 feet and the procedure is repeated until the desired angle is obtained. This method, however, requires the drillstring to be completely non-rotating during the procedure. Other well known methods for deviating a well include a bent sub with a downhole mud motor; employing a whipstick; and using a rebal tool.
U.S. Pat. No. 4,930,586 to Turin et al, dated Jun. 5, 1990 discloses a fluid jet method and apparatus that uses poppet valves to control the discharge of a portion of the drilling fluid in radical directions forming steering jets.
U.S. Pat. Nos. 4,714,118; 4,821,815 and 4,856,600 to Baker et al discloses a fluid jet apparatus and technique that utilize a forward facing, off-axis high pressure rotating jet that is pushed through the soil. The boring device is steered by modulating the rotational speed of the off axis jet and/or by modulating the direction of rotation to cause the boring device to deviate.
Still another device in U.S. Pat. No. 5,148,880 to Lee et al, discloses a downhole tool with a fluid discharge nozzle parallel to the centerline axis of the tool and a blade for directing the fluid exiting the nozzle to an acute angle relative to the drillstring thereby cutting an elongate bore.
However, all these devices are inadequate for drilling long, horizontal bores of distance of up to 25,000 feet and more. Some require the drillstring to be stopped to orientate a cutting jet in the desired direction of deviation. Others require the drillstring to be removed from the hole to install a device to physically force the drillhead in a given direction. Some only permit one deviation, for example, from vertical to horizontal.
It is therefore an object of the present invention to provide an apparatus for boring a continuous underground tunnel either straight ahead (on axis) or deviating to the side (off axis).
It is another object of the present invention to provide and apparatus for boring a continuous underground tunnel that may be used with a hollow, continuously rotating, pushed drillstring.
It is a further object of the present invention to provide an apparatus to drill a continuous underground tunnel by means of high pressure fluid jets.
It is another object of the present invention to provide an apparatus for boring a continuous underground tunnel to distance out to 25,000 feet and more.
SUMMARY OF THE INVENTION
Accordingly, the steerable drillhead of the present invention is located inside of the forward end of a continuously rotating, pushed drillstring. The steerable drillhead includes a radially ported, generally elongate housing with a forwardly attached discharge nozzle and a rearwardly protruding driveshaft; a rotatable valve located in the housing and attached to the driveshaft; an insert that supports the driveshaft and piston and seals against rearwardly flowing drilling fluid; a baseplate located between the valve and the nozzle; and a seal located around the nozzle.
In operation, the rotatable valve receives pressurized water from the radial ports in the housing, directs the water forwardly through internal bores in the valve, to either a first set of bores when the valve is rotated in one direction or to a second set of bores when the valve is rotated in the other direction. Flow through the first set of bores causes a forwardly discharge from the nozzle approximately equal to the diameter of the drillstring that cuts a concentric tunnel and permits the pushed drillstring to travel straight ahead. Flow through the second set of bores causes a forwardly discharge from the nozzle larger than the diameter of the drillstring. By turning the second set of bores "on" only during, for example, the same 1/4 rotation of each revolution and by turning the first set of bores "on" only during the remaining 3/4 rotation of each revolution, the forwardly discharge from the nozzle cuts a non-concentric, oblong tunnel that permits the pushed drillstring to travel in a deviated direction. By selecting a different 1/4 rotation (quadrant) of each revolution, a non-concentric, oblong tunnel may be cut in any one of 4 quadrants; up, down, to the right or to the left. The steerable drillhead is attached forwardly of a mount, gearbox, motor, electronics and batteries.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings in which:
FIG. 1 is a drawing showing the steerable drillhead (SDH) assembly 2 located in drillstring 14.
FIG. 1a is a cross-section of a typical joint of drillstring 14.
FIG. 1b is a drawing showing steerable drillhead assembly 2 along with the major ancillary equipment found in a drilling operation.
FIG. 2 is representation showing the orientation of the four drilling quadrants, in the preferred embodiment, that SDH assembly 2 may be deviated.
FIG. 3 is a side view, partly in cross-section, of SDH assembly 2.
FIG. 4 is a side view of driveshaft 24.
FIG. 4a is an end view of driveshaft 24.
FIG. 4b is an end view of driveshaft 24.
FIG. 5 is a side view of coupler 21.
FIG. 5a is an end view of coupler 21.
FIG. 6 is a side view in cross-section of housing 22.
FIG. 7 is a side view in cross-section of insert 26.
FIG. 8 is a side view in cross-section of valve 28.
FIG. 8a is a top view of valve 28.
FIG. 8b is an end view of valve 28.
FIG. 8c is an end view of valve 28.
FIG. 9 is a cross-section taken through section 9--9 of FIG. 9a.
FIG. 9a is an end view of baseplate 30.
FIG. 9b is a cross-section of a typical bore shape change for bore 82c, 86c or 110a.
FIG. 10 is an end view of baseplate 30.
FIG. 10a is a cross-section taken through sections 10a--10a of FIG. 9a.
FIG. 11 is an end view of nozzle 32.
FIG. 11a is a cross-section taken through section 11a--11a of FIG. 11.
FIG. 11b is a cross-section taken through section 11b--11b of FIG. 11.
FIG. 11c is an end view of nozzle 32.
FIG. 11d is a cross-section of inserts 184.
FIG. 12 is a table showing the angles of bores in nozzle 32 for three configurations of nozzle 32.
FIG. 12a is a table showing the diameters of bores in nozzle 32 for three configurations of nozzle 32 at different flow rates and back pressures.
FIG. 13 is a diagram showing the cross-sectional area cut by each of the four cutting bores and the four quadrants (directions) that SDH 2 may be deviated.
FIG. 14 is a diagram of a theoretical deviated bore, in cross-section, when operating SDH 2 to deviate upwardly (ie. into quadrant 1).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The steerable drillhead (SDH) assembly 2 of the present invention is illustrated by way of example in FIGS. 1-14. As shown in FIGS. 1, 1a and 1b, SDH assembly 2 is shown inside rotating drillstring 14 and providing a continuous underground tunnel between a first entry point "A" and second spaced apart exit point (not shown). Drillstring 14 is made up of a plurality of segments, usually 20 feet long, screwably joined to form a continuous length of up to 25,000 feet or more. Each segment has a threaded male end 14a and a threaded female end 14b screwably joined and forming a substantially constant inside and outside diameter. The constant outside diameter reduces friction between rotating drillstring 14 and the bored tunnel and the constant inside diameter allows the SDH assembly 2 to be inserted into and propelled through drillstring 14 by the use of pressurized drilling fluid, such as water. In the preferred embodiment drillstring 14 is made from 4145 steel alloy and is 4.75 inches O.D. and 3.5 inches I.D.
When SDH assembly 2 is installed in drillstring 14, SDH assembly 2 is both retained and sealed in drillstring 14, as shown in FIG. 1, by reduced diameter section 15 of drillstring 14. In this position, nose 165 is approximately flush with end 17 of drillstring 14.
FIG. 1b shows the system configuration for a typical drilling operation using, for example, the SDH assembly 2 of the present invention. In the preferred embodiment, hydraulic launcher 16 provides rotation of drillstring 14 in a speed range from 0-10 rpm; a maximum torque of 55,000 ft-lbs; and push/pull forces of 280/320 kips, respectively. Pump 18, driven by motor 25, receives water from reservoir 20 and is capable of delivering up to 15,000 psi, at a flow rate up to 200 gpm through drillstring 14 to SDH assembly 2.
SDH assembly 2 provides steering control to drillstring 14 and is a self-contained, battery-operated device that selectively directs high pressure water through a series of orifices and into the area immediately ahead of drillstring 14. The selectively directed high pressure water breaks up the material in the desired direction of travel and pushed drillstring 14 "follows" the bored path. In this way, SDH assembly 2 can be programmed to drill straight ahead or in the direction of any one of the four quadrants shown in FIG. 2. It is to be understood that in the preferred embodiment 4 quadrants were chosen as possible directions to deviate drillstring 14, however the scope of the invention should not be limited to only those possible directions, since virtually any combination of off-axis paths can be drilled.
FIG. 3 shows a cross section of drillhead 12 attached by screws 11 to mount 10, gearbox 8, motor 6, electronics 5 and batteries 4. Casing 170 attaches to the rear portion of drillhead 12.
As shown in FIG. 3, drillhead 12 includes housing 22, driveshaft 2, insert 26, valve 28, baseplate 30, nozzle 32 and seal 166. Driveshaft 24 is rotatably located in housing 22 via caged needle bearing 34 which rides on race 36. Referring to FIGS. 4, 4a, 4b and 3, squared end 38 slidably engages bore 23 of coupler 21. Thrust bearing 40 is located around race 42 and abuts shoulder 44 on one side and abuts thrust washer 46 on the other side. Shaft 60 of driveshaft 24 extends through and is sealed in bore 62 of insert 26 (See FIG. 7) by o-ring 64 located in groove 66 and by seal 68 located in bore 70. Shoulder 63 of driveshaft 24 is located adjacent shoulder 65 of insert 26. The rearward facing side of thrust washer 46 abuts face 47 of housing 22.
Insert 26 is located in housing 22 and is sealed by 1st o-ring 48 in groove 52 abutting bore 56 (See FIG. 6) of housing 22 and by second o-ring 50 in groove 54 abutting bore 58 of housing 22.
Squared end 72 of driveshaft 24 (See FIGS. 4 and 4b) communicates with bore 74 in valve 28 (See FIGS. 8, 8a, and 8b). Shoulder 76 of valve 28 sealably communicates with seal 78 located in bore 80 of insert 26. It can thus be seen that coupler 21, driveshaft 24 and valve 28 rotate as a unit.
Referring now to FIGS. 8-8c, elongated bores 82a, 84a, 86a and 88a are located around the circumference of valve 28. (Note, in FIG. 8b, that the bores are not evenly spaced around the circumference of valve 28.) As can be seen from the drawings, elongated bore 82a changes shape from an elongated bore at 82a (as viewed in FIG. 8a) to a circular bore 82b (as viewed in FIG. 8c). In a similar fashion, elongated bores 84a, 86a and 88a change shape to circular bores 84b, 86b and 88b, respectively. All 4 bores exit valve 28 at face 102. Hollow stop pin 98 is located in bore 100 and extends outwardly from face 102. It should be noted that the forwardly portion of circular bore 86b is the inside of hollow stop pin 98.
Caged roller bearing 104 is located in bore 106 and dowel pin 108 (shown in FIG. 3), is rotatably located therein extending outwardly from face 102. Bleed port 110 extends from bore 74 to face 102.
Face 102 of valve 28 abuts face 112 of baseplate 30 and dowel pin 108 engages bore 114. Hollow stop pin 98 is located in elongated bore 86c. It can thus be seen that valve 28 may be rotated relative to baseplate 30, the rotation limited in one direction by hollow stop pin 98 contacting face 118 of elongated bore 86c and the rotation limited in the other direction by hollow stop pin 98 contacting face 120 of elongated bore 86c. Elongated bore 86c changes shape to circular bore 86d (see FIG. 9b for a typical cross section) and exits baseplate 30 at face 124.
Bore 82b and bleed port 110 communicate with elongated bores 82c and 110a, respectively. Elongated bore 82c changes shape to circular bore 82d and elongated bore 110a changes shape to circular bore 110b. FIG. 9b shows a typical cross section of the shape change of bores 82e, 86c and 110a. It can now be appreciated that since the rotation of valve 28 relative to baseplate 30 is limited, bores 82b, 86b and 110 in valve 28 are, at all times, communicating with their respective bores 82c, 86c and 110a in baseplate 30. However, bore 88b communicates with bore 88c only when valve 28 is rotated in a first direction (i.e. clockwise) relative to baseplate 30, when viewed from the front as shown in FIG. 3. In a similar fashion, bore 84b communicates with bore 84c only when valve 28 is rotated in a second direction (i.e. counterclockwise) relative to baseplate 30, when viewed from the front as shown in FIG. 3.
In this way, bores 84c and 88c may be turned "on" and "off" with one bore always in the "on" or flowing alignment. It should be noted that there is some overlap between these 2 bores when transitioning from flow in one bore or the other which prevents stopping the flow of drilling fluid (ie. water) to these 2 bores altogether. When one bore is "on" the other is "off". Accordingly, shock loads due to inertia effects are significantly reduced.
Face 124 of baseplate 30 abuts face 138 of nozzle 32 and dowel pin 140 communicates with both bore 142 of baseplate 30 and with bore 144 of nozzle 32, thereby positioning the bores in baseplate 30 with the corresponding bores in nozzle 32. O-rings 146 are located in grooves 148, 150 and 152. As shown in FIGS. 10 and 11, bleed port 110b aligns with bore 110c in nozzle 32; bore 82d aligns with bore 82e; bore 86d aligns with bore 86c; bore 88d aligns with bore 88e; and bore 84d aligns with bore 84e. FIG. 11c shows the location of the bores as they exit end 165 of nozzle 32. FIG. 12 is a table showing the angles that the centerline of bores 86e-f; 82e-f; 88e-f; and 84e-f make with the centerline of nozzel 32. Each configuration requires a different nozzle 32.
Bores 86e/f and 82e/f in FIG. 12, should be read in conjunction with FIG. 11a. Note that the centerline of bore 86e/f is directed inwardly towards the centerline of nozzel 32 and is denoted with a minus (-) designation. All other bore centerlines are directed outwardly, away from the centerline of nozzel 32 and are denoted as a positive (+) value. Bores 84e/f and 88e/f in FIG. 12, should be read in conjunction with FIG. 11b. Configuration 2 (narrow) is preferred for highly consolidated (ie. hard) material such as rock, quartz or granite. Configuration 3 (wide) is preferred for soft materials such as sandstone and shale. Configuration 1 (medium) is preferred for medium consolidation that lies between configuration 2 and 3. Other configurations may be employed for specific applications, as desired. Bores 86f, 82f, 88f and 84f may also have different diameters and to facilitate changes in these diameters inserts 184 (see FIG. 11d) may be inserted into each bore. The inserts may also be of a hardened material to improve wear resistance. The diameter of the bores are a function of the flow rate, back pressure at nozzel face 165, and the material that is being cut. FIG. 12a shows the preferred orifice diameters for various combinations of flow rate and back pressure. Other combinations may be adopted by those skilled in the art for various materials. Note in FIG. 11d that bores 86e, 82e, 88e and 84e have the following diameters, respectively: 0.216", 0.271", 0.334", and 0.334".
As shown in FIG. 3, nozzle 32 screwably attaches to housing 22 via threads 164. Seal 166 attaches around nozzle 32/housing 22 interface and includes a tapered, forward extending portion 168 which seals with reduced diameter section 15 of drillstring 14 (see FIG. 4) . Casing 170 is attached to housing 22 via threads 172 and is sealed by o-rings 174.
In operation, SDH assembly 2 is inserted into drillstring 14 and pigged to the forward end by pressurized water until seal 166 abuts and seals with reduced diameter section 15 of drillstring 14. In this position, nose 165 is approximately flush with end 17 of drillstring 14. Pressurized water flows through the annular space between drillstring 14 and casing 170 and into four equally spaced square ports 176 located in housing 22 (see FIGS. 3 and 6). Ports 176 are covered by filter screens 178 to prevent the entry of harmful debris. Water then flows into bores 82a, 84a, 86a and 88a of valve 28 and forwardly towards baseplate 30. Bores 86a to 86f are at all times hydraulically communicating and pressurized water will therefore always flow from bore 86f, cutting away (ie. drilling) a generally circular area shown as 86f in FIG. 13. Similarly, bores 82a to 82f are at all times communicating and therefore will cut away a generally annular area shown as 82f in FIG. 13. Note that drillstring 14 is rotating counterclockwise when viewed from the front, as shown in FIG. 3, so that the preferred right hand threads of the drillstring segments 14 will always be tightening to maintain a fight joint 14c (FIG. 1a). If it is desired to cut straight ahead, valve 28 is caused to rotate clockwise, (when viewed from the front as shown in FIG. 3) relative to baseplate 30, thereby aligning bore 88b with 88c at the valve/baseplate interface and permitting the flow of water through bores 88a to 88f and cutting the generally annular area shown as 88f in FIG. 13. Note, that the combined areas cut by bores 86f, 82f and 88f is just slightly larger in diameter than drillstring 14. Pushed drillstring 14 will then advance straight ahead into this cut area. When cutting straight ahead, bore 84f will remain off.
When it is desired to deviate drillstring 14 away from cutting in the straight ahead mode, drillhead 12 may be operated, in the prefered embodiment, to deviate in the direction of any one of the quadrants (ie. 1,2,3 or 4) shown in FIGS. 2 and 13. (Note that FIGS. 2 and 13 are views looking at the front of SDH 2 and therefore quadrant 2 is to the right and quadrant 4 is to the left).
To deviate, for example, upwardly (towards quadrant 1), bore 84f is turned "on" between points "C" and "D" during each rotation of drillstring 14 and turned "off" between points "D" and "C" during each rotation of drillstring 14 thus cutting the area designated 84f in FIG. 14. Since bores 84f and 88f operate in an opposite fashion, bore 84f is "off" when bore 88f is "on" and vice versa. Bore 88f will be "on" between points "D" and "C" cutting the area designated as 88f in FIG. 14. Bores 86f and 82f are always "on" and cut the area designated as 86f and 82f, respectively, as shown in FIG. 14. Note that the radially inward portion of area 84f overlaps area 88f. Also note, that in practice, bores 84f and 88f are not turned "on" and "off" instantaneously so that the actual area cut will approximate the area shown in FIG. 14. As material is cut, pushed drillstring 14 will follow the deviated path towards area 84f in quadrant 1 (FIG. 14) and turn from a straight ahead path to an upwardly path.
It can now be appreciated, that drillstring 14 may be steered in any direction by simply rotating valve 28 in one direction or the other at the appropriate time during each rotation of drillstring 14. A non-concentric, oblong path may be cut in any desired direction. The preferred embodiment uses 4 quadrants for deviation.
In the preferred embodiment, SDH 2 may operate in conjunction with logging tool 19 which provides real time location information including azimuth and depth. Drillstring length is determined by pigging logging tool 19, with attached cable, down to SDH 2 and recording the length of cable used. When it is desired to determine the locatin of SDH 2, drilling is suspended and drillstring 14 continues to rotate. Logging tool 19 is then pigged to SDH 2 and the location information is sent back via the attached cable to information center 13 and analyzed to determine position. SDH 2 is then instructed to drill straight ahead or in one of the 4 available quadrants.
SDH assembly 2 operates with pressurized water of up to 15,000 psi and above, and therefore considerable forces are present in drillhead 12 which affects the force required to rotate driveshaft 24/valve 28. Since SDH assembly 2 is a self continued, battery powered, limited size device with limited power and operational time,, it is necessary to maximize operating characteristics to increase operating time. Accordingly, gearbox 8 increases the torque output of motor 6 to driveshaft 24. Thrust bearing 40 is fitted and reduces the force required to rotate driveshaft 24/valve 28. In addition, bleedport 110 to 110d "balances" valve 28 so that the sum of the forces tending to move valve 28 forwardly approximately equals the forces tending to move valve 28 rearwardly. Thus, bleedport 110 communicates with high pressure area 180 in bore 74 of valve 8 (see FIGS. 8 and 8a) and with lower pressure area 182 at nose 165 of nozzle 32 (see FIGS. 3 and 11a).
Obviously, many modifications and varations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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An apparatus for boring a continuous underground tunnel and located insidef the forward end of a continuously rotating, pushed drillstring includes a housing for receiving pressurized drilling fluid, a nozzle including bores, attached forwardly to the housing for discharging the pressurized drilling fluid from the nozzle, a rotatable valve located in said housing for receiving and forwardly directing pressurized drilling fluid from the housing to the nozzle. The valve may be rotated in a 1st position, thereby directing the pressurized drilling fluid to a first set of bores in the nozzle for boring straight ahead. The valve may also be rotated in a 2nd position, thereby directing the pressurized drilling fluid to a second set of bores. By maintaining the valve in the 1st position for 1/4 rotation of each revolution of the drillstring and then maintaining the valve in the 2nd position for the remaining 3/4 rotation of each revolution of the drillstring, an off axis (curved) tunnel may be bored.
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RELATED APPLICATION
This application is a division of application Ser. No. 11/015,483, filed Dec. 16, 2004, which claims priority under 35 U.S.C. § 119(e) to Provisional Application No. 60/531,526, filed Dec. 18, 2003, the disclosures of which are hereby incorporated by reference in their entirety and are hereby made a part of this specification.
FIELD OF THE INVENTION
The invention relates to a method for cleaning semiconductor surfaces to achieve to removal of all kinds of contamination (particulate, metallic, and organic) in one cleaning step. The method employs a cleaning solution for treating semiconductor surfaces which is stable and provokes less or no metal precipitation on the semiconductor surface.
BACKGROUND OF THE INVENTION
The conventional RCA cleaning s for semiconductor substrates consists of two steps involving different solutions: an alkaline solution, the so called SC1 solution and an acidic solution, SC2. The SC1 solution is composed of 1 part ammonia (NH 4 OH), 1 part hydrogen peroxide (H 2 O 2 ) and 5 parts ultra pure water (H 2 O) and is often referred to as APM-cleaning (i.e. Ammonia Peroxide Mixture). Originally, it was used to remove organic residues by oxidation. Later it has been proven to be very efficient to remove particles.
A drawback of the SC1 solution is that metallic contamination such as Fe and Cu are found to catalyze the decomposition reaction of the peroxide (see e.g. Mertens et al., Proc. of the 5 th Internat. Symp. on Cleaning Technology in Semiconductor Device Manufacturing PV97-35 (1997)) leading to a decrease in the bath lifetime.
Chemical solutions comprising an oxidizing compound have often problems related to the stability of the solution. In pure form, aqueous solutions are stable over extended periods of time. However, the presence of certain metal ions in the solution causes decomposition of the oxidizing compound. Consequently, stabilizers to prevent such decomposition are preferably added. Stabilizers can include, e.g., a complexing compound, such that the complexing compound will bind to the metal, and consequently the metal is not available for reaction with the oxidizing compound. Thus, the decomposition of the oxidizing compound is substantially inhibited and the lifetime of the solution is increased.
Very stringent specifications must be met by oxidizing solutions for specialized applications such as semiconductor applications or reagent chemicals.
An overview of stabilizing oxidizing compound, and more specifically hydrogen peroxide solutions, is given in Kirk-Othmer Encyclopedia of Chemical Technology (4 th edition), vol. 13 pg 965.
Another problem associated with SC1 cleaning solutions is that metals precipitate on silicon surfaces. Aluminum, iron and zinc especially have been shown to adsorb strongly on the wafer surface (see e.g. Mertens et al., Proc. of the 8 th Internat. Symp. On Silicon Materials Science and Technology PV98-1 (1998)). In order to remove the metallic surface contamination, the SC2 solution consisting of 1 part hydrochloric acid, 1 part hydrogen peroxide and 6 parts ultra-pure water is used. However, it is expensive to obtain hydrochloric acid of sufficient quality for the usage in SC2 solution. There is also a risk of re-contaminating the surface with particles. Problems also occur in spray tools due the corrosive behavior of hydrochloric acid.
With the progress in semiconductor manufacturing the requirements concerning particle and metal contamination as well as roughness of the silicon surfaces became more stringent. This led to a number of variations of the RCA clean.
The potential problems related to the SC2 and the consideration to reduce process time and equipment by leaving out this acidic step led to the development of single-stage cleaning procedures. This can be done by using chemicals with reduced amount of metallic impurities. For that purpose, advanced purification procedures are established for obtaining ultra-pure water, ammonia and hydrogen peroxide. However, these chemicals are very expensive and the purity is not always assured when they are used in a cleaning bath. Moreover, the cleaning solution is not very robust with respect to metal contamination from the semiconductor substrate and from the hardware.
Besides this, an extra step in the cleaning cycle to remove residual metallic contamination implies extra hardware, e.g., a SC2-tank and a rinse tank need to be used, and more chemicals. Leaving out this extra step results in a reduction of the hardware cost and a reduction of the amount of chemicals used in the cleaning cycle.
U.S. Pat. No. 5,466,389 describes cleaning solutions containing a complexing agent such as EDTA in combination with a nonionic surfactant. However, these cleaning solutions suffer from the drawback of weak stability of EDTA in peroxide containing cleaning solutions. In addition, in general, nonionic surfactants cannot be rinsed off easily from the wafer surface and traces of organic contamination are left on the wafer surface.
U.S. Pat. No. 5,885,362 describes a method for treating a surface of a substrate with a surface treatment composition. The surface treatment composition comprises a liquid medium containing a complexing agent as a metal deposition preventive. The surface treatment composition is improved by incorporating at least two complexing agents. A first complexing agent is preferably an aromatic hydrocarbon ring with at least an OH or O − group bonded to a carbon atom constituting the ring. A second complexing agent is compound having a donor atom, in the molecular structure.
U.S. Pat. Nos. 5,290,361 and 5,302,311 describe an aqueous hydrogen peroxide solution further comprising a complexing compound containing phosphonic acid groups and showing complexing ability. Cleaning solutions comprising phosphonic acid groups are not effective because enhanced deposition of Cu has been measured. In addition, there is always a risk of leaving P-contamination on the wafer surface which makes the cleaning solutions less suitable.
U.S. Pat. Nos. 5,280,746 and 5,840,127 describe the use complexing agents with hydroxamate functional groups. However, these complexing agents have limited stability in cleaning solutions containing peroxide.
U.S. Pat. No. 6,066,609 describes an aqueous cleaning solution comprising a base, hydrogen peroxide and a complexing agent being a crown ether with sidegroups able to complex metallic species. However the phosphonic acid side groups may also contribute to unwanted P contamination on the wafer surface. In addition, these complexing agents show a limited stability and a lower metal removal performance.
SUMMARY OF THE INVENTION
In the preferred embodiments, the problems related to removal of metals as mentioned above in regard to the prior art methods and solutions are avoided. The new solution for treating a surface is preferably stable and provokes less or no metal precipitation on the surface.
A new single-step method is provided for cleaning semiconductor surfaces so as to removal of all kinds of contamination (particulate, metallic and organic) in one cleaning step.
In a first aspect, a composition is provided comprising an alkaline compound and a complexing compound having a chemical formula as depicted Formula I:
wherein X is selected from the group consisting of NO 2 and SO 3 H; and wherein R 1 , R 2 , and R 3 are independently selected from the group consisting of a hydrocarbyl group and hydrogen.
In an embodiment of the first aspect, SO 3 H is in an acidic form or in a form of a salt.
In an embodiment of the first aspect, the composition further comprises an oxidizing compound.
In an embodiment of the first aspect, the composition is in the form of an aqueous composition.
In an embodiment of the first aspect, R 1 , R 2 , and R 3 are hydrogen.
In an embodiment of the first aspect, the hydrocarbyl group is an alkyl chain.
In an embodiment of the first aspect, the hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, isopropyl, and butyl.
In an embodiment of the first aspect, the complexing compound has a chemical formula as represented in Formula II:
In an embodiment of the first aspect, the complexing compound has a chemical formula as represented in Formula IIb:
In an embodiment of the first aspect, the alkaline compound comprises an inorganic basic compound or an organic basic compound.
In an embodiment of the first aspect, the alkaline compound is selected from the group consisting of ammonia and organic amine.
In an embodiment of the first aspect, the organic amine is selected from the group consisting of choline(hydroxyltrialkylammoniumhydroxide), guanidine compounds, alkanolamine, and tetraalkylammoniumhydroxide.
In an embodiment of the first aspect, the composition further comprises an oxidizing compound selected from the group consisting of hydrogen peroxide and an oxidizing anion.
In an embodiment of the first aspect, the composition further comprises from about 0.001 weight % to about 30 weight % of an oxidizing compound.
In an embodiment of the first aspect, the composition comprises from about 0.001 weight % to about 10 weight % of the complexing compound.
In an embodiment of the first aspect, the composition comprises from about 0.001 weight % to about 30 weight % of the alkaline compound.
In a second aspect, a method for treating a semiconductor substrate is provided, the method comprising treating the semiconductor substrate with a composition comprising a complexing compound having a chemical formula as depicted Formula I:
wherein X is selected from the group consisting of NO 2 and SO 3 H; and wherein R 1 , R 2 , and R 3 are independently selected from the group consisting of a hydrocarbyl group and hydrogen.
In an embodiment of the second aspect, the composition is an aqueous composition.
In an embodiment of the second aspect, the composition further comprises an oxidizing compound.
In an embodiment of the second aspect, the composition further comprises an alkaline compound.
In an embodiment of the second aspect, R 1 , R 2 , and R 3 are hydrogen.
In an embodiment of the second aspect, the hydrocarbyl group is an alkyl chain.
In an embodiment of the second aspect, the hydrocarbyl group is selected from the group consisting of methyl, ethyl, propyl, isopropyl, and butyl.
In an embodiment of the second aspect, the complexing compound has a chemical formula as represented in Formula II:
In an embodiment of the second aspect, the complexing compound has a chemical formula as represented in Formula IIb:
In an embodiment of the second aspect, the composition further comprises an oxidizing compound selected from the group consisting of hydrogen peroxide and an oxidizing anion.
In an embodiment of the second aspect, the composition further comprises an alkaline compound comprising an inorganic basic compound or an organic basic compound.
In an embodiment of the second aspect, the alkaline compound is selected from the group consisting of ammonia and organic amine.
In an embodiment of the second aspect, the organic amine is selected from the group consisting of choline(hydroxyltrialkylammoniumhydroxide), guanidine compounds, alkanolamine, and tetraalkylammoniumhydroxide.
In an embodiment of the second aspect, the composition further comprises from about 0.001 weight % to about 30 weight % of an oxidizing compound.
In an embodiment of the second aspect, the composition comprises from about 0.001 weight % to about 10 weight % of the complexing compound.
In an embodiment of the second aspect, the composition further comprises from about 0.001 weight % to about 30 weight % of an alkaline compound.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the molecular structure of the complexing compound.
FIG. 2 depicts the molecular structure of the complexing molecules according to a preferred embodiment.
FIG. 3 depicts Fe removal efficiency of different complexing agents as function of bath age.
FIG. 4 depicts Fe removal efficiency of different complexing agents as function of bath age.
FIG. 5 depicts the effect of EDTA and nitrocatechol on the decomposition reaction of peroxide in an APM cleaning mixture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description and examples illustrate a preferred embodiment of the present invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a preferred embodiment should not be deemed to limit the scope of the present invention.
In a preferred embodiment, a novel composition is disclosed. The composition comprises a complexing compound and an alkaline compound. The composition can further comprise an oxidizing compound. The composition can be in the form of an aqueous solution.
The complexing compound can have a chemical formula as given in FIG. 1 , wherein X is selected from the group consisting of NO 2 or SO 3 H, and wherein R 1 , R 2 , and R 3 are a hydrocarbyl group or hydrogen. R 1 , R 2 , and R 3 can be selected from the group consisting of methyl, ethyl, or (iso)propyl or butyl. Most preferably, R 1 , R 2 , and R 3 are each hydrogen. When X is SO 3 H, the complexing compound can be in acidic form or in the form of a salt. The salt is preferably an ammonium salt.
In another embodiment, R 1 , R 2 , and R 3 are independently selected from the group comprising hydrogen (H) or any organic group. R 1 , R 2 , and R 3 can have a different chemical structure. The organic group can be any possible sequence of C, N, O or S atoms linked to each other by single, double, or triple bonds such that the first compound complexes the desired metals. The organic group can be selected from the group comprising aliphatic side chains, heterocycles, and aromatic structures.
The organic side chain is any possible sequence of carbon atoms linked to each other by a single, double, or triple bound, and optionally is characterized by the presence of functional groups linked to the carbon atoms. Functional groups can be alcohol, carboxyl, carbonyl, aldehyde, ketone, ether, ester, amine, amide, or halogen containing groups.
The heterocycle can a crown ether, a cryptant, a calixarene, or the like.
The complexing compound preferably has a chemical structure such that at least aluminum is complexed. Furthermore, the chemical structure is such that Fe and Zn are complexed.
Although the amount of the complexing compound is not particularly limited, it is determined by the degree of metal contamination and on the kind of other compounds being present in the solution. Furthermore, the amount of complexing compound is determined by the specific chemical structure of the complexing compound. In an embodiment, the amount of the complexing agent in the composition can be from about 10 −4 weight % to about 10 weight %, preferably from about 10 −3 weight % to about 1 weight %.
For the purpose of the preferred embodiments, weight % is understood as the percentage of weight of the specified compound in the composition.
In a preferred embodiment, the complexing compound is represented in FIG. 2 a or 2 b . For the purpose of the preferred embodiments, the complexing compound represented in FIG. 2 a will be referred to as nitrocatechol, while the complexing compound as represented in FIG. 2 b will be referred to as sulfocatechol. The complexing compound has a chemical composition such that at least Aluminum is complexed. Moreover, iron, copper and zinc are preferably complexed.
The composition as provided in the first aspect can be used to reduce the concentration of the metals on the surface of the substrate or in a solution.
The oxidizing compound is a chemical compound having oxidizing properties towards organic species, metallic compounds, inorganic particles, silicon, and the like.
The oxidizing compound is a compound selected from the group comprising hydrogen peroxide or oxidizing anions. The oxidizing anions can be, e.g., nitric acid and its salts, nitrate, persulfate, periodate, perbromate, perchlorate, iodate, bromate and chlorate salts of ammonium. Preferably, the oxidizing compound is hydrogen peroxide.
The concentration of the oxidizing compound can be, but is not limited hereto, to from about 0.0001 weight % to about 99 weight %, preferably from about 0.001 weight % to about 90 weight %, and more preferably from about 0.001 weight % to about 30 weight %.
The alkaline compound or base can be any chemical compound with a pH higher than about 7. The alkaline compound can be an organic or inorganic compound. The alkaline compound can be an organic base, ammonia, ammonium hydroxide, or an alkaline solution containing metal ions such as potassium or sodium. The organic base can be a quaternary ammonium hydroxide such as tetraalkyl ammonium hydroxide in which the alkyl groups can contain hydroxy- and alkoxy-containing groups with 1, 2, 3, or 4 carbon atoms in the alkyl or alkoxy group. The organic base can further be an organic amine such as an alkanol amine. Alkanol amines can be 2-aminoethanol, 1-amino 2-propanol, 1-amino 3-propanol. Preferably, the alkaline compounds are tetramethyl ammonium hydroxide, and trimethyl 2-hydroxy ethyl ammonium hydroxide (choline) and ammonium hydroxide.
The amount of the alkaline compound is preferably from about 0.0001 weight % to about 90 weight % of the composition, more preferably from about 0.001 weight % to about 50 weight %, and most preferably from about 0.001 weight % to about 30 weight %.
The composition can further comprise a surfactant.
A surfactant is a surface-active agent comprising a lyophobic group and a lyophilic group. The lyophobic group can be a straight-chain alkyl group or a branched-chain alkyl group (from C8 to C20), a long-chain (from C8 to C20) alkyl benzene residue, an alkylnaphthalene residue (C3 and higher alkyl groups), high-molecular-weight propylene oxide polymers (polyoxypropylene glycol derivatives), long-chain perfluoroalkyl, or polysiloxane groups.
Depending upon the lyophilic group, the surfactant can be an anionic, cationic, nonionic or zwitterionic surfactant. Anionic surfactants can be carboxylic acids or carboxylic acid salts (such as sodium and potassium salts of straight-chain fatty acids), sulfonic acids or sulfonic acid salts (such as linear alkylbenzenesulfonates, higher alkylbenzenesulfonates, benzenesulfonates, toluenesulfonates, xylenesulfonates, and cumenesulfonates, ligninsulfonates, petroleum sulfonates, N-acyl-n-alkyltaureates, paraffin sulfonates, secondary n-alkanesulfonates, α-olefin sulfonates, sulfosuccinate esters, alkylnaphthalenesulfonates or isethionates), sulfuric acid ester salts (such as sulfated linear primary alcohols, sulfated polyoxyethylenated straight-chain alcohols or sulfated triglyceride oils), phosphoric and polyphosphoric acid esters. Cationic surfactants can be primary amines and their salts, diamines and polyamines and their salts, quaternary ammonium salts (such as tetralkylammonium salts or imidazolinium salts), polyoxyethylenated long-chain amines [RN(CH 2 CH 2 O) x H] 2 ), quaternized polyoxyethylenated long-chain amines or amine oxides (such as N-alkyldimethylamine oxides). Nonionic surfactants can be polyoxyethylenated alkylphenols, polyoxyethylenated straight-chain alcohols, polyoxyethylenated polyoxypropylene glycols, polyoxyethylenated mercaptans, long-chain carboxylic acid esters (such as glyceryl and polyglyceryl esters of natural fatty acids, propylene glycol, sorbitol or polyoxyethylenated sorbitol esters, polyoxyethylene glycol esters and polyoxyethylenated fatty acids), alkanolamides, tertiary acetylenic glycols, polyoxyethylenated silicones, N-alkylpyrrolidones or alkylpolyglycosides. Zwitterionic surfactants have both anionic and cationic charges present in the lyophilic portion (such as α-N-alkylaminopropionic acids, N-alkyl-α-iminodipropionic acids, imidazoline carboxylates, N-alkylbetaines, amine oxides, sulfobetaines or sultaines) (M. J. Rosen, Surfactants and Interfacial phenomena, 2 nd Edition, John Wiley and Sons, New York, 1989).
In a preferred embodiment, the composition comprises ammonium hydroxide, hydrogen peroxide, water (hereafter called APM mixtures) and a complexing compound. The complexing compound is selected from the molecules described in FIG. 2 . The composition is particularly suitable for treating, particularly cleaning a semiconductor substrate.
APM-cleaning mixtures comprising a complexing agent according to the preferred embodiments are robust with respect to metal contamination coming from the fresh chemicals as well as with respect to metal contamination introduced in the course of its use for cleaning. The robustness of the basic APM process can be improved by the addition of complexing agents that keep the metals in solution and prevent the catalysis of the peroxide decomposition.
The volume mixing ratio of NH 4 OH(29%)/H 2 O 2 (30%)/H 2 O is preferably 0.25/1/5, but can vary depending upon various factors.
In a second aspect, a method for treating a semiconductor substrate is provided. The semiconductor substrate is treated with a composition comprising a complexing compound. In an embodiment, the composition further comprises an oxidizing compound. In another embodiment, the composition further comprises an alkaline compound. In a preferred embodiment, the composition is an aqueous composition comprising a complexing compound, an oxidizing compound and an alkaline compound. The composition can be an APM cleaning composition.
The composition can be, but is not limited hereto, the composition described in the first aspect. The composition is particularly useful for cleaning a substrate such that particles are oxidized and metallic contamination is removed. The complexing compound is for complexing metals being present on the surface of the substrate and in the solution. Additionally, the lifetime of the solution is increased since the decomposition of the oxidizing compound is substantially inhibited.
A substrate can include, but is not limited to, a substrate such as semiconducting material, glass, quartz, ceramics, metal, plastic, magnetic material, superconductor and the like.
Preferably, the substrate is a semiconductor substrate. Semiconductor substrate can be any possible substrate used in semiconductor processing. The semiconductor substrate can be a substrate selected from the group, but not limited hereto, comprising a substrate made of silicon, germanium, gallium arsenide, indium phosphide and the like.
The semiconductor substrate can include, e.g., the substrates as mentioned above covered entirely or partially with a thin film of, e.g., an oxide, a nitride, a metal, a polymeric insulating layer, an anti-reflecting coating, a barrier, a photoresist layer and the like.
The preferred embodiments are particularly relevant for cleaning or etching a semiconductor substrate for which the surface is preferably highly clean.
When the composition is used for treating a substrate, the weight concentration of the alkaline compound in the cleaning solution is typically from about 0.001 weight % to about 100 weight %, preferably from about 0.1 weight % to about 20 weight %, and more preferably from about 0.1 weight % to about 5 weight % by weight.
For ammonium hydroxide, the weight concentration of the alkaline compound in the cleaning solution is typically from about 0.001 weight % to about 30 weight %, preferably from about 0.1 weight % to about 20 weight %, and preferably from about 0.1 weight % to about 5% by weight. For other alkaline compounds, the weight concentration is similar, and a function of the strength of the alkaline compound.
For peroxide, the weight concentration the hydrogen peroxide is typically but not limited to 0.001-100%, 0.1-20% and preferably 0.1-5% by weight.
In a preferred embodiment, a composition for treating a semiconductor surface comprises ammonium hydroxide, hydrogen peroxide, water (hereafter called APM mixtures) and additionally a complexing compound. The complexing compound is selected from the molecules described in FIG. 1 .
APM-cleaning mixtures comprising a complexing agent according to the preferred embodiments are robust with respect to metal contamination coming from the fresh chemicals as well as with respect to metal contamination introduced in the course of its use for cleaning. The robustness of the basic APM process can be improved by the addition of complexing agents that keep the metals in solution and prevent the above mentioned catalysis of the peroxide decomposition.
The volume mixing ratio of NH 4 OH(29%)/H 2 O 2 (30%)/H 2 O is typically 0.25/1/5, but can vary depending upon various factors.
The cleaning solution is prepared with the amounts as described above and afterwards the semiconductor substrate is treated with the cleaning solution.
In the best mode known to the applicant, the molecule as described in FIG. 2 b is selected and added in the amounts described above. The complexing agent can be added as the pure compound to the cleaning solution. Alternatively, the complexing agent can be dissolved in either water, ammonia or peroxide or a dilution of the two latter chemicals and added as such to the cleaning solution.
It is a further aim to provide a process for treating a semiconductor substrate comprising the steps of treating the semiconductor substrate with the cleaning solution as described above and drying the semiconductor substrate, and optionally rinsing the semiconductor substrate. The process can be performed after treating the semiconductor substrate with the cleaning solution as described above.
In the step of treating the semiconductor substrate with the cleaning solution, the semiconductor substrate can be immersed in a bath containing the cleaning solution. Alternatively, the cleaning solution can be dispensed or sprayed onto the semiconductor substrate for instance by using a spray processor. In all cases, the cleaning performance of the solution can be enhanced by using a megasonic transducer.
The temperature range for treating the semiconductor substrate with the cleaning solution is typically from about 0° C. to about 95° C., preferably from about 10° C. to about 80° C., and more preferably from about 20° C. to about 70° C.
The composition is stable in this temperature range. This is an advantage compared to prior art solutions, where the metal-complexing compound complex becomes unstable due to an increase in temperature.
In the step of drying the semiconductor substrate, several techniques known in the art can be used, e.g., spin-drying, Maragoni-drying, drying techniques using organic vapors.
The step of rinsing the semiconductor substrate comprises treating the semiconductor substrate with DI water or treating the semiconductor substrate with a diluted acidic solution or with DI water containing both complexing agents wherein the total amount is preferably from about 1 ppm to about 100000 ppm, more preferably from about 10 ppm to about 10000 ppm, and most preferably from about 100 ppm to 1000 ppm.
It is a further aim to provide a process for treating a semiconductor substrate comprising the step of treating the semiconductor substrate with any cleaning solution and/or treating the semiconductor substrate with any rinsing solution
The any cleaning solution can be any cleaning solution, not being limited to the compositions described in this application. The rinsing solution comprises the first compound and the second compound, as described in the first aspect. The amount of the complexing agent in the composition can be from about 10 −4 weight % to about 10 weight %, preferably from about 10 −3 weight % to about 1 weight %.
This rinsing solution can also comprise a surfactant in an amount of from about 0.1 weight % to about 10 weight %.
No additional alkaline compound is typically to be added to the rinsing solution; however in certain embodiments it can be desired. The pH range of the rinsing solution is preferably from about 5 to about 8. The rinse solution can be dispensed or sprayed onto the semiconductor surface as described above. During rinsing the performance can also be enhanced by using a megasonic transducer.
The process of treating a semiconductor substrate with a cleaning solution comprising the above mentioned steps can be performed for a predetermined number of semiconductor substrates. After treating at least one substrate, but preferably after treating more substrates, the composition of the cleaning solution can be modified by, e.g., adding extra alkaline compound, adding extra complexing compound, adding oxidizing compound such that the initial composition of the cleaning solution is kept constant as function of the process time.
COMPARATIVE EXAMPLES
The preferred embodiments will be further described using non-limiting examples and drawings.
The effectiveness of the new composition concerning the inhibition of metal catalyzed decomposition of peroxide, the prevention of metal outplating on silicon wafers in metal contaminated APM cleaning solutions and the removal of metallic contamination from silicon wafer surfaces using APM cleaning solutions is described. A comparison is made with other types of complexing agents. Those complexing agents contain as functional groups either phosphonic acids, such as diethylene triamine penta-methylenephosphonic acid (DTPMP) and cyclo-triaminotriethylene-N,N′,N″-tris(methylenephosphonic acid) (c-Tramp), carboxylic acids, such as ethylene diamino tetra acetic acid (EDTA), hydroxamates, such as Desferal, and other well known complexing agents as calmagite, pyrogallol, Erio T and acetylacetone. An overview of the different chemicals used for the experiments is given in Table 1. All experiments were done in a class 1000 clean room environment or better.
TABLE 1
Chemicals used for preparation of APM baths.
Chemical
Vendor
Grade
H 2 O 2 30 (w/w)%
Ashland
TB(*)
NH 4 OH 29 (w/w)%
Ashland
TB(*)
EDTA
Merck
DMHP
Aldrich
Tiron
Aldrich
acetylacetone
Aldrich
Calmagite
Acros
ErioT
Acros
nitrocatechol
Acros
sulfocatechol
**
Pyrogallol
Riedel-de-Haën
Extra pure
c-Tramp
Desferal
Novartis
(*)TB-grade corresponds with a specification of maximal 100 ppt of metal ions in the chemical.
** Prepared as mentioned in Beilsteins Handbuch der Organischen Chemie, IV. Ausg. Grundwerk, Bd.11, S.294.Springer. Berlin 1928
Example 1
Metal Deposition Experiments from APM Mixtures in Presence of Different Complexing Agents
The efficiency of complexing agents to suppress the deposition of metallic contamination onto wafer surfaces was evaluated. This was done through intentionally spiking controlled trace amounts of metallic contamination to cleaning solutions. For these metal deposition tests, p-type monitor wafers with a diameter of 150 mm and <100> orientation were used. The wafers were pre-cleaned using IMEC Clean® 10′ H 2 O/O 3 +10′ OFR+2′ 0.5% HF+10′ OFR at pH 2 and O 3 +marangoni drying, rendering a perfectly clean hydrophilic surface.
The metal deposition experiments were performed in a static quartz tank with a quartz cover plate. This tank was not equipped with a megasonic transducer. APM mixtures were prepared containing 1 w-ppb of different metals of interest with and without the complexing agent. The metals spiked to the APM bath were added from AAS-standard solutions (Merck). After a bath age of 5 minutes, three wafers were immersed for 10 minutes, rinsed for 10 minutes in an overflow rinse tank and dried with a commercially available Marangoni drier (STEAG). The resulting metal contamination was measured with straight TXRF or VPD-DSE-DC-TXRF (Vapor Phase Decomposition—Droplet Surface Etching—Droplet Collection Total X-Ray Fluorescence). Determination of Al wafer surface concentration was done using VPD-DC GF-AAS (Graphite Furnace Atomic Absorption Spectroscopy).
In Table 2, an overview of the metal deposition from intentionally metal contaminated APM cleaning mixtures and the effect of different complexing agents upon preventing the metal deposition is summarized. It is shown that nitrocatechol and sulfocatechol are very effective to prevent deposition of Al.
TABLE 2
Metal surface concentration (10 10 at/cm 2 ) after 10 min dip in
0.25/1/5 APM at 50° C. spiked with 1 w-ppb metals and
different complexing agents followed by 10 min. OFR and MgDry.
CA
Conc (M)
Fe
Zn
Al
None
—
129.7 ± 3.4
46.82 ± 1.28
299.6 ± 4.6
Tiron
1.3 × 10 −3
0.15 ± 0.1
8.0 ± 0.2
0.7 ± 0.04
DMHP
2.7 × 10 −4
0.21
22.26
99.9 ± 1
EDTA (70° C.)
3.2 × 10 −5
NA
NA
272 ± 16
EDTA (RT)
3.2 × 10 −4
2.7
27.7
NA
ErioT
1.3 × 10 −4
3 ± 1.5
0.5 ± 0.09
513 ± 32
Calmagite
1.3 × 10 −4
64 ± 39
3.92 ± 0.96
42 ± 3
Nitrocatechol +
1.3 × 10 −3
NA
NA
<0.126
EDTA
1.3 × 10 −4
sulfocatechol
1.3 × 10 −3
<1.2
13.7 ± 0.4
<0.83
Acetylacetone
1.3 × 10 −3
140 ± 6
41 ± 3
319 ± 14
Acetyl-
1.3 × 10 −3
<0.15
1.2 ± 0.08
228 ± 15
acetone +
1.3 × 10 −4
EDTA
c-tramp
2.7 × 10 −5
0.82
0.95
366 ± 2.5
Desferal
2.7 × 10 −5
1.33 ± 0.18
45.6 ± 0.1
11.5 ± 0.18
Pyrogallol
1.3 × 10 −3
80.7 ± 2.4
30.8 ± 0.3
327 ± 18
The performance of nitrocatechol and sulfocatechol is also compared with other complexing agents. In first instance, different complexing agents for Al that are described in literature to be efficient complexants for Al are compared. Erio T, pyrogallol, EDTA, Desferal, and Tiron which known to have a good ability to complex Al (see stability constants summarized in Table 3). However, those complexants show a much lower efficiency to complex Al in the APM cleaning solution compared to nitrocatechol and sulfocatechol.
It is shown that the commonly known complexant EDTA is not able to keep the Al in solution and has also no effect on preventing the outplating of Zn. The complexing agent Tiron which has a similar ring-structure as nitrocatechol and sulfocatechol but different sidegroups, shows a comparable effectiveness in preventing metal deposition from a contaminated bath.
TABLE 3
Overview of bindings constants of different compounds for Al.(*)
K1
B2
K3
Tiron
19.02
31.1
2.4
EDTA
16.95
25.04
—
Pyrogallol
24.50
44.55
13.40
calmagite
—
—
—
erioT
—
—
—
nitrocatechol
13.75
25.44
Sulfocatechol**
16.6
29.9
9.3
acetylacetone
8.6
16.5
5.8
DMHP
12.20
23.25
9.37
Desferal
24.5
—
—
(*)Stability constants extracted from the SCQUERY database (2002, IUPAC and Academic Software) - SCQUERY version 5.15
**L. Havelkova and M. Bartusek Coll. Czech. Chem. Commun. vol. 34 (1969)
Example 2
Removal of Metallic Contamination from Silicon Wafer Surfaces Using APM Cleaning Solutions with Different Metal Complexing Agents
The final metal surface concentration after cleaning intentionally metal contaminated wafers using a 0.25/1/5 APM clean with and without any complexing agent at 50° C. is summarized in Table 4.
The metal-contaminated wafers were prepared using standard spin contamination procedure.
TABLE 4
Metal surface concentration (10 10 at/cm 2 ) after cleaning
10 12 at/cm 2 metal contaminated wafers with 10 min 0.25/1/5
APM at 50° C. with different complexing agents (bath age = 5′)
followed by 10 min. OFR and MgDry.
CA
Conc (M)
Fe
Zn
Al
No APM
98.75 ± 0.84
91.13 ± 3.03
177 ± 14.1
clean
None
—
40.64
31.06
164
Tiron
1.3 × 10 −3
0.41 ± 0.05
1.8 ± 0.5
16.4 ± 0.25
EDTA
1.3 × 10 −3
0.15 ± 0.04
0.47 ± 0.05
314 ± 12
ErioT
1.3 × 10 −4
0.33 ± 0.09
1.77 ± 0.17
282 ± 6
Calmagite
1.3 × 10 −4
<0.14
1.22 ± 0.15
120 ± 4
Nitro-
1.3 × 10 −3
0.2 ± 0.1
18.37 ± 0.04
2.9 ± 0.5
catechol
sulfocatechol
1.3 × 10 −3
<0.16
2.82 ± 0.17
6 ± 0.6
Acetyl-
1.3 × 10 −3
<0.08
1.62 ± 0.06
139 ± 12
acetone +
1.3 × 10 −4
EDTA
It can be concluded that nitro- and sulfocatechol can more efficiently clean Al from the wafer surface compared to the other complexing agents used.
In FIGS. 3 and 4 , the efficiency of nitrocatechol to remove metal contamination using APM mixtures is examined by investigating the removal efficiency as function of the lifetime of the complexing agents in the APM cleaning bath. A comparison is made with EDTA and Tiron. Tiron it is known to be able to complex Al contamination in APM cleaning baths.
These graphs show that nitrocatechol has a good performance concerning removal of Al from the wafer surface as a function of the bath lifetime.
Example 3
Decomposition of Peroxide in APM Cleaning Mixtures in Presence of Trace Metal Contamination and Metal Complexing Agents
The effect of the addition of a complexing agent to APM cleaning solutions on the kinetics of the decomposition reaction of H 2 O 2 has been investigated ( FIG. 5 ). Well controlled amounts of metallic contamination were added to the cleaning mixture under study.
As hydrogen peroxide decomposes, an amount of oxygen gas is liberated following the overall reaction
2H 2 O 2 O 2 +2H 2 O
The decay of the total peroxide concentration in the APM mixture can be monitored by measuring the time-dependent increase of the pressure due to the O 2 -evolution in a dedicated set-up as described by Schmidt.
Numerical integration over time yields the actual peroxide concentration in the bath. It is convenient to use peroxide concentrations normalized to its initial value [H 2 O 2 ] i as
[
H
2
O
2
]
n
=
[
H
2
O
2
]
[
H
2
O
2
]
i
Since the decomposition reaction is mainly catalyzed by Fe and in a lesser content Cu (Mertens et al. Proc. of the 5 th Internat. Symp. on Cleaning Technology in Semiconductor Device Manufacturing PV97-35 (1997)), the decay of peroxide concentration in a metal contaminated bath and in presence of a CA, illustrates the ability of complexing primarily Fe in the APM bath.
The decomposition rate as function of bath age is determined in APM mixtures (0.25/1/5 29% NH 4 OH/30% H 2 O 2 /H 2 O) spiked with 1 w-ppb of the metals of interest with and without different complexing agents. The effect of different additives on the inhibition of the metal catalyzed decomposition reaction of peroxide in APM cleaning mixtures is shown in FIG. 9 . This graph shows the normalized H 2 O 2 concentration as function of bath age for an APM mixture at 50° C. spiked with nitrocatechol. A comparison is also made with EDTA. Both complexing agents were use at a concentration of 1.3×10 −3 M. The complexing agents are found to suppress to some extent the decomposition reaction, at least when the mixture is fresh. For EDTA the suppression action vanishes a little faster over time. This may be attributed to the destruction of the complexing agent or more specifically of the metal-complex in the hot APM. The lifetime of nitrocatechol amounts to 200 min. This value corresponds to acceptable bath lifetimes.
In FIG. 5 , the dotted line refers to EDTA ( 51 ), while the full line refers to nitrocatechol ( 52 ).
All references cited herein are incorporated herein by reference in their entirety. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.
The term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
All numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the preferred embodiments. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.
The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims.
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The invention relates to a method for cleaning semiconductor surfaces to achieve to removal of all kinds of contamination (particulate, metallic and organic) in one cleaning step. The method employs a cleaning solution for treating semiconductor surfaces which is stable and provokes less or no metal precipitation on the semiconductor surface.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation from U.S. patent application Ser. No. 12/911,541, filed Oct. 25, 2010, which is a continuation from U.S. patent application Ser. No. 11/551,684, filed Oct. 20, 2006, now U.S. Pat. No. 7,853,316, issued Dec. 14, 2010, which claims priority to U.S. Provisional Patent Application Ser. No. 60/728,481, filed Oct. 20, 2005, and which is a continuation-in-part “CIP” of U.S. patent application Ser. No. 10/548,982, which was filed Sep. 7, 2005 and granted a U.S. national stage filing date of May 2, 2006, now U.S. Pat. No. 7,711,413, issued May 4, 2010, which claims priority to PCT International Patent Application No. PCT/US2004/012773, filed Apr. 23, 2004 and which claims priority to U.S. Provisional Patent Application Ser. No. 60/466,215, filed Apr. 28, 2003, all of which are herein expressly incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to catheter probes based on the use of a fiber that does not rotate. More specifically, the present invention relates to optical coherence tomography based on the use of an optical fiber that does not rotate, which is enclosed in a catheter portion.
[0003] Myocardial infarction or heart attack remains the leading cause of death in our society. Unfortunately, most of us can identify a family member or close friend that has suffered from a myocardial infarction. Until recently many investigators believed that coronary arteries critically blocked with atherosclerotic plaque that subsequently progressed to total occlusion was the primary mechanism for myocardial infarction. Recent evidence from many investigational studies, however, clearly indicates that most infarctions are due to sudden rupture of non-critically stenosed coronary arteries due to sudden plaque rupture. For example, Little et al. (Little, W C, Downes, T R, Applegate, R J. The underlying coronary lesion in myocardial infarction: implications for coronary angiography. Clin Cardiol 1991, 14: 868-874, incorporated by reference herein) observed that approximately 70% of patients suffering from an acute plaque rupture were initiated on plaques that were less than 50% occluded as revealed by previous coronary angiography. This and similar observations have been confirmed by other investigators (Nissen, S. Coronary angiography and intravascular ultrasound. Am J Cardiol 2001, 87 (suppl): 15A -20 A, incorporated by reference herein).
[0004] The development of technologies to identify these unstable plaques holds the potential to decrease substantially the incidence of acute coronary syndromes that often lead to premature death. Unfortunately, no methods are currently available to the cardiologist that may be applied to specify which coronary plaques are vulnerable and thus prone to rupture. Although treadmill testing has been used for decades to identify patients at greater cardiovascular risk, this approach does not have the specificity to differentiate between stable and vulnerable plaques that are prone to rupture and frequently result in myocardial infarction. Inasmuch as a great deal of information exists regarding the pathology of unstable plaques (determined at autopsy) technologies based upon identifying the well described pathologic appearance of the vulnerable plaque offers a promising long term strategy to solve this problem.
[0005] The unstable plaque was first identified and characterized by pathologists in the early 1980's. Davis and coworkers noted that with the reconstruction of serial histological sections in patients with acute myocardial infarctions associated with death, a rupture or fissuring of athermanous plaque was evident (Davis M J, Thomas A C. Plaque fissuring: the cause of acute myocardial infarction, sudden death, and crescendo angina. Br Heart J 1985; 53: 3 63-37 3, incorporated by reference herein). Ulcerated plaques were further characterized as having a thin fibrous cap, increased macrophages with decreased smooth muscle cells and an increased lipid core when compared to non-ulcerated atherosclerotic plaques in human aortas (Davis M J, Richardson E D, Woolf N. Katz O R, Mann J. Risk of thrombosis in human atherosclerotic plaques: role of extracellular lipid, macrophage, and smooth muscle cell content, incorporated by reference herein). Furthermore, no correlation in size of lipid pool and percent stenosis was observed when imaging by coronary angiography. In fact, most cardiologists agree that unstable plaques progress to more stenotic yet stable plaques through progression via rupture with the formation of a mural thrombus and plaque remodeling, but without complete luminal occlusion (Topol E J, Rabbaic R. Strategies to achieve coronary arterial plaque stabilization. Cardiovasc Res 1999; 41: 402-417, incorporated by reference herein). Neovascularization with intra-plaque hemorrhage may also play a role in this progression from small lesions, i.e., those less than about 50% occluded, to larger significant plaques. Yet, if the unique features of unstable plaque could be recognized by the cardiologist and then stabilized, a dramatic decrease may be realized in both acute myocardial infarction and unstable angina syndromes, and in the sudden progression of coronary artery disease.
SUMMARY OF THE INVENTION
[0006] The present invention uses depth-resolved light reflection or Optical Coherence Tomography (OCT) to identify the pathological features that have been identifie3d in the vulnerable plaque. In OCT, light from a broad band light source or tunable laser source is split by an optical fiber splitter with one fiber directing light to the vessel wall and the other fiber directing light to a moving reference mirror. The distal end of the optical fiber is interfaced with a catheter for interrogation of the coronary artery during a heart catheterization procedure. The reflected light from the plaque is recombined with the signal from the reference mirror forming interference fringes (measured by an photovoltaic detector) allowing precise depth-resolved imaging of the plaque on a micron scale.
[0007] OCT uses a superluminescent diode source or tunable laser source emitting a 1300 nm wave length, with a 50-250 nm band width (distribution of wave length) to make in situ tomographic images with axial resolution of 2-20 μm and tissue penetration of 2-3 mm. OCT has the potential to image tissues at the level of a single cell. In fact, the inventors have recently utilized broader band width optical sources so that axial resolution is improved to 4 um or less. With such resolution, OCT can be applied to visualize intimal caps, their thickness, and details of structure including fissures, the size and extent of the underlying lipid pool and the presence of inflammatory cells. Moreover, near infrared light sources used in OCT instrumentation can penetrate into heavily calcified tissue regions characteristic of advanced coronary artery disease. With cellular resolution, application of OCT may be used to identify other details of the vulnerable plaque such as infiltration of monocytes and macrophages. In short, application of OCT can provide detailed images of a pathologic specimen without cutting or disturbing the tissue.
[0008] One concern regarding application of this technology to image atherosclerotic plaques within the arterial lumen is the strong scattering of light due to the presence of red blood cells. Once a catheter system is positioned in a coronary artery, the blood flow between the OCT optical fiber and artery can obscure light penetration into the vessel wall. One proposed solution is the use of saline flushes. Saline use is limited in duration, however, since myocardial ischemia eventually occurs in the distal myocardium. The inventors have proposed the use of artificial blood substitutes in the place of saline. Artificial hemoglobin or artificial blood including hemoglobin is non-particulate and therefore does not scatter light. Moreover, artificial hemoglobin is about to be approved by the United States Food and Drug Administration as a blood substitute and can carry oxygen necessary to prevent myocardial ischemia. Recently, the inventors demonstrated the viability of using artificial hemoglobin to reduce light scattering by blood in mouse myocardium coronary arteries (Villard J W, Feldman M D, Kim Jeehyun, Milner T O, and Freeman G L. Use of a blood substitute to determine instantaneous murine right ventricular thickening with optical coherence tomography. Circulation 2002, Volume 105: Pages 1843-1849, incorporated by reference herein).
[0009] An OCT catheter to image coronary plaques has been built and is currently being tested by investigators. (Jang I K, Bouma B E, Hang O H, et al. Visualization of coronary atherosclerotic plaques in patients using optical coherence tomography: comparison with intravascular ultrasound. JACC 2002; 3 9: 604-609, incorporated by reference herein). The prototype catheter consists of a single light source and is able to image over a 360 degree arc of a coronary arterial lumen by rotating a shaft that spins the optical fiber. Because the rotating shaft is housed outside of the body, the spinning rod in the catheter must rotate with uniform angular velocity so that the light can be focused for equal intervals of time on each angular segment of the coronary artery. Mechanical drag in the rotating shaft can produce significant distortion and artifacts in recorded OCT images of the coronary artery. Unfortunately, because the catheter will always be forced to make several bends between the entry point in the femoral artery to the coronary artery (e.g., the 180 degree turn around the aortic arch), uneven mechanical drag will result in OCT image artifacts As the application of OCT is shifted from imaging gross anatomical structures of the coronary artery to its capability to image at the level of a single cell, non-uniform rotation of the single fiber OCT prototype will become an increasingly problematic source of distortion and image artifact.
[0010] Essentially, current endoscope type single channel OCT systems suffer by non-constant rotating speed that forms irregular images of a vessel target. See U.S. Pat. No. 6,134,003, incorporated by reference herein. The approach of a rotary shaft to spin a single mode fiber is prone to produce artifacts. The catheter will always be forced to make several bends from its entry in the femoral artery, to the 180 degree turn around the aortic arch, to its final destination in the coronary artery. All these bends will cause uneven friction on the rotary shaft, and uneven time distribution of the light on the entire 360 degree arch of the coronary artery. As the application of OCT is shifted from gross anatomical structures of the coronary artery to its capability to image at higher resolutions (i.e., the level of a single cell), then non-uniform rotation of the single fiber OCT will become a greater source of artifact.
[0011] The present invention overcomes this disadvantage of current single mode endoscope OCT by putting a rotating part at the end of the fiber probe. The rotating part is driven by biocompatible gas or liquid pumped externally. The rotating part is based on a miniature turbine, screw or water wheel, or nanotechnology. The single mode fiber itself remains stationary, but only a prism reflecting incident light to the target vessel wall will rotate at constant speed.
[0012] The present invention pertains to a catheter imaging probe for a patient. The probe comprises a conduit through which energy is transmitted. The probe comprises a first portion through which the conduit extends. The probe comprises a second portion which rotates relative to the conduit to redirect the energy from the conduit.
[0013] The present invention also pertains to a rotating tip assembly suitable for use with the inventive catheter imaging probe. The rotating tip assembly comprises generally an axle having a plurality of turbine-like members projecting generally radially outward from a central longitudinal axis of the axle, the axle further having a central longitudinal bore extending along the entire longitudinal axis of the axle. A distal end of the axle is beveled at an angle suitable to permit the reflection or refraction of optical energy at a predetermined angle away from the central longitudinal axis of the axle, then to gather light reflected back from the environment surrounding the catheter tip and transmit the same to the optical fiber. An outer housing having optically transparent properties is provided and is mounted on a distal end of a catheter body. A catheter end cap having a central longitudinal bore and a plurality of fluid flow ports passing through the catheter end cap and oriented co-axial with the longitudinal axis of the catheter end cap and the catheter body is provided. The catheter end cap is affixed within a distal end of the central longitudinal bore in the catheter body, and axle having the plurality of turbine-like members is concentrically and co-axially engaged within the central longitudinal bore of the catheter end cap and is rotatable therein. A second cap is provided which comprises generally concentrically aligned annular members, a first inner annular member defining a central longitudinal bore of the second cap and being in concentric spaced-apart relationship with a second outer cylindrical member so as to define an annular opening there between. The annular opening is maintained by spacer or rib members. The second outer cylindrical member has a plurality of fluid flow ports passing through a distal end surface thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of the rotating tip assembly of the present invention depicting fluid flows there through and optical inputs.
[0015] FIG. 2 is a perspective view of a first embodiment of a turbine member in accordance with the present invention.
[0016] FIG. 3 is a perspective cut-away view of the rotating tip assembly of the present invention.
[0017] FIG. 4A is an end elevational view of a housing cap for the rotating tip assembly of the present invention.
[0018] FIG. 4B is a perspective end view of the housing cap for the rotating tip assembly of the present invention.
[0019] FIG. 5A is a side end elevational view of the cap member for the rotating tip assembly of the present invention.
[0020] FIG. 5B is a perspective view of the cap member for the rotating tip assembly of the present invention
[0021] FIG. 6 is an end elevational view of an alternative embodiment of the housing cap in accordance with the present invention.
[0022] FIG. 7 is a perspective view of an alternative embodiment of the turbine member in accordance with the present invention.
[0023] FIG. 8 is a perspective view of an alternative embodiment of the second cap member in accordance with an embodiment of the present invention.
[0024] FIG. 9 is a perspective view of an alternative embodiment of the rotating tip assembly in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In the accompanying figures, like elements are identified by like reference numerals among the several preferred embodiments of the present invention. A rotating catheter tip assembly 10 comprises a housing 12 and a turbine 16 , as shown in FIG. 1 . The housing 12 includes a conduit 27 that extends through the housing 12 and turbine 16 , whereby the turbine 16 rotates relative to the conduit 27 to redirect energy from the conduit 27 . Preferably, conduit 27 is a radiation waveguide, and more preferably the radiation waveguide is an optical fiber. The rotating catheter tip assembly 10 rotates a reflecting material 17 , which then reflects energy emanating from the conduit 27 . The reflecting material 17 is coupled with a focusing element 19 to focus the energy from conduit 27 to a target. For purposes of this detailed description, it will be understood that light is redirected from an optical fiber and reflected light from a given in vivo target is then gathered and redirected back to the optical fiber through the focusing element 19 . The focusing element 19 may be any type of lens, GRIN lens, and the like suitable to focus optical energy. The focusing element 19 can be attached to the conduit, as to not rotate and alternatively, there is a space in between the focusing element 19 and the conduit 27 , whereby the focusing element 19 is attached to turbine 16 as to rotate thereby.
[0026] The turbine 16 includes a center axle 22 and a plurality of vane members 18 , as shown in FIG. 2 . The center axle 22 includes a central longitudinal bore 26 , through which the conduit 27 extends. The center axle 22 includes a window opening 24 at the distal end, through which reflecting material 17 reflects energy emanating from the conduit 27 . The vane members 18 project radially outward from center axle 22 and provide a rotating torque to the center axle 22 when a flowing fluid (gas or liquid) flows against the vane members 16 , thereby causing the center axle 22 to rotate about the conduit 27 . Preferably, the vane members 16 can have a predetermined curvature along the longitudinal axis of the turbine 16 . The vane members 16 can be spiral shaped, or in any other configuration which permits rotation of the turbine 16 . Preferably, the turbine 16 is made from stainless steel, plastic tygon or Teflon. Alternatively, the turbine 16 includes knobs to support the axle 22 and allows the axle 22 to rotate without wobbling.
[0027] The housing 12 includes a cylinder 32 , a housing cap 14 , and a cap member 20 , as shown in FIG. 3 . The cylinder 32 includes a central chamber 33 , a distal opening 29 , and outlet channels 30 . The central chamber 33 houses the turbine member 16 and includes an inflow and an outflow, which define a fluid flow pathway 48 . The inflow runs along the turbine member 16 , while the outflow runs along the outlet channels 30 . The housing cap 14 includes a plurality of fluid inlet ports 42 , a plurality of fluid outlet ports 44 , and a central opening 40 , as shown in FIGS. 4 a and 4 b . The fluid inlet ports 42 attach to fluid inlet tubes 41 , as shown in FIG. 1 . The fluid inlet tubes 41 are connected to a fluid source (not shown). The fluid inlet ports 42 pass through a generally central portion of the housing cap 14 , to transmit fluid to central chamber 33 . The fluid inlet ports 42 generally align with turbine member 16 . The fluid outlet ports 44 pass through a relatively peripheral portion of the housing 14 and align with the outlet channels 30 and outlet tubes 43 , as shown in FIG. 1 . The central opening 40 includes a concentric recessed seat 39 , as shown in FIG. 4 , in which the axle 22 sits and substantially rotates thereabout. Concentric recessed seat 39 is formed to permit the axle 22 to rotate without wobbling. The central opening 40 co-axially aligns with longitudinal bore 26 and permits conduit 27 to be passed there through, whereby the turbine member 16 is freely rotatable without rotate conduit 27 . The axle 22 is co-axially aligned to an opening 29 at a distal end of the housing 12 and opening 29 permits axle to rotate about an axis. Preferably the housing 12 is made from Teflon. Alternatively, the housing 12 includes a cover transparent to the energy and which encapsulates the turbine 16 , so that no fluid can escape from the housing except through the channels 30 . Preferably, the transparent cover is made from any biocompatible transparent plastic. Such plastic can include Polymethyl methacrylate (PMMA) or the like.
[0028] The cap member 20 includes an inner annular member 28 , an outer annular member 27 , a plurality of spacer rib members 34 , and a plurality of spaces 35 , as shown in FIGS. 5 a and 5 b . The cap member 20 is concentrically mounted onto the distal end of the axle 22 through inner annular member 28 , as shown in FIG. 5 b . The inner annular member 28 permits axle 22 to freely rotate thereabout, without wobbling. The inner annular member 28 and outer annular member 27 are connected by spacer rib members 34 and are concentrically spaced apart. The spaces 35 between adjacent pairs of spacer rib members 34 provide outflow pathways for the fluid flow 48 to pass from the central chamber 33 to the distal end of housing 12 and then to outlet channels 30 . A plurality of fluid flow ports (not shown) may be provided in a distal surface of the cap member 20 and define a distal end of spaces 35 to channel fluid flow out of spaces 35 .
[0029] At the distal end of the axle 22 , a reflecting material 17 (not shown) is attached to the center axle 22 at window 24 , as shown in FIG. 1 . The reflecting material redirects energy from the conduit 27 . The reflecting material preferably includes a prism or a mirror, which reflects energy from the conduit, the prism rotating with the center axle 22 . In one embodiment the energy is radiant energy. Preferably, a lens focuses energy onto the patient. The lens can be a microlens, GRIN lens, or optical fiber lines. The probe preferably includes a fluid source connected to the inlet tube.
[0030] The fluid is provided to the inlet tubes 41 , as shown in FIG. 1 . The fluid is provided by a fluid source (not shown). Preferably, the fluid source is a pump. The pump can be any standard fluid pump, as known and recognized by those skilled in the art. Preferably, the fluid is chosen from a group consisting of oxygen, carbon dioxide, nitrogen, helium, saline, water, d5W or artificial blood such as Oxyglobin. Alternatively, any gas that can be dissolved into blood or tissue relatively easily can be used. Accordingly, a gas pump would used to provide fluid to the inlet tubes 41 .
[0031] The preferred dimensions of the outer diameter of the housing 12 is 2 mm, the outer diameter of the turbine 16 is 1.4 mm, the outer diameter of the inlet tube 42 is 0.2 mm, the outer diameter of the outlet tube 44 is 0.2 mm. The speed can be 30 rotations per second. The turbine pitch can be 4 pitch/mm, while the speed of the gas flow can be 120 mm/sec and target flow rate is 3 mm 3 /sec. The above are all examples. The invention is not limited to these values. For instance, to obtain a finer image, the flow rate is lower and the time it takes to obtain an image is then longer.
[0032] Alternatively, the turbine 16 includes wart to reflect energy coming through a radiation energy guide back to the radiation energy guide. The reflective wart can be any reflective material on the axle 22 . Preferably, the wart is block shape with a flat wall shape. The wart rotates with the turbine and the energy reflected by the wart indicates current angular position of the prism. The wart identifies one angular position of the rotating portion when the light hits and gets back form the wart. The wart may be a flat wall facing the radiation energy guide to reflect back. The wart can be molded into the axle, and flat wall can have a reflective material, such as a mirror placed on it to increase the reflection. The width of the wart is small compared to the circumference of axle 22 , so as to identify a given point, and is high enough to block the energy emitted from optical fiber, so it is reflected by wart.
[0033] In operation, the assembly may be connected to a sample arm of a single mode fiber OCT. In the center of an OCT probe, the turbine 16 is connected to a prism. Gas or liquid flows through the inlet port 42 into the turbine chamber 32 . The turbine 16 is supported by positioning between the housing cap 14 and cap member 20 to maintain constant position during rotation. At the center of the turbine 16 , the central longitudinal bore 26 includes an optical fiber. During rotation of the turbine 16 , the optical fiber remains stationary. In spectral domain phase sensitive OCT, the reference reflecting surface is within the catheter.
[0034] A probing light will be launched from the single mode optical fiber through a lens having a curvature to focus the light onto target tissue area. A rotating prism connected to the turbine reflects incoming light toward target tissue area on the vessel wall, enabling the imaging system to scan 360 degrees around an inner vessel wall at a constant speed. The reflected light from the target tissue returns to the fiber through the prism. A standard analysis of the light is then performed to obtain the image, as in U.S. Pat. No. 6,134,003, incorporated by reference herein. Gas or liquid gone through the turbine 16 exits the probe through an outlet tube 44 . The rotation direction and speed of the turbine are controlled by the pressure difference between inlet ports 42 and outlet ports 44 . Applying a gas or liquid through an inlet tube pressure is induced to the turbine which rotates; therefore, a prism put on the end of the turbine rotates as well. Finally, an imaging system can scan 360 degrees around the inner vessel wall at a constant speed.
[0035] FIG. 6 depicts an alternative embodiment of a housing cap 14 , synonymously termed a catheter cap 14 , which is mountable on a distal open end of a catheter body (not shown) such that central flange 41 seats against the distal end of the catheter body (not shown). The fluid inlet openings 42 and fluid outlet openings 44 consist of channels which permit fluid flow to pass through the catheter cap 14 in the manner discussed above. Central opening 40 again accommodates passage of the optical fiber 27 therethrough and is co-axially aligned with the central bore of 26 of the turbine member 16 as depicted in FIG. 7 . The proximal and distal ends of the catheter cap 14 projects from the central flange 41 and are preferably mirror images of one another about the central flange 41 .
[0036] An alternative embodiment of the turbine member 16 is illustrated in FIG. 7 . The principal difference between the first embodiment of the turbine member illustrated in FIGS. 1-5 is that there is a space in between the focusing element 19 and the conduit 27 . The space may be an air space or an optical gap providing for the optical energy permission to expand before being focused by the focusing element. In this embodiment, the focusing element 19 and the reflecting material 17 both rotate about the axis by the axle 22 , by being substantially connected to the axle by optical glue, or the like. Also, the curved or helical pitch of the turbine vanes 18 is greater than that depicted in FIGS. 1-5 , such that they subtend approximately a 90 degree arc about the circumference of the axle 22 .
[0037] A second embodiment of a cap member 20 is depicted in FIG. 8 , and is synonymously termed second cap member 60 . The second cap member 60 includes a central opening 64 , a collection channel 65 and a plurality of outflow ports 66 . The central opening 64 is concentrically mounted onto the distal end of the axle 22 to permit axle 22 to rotate freely thereabout. The collection channel 65 is connected to the outflow ports 66 , to permit the outflow of fluid. The outflow ports are substantially aligned with the outflow ports 66 of the catheter cap 14 , to allow the outflow to return to the fluid source (not shown). Second cap member 60 is similar to second cap member 60 , in that it has an inner annular member 64 through which the axle 22 of turbine member, and an outer annular member 62 which is in concentrically spaced apart relationship therewith 16 passes except that after fluid flows through the spaces 35 it enters a return path by passing through outlet flow ports 66 which are provided about a peripheral portion of a distal surface of the second cap member 60 and enter the fluid outlet channels 30 in the housing 12 .
[0038] FIG. 9 demonstrates the complete assembly 100 of the catheter cap 14 , second cap member 60 , with turbine member 16 therebetween.
[0039] The present invention also pertains to a method for imaging a patient. The method comprises the steps of inserting a catheter into a patient, rotating a turbine 16 of the catheter relative to a conduit 27 , extending through the turbine 16 of the catheter, redirecting energy transmitted through the conduit 27 to the patient and receiving the energy reflected or backscattered to the turbine, and redirecting reflected energy to the conduit 27 .
[0040] Preferably, the rotating step includes flowing fluid through an inlet tube 41 to the turbine 16 to turn an axle 22 of the turbine 16 .
[0041] Preferably, the flowing step includes flowing the fluid against a plurality of vane members 18 which extend from a rotating center axle 22 of the turbine 16 to create a rotating torque on the center axle 22 to rotate about the conduit 27 that extends through the center axle 22 . The axle 22 preferably has reflecting material 17 attached to the distal end of the axle 22 , which redirects the energy from the conduit 27 . Preferably, the conduit 27 is an optical fiber.
[0042] The reflecting material 17 preferably includes a prism or mirror which reflects light from the conduit, and includes rotating the prism with the axle as the axle is rotated by the flowing fluid. Preferably, the rotating step includes the step of rotating the center axle 22 that is supported by knobs of the cylinder of the turbine in which the center axle 22 is disposed. Preferably, flowing the fluid from the inlet tube 41 through a chamber 33 and removing the fluid flowing from the housing 12 through at least one outlet tube 43 .
[0043] In the foregoing described embodiment of the invention, those of ordinary skill in the art will understand and appreciate that an assembly is described which provides a fluid drive mechanism for rotating a mirror about the central longitudinal axis of the assembly while transmitting optical energy from a co-axial optical fiber which is maintained stationary within the central axis of the assembly, such that light energy may be reflected or refracted perpendicular to the central longitudinal axis of the catheter and traverse a 360 degree arc.
[0044] Although the invention has been described in detail in the foregoing embodiments for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be described by the following claims.
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The present invention relates to a rotating catheter tip for optical coherence tomography based on the use of an optical fiber that does not rotate, that is enclosed in a catheter, which has a tip rotates under the influence of a fluid drive system to redirect light from the fiber to a surrounding vessel and the light reflected or backscattered from the vessel back to the optical fiber.
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The present invention relates to an assembly for actuating the weaving mechanism for a weaving loom, in particular a direct-drive actuating assembly.
BACKGROUND ART
As is known, conventionally mechanical actuation of a weaving loom is performed by means of a main motor connected to a main shaft of the loom. The term “main shaft” is therefore understood as meaning the shaft which provides the motion to the main weaving components of the loom, such as the sley and reed, the grippers or the weft insertion nozzles, other devices such as the weft supply device, cutters, tensioners and, finally, the weave machine as well.
Normally the weave machine can be engaged with and disengaged from the main shaft and a secondary motor is also envisaged, said motor being connected to the weave machine by a respective coupling device and which is used to find the pick and move the whole loom in a slow running condition. Precisely in order to satisfy this requirement, it is known to use a coupling system comprising clutch, brake and flywheel between the main motor and the weaving mechanism and the weave machine.
It has also been proposed to simplify considerably this basic structure, by eliminating the secondary motor and the main coupling device with the associated flywheel.
A known device is, for example, that described in European patent application No. 01112634.9, in which it is taught to use a single motor connected, via a continuous drive, to the weave machine and able to drive, by means of an engageable and disengageable transmission, the other weaving components of the loom as well.
These solutions, however, have certain drawbacks. In particular, the dimensions of these actuating assemblies are considerable and occupy their own position on the loom which cannot be used in any other way. Moreover, the provision of the coupling devices involves design, manufacture and maintenance costs.
Moreover, the actuating assembly is normally located on one of the two sides of the loom and therefore imputs torques at one end only: this means that the torque moments which are generated on the transmission members of the loom, especially if the latter is fairly high, are considerable. This characteristic is such that the transmission shafts which extend over the whole height of the loom (for example the sley-actuating cam shaft) must be designed with appropriate dimensions and suitably supported, i.e. it is required to use large sections (=more material and greater weight) and a plurality of supports which-interfere with the other components of the loom.
Moreover, the angular deformations and strains of these shafts produce angular offsets of the ends of the shafts and result in abnormal displacements of the weaving components actuated by these shafts. For example, the torsional force acting on the cam shaft actuating the sley may result in a difference of displacement between the two ends of the reed which as a result does not move perfectly perpendicularly with respect to the warp yarns, causing inevitable weaving defects.
The object of the present invention is to provide an arrangement of the assembly for actuating the weaving mechanism which overcomes the drawbacks described above.
In particular, it is provided to simplify the series of components forming the loom actuating mechanism in order to reduce the inertial phenomena (thus increasing, among other things, the rapidity of response during the start-up and stoppage transients); ensure the symmetry of the general structural lay-out, in particular the resistive and applied loads, so as to optimise the structural response of the loom to the dynamic actions; and reduce the dimensions and the structural complexity, so as to achieve also savings in terms of costs.
SUMMARY OF THE INVENTION
The abovementioned objects are achieved by means of an actuating assembly, the main features of which are described in the accompanying main claims.
Other aspects of the invention are highlighted in the secondary claims.
The loom according to the invention is provided with two actuating systems which are mechanically independent, but coordinated during operation, respectively for the weaving mechanism and for the weave machine. Each actuating system comprises an independent motor controlled by a control unit which manages the whole loom. In particular, the synchronized operation of the two motors is controlled via an electric axis. If necessary a mechanical safety device (not shown in the drawings for the sake of clarity) is present and able to intervene in the event of a malfunction in order to prevent under all circumstances that desynchronisation between weaving mechanism and weave machine exceeds a value considered dangerous, so as to avoid damaging the (woven) article and/or the machine. The separate division of the drive systems between the two systems (weaving mechanism and weave machine) is also combined with a favourable modification of the structural lay-out of the loom: the main motor connected to the weaving mechanism, according to the invention is arranged centrally in the loom, so as to distribute the torque equally on either side of the loom and actuate in a uniform and balanced manner both the cam follower system for the motion of the sley and the pairs of weft insertion mechanisms (for example the pairs of grippers).
According to an advantageous feature of the invention, the main motor is connected via a direct drive to the weaving mechanism by means of the main shaft, eliminating the need for an electromechanical coupling device and any associated gear trains. This advantageous result arises from the fact that there no longer exists the need to actuate both the weaving mechanism and the weave machine using the same motor, which would instead require a facility for disengaging the transmission.
According to this advantageous embodiment, a second independent motor is provided, said motor being assigned exclusively to the actuation of the weave machine, and is connected via an electric axis to the first motor.
According to a preferred embodiment, the first motor is integrated with the main shaft (motor-driven shaft), the latter coinciding with the axis of rotation of the said motor.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristic features and advantages of the present invention will nevertheless emerge more clearly from the detailed description which follows, considered together with the accompanying drawings, in which:
FIG. 1 is a schematic view of the main mechanical components of a gripper loom with a logical diagram of the interdependent connections;
FIG. 2 is a view, similar to that of FIG. 1 , with reference to an air loom; and
FIG. 3 is a perspective view of the main motor used in the middle of the loom according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 , a gripper loom comprises a weave machine 1 which interacts with the transverse movement of the warp yarns and therefore produces the weave of the fabric which is formed, and a weaving mechanism comprising, depending on the situation, a sley 2 , a pair of weft insertion grippers 3 a – 3 b, and other accessory equipments, such as the supply device 4 , cutters (not shown) and other components.
According to one embodiment of the invention, the weaving mechanism and the weave machine are operated by two independent actuating motors, M 1 and M 2 respectively.
These two motors are also joined together via an electric axis by a control unit 5 which, suitably programmed, manages operation of the whole loom. It must be pointed out, in this connection, that the control unit 5 has the function of keeping synchronised, in accordance with a specific loom operating program, the two motors M 1 and M 2 not only during normal operation, but also in anomalous or transient conditions (start-up and stoppage, finding of the pick, slow forwards and reverse running, etc.). Sensing of the position of the two motors M 1 and M 2 is performed by means of (angular) position transducers, preferably absolute-reference encoders, such that correct synchronism between the two motors may be restored also after a stoppage followed by a movement of only one of the two motors.
According to a preferred embodiment of the invention, moreover, the main motor M 1 is arranged in a substantially symmetrical position on the loom, as clearly illustrated in FIGS. 1 and 2 . The motor M 1 , in particular, has two opposite power take-off points from where two opposite sections 6 a and 6 b of a main shaft of the loom depart.
The outer or distal ends of the two shaft sections 6 a and 6 b also have, fixed to them, the main loads of the weaving mechanism, for example cam/follower devices 7 a and 7 b for actuating the two ends of the sley 2 , as well as devices 8 a and 8 b for moving the pair of grippers 3 a and 3 b.
In the figures, the motor M 1 is arranged in a central position on the cross-piece supporting the sley (not shown) by means of suitable fixing brackets S 1 and S 2 ( FIG. 3 ). Said motor is equipped with bearings supports of suitable size for supporting the two sections 6 a and 6 b of the main drive motor.
The sections 6 a and 6 b of the main shaft have a variable length depending on the height of the loom and are connected to said motor by means of any mechanical joint of the known type.
The system formed by the shaft and by the supports must be able to withstand the torsional and flexural loads imparted by the torque of the main motor and by the resistive loads; moreover, this system must not be subject to elastic instability phenomena.
The motor is provided internally with a motor-driven shaft having a suitable torsional rigidity and based preferably on “brushless” but also variable reluctance or asynchronous technology.
The motor-driven shaft may terminate at a short distance from the ends of the motor or may comprise at least a portion of the opposite sections of the drive shaft. The length of the motor also depends on the torque to be generated and the permissible transverse dimension which, as can be understood, must be as small as possible.
FIG. 2 shows an air loom which comprises a main motor M 1 suitably designed for transferring the necessary torque to the main shaft actuating the sley 2 . The control unit 5 has the function of co-ordinating via an electric axis the two motors M 1 and M 2 as well as the air nozzle device 10 for insertion of the weft yarns.
Such a layout has numerous advantages and allows the objects described in the preamble to be achieved.
In fact, the singular distribution of the loads between the two motors and the elimination of the reducer, electromagnetic coupling, clutch brake and flywheel constitute an advantage from the point of view of simplification and costs.
Moreover, the barycentric (with reference to the resistive loads) location of the main shaft motor permits a drastic reduction in the maximum torque moments at the ends of the loom, with a notable advantage in terms of the stresses applied. This allows, as a result, to use lighter shafts and a reduction, compared to the prior art, in the number of supports and bearings, thus reducing the inertial phenomena of the machine. The bearings of the engine are able to perform advantageously also the function of bench supports for the output shaft. On a loom of relatively small height it is likely that the supports of the two sections of the main drive shaft be provided exclusively at the ends, the centre being supported by the same bearings of the motor-driven shaft M 1 which transmits the stresses to the loom via the supports S 1 and S 2 .
Finally, the symmetrical distribution of the loads between the two sections of the main drive shaft helps improve the energetic efficiency of the machine, ensure uniform beating-up of the fabric and equalise the weft conveying and exchange operations performed by the two grippers.
With the motor in a barycentric position with respect to the loads, equivalent stresses, and hence strains, are achieved at the two ends of the loom: this also allows the sley to be controlled in a perfectly uniform manner, without irregular displacements being imparted to its two ends, therefore resulting in correct operation devoid of weaving defects.
From a constructional point of view, in fact, as a result of the central position of the motor, the elastic deformation energy U of each shaft section projecting from the motor M 1 may be reduced drastically, resulting in a more rigid transmission:
U= ½ T 2 l /( JG )
where U=elastic deformation energy; T=torque; l=length of the shaft section; J=polar moment of inertia; G =transverse elasticity modulus.
The central position of the motor results in a reduction in the angle of elastic torsion of the two sections of the actuating shaft—compared to a configuration where the motor is positioned on one side—and theoretically zero relative angular offset between the two actuating devices (which is otherwise notably present, according to the prior art, in particular during the start-up transients), helping ensure that the sley remains parallel to the beam and to the weft, in particular during the start-up and stoppage transients, therefore reducing the weaving defects upon stoppages.
It is understood, however, that the invention is not limited to the particular configurations illustrated above, which form only non-limiting examples of the scope of the invention, but that numerous modifications are possible, all within the competence of a person skilled in the art, without thereby departing from the scope of the invention itself.
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An actuating assembly for a weaving loom includes at least a first motor for actuating the weaving mechanism with a dual power take-off, the two power take-off points being connected to two opposite sections of a main drive shaft able to move devices for actuating the weaving mechanism which are located respectively on the two sides of the loom.
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FIELD OF THE INVENTION
[0001] The present invention is directed to a wall article hanger and a method of use, and in particular, to a hanger that is especially adapted to interface with a d-ring assembly mounted on the back of a wall article.
BACKGROUND ART
[0002] In the prior art, a number of techniques are employed to hang a wall article such as a picture, painting, mirror, tapestry, etc. One such technique employs a nail or other member that is attached to the wall, whereby the nail acts as the support for the article to be hung. The article to be hung can then be fitted with a wire, and the wire is slipped over the protruding nail to support the article. The article can also use other types of hanging devices such as serrated plates that are attached to the back of a frame, with the nail engaging one of the serrations on the plate for frame support. The article can also be hung by attaching a hanger device having a loop, whereby the nail would engage the loop for article support.
[0003] A picture hanger using a loop is illustrated in FIG. 1 and is commonly referred to as a d-ring. In fact, the d-ring is an assembly of a bent plate and a ring. The d-ring assembly of FIG. 1 is designated by the reference numeral 10 and includes a plate 1 that is bent or folded at 2 to form a pair of opposing plate sections 3 and 5 . Each section has a pair of openings 7 , each of which being sized to allow a fastener, e.g., a screw, nail, or the like to pass through the openings 7 and secure the two plate sections 3 and 5 to a wall article.
[0004] The plate is shaped at fold 2 with an opening 9 and a pair of curved folds 11 . The ring 13 passes through each curved fold 11 , each end of the ring 13 being bent upwardly at the opening 15 that is between the folds 11 to retain the ring in place. Once the plate 1 is attached to a wall article, the ring 13 can hang on a nail or other protrusion from a wall to support the wall article. In another use, two spaced apart d-ring assemblies 10 can be utilized with a wire extending between the two, the wire being used to hang onto a nail protruding from the wall.
[0005] Another class of wall article hanging devices are disclosed in U.S. Patent Nos. D339,981, 5,328,139, 5,588,629, 5,758,858, and 6,095,478 to Barnes. These patents run counter to the conventional wall article hanging techniques that first attach an element to the wall, and then hang the wall article off that wall element. In the Barnes' patents, a hanging device is first attached to the wall article to be hung, and then the wall article is secured to a wall surface. Using the Barnes' device and method, there is no need for locating a nail or the like at a predetermined location on the wall so as to position the wall article in the proper location. That is, the wall article itself is used for positioning in the proper site on the wall.
[0006] The Barnes' devices are also advantageous in that the wall article is secured in such a fashion that the article remains stationary after attachment, and the constant article leveling that goes on when a wire and nail are used is eliminated.
[0007] The hangers of the Barnes' patents are designed to be attached to a wall article frame using prongs of the device itself or fasteners.
[0008] Another Barnes hanger is disclosed in co-pending application Ser. No. 09/851,323 as a two piece system with a first piece attached to the wall article and a second piece designed to engage the wall surface and link to the first piece attached to the wall article for wall article support. This arrangement can even use a specially modified d-ring as the first piece, wherein the d-ring employs flanges or other means to establish the link with the second piece for wall article support. While this type of a wall article hanger is useful, it still requires modification of the prior art d-ring.
[0009] Accordingly, a need still exists to hang pictures using the Barnes methodology and the d-ring concept but without having to modify existing d-ring assemblies. The present invention solves this need by providing a wall article hanger device that interfaces with prior art d-ring assemblies to allow the wall article employing the d-ring assembly to be attached to the wall without the need for a wire and a nail or aligning the d-rings with nails, or other fasteners extending from the wall.
SUMMARY OF THE INVENTION
[0010] It is a first object of the present invention to provide an improved wall article hanging device.
[0011] Another object of the invention is to provide a hanging device that is adapted for use with prior art d-ring assemblies.
[0012] Still another object of the invention is a method of hanging wall articles that employ d-ring assemblies.
[0013] Other objects and advantages of the present invention will become apparent as a description thereof proceeds.
[0014] In satisfaction of the foregoing objects and advantages, the present invention provides an improved wall article hanger for use with a d-ring assembly having a plate body adapted to attach to the wall article and a movable ring mounted to the plate body. The inventive hanger comprises an elongated body having a first end portion and a center portion having one or more arms extending from the center portion and adapted to attach to the movable ring. A second end portion is provided that has at least one prong protruding at an angle from a longitudinal axis of the elongated body. The prong is adapted to penetrate the wall to support the wall article. The elongated body is sized in length so that the first end portion contacts a portion of the plate body to keep the elongated body generally aligned with the d-ring assembly after attachment thereto.
[0015] The second end portion can have a plate, the plate forming a bridge between the at least one prong or plate body and a rear surface of the wall article so that forces applied to the wall article are transmitted directly to the at least one prong via the plate.
[0016] The hanger can use a pair of arms with each arm extending from a side of the elongated body. The arm or arms can have a curved shape to accommodate attachment to the d-ring or an l-shape. The free end of the arm or arms can also be curved to ease attachment to the ring.
[0017] More than one prong can be used, and the prongs can have various configurations providing they are adapted to penetrate the wall surface, preferable dry wall.
[0018] The invention also entails a method of hanging the wall article using the d-ring assembly and the hanger. In one mode, the elongated body is attached to the ring of the D-ring assembly. The wall article is then pressed against a wall surface so that the at least one prong on the body penetrates the wall surface to support the wall article. When using the plate on the body, the wall article pressing step causes the rear surface of the wall article to press against the plate, thereby directing the wall article pressing force along the plate and to the prong so as to maximize the pressing effect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Reference is now made to the drawings of the invention wherein:
[0020] FIG. 1 is a perspective view of a prior art d-ring assembly;
[0021] FIG. 2 is a perspective view of one embodiment of the wall article hanger of the present invention;
[0022] FIG. 3 is a perspective view of the FIG. 2 embodiment in use with the d-ring assembly of FIG. 1 ; and
[0023] FIG. 4 is a cross section view along the line IV-IV of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The present invention offers significant advantages in the field of hanging wall articles. The invention overcomes the problems of having to use wire and nail or accurately positioned nails of the like when trying to hang wall articles with d-ring assemblies. With the inventive wall article hanging device, there is no need to use wires and/or nails in a wall to hang a wall article such as a picture. There is also no need to use nails, moly bolts or other fasteners to hang a picture or other wall article that has one or more d-ring assemblies attached to a back thereof. With the inventive hanging device, one merely has to attach the inventive hanger to the ring of the d-ring assembly, position the wall article in its desired location, and push the wall article towards the wall so that the prongs on the wall article hanger penetrate the wall to support the wall article.
[0025] Referring now to FIG. 2 , one embodiment of the present invention as a wall article hanger is designated by the reference numeral 20 with a main plate-like body 21 . The hanger 20 also a plate 23 and a pair of prongs disposed at one end of the body 21 . The plate 23 and prongs 25 are angled with respect to the longitudinal axis of the plate body 21 . Each of prongs 25 is intended to penetrate a wall for support of a wall article. The function of the plate 23 will be described below. While the prongs 25 are shown as being plate-like, they could take on other shapes such as pins with a circular or similar cross sectional shape or virtually any other shape that could penetrate a given wall surface for hanging of the wall article. The preferred wall surface is one that is easily penetrated by the prongs, e.g., sheet rock or the like.
[0026] The plate 23 has a length “x” measured from the edge 27 to the intersection of the body 21 and the plate 23 . The prongs extend from this intersection as well. The significance of the dimension “x” will be described below.
[0027] Beside the capability to attach to a wall surface, a second aspect of the hanger of the invention entails attachment to a d-ring assembly. To achieve this in one mode, the body 21 has a pair of arms 31 extending from a mid section portion 33 . The arms 31 have a first curvature to accommodate the ring 13 of the d-ring assembly 10 of FIG. 1 when the hanger is attached to the d-ring assembly. The arms also have ends 37 , each curved in an opposite fashion to entry of the ring 13 into the space 39 created by the arms 31 .
[0028] A third aspect of the hanger of the invention is an anti-rotation feature to ensure that the hanger 20 stays in place during the actual attachment of the wall article to a wall. In this aspect, the body 21 is sized so that a stop portion 35 extends below the mid section portion 33 , with the anti-rotation feature discussed below.
[0029] FIGS. 3 and 4 show the hanger 20 attached to the d-ring assembly 10 of FIG. 1 . In attaching the hanger 20 to the d-ring assembly 10 , the ring 13 is slid against a rear of the body 21 with the ends 37 sliding beneath the d-ring 13 . As noted above, the arms 33 are curved in shape to form the space 39 , see FIG. 4 , to retain the ring 13 in place.
[0030] The stop portion 35 extends below the fold 2 of the d-ring assembly 10 . The extension of the stop portion 35 prevents the d-ring 13 from rotating in the “Y” direction. This is important when the manner of attaching the wall article to a wall surface is explained. If the stop portion is eliminated, the d-ring 13 could rotate in the “Y” direction and the prongs 25 would not be in the proper orientation for hanging of the wall article. If the stop portion 35 were eliminated, one could hold the hanger 20 upright during the hanging process and hang the wall article. Thus, the inventive hanger could be made without the stop portion 35 just that it would be highly inconvenient since one would then be left with only one hand to hold the wall article.
[0031] Besides the anti-rotation feature associated with the stop portion 35 , the attachment feature of the arms 31 , the wall insertion function of the arms, the hanger employs the plate 23 as a spacer. That is, the plate dimension “x” should be of sufficient length so that when the wall article is attached to the wall, the prongs 25 are properly inserted.
[0032] In this regard, the manner of attaching a wall article will now be described. Since this invention is directed to the use of d-ring assemblies, it is assumed that the wall article to be hung as one or more d-ring assemblies. For purposes of explaining how a wall article is hung, a wall article with a one d-ring assembly will be described, although two or more can be used as well. With reference to FIG. 4 , the d-ring assembly 10 attached to a wall article 50 using fasteners 51 . The hanger 20 is then attached to the d-ring assembly 10 as shown in FIG. 3 . It should be noted that in a preferred embodiment, the hanger 20 is attached to the ring 13 so that the stop portion 35 contacts the plate section 5 since the opposing plate section 3 is flat where it contacts the wall article. The plate section 5 has a slight bulge at the fold 2 which would prevent the plate section 5 from lying perfectly flat against the wall article rear face.
[0033] With the hanger 20 attached to the d-ring assembly 10 , the wall article is positioned on a surface 55 of wall 57 where it is to be hung. Because of the stop portion 35 , the longitudinal axis of the hanger 20 remains aligned with a longitudinal axis of the d-ring assembly 10 so that the prongs 25 are in the right position for penetration into the wall 57 . Again, without the stop portion 35 , one would have to support the hanger 10 so that the prongs are in the proper orientation. With the stop portion 35 , the prongs are self-aligned and the wall article 50 is then merely pressed against the wall surface 55 . With this pressing action, the prongs 25 contact the wall surface 57 , initially forcing the edge 27 against the rear surface 59 of the wall article 50 . Further pressing of the wall article 50 forces the prongs 25 into the wall for supporting the pictures.
[0034] As is evident from FIG. 4 , the prongs 25 are angled with respect to the longitudinal axis of the plate 21 so that the prongs enter the wall on an angle for support purposes. As noted above and in a preferred embodiment, the dimension “x” of the plate 23 should be long enough so that surface 59 of the wall article 50 contacts the edge 27 . With this arrangement, the force applied to the wall article is directly applied to the prongs for insertion purposes. If the plate 23 dimension “x” were of insufficient length, a gap would exist between the edge 27 and surface 29 , and the prongs would have to be inserted as a result of forces applied to lower portions of the hanger, i.e., on the plate 21 at its mid section portion 33 . Therefore, it is preferred that the plate 23 is present and made of sufficient length to allow the pressing force on the wall article to be directly applied to the edge 27 .
[0035] Preferably, the plate 23 lies in the same plane as the prongs for ease of manufacture. However, the plate could be angled with respect to the prongs without the loss of the spacer function, if so desired.
[0036] It should also be understood that it is preferred to use two prongs 25 when using just one hanger, since the presence of two prongs embedded into the wall surface minimizes or prevents rotation of the wall article 50 . Of course though, a one prong hanger with one d-ring assembly could be used, if article rotation was not a concern. If a wall article had two d-ring assemblies, a hanger with only one prong could be used with each d-ring assembly, thus leaving two prongs to support the wall article.
[0037] The stop portion 35 is shown as being wider than the remainder of the plate 21 in the first embodiment. However, it could take on other configurations, as long as it extended to a point in contact with the plate 1 of the d-ring assembly 10 .
[0038] Likewise, the arms 31 are exemplary in their shape and design, and other arm configurations could be employed to attach the plate 21 to the d-ring assembly. While the arms have the curved shapes to create the space 39 , and make it easier to engage the ring 13 , the arms could merely have an l-shape (as viewed from the side) with the spacing between the arms and the back of plate 21 sized to make a tight engagement on the ring 13 . As another example, a single arm could be used for attachment purposes, and the arm could extend from a centerline of the body 21 , rather than from opposing edges like the FIG. 1 embodiment. Moreover, instead of the arms 31 extending towards the prongs 25 , the arms 31 could extend in the opposite direction or toward the stop portion 35 . The hanger is preferably made as a unitary or one piece construction, by stamping and forming operations. Of course, though, the hanger 20 could be made in any way providing that the end product embodies at least the wall insertion, and ring attachment functions.
[0039] The hanger can be made of any material, but a steel material is preferred due to its strength, and ease of working/forming into the hanger shape.
[0040] As such, an invention has been disclosed in terms of preferred embodiments thereof which fulfills each and every one of the objects of the present invention as set forth above and provides a new and improved wall article hanging device and method of use.
[0041] Of course, various changes, modifications and alterations from the teachings of the present invention may be contemplated by those skilled in the art without departing from the intended spirit and scope thereof. It is intended that the present invention only be limited by the terms of the appended claims.
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A wall article hanger and method of hanging a wall article that uses a d-ring assembly comprises providing a prong-containing hanger device that attaches to the d-ring assembly and remains in a relatively vertical position after being attached. With the hanger device in place, the prongs are angled towards the wall surface that the wall article is to be hung on. The wall article can then be pushed toward the wall, such that the prongs penetrate the wall and support the wall article.
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The present invention relates to a nanofiber web preparing apparatus and method via electro-blown spinning, in particular, in which both of thermoplastic and thermosetting resins are applicable, such that the polymer solution does not need to be heated and electrical insulation is readily realized. Herein, “electro-blown” means injecting compressed air while applying a high voltage during spinning of nanofiber, and “electro-blown spinning” means spinning using an electro-blown method.
In general, consumption of non-woven cloth is gradually increasing owing to various applications of non-woven cloth, and manufacturing processes of non-woven cloth are also variously developing.
A variety of studies have been carried out in many countries including the USA for developing technologies for manufacturing non-woven cloth composed of ultra-fine nanofiber (hereinafter it will be referred to as ‘nanofiber web’) which is advanced for one stage over conventional super-fine fiber. Such technologies are still in their initial stage without any commercialization while conventional technologies remain in a stage in which super-fine fibers are prepared with a diameter of about several micrometer. Nanofiber having a diameter of about several nanometer to hundreds of nanometer cannot be prepared according to conventional super-fine fiber technologies. Nanofiber has a surface area per unit volume, which is incomparably larger than that of conventional super-fine fiber. Nanofiber having various surface characteristics, structures and combined components can be prepared so as to overcome the limitations of physical properties of articles made of conventional super-fine fiber while creating articles having new performance.
It is well known that a nanofiber web using the above nanofiber preparing method can be used as an ultra precise filter, electric-electronic industrial material, medical biomaterial, high-performance composite, etc.
The technologies in use for preparing ultra-fine fiber up to the present can be classified into three methods: flash spinning, electrostatic spinning and meltblown spinning. Such technologies are disclosed in Korean Laid-Open Patent Application Serial Nos. 10-2001-31586 and 10-2001-31587, entitled “Preparing Method of Ultra-Fine Single Fiber” previously filed by the assignee.
Korean Laid-Open Patent Application Serial No. 10-2001-31586 discloses that nanofiber in nanometer scale can be mass-produced with high productivity and yield by systematically combining melt-blown spinning and electrostatic spinning. FIG. 3 schematically shows a process for explaining this technology. Referring to FIG. 3 , a thermoplastic polymer is fed via a hopper 10 into an extruder 12 where the thermoplastic polymer is melted into a liquid polymer. The molten liquid polymer is fed into a spinneret 14 and then spun via a spinning nozzle 16 together with hot air into an electric field. An electric field is generated between the spinning nozzle 16 charged with voltage and a collector 18 . Nanofibers spun onto the collector 18 are collected in the form of a web by a vacuum blower 20 .
Korean Laid-Open Patent Application Serial No. 10-2001-31587 discloses that nanofiber in nanometer scale can be mass-produced with high productivity and yield by systematically combining flash spinning and electrostatic spinning. FIG. 4 schematically shows a process for explaining this technology. Referring to FIG. 4 , a polymer solution is fed from a storage tank 22 into a spinneret 26 with a compression pump 24 , and spun into an electric field via a decompressing orifice 28 and then via a spinning nozzle 30 . An electric field is generated between the spinning nozzle 30 charged with voltage and a collector 32 . Nanofibers spun onto the collector 32 are collected in the form of a web by a vacuum blower 34 .
It can be understood that the nanofiber webs composed of nanofiber can be prepared according to the two technologies as above.
However, the foregoing conventional technologies have many drawbacks in that electrical insulation is not readily realized, applicable resin is restricted and heating is needed.
SUMMARY OF INVENTION
The present invention has been made to solve the foregoing problems and it is therefore an object of the present invention to provide a nanofiber web preparing method in which both of thermoplastic and thermosetting resins are applicable, such that a polymer solution does not need to be heated and electrical insulation is readily realized.
It is another object of the invention to provide a nanofiber web preparing apparatus for conducting the above preparing method.
According to an aspect of the invention to obtain the above objects, it is provided a nanofiber web preparing method comprising the following steps of feeding a polymer solution, which is dissolved into a given solvent, to a spinning nozzle; discharging the polymer solution through the spinning nozzle, which is charged with a high voltage, while injecting compressed air via the lower end of the spinning nozzle; and collecting fiber spun in the form of a web on a grounded vacuum collector under the spinning nozzle.
According to another aspect of the invention to obtain the above objects, it is provided a nanofiber web preparing apparatus comprising a storage tank for preparing a polymer solution; a spinning nozzle for discharging the polymer solution fed from the storage tank; an air nozzle disposed adjacent to the lower end of the spinning nozzle for injecting compressed air; high voltage charging means connected to the spinning nozzle; and a grounded collector for collecting spun fiber in the form of a web which is discharged from the spinning nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a construction of a nanofiber web preparing apparatus of the invention;
FIG. 2A is a sectional view of a spinneret having an air nozzle on a knife edge;
FIG. 2B is a sectional view of another spinneret having a cylindrical air nozzle;
FIG. 3 schematically shows a nanofiber preparing process via systematic combination of melt-blown spinning and electro-blown spinning; and
FIG. 4 schematically shows a nanofiber preparing process via systematic combination of flash spinning and electrostatic spinning.
DETAILED DESCRIPTION
FIG. 1 shows a construction of a nanofiber web preparing apparatus of the invention for illustrating a nanofiber web preparing process, and FIGS. 2A and 2B show nozzle constructions for illustrating spinning nozzles and air nozzles. The nanofiber web preparing process will be described in detail in reference to FIGS. 1 to 2B .
A storage tank 100 prepares a polymer solution via combination between polymer and solvent. Polymers available for the invention are not restricted to thermoplastic resins, but may utilize most synthetic resins, including thermosetting resins. Examples of the suitable polymers may include polyimide, nylon, polyaramide, polybenzimidazole, polyetherimide, polyacrylonitrile, PET (polyethylene terephthalate), polypropylene, polyaniline, polyethylene oxide, PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), SBR (styrene butadiene rubber), polystyrene, PVC (polyvinyl chloride), polyvinyl alcohol, PVDF (polyvinylidene fluoride), polyvinyl butylene and copolymers or derivative compounds thereof. The polymer solution is prepared by selecting a solvent according to the above polymers. Although the apparatus shown in FIG. 1 adopts a compression arrangement which forcibly blows compressed air or nitrogen gas into the storage tank 100 in order to feed the polymer solution from the storage tank 100 , any known means can be utilized without restricting feed of the polymer solution. The polymer solution can be mixed with additives including any resin compatible with an associated polymer, plasticizer, ultraviolet ray stabilizer, crosslink agent, curing agent, reaction initiator and etc. Although dissolving most of the polymers may not require any specific temperature ranges, heating may be needed for assisting the dissolution reaction.
The polymer solution is discharged from the storage tank 100 through a spinning nozzle 104 of a spinneret 102 which is electrically insulated and charged with a high voltage. After heating in an air heater 108 , compressed air is injected through air nozzles 106 disposed on either side of the spinning nozzle 104 .
Now reference will be made to FIGS. 2A and 2B each illustrating the construction of the spinning nozzle 104 and the air nozzle 106 in the spinneret 102 . FIG. 2A shows the same construction as in FIG. 1 in which the air nozzle 106 is formed by a knife edge on both sides of the spinning nozzle 104 . In the spinning nozzle 104 shown in FIG. 2A , the polymer solution flows into the spinning nozzle 104 through an upper portion thereof and is injected through a capillary tube in the lower end. Since a number of spinning nozzles 104 of the above construction are arranged in a line at given intervals, air nozzles 106 may be formed by knife edges at both sides of the spinning nozzles 104 parallel to the arrangement thereof, and nanofibers can be advantageously spun with the number of spinning nozzles 104 . Referring to preferred magnitudes of the components, the air nozzles 106 each have an air gap “a” which is suitably sized in the range of about 0.1 to 5 mm and preferably of about 0.5 to 2 mm, whereas the lower end capillary tube has a diameter “d” which is suitably sized with in the range of about 0.1 to 2.0 mm and preferably of about 0.2 to 0.5 mm. The lower end capillary tube of the air nozzle 106 has a suitable length-to-diameter ratio L/d, which is in the range of about 1 to 20 and preferably about 2 to 10. A nozzle projection “e” has a length corresponding to the difference between the lower end of air nozzle 106 and the lower end of spinning nozzle 104 , and functions to prevention fouling of the spinning nozzle 104 . The length of the nozzle projection “e” is preferably about −5 to 10 mm, and more particularly 0 to 10 mm.
The spinning nozzle 104 shown in FIG. 2B has a construction which is substantially equivalent to that shown in FIG. 2A , while the air nozzle 106 has a cylindrical structure circularly surrounding the spinning nozzle 104 , in which compressed air is uniformly injected from the air nozzle 106 around nanofibers, which is spun through the spinning nozzle 104 , so as to have an advantageous orientation over the construction of FIG. 2A , i.e. the air nozzles formed by the knife edge. Where a number of spinning nozzles 104 are necessary, spinning nozzles 104 and air nozzles 106 of the above construction are arranged within the spinneret. However, a manufacturing process of this arrangement is more difficult than that in FIG. 2A .
Now referring to FIG. 1 again, the polymer solution discharged from the spinning nozzle 104 of the spinneret 102 is collected in the form of a web on a vacuum collector 110 under the spinning nozzle 104 . The collector 110 is grounded, and designed to draw air through an air collecting tube 114 so that air can be drawn through a high voltage region between the spinning nozzle 104 and the collector 110 and the suction side of a blower 112 . Air drawn in by the blower contains solvent and thus a Solvent Recovery System (SRS, not shown) is preferably designed to recover solvent while recycling air through the same. The SRS may adopt a well-known construction.
In the above construction for the preparing process, portions to which voltage is applied or which are grounded are obviously divided from other portions so that electrical insulation is readily realized.
The invention injects compressed air through the air nozzle 106 while drawing air through the collector 110 so that nozzle fouling can be minimized in an optimum embodiment of the invention. As not apparently described in the above, nozzle fouling acts as a severe obstructive factor in preparation processes via spinning except for melt-blown spinning. The invention can minimize nozzle fouling via compressed air injection and vacuum. The nozzle projection “e” more preferably functions to clean nozzle fouling since compressed air injected owing to adjustment of the nozzle projection “e” can clean the nozzles.
Further, various substrates can be arranged on the collector to collect and combine a fiber web spun on the substrate so that the combined fiber web can be used as a high-performance filter, wiper and so on. Examples of the substrate may include various non-woven cloths such as melt-blown non-woven cloth, needle punched and spunlaced non-woven cloth, woven cloth, knitted cloth, paper and the like, and can be used without limitations so long as a nanofiber layer can be added on the substrate.
The invention has the following process conditions.
Voltage is applied to the spinneret 102 preferably in the range of about 1 to 300 kV and more preferably of about 10 to 100 kV with a conventional high voltage charging means. The polymer solution can be discharged in a pressure ranging from about 0.01 to 200 kg/cm 2 and in preferably about 0.1 to 20 kg/cm 2 . This allows the polymer solution to be discharged in large quantities adequate for mass production of nanofibers. The process of the invention can discharge the polymer solution with a high throughput rate of about 0.1 to 5 cc/min hole as compared with electrostatic spinning methods.
Compressed air injected via the air nozzle 106 has a flow rate of about 10 to 10,000 m/min and preferably of about 100 to 3,000 m/min. Air temperature is preferably in the range of about room temperature to about 300° C. and more preferably between about 100° C. and room temperature. A Die to Collector Distance (DCD), i.e. the distance between the lower end of the spinning nozzle 104 and the vacuum collector 110 , is preferably about 1 to 200 cm and more preferably 10 to 50 cm.
Hereinafter the present invention will be described in more detail in the following examples.
A polymer solution having a concentration of 20 wt % was prepared using polyacrylonitrile (PAN) as a polymer and DMF as a solvent and then spun through a spinneret having knife edge air nozzles as shown in FIG. 1 . The polymer solution was spun according to the following condition, in which a spinning nozzle had a diameter of about 0.25 mm, L/d of the nozzle was 10, DCD was 200 mm, a spinning pressure was 6 kg/cm 2 and an applied voltage was 50 kV DC.
The spinneret on the knife edge constructed as in FIG. 1 was used in the following examples. The diameter of the spinning nozzle was 0.25 mm, L/d of the nozzle was 10, and DCD was varied in examples 1 to 3 and set to 300 mm in examples 4 to 10. The number of the spinning nozzles was 500, the width of a die was 750 mm, the nozzle projection “e” was about 0 to 3 mm, and the flow rate of compressed air was maintained at 300 to 3,000 m/min through the air nozzle.
TABLE 1
Spinning
App.
DCD
Pressure
Voltage
No.
Polymer
Solvent
Conc. (%)
(mm)
(kgf/cm2)
(kV)
Ex. 1
PAN
DMF
15
350
3
30
Ex. 2
PAN
DMF
20
160
4
40
Ex. 3
PAN
DMF
20
200
6
50
Comp.
PAN
DMF
25
Ex. 1
Example 1 was good in fluidity and spinning ability, but poor in formation of web. Examples 2 and 3 were good in fluidity, spinning ability and formation of web. Examination of SEM pictures showed fiber diameter distribution of about 500 nm to 2 μm. In particular, Example 3 demonstrated uniform fiber diameter distribution in the range of 500 nm to 1.2 μm. In Comparative Example 1, it was difficult to prepare a PAN 25% solution and thus no result was obtained.
TABLE 2
Spinning Pressure
App. Voltage
Diam. Distribution
No.
(kgf/cm 2 )
(kV)
(nm)
Ex. 4
3
21
933.96-1470
Ex. 5
3
30
588.69-1000
Ex. 6
2.9
40
500.9-970.8
Ex. 7
3
60
397.97-520.85
Ex. 8
3.1
80
280.01-831.60
Ex. 9
3.5
40
588.69-933.77
Ex. 10
4
40
633.9-1510
Table 2 reports conditions and their results of Examples 4 to 10, which used nylon 6,6 for polymer and formic acid for solvent. The polymer solution concentrations were 25%. Fiber diameter distributions in Table 2 were determined by SEM picture examination, in which nanofibers having uniform diameters are irregularly arranged in the form of a web.
As set forth above, the present invention forms webs of nanofibers with a fiber fineness ranging from about several nanometers to hundreds of nanometers. Also the preparing process of the invention has a higher throughput rate compared to conventional electrostatic spinning, thereby potentially mass producing nanofibers. Further, since a polymer solution is used, the invention has advantages in that the necessity of heating polymer is reduced and both thermoplastic and thermosetting resins can be used.
Moreover, in the arrangement used for the electro-blown spinning, the spinneret can be readily electrically insulated while solvent can be recovered via vacuum.
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The invention relates to a nanofiber web preparing apparatus and method via electro-blown spinning. The nanofiber web preparing method includes feeding a polymer solution, which is a polymer dissolved into a given solvent, toward a spinning nozzle, discharging the polymer solution via the spinning nozzle, which is charged with a high voltage, while injecting compressed air via the lower end of the spinning nozzle, and collecting fiber spun in the form of a web on a grounded suction collector under the spinning nozzle, in which both of thermoplastic and thermosetting resins are applicable, the solution does not need to be heated and electrical insulation is readily realized.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. patent application Ser. No. 10/339,178, filed Jan. 9, 2003, now U.S. Pat. No. 6,986,217 which claims priority in U.S. Provisional Patent Application No. 60/347,178, filed Jan. 9, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hand held appliance for the care of garments and other items made of fabric. More particularly, the present invention relates to a hand held appliance for applying steam and/or heat to garments, fabrics and the like.
2. Description of the Prior Art
Portable hand held devices for applying steam are particularly useful in removing wrinkles and improving the appearance of hanging garments, draperies, upholstery, and other items made of fabric. When traveling, these devices may be especially effective for freshening clothes that have been packed in luggage. They are also useful for improving the appearance of hanging draperies without removing them, straightening and flattening upholstery, opening seams, and, generally, for smoothing fabric during sewing operations. In all of these applications, it is not only important to apply steam to the fabric, but to do so in a safe and easy manner. It is also important to be able to apply a desired amount of steam to a particular portion of the fabric being treated.
There are several factors that make the steaming operation difficult. An appliance that is large may occupy a significant amount of space rendering it unsuitable for use when traveling. An appliance that is bulky and heavy may be difficult to manipulate and thus inhibit applying the proper amount of steam for the time required to remove wrinkles. In addition, a bulky appliance may make it difficult to operate the controls. An appliance that does not accommodate different voltages encountered in different countries may be inconvenient. Also, the construction of the appliance may make filling with water difficult and may require a user to carry the entire appliance to a source of water. Certain types of fabric may also require an additional operation during the steaming operation such as the application of pressure over an area, brushing, or scrubbing.
Therefore, there exists a need for a hand-held garment steamer that is relatively lightweight, convenient to maneuver and operate, including filling the water tank thereof, and operable from multiple voltage sources.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a hand-held steamer for applying steam to an article of fabric construction.
It is another object of the present invention to provide such a steamer that is relatively lightweight and easy to hold.
It is yet another object of the present invention to provide such a steamer that applies steam and/or heat in a consistent manner.
It is a further object of the present invention to provide such a steamer that uses different voltages that may be found in various countries.
It is a still further object of the present invention to provide such a steamer having a detachable reservoir that is easily filled.
It is a still further object of the present invention to provide such a steamer with at least one attachment for performing operations on an item while steaming.
These and other objects and advantages of the present invention are achieved by a hand held appliance for use in applying steam to a garment or other article preferably made of fabric. Advantageously, the garment steamer of the present invention preferably is lightweight, comfortably held in the hand of a user, and suitably sized for easy, convenient transport such as traveling. The garment steamer of the present invention preferably includes functionality to provide a consistent application of steam and heat, either alone or in combination with the other, to an article of fabric construction and accommodates multiple voltage sources. A detachable reservoir is provided to facilitate easy filling thereof. The present invention preferably includes one or more attachments for performing various fabric treatment operations, such as but not limited to brushing, combing, flattening, and scrubbing fabric, and removing lint therefrom.
The steamer of the present application includes a pump, a steam generator or boiler, a steam discharge switch, and a removable water tank or reservoir. Power is selectively applied through a steam discharge switch to the pump. The pump pumps water from the reservoir to the boiler. The water is converted to steam in the boiler. The steam is discharged from the steamer through a number of openings disposed in an outer surface of a head portion of the steamer. The steamer preferably has a soleplate that is heated for applying heat to an article of fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a garment steamer accordance with the present invention;
FIG. 2 is a perspective view of the appliance of FIG. 1 , including an attachment attached thereto in accordance with the present invention;
FIG. 3 is a side view of a garment steamer in accordance with another embodiment of the present invention; and
FIG. 4 is a perspective view of the appliance of FIG. 3 illustrating, inter alia, the soleplate thereof.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the figures and, in particular, FIG. 1 , there is shown a hand held garment steamer generally represented by reference numeral 105 .
Steamer 105 has a housing 110 that houses, and preferably encloses, a boiler 115 and a pump 120 . Housing 110 has a nozzle 150 at a head portion end thereof and a handle connected to and extending from the head portion. A steam discharge switch 125 is mounted in or to housing 110 with its actuator 130 protruding through an opening in housing 110 .
A first water pipe 135 is provided to convey water from water tank or reservoir 145 to a pump 120 . A second water pipe 140 conveys water from pump 120 to a boiler 115 . In boiler 115 , the water is heated from a liquid state to steam. It should be appreciated that the boiler may be varied to include any type of steam generator compatible with the other aspects of the present invention.
The steam generated in boiler 115 is discharged (i.e., expelled) from at least one, and preferably a number of, nozzles 150 located on at least one outer surface of the head portion of steamer 105 .
Power for steamer 105 is derived from an external power source (not shown) through an electrical cable 155 . Cable 155 provides an electrical connection from the external power source to pump 120 , boiler 115 , and other components of steamer 105 requiring electrical energy. It should be appreciated by those skilled in the art that steamer 105 may be powered by an internal power source such as a battery.
Reservoir 145 is preferably detachable (i.e., removable) from housing 110 . In a preferred embodiment, reservoir 145 is connected to steamer 105 at the head portion end of the steamer. Reservoir 145 is selectively released by actuation of a reservoir release button 160 .
Upon detachment from housing 110 , reservoir 145 may be conveniently filled with a liquid such as water. Reservoir 145 may be filled through a fill port 165 that optionally includes valving to prevent spillage while water tank 145 is disengaged from housing 110 . Water tank 145 may be filled through another port or cap, an example of which is shown as filler cap 170 .
In an aspect of the present invention, reservoir 145 is preferably at least partially translucent to facilitate a visual determination of the amount of water contained present in reservoir 145 .
Once filled, water tank can be connected to housing 110 so that port 165 engages with first water pipe 135 . First water pipe 135 provides a conduit for liquid transport between reservoir 145 and pump 120 . Pump 120 is an electrical pump and can be a rotary vane, peristaltic, or any other type of pump suitable for pumping liquid according to the teachings of the present invention.
In an aspect of the present invention, pump 120 may operate at a fixed voltage or over a number of different voltages. For instance, pump 120 may operate only at 115 VAC or a multitude of voltages common to different countries. Preferably, the accommodated voltages have a range about 100 VAC to about 230 VAC.
Electrical cable 155 provides electrical power to housing 110 and, in particular, to pump 120 through a steam discharge switch 125 . Cable 155 may also have at least one safety device 185 in the form of a fuse, circuit breaker, thermal cut-off, or other safety device appropriate for use in the steamer of the present invention.
Upon actuation, steam discharge switch 125 serves to complete an electrical circuit including pump 120 and cable 155 , either directly or indirectly, for example by use of a relay. Thus, steam discharge switch 125 operates to cause the application of electrical power to pump 120 .
In another aspect of the present invention, steam discharge switch 125 may operate to cause a variable amount of power to be applied to pump 120 depending upon the amount of actuation by a user. In one aspect, steam discharge switch 125 may be locked or fixed in position to cause a constant amount of electrical power to be applied to pump 120 without further actuation by a user.
Second water pipe 140 provides a conduit from pump 120 to the steam generator (e.g., boiler 115 ). Upon application of power from steam discharge switch 125 , pump 120 pumps (i.e., draws) water from reservoir 145 through first water pipe 135 and pumps water through second water pipe 140 to boiler 115 .
Cable 155 also provides electrical power to boiler 115 . In an aspect hereof, boiler 115 receives electrical power so long as cable 155 is plugged into a suitable source of electrical power. In another aspect hereof, boiler 115 receives electrical power through steam discharge switch 125 , and thus may receive variable or constant power according to the configuration of switch 125 .
Boiler 115 uses the electrical power to produce heat for converting the water pumped from reservoir 145 to steam. Boiler 115 may be a “flash” boiler, capable of producing steam almost instantaneously upon the introduction of water from second water pipe 140 . Boiler 115 can include a safety device in the form of a thermal cut-off 180 (or any other applicable safety device) to prevent overheating of the boiler.
In a manner similar to pump 120 , boiler 115 may operate at a fixed voltage (e.g., 115 VAC) or over a number of different voltages that may be found in different countries (e.g., a range of about 100 VAC to about 230 VAC).
In another aspect of the present invention, a number of attachments may be mounted onto the steamer. The attachments are preferably connected to the head portion of the steamer and cover, at least partially, a surface face area of the head portion. The attachments aid in the steaming and/or fabric treatment processes being performed on a particular article of fabric.
FIG. 2 shows an attachment including brush attachment 190 and a lint remover attachment 195 . Brush attachment 190 and lint removing attachment 195 may be used individually, together, or in any combination with the steaming capability of the steamer 105 . It should be appreciated that other attachments, such as a comb, fabric pill remover, etc. are within the scope, and thus covered by the present invention.
FIG. 3 shows another embodiment of the steamer of the present invention and is generally represented by the reference numeral 205 . Although the configuration of housing 220 differs from the steamer of FIG. 1 , both steamer 205 and housing 220 preferably function in a manner similar to as steamer 105 and housing 110 , respectively, of FIG. 1 . Boiler 115 of appliance 205 can be regulated by a thermostatic device 210 to control production of steam at a particular range of temperature and delivery rate. A temperature dial 215 may be connected to thermostatic device 210 for selection of a particular steam temperature.
FIG. 4 shows an attachment 405 with a brush attachment 410 and lint remover attachment 415 , both preferably incorporated into a single attachment 405 .
Appliance 205 has a sole plate 420 that facilitates applying pressure and heat to the article of fabric being treated with the steamer of the present invention. Sole plate 420 has nozzles 150 disposed therein. It should be appreciated that sole plate 420 can be made of metal or any other suitable, preferably heat conductive, material for providing an even heat distribution to an article of fabric.
It should also be appreciated by those skilled in the art that the particular garment steamer functions and other aspects of the teachings herein are but examples of the present invention. Thus, they do not limit the scope or variety of applications that the present invention may be suitably implemented. Thus, it should be understood that the foregoing description is only illustrative of a present implementation of the teachings herein. Various alternatives and modification may be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the disclosure herein.
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A hand held appliance for use in applying steam to a garment or other item made of fabric includes a pump, a boiler and a switch. Power is applied through the switch to the pump. The pump pumps water from the water tank to the boiler. The water is converted to steam in the boiler and is expelled from the appliance through a set of nozzles. The appliance may include optional attachments for performing other operations on garments or fabric, for example, applying pressure, brushing, scrubbing or lint removal.
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BACKGROUND OF THE INVENTION
This invention relates to toilet seats for human use and means for ensuring that such toilet seats are always in the horizontal position after use.
The commonly available type of toilet seat consists of a seat and lid, both of which are hinged and attached at the rear of the toilet bowl in order that the lid or the lid and seat together may be elevated to the vertical position to rest against the toilet tank mounted behind the toilet bowl. This is a convenient means of providing a toilet seat which can be used in the horizontal position by either males or females and which can also be raised for cleaning purposes or for use by males. Thus, the standard toilet seat is a well designed and convenient to use apparatus, which is functional and yet which may be covered and therefore made more aesthetically pleasing by lowering the toilet lid after using.
One disadvantage of the arrangement described above is that either the lid or the lid and toilet seat together may be left in the upright position after use. This is a disadvantage in that it is considered unsightly by many and can be a nuisance to have to lower the toilet seat before use. In addition, a more serious problem exists in that if an individual forgets to lower the toilet seat before sitting down on the toilet, inconvenience and nuisance to the user may result at best, and at worst, the user risks sustaining injury from the unexpected fall.
SUMMARY OF THE INVENTION
The present invention seeks to remedy this problem by providing a toilet seat which can only rest in the horizontal position and which, for use in the upright position, must be held by the user in that upright position while in use. By preventing the toilet seat from ever being rested in the upright position, the problems described above are avoided.
There is thus disclosed an automatic seat lowering mechanism for a toilet seat on a toilet bowl comprising arm means having a first end adapted to be attached to an outer edge position of a toilet seat and to project downwardly away from the plane of the toilet seat so as to be disposed clear of the toilet bowl, and having a second end adapted to be supported by a leg of a user whereby in use, the toilet seat is held in an upright position by the second end of the arm means being supported by the leg of the user, and whereby the toilet seat will fall under the force of gravity acting on the arm means or on the toilet seat and the arm means in combination when the second end of the arm means is not supported by the leg of the user.
According to another aspect of the invention, there is disclosed an automatic seat lowering mechanism for a toilet seat with or without a toilet lid on a toilet bowl comprising arm means having a first end adapted to be attached to an outer edge position of a toilet seat and to project downwardly away from the plane of the toilet seat so as to be disposed clear of the toilet bowl, and having a second end adapted to be supported by a leg of a user, overbalancing means adapted to be positioned to stop the toilet seat or toilet lid from being raised into an upright position beyond a point where the toilet seat will remain in the upright position without support due to the force of gravity acting on the arm means or on the toilet seat and the arm means in combination, whereby in use, the toilet seat is held in an upright position by the second end of the arm means being supported by the leg of the user, and whereby the toilet seat will fall under the force of gravity acting on the arm means or on the toilet seat and the arm means in combination when the second end of the arm means is not supported by the leg of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of the apparatus of the invention installed on the toilet seat;
FIG. 2 is a perspective view of the apparatus of the invention when held in the upright position;
FIG. 3 is a view in section illustrating one possible means of attaching the arm to the toilet seat;
FIG. 4 is a view in section illustrating another possible means of attaching the arm to the toilet seat;
FIG. 5 is a sectional view of the adjustable stop mechanism;
FIG. 6 is a view in section illustrating another possible means of attaching the arm to the toilet seat;
FIG. 7 is a view of a toilet showing an alternative embodiment of a stop means for overbalancing the toilet seat;
FIG. 8 is an elevation view of the embodiment of FIG. 7, and
FIGS. 9a and 9b are a front elevation view and an end elevation view respectively of the embodiment of FIG. 7 showing in greater detail the construction of the alternative embodiment of the stop means.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a toilet 1 and toilet seat 2 of conventional design are illustrated. Toilet lid 3 is shown in the raised position resting against the front of toilet tank 4.
In one embodiment of the invention, the apparatus of the invention consists of an arm 21, a flange 22 to which the arm is connected at one of its ends and a foot 23 at the other end of the arm. As shown in FIG. 3, the flange 22 of the invention is attached to the underside 24 of the toilet seat at one side of the seat as illustrated in FIGS. 1 and 2. The attachment to the toilet seat 2 can be done by any convenient means such as with screws 25 and/or glue between the top of the flange and the bottom of the seat.
Foot 23 may be optionally attached to the opposite end of the arm 21 for the comfort of the user, although this is by no means necessary to the functioning of the invention. In a preferred embodiment however, the foot is provided and it is advantageous to cause this foot to be weighted in order to provide more leverage about the hinge of the toilet seat.
To install the invention, the arm is attached to the side of a toilet seat as shown in FIG. 1, preferably about half way along one side between the front of the toilet seat and the toilet seat hinge at the rear. The point of maximum rotation of the toilet seat away from the horizontal is checked to ensure that the toilet seat will always fall of its own accord due to the effect on the toilet seat of gravity acting on the toilet seat, arm and foot if present. If necessary, an additional stop is installed as described hereinafter to ensure that the toilet seat will fall under the influence of gravity from any possible position into which it is capable of being placed.
Thus, through a combination of the weight of the arm and any associated foot with or without extra weight, and an optional stop mechanism where necessary, the toilet seat is installed in such a fashion that it is always overbalanced and must always fall forward.
In operation, when it is desired to use the toilet seat in the down position, the invention has no effect and causes no inconvenience to the user. However, when it is desired to use the toilet seat in the upright position, the toilet seat 2 may be swung upwardly either by grasping the seat itself or by grasping arm 21. When in the maximum upright position, the top of the toilet lid is prevented from further angular rotation about its hinge, for example by the wall of the toilet tank or by stop 54 if it is installed. In this position, arm 21 and foot 23 project outwardly towards the user. In a preferred embodiment, foot 23 is provided to rest comfortably against the user's leg allowing the user to support the seat without the use of his hands. When the user is finished, the seat may be lowered in the normal fashion. In the unlikely event that the user forgets to lower the seat, the leverage provided by the weight of the arm and foot coupled with any extra overbalancing of the seat provided by the optional stop mechanism will act to cause the seat to fall. However, as the seat is always pressing against the user's leg by means of the arm and foot, it is most unlikely that the user would forget to lower the seat.
If required in order to cause the toilet seat to fall under the influence of gravity alone, the overbalancing mechanism may be installed as shown in FIG. 2 and adjusted as desired by means of the threaded adjustable stop 54 to prevent either the toilet seat alone or the toilet seat and the lid from remaining in the upright position. When in the maximum upright position, the top of the toilet lid contacts the end of the adjustable stop 54.
FIG. 5 illustrates one embodiment of an overbalancing mechanism of the invention. Clip 51 is designed to clip over the front wall 52 of the toilet tank 4. Threaded receptacle 53 is attached to clamp 51 and is designed to provide a receptacle for threaded adjustable stop 54. By threading the adjustable stop 54 in or out as required, the point of maximum angular displacement of the toilet seat/lid assembly from the horizontal position can be adjusted such that either the toilet seat alone or both the toilet seat and the lid in combination with the leverage introduced by the arm are overbalanced and thus unable to remain upright. Instead, they will be constrained by the force of gravity to fall downward.
FIGS. 7, 8, 9a and 9b illustrate another embodiment 80 of an overbalancing mechanism. In this embodiment, a flat strip 83 of metal is provided which is bolted on to the toilet bowl through two holes 84 provided in the strip with the same two bolts that hold the toilet seat assembly to the toilet. A fixed arm 81 is provided on one end of the strip 83, and is arranged to stop the toilet seat when it is in the raised position by contact with the stop 82 such that the leverage of the arm and foot will still be sufficient to drop the toilet seat. In order to provide for adjustment of the position of the fixed arm 81 with respect to the position of the toilet seat during installation, the holes 84 may be made as elongated slots (not shown) extending from left to right as seen in FIGS. 7 and 9a. This will permit some latitude in positioning of the strip during installation in order that the fixed arm 81 is aligned properly with the toilet seat to provide a stop as described above.
In many instances, the overbalancing mechanism such as shown at 50 or 80 will not be required, where, for example, toilet seat covers are used on the toilet lid which themselves have the effect of overbalancing the toilet seat. As well, the leverage on the toilet seat introduced by the weight of the arm and foot will tend to cause the toilet seat to return to its horizontal resting position on the toilet bowl, even when the seat is raised beyond the vertical position. Thus, in many installations, an overbalancing mechanism will not be required as the leverage provided by the arm and foot will accomplish this function.
The foot 23, though not strictly necessary for the functioning of the invention, is provided in order to avoid any discomfort on the part of the user from the end of the arm 21 sticking into the user's leg. The foot is preferably arranged in such a way that a child cannot gain a foothold on it to climb up on the toilet. Accordingly, as shown in the drawings, the foot has been provided with a shoulder 26 for this purpose.
It has been found that a total length for the arm and foot of approximately 8 inches seems most appropriate. Although not shown in the drawings, it is anticipated that the arm 21 could optionally be made adjustable in length in order to suit the convenience of users. This adjustment could be provided by making the arm 21 from two separate arms, one threadably engaging the other. Alternatively, the arm could be made of two pieces telescoping one within the other and be provided with a clamp to secure the arm at the desired length. At the same time, it is desirable that there be a clearance if possible between the bottom of the device and the floor in order that the apparatus of the invention not interfere with normal floor cleaning activities.
When the arm is approximately 8 inches in length and is attached to the edge of a standard household toilet seat along one side approximately midway between the front of the seat and the toilet seat hinge at the rear, it has been found that a weighted foot of about 5 to 7 ounces is generally sufficient to effect overbalancing of the seat in most installations, without the need to provide a separate overbalancing mechanism as shown in FIG. 5, by way of example.
The arm and the foot should preferably be made of non-toxic material in view of the possibility of children attempting to put their mouths on the apparatus.
The arm may be attached to the toilet seat in a number of ways other than that described above. For example, the arm could be attached to the seat by means of a friction clip 41 as shown in FIG. 4 or by means of a thumbscrew or setscrew type of arrangement as is shown in FIG. 6.
The arm and the flange can be formed of a one piece moulded plastic if desired, or could be attached together by means of gluing, screws or by the arm threadably engaging the flange.
The overbalancing mechanism described herein may also be attached directly to the front of the toilet tank without the use of a clip, as by gluing or sticking it to the ceramic front face of the tank.
The invention is designed to improve the aesthetics of the toilet, and to this end, would be provided in tasteful colours to match the decor of the seat and lid.
It is to be understood that the scope of the invention is not to be restricted to the embodiments described above but is to be interpreted in light of the claims which follow.
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An attachment for a toilet seat is provided which ensures that a toilet seat may not be left in the upright position. An arm attaches to one side of the toilet seat and projects downwardly outside the toilet bowl. The toilet seat is arranged so that it will always fall forward from any position due to the force of gravity on the seat and the leverage caused by the weight of the arm. An optional stop mechanism is provided to limit the rearward travel of the toilet seat to ensure that the seat will always fall forward. In use, the toilet seat is held in the upright position by resting the arm against the user's leg.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a fluid generator for converting fluid pressure to work and, more particularly, to a fluid pressure generator for converting fluid pressure to electricity.
2. Description of the Prior Art
Hydroelectric power plants are well known in the art. These plants are typically constructed near a dam. The plants direct water from a lake or retention area behind the dam, across a turbine or other means for converting the fluid pressure into mechanical motion, and thereafter convert this mechanical motion into electricity. One drawback associated with prior art hydroelectric power plants is the time, expense and maintenance associated with their construction. Such plants often cost millions of dollars and take years to construct. Another drawback associated with such prior art hydroelectric plants is their weight and lack of portability. These plants are typically constructed out of concrete, weighing hundreds of thousands of pounds. Due to their size, weight, time of construction and customized nature, they are not portable from one body of water to another. It would, therefore, be desirable to produce a low-cost, lightweight system for converting fluid pressure to work. It would also be desirable to provide such an assembly with means for adapting the assembly to various terrains and bodies of water. It would also be desirable to provide a fluid pressure conversion means which is easily set up and taken down at a desired site. The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.
SUMMARY OF THE INVENTION
In an advantage provided by this invention, an inexpensive fluid actuated power generator is provided.
Advantageously, this invention provides an efficient conversion of fluid pressure to work.
Advantageously, this invention provides a lightweight generator for converting fluid pressure to work.
Advantageously, this invention provides a portable fluid actuated power generator.
Advantageously, this invention provides a fluid actuated power generator, adaptable to a plurality of terrains.
Advantageously, this invention provides means for converting fluid pressure into a substantially constant electrical output.
Advantageously, in a preferred example of this invention, a motor is provided, comprising means for directing a fluid from a first body of fluid to a second body of fluid, for converting hydraulic pressure into mechanical motion, having a generator operably coupled to said converting means, and modulating a flow of fluid from said directing means to said converting means.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 illustrates a side elevation of the fluid generator of the present invention;
FIG. 2 illustrates a perspective view in cross section of the vane motor of the present invention;
FIG. 3 illustrates a top elevation in cross-section of the vane motor of FIG. 2;
FIG. 4 illustrates an alternative embodiment of the present invention, utilizing a flexible fluid delivery tube; and
FIG. 5 illustrates an alternative embodiment of the present invention, utilizing a vane motor coupled to a vane pump-to-pump fluid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A fluid actuated generator is shown generally as ( 10 ) in FIG. 1 . As shown in FIG. 1, the generator ( 10 ) is provided around a dam ( 12 ) retaining a first body of water ( 14 ) above a second body of water ( 16 ). Although the generator ( 10 ) is shown in fluid communication with both bodies of water ( 14 ) and ( 16 ), the generator ( 10 ) may be provided in fluid communication with only the first body of water ( 14 ) and drained as desired. As shown in FIG. 1, the generator ( 10 ) is provided with an inlet ( 18 ) defined by a first end ( 20 ) of a first tube ( 22 ). The tube ( 22 ) is preferably constructed of polyvinyl chloride having a thickness of one centimeter, and a diameter of ten centimeters. Although the first tube ( 22 ) may be of any desired dimensions, it is preferably of a diameter between one millimeter and one meter, more preferably, between one centimeter and fifty centimeters, and most preferably, between two centimeters and fifteen centimeters.
As shown in FIG. 1, provided around the first end ( 20 ) of the first tube ( 22 ) is a cage ( 24 ), preferably constructed of steel wire and defining a plurality of inlets of a size sufficient to filter debris from entering the first tube ( 22 ). As shown in FIG. 1, the first tube ( 22 ) is coupled to the dam ( 12 ) by a plastic cuff ( 26 ), secured around the first tube ( 22 ) and releasably secured to a steel piton ( 28 ). Preferably the piton ( 28 ) is screwed, hammered, or otherwise coupled into securement with the dam ( 12 ). Alternatively, the piton ( 28 ) may be a pole coupled to a base for supporting the first tube ( 22 ) at a predetermined distance from the dam ( 12 ).
As shown in FIG. 1, the first tube ( 22 ) is provided with a second end ( 30 ), screwed into or otherwise releasably coupled to a first end ( 32 ) of a second tube ( 34 ). Similarly, the second tube ( 34 ) is secured to the dam ( 12 ) by a second cuff ( 36 ) and piton ( 38 ). The second tube ( 34 ) is also provided with a second end ( 40 ), coupled to a third tube ( 42 ). The third tube ( 42 ) is coupled to a fourth tube ( 44 ), and the fourth tube ( 44 ) is coupled to a fifth tube ( 46 ) in a manner such as that described above. As shown in FIG. 1, the first tube ( 22 ), fourth tube ( 44 ) and fifth tube ( 46 ) are straight sections, whereas the second tube ( 34 ) and third tube ( 42 ) are curved sections. By providing a plurality of straight sections and curved sections, and making the providing the tubes ( 22 ), ( 34 ), ( 42 ), ( 44 ) and ( 46 ) with similar connection means, the tubes ( 22 ), ( 34 ), ( 42 ), ( 44 ) and ( 46 ) may be assembled in any desired orientation to accommodate any desired curvature of the dam ( 12 ) or any other structure.
Similarly, the cuffs ( 26 ) and ( 36 ), and pitons ( 28 ) and ( 38 ) may be constructed of any suitable dimensions and connection means to secure the final construction of the tubes ( 22 ), ( 34 ), ( 42 ), ( 44 ) and ( 46 ) to the dam ( 12 ). Alternately, the tubes ( 22 ), ( 34 ), ( 42 ), ( 44 ) and ( 46 ) may rest directly on the dam ( 12 ), or secured in relationship thereto by any other suitable means known in the art. As shown in FIG. 1, the fifth tube ( 46 ) is coupled to a variable control valve ( 48 ). Although the variable control valve ( 48 ) may be of any type known in the art, in the preferred embodiment, the valve ( 48 ) is of the needle valve variety, translating rotation of the needle valve into a modulation of fluid flow across the valve. Coupled to the valve ( 48 ) is a motor ( 50 ). Although the motor ( 50 ) is preferably a vane motor, it may be any suitable device for translating fluid pressure into mechanical motion.
Preferably, as shown in FIGS. 2 and 3, the motor ( 50 ) is provided with a drive shaft ( 52 ), coupled to a casing ( 54 ) by a bushing ( 56 ). The casing ( 54 ) defines a fluid inlet ( 58 ) and a fluid outlet ( 60 ). In the preferred embodiment, the fluid inlet ( 58 ) is coupled into fluid communication with the valve ( 48 ). (FIGS. 1 - 2 ). The casing ( 54 ) is provided with a hollow interior ( 62 ) in fluid communication with the inlet ( 58 ) and outlet ( 60 ). The hollow interior ( 62 ) is defined by an outer race ( 64 ). Provided within the hollow interior ( 62 ) is an inner drum ( 66 ), which comprises a front plate ( 68 ), a back plate ( 70 ), and a cylindrical inner race ( 72 ). (FIGS. 2 and 3 ). As shown in FIG. 2, the inner race ( 72 ) is provided with a first aperture ( 74 ), a second aperture ( 76 ), a third aperture ( 78 ), and a fourth aperture ( 80 ).
Provided within the inner drum ( 66 ) is a first vane assembly ( 82 ), which includes a first vane ( 84 ) and a third vane ( 86 ), each secured to a lost motion linkage ( 88 ). The first vane ( 84 ) and third vane ( 86 ) are wider than the first lost motion linkage ( 88 ), leaving a first C-shaped cutout ( 90 ) in the first vane assembly ( 82 ). A second vane assembly ( 92 ) is also provided, comprising a second vane ( 94 ), a fourth vane ( 96 ) and a second lost motion linkage ( 98 ). The second vane ( 94 ) and fourth vane ( 96 ) are secured to the second lost motion linkage ( 98 ) in a manner similar to that described above to provide a second C-shaped cutout ( 100 ).
The first vane assembly ( 82 ) and second vane assembly ( 92 ) are constructed in a manner which positions the first vane ( 84 ) and third vane ( 86 ) perpendicular to the second vane ( 94 ) and fourth vane ( 96 ). The first lost motion linkage ( 88 ) is provided within the second C-shaped cutout ( 100 ) of the second vane assembly ( 92 ), and the second lost motion linkage ( 98 ) is provided within the first C-shaped cutout ( 90 ) of the first vane assembly ( 82 ). Preferably, the vane assemblies ( 82 ) and ( 92 ) are constructed of stainless steel and are provided near their ends ( 102 ) with wear resistant tips ( 104 ), constructed of an aluminum nickel bronze alloy, such as those alloys well known in the art to be of superior wear resistance. The tips ( 104 ) are rounded with a tighter radius of curvature than the outer race ( 64 ). The tips ( 104 ) are secured to the vane assemblies ( 82 ) and ( 92 ) by weldments or similar securement means. The first lost motion linkage ( 88 ) defines an interior space ( 106 ) with a width approximately one-half of its length. Provided within this interior space ( 106 ) is a stainless steel drum shaft ( 108 ). Secured around the drum shaft ( 108 ) is a guide block ( 110 ). The guide block ( 110 ) has a square cross-section with a width only slightly smaller than the width of the interior space ( 106 ), defined by the first lost motion linkage ( 88 ). The guide block ( 110 ) is preferably the same depth as the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ), and extends from the interior space ( 106 ) of the first lost motion linkage ( 88 ) into an interior space (not shown) defined by the second lost motion linkage ( 98 ). This construction allows longitudinal movement of the vane assemblies ( 82 ) and ( 92 ) relative to the guide block ( 110 ) and drum shaft ( 108 ), but prevents lateral movement in relationship thereto.
The drum shaft ( 108 ) is coupled to a back plate ( 112 ) bolted to the casing ( 54 ). FIGS. 2 and 3 ). As shown in FIG. 3, the drum shaft ( 108 ) is centered within the hollow interior ( 62 ) defined by the outer race ( 64 ). The drive shaft ( 52 ) is positioned slightly higher than the drum shaft ( 108 ), and is coupled to a front plate ( 114 ) bolted to the casing ( 54 ). The drive shaft ( 52 ) is parallel to, but on a different axis than the drum shaft ( 108 ). Since the shafts ( 52 ) and ( 108 ) each rotate on a different axis, the back plate ( 112 ) must be provided with a large, circular aperture ( 116 ), into which is secured a bearing ( 118 ). The bearing ( 118 ) supports the inner drum ( 66 ) against the casing ( 54 ) and allows the drum shaft ( 108 ) to extend out of the casing ( 54 ) and rotate on its own axis. The bearing ( 118 ) also maintains a substantially fluid tight seal to prevent the escape of pressurized fluid out of the casing ( 54 ).
As water ( 120 ) enters the fluid inlet ( 58 ) under pressure, the water presses against a face ( 122 ) of the second vane ( 94 ), forcing the inner drum ( 66 ) into a counterclockwise rotation. (FIG. 2 ). When the fourth vane ( 96 ) is closest to a ceiling ( 124 ) of the casing ( 54 ), the majority of the fourth vane ( 96 ) is located within the inner drum ( 66 ). Accordingly, the amount of the fourth vane ( 96 ) exposed to the water ( 120 ) is reduced, as is its drag coefficient. A larger drag coefficient would allow the water ( 120 ) to force the inner drum ( 66 ) toward a clockwise rotation, thereby reducing the efficiency of the motor ( 50 ).
As the water ( 120 ) presses against the face ( 114 ) of the second vane ( 94 ), the second vane ( 94 ) moves along an abrasion plate ( 125 ), preferably constructed of titanium or similar abrasion resistant material, preferably being less than five millimeters and, more preferably, less than one millimeter, while being preferably greater than 1/100th of a millimeter and, more preferably, more than 1/50th of a millimeter from the tips ( 104 ) of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) as they rotate past. As the second vane ( 94 ) rotates toward the end of the abrasion plate ( 125 ), the first vane ( 84 ) moves toward the abrasion plate ( 125 ) and the water ( 120 ) presses against a face ( 126 ) of the first vane ( 84 ), thereby continuing the counterclockwise rotation of the drum shaft ( 108 ) and the inner drum ( 66 ). As the inner drum ( 66 ) continues to rotate, the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) extend and retract relative to the inner drum ( 66 ). The retraction reduces the drag coefficient of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) when the vanes are near the ceiling ( 124 ) to reduce reverse torque on the inner drum ( 66 ). Conversely, the extension increases the drag coefficient of the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) as the vanes approach the abrasion plate ( 125 ) to allow the water ( 120 ) to provide maximum forward torque to the inner drum ( 66 ) through the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ). As the vanes ( 84 ), ( 86 ), ( 94 ) and ( 96 ) move past the abrasion plate ( 125 ), the water ( 120 ) exhausts through the fluid outlet ( 60 ). Obviously, the motor ( 50 ) can be constructed of any desired material of any suitable dimensions.
As shown in FIG. 1, coupled to the drive shaft ( 52 ) of the motor ( 50 ) is a waterproof electric generator ( 128 ). The generator ( 128 ) is preferably coupled to the drive shaft ( 52 ) via a watertight bushing ( 130 ), such as those well known in the art. While the generator ( 128 ) is preferably electric, it may, of course, be of any suitable type of power storage or transmission device known in the art, actuated by heat, mechanical, pneumatic or hydraulic power.
As shown in FIG. 1, an electrical cord ( 132 ) is coupled to the generator ( 128 ) and extends out of the secondary body of water ( 16 ) for coupling to batteries (not shown), or any other desired electrical device. Also coupled to the generator ( 128 ) is a voltage meter ( 134 ) which, in turn, is coupled to a circuit board ( 136 ). Preferably, the voltage meter ( 134 ) and circuit board ( 136 ) are made watertight so as to prevent contact with the water ( 120 ). The circuit board ( 136 ) is coupled to a motor ( 138 ) which, in turn, is operably coupled to the valve ( 48 ). The circuit board ( 136 ) is designed to monitor the voltage meter ( 134 ) and electronically adjust the flow of water ( 120 ) through the variable control valve ( 48 ), through the use of the motor ( 138 ). If the pressure on the water increases, thereby driving the motor ( 50 ) faster, and increasing the output of the generator ( 128 ), the circuit board signals the motor ( 138 ) to close the valve ( 48 ) slightly to modulate the electricity produced by the generator ( 128 ). Alternatively, if the pressure on the water ( 120 ) reduces, the circuit board ( 136 ) monitors a voltage drop from the voltage meter ( 134 ) and signals the motor ( 138 ) to open the valve ( 48 ) slightly to increase the flow of water ( 120 ) through the valve ( 48 ), thereby driving the motor ( 50 ) more quickly and causing the generator ( 128 ) to produce more electricity.
An alternative embodiment of the present invention is shown in FIG. 4, which utilizes a flexible hose, such as a garden hose or braided pressurized fluid hose to draw water from the body of water ( 14 ) and run the generator ( 128 ). As shown in FIG. 4, a second hose ( 142 ) is coupled to the motor ( 50 ) and run into a storm sewer ( 144 ), or similar depository if there is no second body of water available. In this embodiment, the flexible hose ( 140 ) may either be secured to the ground using stakes or brackets (not shown), or may simply laid along the ground and later coiled for transport. Still another embodiment of this present invention is detailed in FIG. 5, wherein a first motor ( 146 ) is coupled to a second motor ( 148 ), which, in turn, is coupled to an outlet hose ( 150 ). In this embodiment, the first motor ( 146 ) acts as a driving means to turn 49 the shaft ( 152 ). The shaft ( 152 ) is coupled to the second motor ( 148 ), which, in this embodiment, acts as a pump, driven by the shaft ( 152 ), and drawing water ( 154 ) through an inlet ( 156 ), and forcing the water ( 154 ) through the hose ( 150 ), where it may be used to irrigate crops, fill wells, or for any other desired purpose.
An advantage provided in all of the foregoing embodiments is that the fluid actuated generator ( 10 ) may be readily disassembled with a minimum of tools, transported in a vehicle, and reconfigured at an alternate site. Preferably, the components are designed for assembly by hand, without tools, in the field. Preferably, all of the components of the fluid actuated generator ( 10 ) comprise an area less than three square meters and, more preferably,. an area less than one square meter. Similarly, all of the components of the generator preferably collectively weigh less than five hundred kilograms and, more preferably, less than fifty kilograms. In the most preferred embodiment of the present invention, a single individual will be able to take down the fluid actuated generator ( 10 ) in a manner of minutes, carry the components to a vehicle (not shown), transport the components in that vehicle, and set up the fluid actuated generator ( 10 ) in an alternate location quickly and efficiently.
Although the invention has been described with respect to a preferred embodiment thereof, it is also to be understood that it is not to be so limited, since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims. For example, it should be noted that any desired motor ( 50 ) may be used, including a standard turbine or vane motor, and that any type of generator, including both direct current and alternating current generators, may be utilized in accordance with the present invention.
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A fluid actuated power assembly for generating power from a pressurized fluid. A tube is provided for siphoning fluid from a body of water to a vane motor. A generator is coupled to the vane motor to produce electricity. The tube is preferably modular and adaptable to a plurality of configurations. This allows the entire assembly to be portable and adaptable to many different types of fluid sources.
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TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to a control coupling for a delimbing and cutting apparatus for feeding means and for changing their feeding speed.
BACKGROUND OF THE INVENTION
[0002] For the processing of tree trunks, a harvester head, i.e. an apparatus for the delimbing and cutting of tree trunks, is used for the purpose of gripping an upright growing tree, cutting the tree and felling it, after which the tree trunk is delimbed and cut into pieces of fixed length by means of a sawing device. One known harvester head is disclosed in WO publication 00/15025. The harvester head is normally connected to the end of the boom assembly of a forest working machine. The har-vester head is connected to the boom assembly in an articulated man-ner, and it comprises the necessary actuator means, normally hydraulic cylinders and hydraulic motors, by means of which the position of the head and its different functions can be controlled. The harvester head comprises delimbing means which can be articulated in relation to the frame structure and which comprise delimbing blades for delimbing branches while the trunk is supported and forced through the appara-tus. The means used as the feeding means comprise a feed roll or a feed track assembly which is pressed against the trunk and pulls it through the apparatus. The harvester head also comprises cutting means, for example a chain saw, for cutting the tree trunk.
[0003] One known rubber feed pulley is disclosed in WO publication 95/01856, in which non-skid devices are connected by chains to the outer rim of the feed pulley. Another feed pulley is also presented in FI patent 102664. A shock absorbing feed pulley is presented in FI patent 97785, in which a rigid metal jacket with friction means is fitted on a gummy elastic rubber layer. One feeding device comprising a roll mat is disclosed in U.S. Pat. No. 3,669,161. The number of feed pulleys is normally two, but in WO 99/41972 and Fl patent 97340 there are four feed pulleys, wherein the feed pulley motors of the same side are cou-pled in series and the feed pulley motors of opposite sides are coupled in parallel. Two motors of opposite sides are coupled mechanically together to prevent the rotation of the feed pulleys at different speeds, particularly at high feeding speeds.
[0004] The feed motors have normally a fixed rotational capacity, wherein the feeding speed is constant and only depends on the volume flow sup-plied to the motor. Also variable-speed motors are known, but they are larger in size and normally require a reduction gear, wherein their size increases further. To keep the speeds equal in the different feed pul-leys, valves or auxiliary feed pulleys and their mechanical couplings must be used, wherein the size and weight of the harvester head are increased and the placement of the components becomes more diffi-cult. In some radial piston motors, the volume flow can be divided, for example, to one half of the pistons only, wherein the speed is doubled (and the torque and the tractive force are halved). In this case, a com-mon disadvantage is poor efficiency, when the pistons are not all in operation.
SUMMARY OF THE INVENTION
[0005] It is an aim of the present invention to eliminate the above-presented drawbacks and to provide such a control circuit for the feeding means of the harvester head, which utilizes a motor of a given type and vari-ous couplings therein, to achieve multi-speed feeding in as simple a way as possible.
[0006] By means of the coupling according to the invention, it is possible to expand the ranges of tractive force and feeding speed of the respective feeding motor with a fixed volume. The coupling and the motors according to the invention can also be installed afterwards in the har-vester end, wherein the alternatives for the feeding speed in known apparatuses are increased. The motor used has a structure with a light weight compared with corresponding motors with adjustable speed.
[0007] A particular advantage is the coupling of the motors, whereby the speeds of two different feed pulleys can be locked together, wherein the aim is to prevent skid. The coupling can be used at high feeding speeds. The selection of the speeds is simple, because it can be implemented by on/off control. By suitable selection of the motor, speed steps are achieved which are smaller than in corresponding two-speed motors. With a suitable motor and different couplings, it is possible to achieve even a four-step feeding speed and an adjustment of even steps.
[0008] The invention utilizes a multi-capacity motor which is known, for exam-ple, from U.S. Pat. No. 6,099,273. The motor is a radial piston motor com-prising an input and output connection as well as an extra connection which can be used as an input or output connection. The motor also comprises a selector, i.e. a stem in a drilling, by means of which some of the pistons direct the used volume flow to the normal output connec-tion and the other pistons feed it to the auxiliary output connection. In this way, the motor has at least two different capacities (dual-capacity motor), wherein it comprises, in a way, two half-motors. Alternatively, the extra connection can be an auxiliary inlet connection, through which the volume flow is supplied to one of the half-motors. Because of the common shaft, however, the rotation speeds of the half-motors are the same. Said selector can also be missing, in which case the motor always has three connections available, one being connected to all the pistons and the two others being connected to specific separate pis-tons only, wherein the speeds to be achieved will depend on the cou-plings with which the motor is controlled.
[0009] U.S. Pat. No. 6,099,273 utilizes three said motors and the coupling there-between in the transmission of a vehicle. The most typical coupling of two separate motors is one in which two half-motors located in different motors are always coupled in series. Publication EP 1 026 025 A1 pre-sents examples of such series connections when they are applied in the wheels of a vehicle. U.S. Pat. No. 6,230,829 and EP publication 0 547 947 B1 also present a vehicle transmission utilizing said motor.
[0010] The basic principle of the invention is the use of said motors as feed motors at the harvester head and the possibility to connect them either in parallel or in such a way that only two half-motors are in series. By means of the connections, two different feeding speeds are achieved. Furthermore, the invention utilizes the connection of all the half-motors in series, wherein at least three different speeds can be used. When the rotational capacities of the half-motors differ from each other, four different feeding speeds are achieved. Furthermore, when the ratio of the rotational capacities of the half-motors is approximately 1:2, it is possible to achieve three speeds with a substantially equal change and a very fast fourth speed. Moreover, said adjustment of even steps is achieved in the whole rotational capacity of the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be illustrated in the following description with refer-ence to the appended drawings, in which:
[0012] FIGS. 1 to 4 show the principles of coupling half-motors when they are coupled in parallel, partly in series with each half-motor separately, and when they are coupled in series;
[0013] FIGS. 5 to 7 show the more detailed structures of the control circuits to implement the couplings of FIGS. 1 to 4 , when two different feeding speeds can be further achieved with the motors, and
[0014] FIGS. 8 and 9 show the more detailed structures of the control circuits to implement the couplings of FIGS. 1 to 4 , when four differ-ent feeding speeds can be further achieved with the motors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Table 1 shows three different motor models and example cases A, B and C of how the achievable rotational speed n of the feed roll varies according to the rotational capacity Vg of the two half-motors of the motor (Vg 1 and Vg 2 ) and when the feed volume flow remains the same. Furthermore, the feed force and speed of the feed roll depend on the pressure used and on the dimensions of the feed roll. The cou-pling 1 is a parallel coupling according to FIG. 1 , and the coupling 2 is a series coupling of two half-motors as shown in FIG. 2 . In the motor A, the ratio between the rotational capacities Vgl and Vg 2 is 1:2, wherein the coupling of FIG. 3 yields 67% and 83% of the rotational capacity Vg of the coupling of FIG. 1 and FIG. 2 , respectively, and the coupling of FIG. 4 yields the highest speed, wherein the rotational capacity Vg is 50% smaller than in the coupling 1 of FIG. 1 . To achieve four different speeds, it is required that the rotational capacities Vgl and Vg 2 in the same motor differ from each other, wherein their ratio differs from the value 1:1. With the ratio 1:2, equal changes are achieved in the rota-tional capacity Vg. Even if the ratio of the rotational capacities Vgl, Vg 2 were 1:2 or variable, half-motors refer to all the different alterna-tives in this description.
TABLE 1 Motor A B C Size 943 cc 1048 cc 1404 cc Vg1 (cc/r) 314 419 561 Vg2 (cc/r) 629 629 843 Coupling 1: 100% 100% 100% Rotational speed n1 Coupling 2: 120% 125% 125% Rotational speed n2 Coupling 3: 150% 143% 143% Rotational speed n3 Coupling 4: 200% 200% 200% Rotational speed n4
[0016] FIG. 1 shows the coupling of the motors 1 and 2 in parallel, wherein the volume flow from the valve 6 is divided separately to the motors 1 and 2 (the connections A 2 , B 2 and R 1 are coupled together and to the channel 4 ) and wherein it also returns separately from the motors 1 and 2 (the connections Al, B 1 and R 2 are coupled together and to the channel 5 ). The half-motors 1 a , 1 b , 2 a , 2 b of the same motor 1 , 2 are indicated with motor symbols drawn next to each other. At the same time, the common shaft is illustrated, as well as the fact that the half-motors always have a common rotational speed. Alternatively, the half-motors are indicated with a symbol which comprises two motor sym-bols within each other. Each half-motor comprises two basic connections which are for the supply and for the return of the volume flow. In the connections of FIGS. 1 to 4 , either the first or the second basic connections of two half-motors are permanently joined to a con-nection R 1 or R 2 , wherein the connection is preferably within the motor. In practice, the motors 1 and 2 are completely equal models.
[0017] Preferably, the motors 1 , 2 comprise three connections which are always in use. Each motor 1 , 2 comprises one return connection R 1 , R 2 and two working connections A 1 , A 2 and B 1 , B 2 . One should bear in mind that a pressurized volume flow can also be conducted to the return connection, and the volume flow of the half-motors can also be returned via the working connection. At the same time, the direction of rotation of the motors is reversed, which is the normal way of use when, for example during delimbing, the tree is reversed for some length, stopped, and the feeding is continued again. With the coupling alternatives of the two different motors 1 , 2 , it is possible to achieve the desired speed alternatives, even though the capacities Vgl, Vg 2 of each motor 1 , 2 were constant. The different coupling alternatives, which are illustrated in FIGS. 1 to 4 , are implemented with different valve means, which are shown in FIGS. 5 to 9 . In connection with FIGS. 2 to 4 , reference numerals are used, which correspond to FIG. 1 .
[0018] In FIG. 1 , the common rotational speed n of the motors 1 , 2 can be rep-resented by the formula n 1 =Q/2·(Vg 1 +Vg 2 ), which is simultane-ously the rotational speed of the wheel guiding the feed pulley or feed roll, when no gears are used. Valve means 3 , for example a spool valve with 3 positions, are used to select the direction of rotation of the motors 1 , 2 , wherein the volume flow is fed either to the channel 4 (in which case the return flow comes from the channel 5 ) or to the channel 5 (in which case the return flow comes from the channel 4 ). In the mid-dle position of the valve 3 , the channels 4 , 5 are closed and the motors are stopped. The valve 3 may also have a position, in which the motors 1 , 2 are let on free circulation. The control circuit feeding the valve 3 is known as such, and it comprises at least a pressure connection P and a return connection T for the valve 3 . Furthermore, the valve 3 com-prises a pressure connection P and a return connection T. Preferably, the valve 3 is a pressure-controlled proportional directional valve as shown in FIG. 7 , comprising connections for the channels 4 , 5 , P and T.
[0019] The tree trunk is placed between the feed pulleys, wherein the direction of rotation of each feed pulley and the motor must be such that they always transfer the tree trunk in the same direction. Consequently, the motor 1 revolves, for example, counter-clockwise, wherein the motor 2 always revolves clockwise, and vice versa.
[0020] In FIG. 2 , the rotational speed n of the motors 1 , 2 can be represented by the formula n 2 =Q/(Vgl+2·Vg 2 ), (n 2 >n 1 ), wherein the connec-tions R 1 , B 2 are coupled together (and to the channel 4 ), and the con-nections B 1 , R 2 are coupled together (and to the channel 5 ), and the half-motors 1 a , 2 a (low capacities Vgl) are coupled in series (the con-nections A 1 , A 2 being coupled together). The aim of the coupling is to tie the rotational speeds of the motors 1 and 2 to be equal. The feed pulleys (not shown in the figures) are coupled in a way known as such on the shaft of the motors 1 , 2 , which is shown in FIG. 7 .
[0021] In FIG. 3 , the rotational speed n of the motors 1 , 2 can be represented by the formula n 3 =Q/(2·Vg 1 +Vg 2 ), (n 3 >n 2 , when Vg 1 <Vg 2 , and n 3 =n 2 , when Vgl=Vg 2 ), wherein the connections R 1 , A 2 are cou-pled together (and to the channel 4 ), and the connections A 1 , R 2 are coupled together (and to the channel 5 ), and the half-motors 1 b , 2 b (high capacities Vg 2 ) are coupled in series (the connections B 1 , B 2 being coupled together). The coupling corresponds to the coupling of FIG. 2 , if Vg 1 =Vg 2 . The aim of the coupling is again to tie the rota-tional speeds of the motors 1 and 2 to be equal.
[0022] In FIG. 4 , the rotational speed n of the motors 1 , 2 can be represented by the formula n 4 =Q/(Vg 1 +Vg 2 ), (n 4 >n 3 ), wherein both the half-motors 1 a , 2 a (low capacities Vg 1 ) and the half-motors 1 b , 2 b (high capacities Vg 2 ) are coupled in series. Only the connection R 1 is cou-pled to the channel 4 , and only the connection R 2 is coupled to the channel 5 .
[0023] We shall now look at FIGS. 5 to 9 to discuss the different valve means by which the couplings of FIGS. 1 to 4 can be achieved. In the FIGS. 5 to 9 , the different valve means are shown in the way in which they are coupled to the connections R 1 , R 2 , A 1 , A 2 , B 1 , B 2 of FIGS. 1 to 4 or to the channels 4 , 5 .
[0024] FIG. 5 shows a control circuit with 2 speeds (the connections of FIGS. 1 and 2 ), which is implemented by means of a 2-position 4-way spool valve 6 with pressure control and spring return, whose inlet side is coupled separately to the connections A 1 and B 2 (the connection B 2 communicating with the connections R 1 , 4 ), and whose outlet side is coupled separately to the connections A 2 and B 1 (the connection B 1 communicating with the connections R 2 , 5 ). The valve 6 is controlled via a pressure channel 7 which, in turn, is controlled by a 2-position 3-way spool valve 8 with electrical control and spring return. By the positions of the valves 6 , 8 shown in FIG. 5 , it is possible to achieve the speed n 1 . In connection with the valves, the inlet and outlet sides refer to the direction of the volume flow when the volume flow is supplied into the channel 4 , but when the direction of rotation is changed, the direction of the volume flow is changed as well.
[0025] FIG. 6 shows a 2-speed (couplings according to FIGS. 1 and 2 ) con-trol circuit, which is implemented by means of cartridge valves with pressure control and spring return, namely 9 a (connection A 1 being coupled to the inlet side, which is so-called cartridge B-connection, and connection A 2 being coupled to the outlet side, which is so-called car-tridge A connection), 9 b (connection A 1 on the inlet side and connec-tion B 1 , R 2 and 5 on the outlet side) and 9 c (connection R 1 , 4 being coupled to the inlet side, which is an A-connection, and connection A 2 to the outlet side). A pilot valve is a 2-position 4-way spool valve 10 with electrical control and spring return, to whose outlet side valve 9 a is coupled separately and valves 9 b , 9 c are coupled together. By the positions of the valves 9 a , 9 b , 9 c and 10 shown in FIG. 6 , it is possible to achieve the speed n 1 . The valves of FIGS. 5 and 6 are placed in a separate frame which is connected for example to the motor, or they are integrated in a valve block which is placed in the harvester head and in which also the other valves controlling the harvester head are.
[0026] FIG. 7 shows a 2-speed (connections of FIGS. 1 and 2 ) control circuit which is implemented by means of two 2-position 4-way spool valves with pressure control and spring return, namely 11 a (inlet side coupled to separate connections A 1 , B 1 and outlet side coupled independently to connection R 2 and simultaneously to channel 5 ) and 11 b (outlet side coupled to separate connections A 2 , B 2 and inlet side coupled inde-pendently to connection R 1 and simultaneously to channel 4 ). The valves 11 a , 11 b are controlled via a pressure channel 12 which, in turn, is controlled by a 2-position 3-way spool valve 13 with electrical control and spring return. The outlet side of the valve 11 a and the inlet side of the valve 11 b are connected by an independent channel 11 c.
[0027] The valves 11 a , 11 b are integrated in the motor, wherein the valves are implemented as stems or selectors which are placed in a drilling which, in turn, is provided in the motor. Typically, the drilling comprises sepa-rate annular channels which are connected by channels provided in the stem in a desired way, when the stem is fitted in the drilling and it is moved into two different positions which correspond to the couplings of FIG. 7 . The annular channels, in turn, communicate, for example in the motor 1 , with the channels A 1 , B 1 and R 1 as well as with the dis-placement volumes of the pistons. The drilling of the motor is known as such, and it can be fitted with a stem which, in turn, is designed in such a way that the couplings according to FIG. 7 and the invention are possible. The final design and manufacture of the stem as such is easy for a man skilled in the art on the basis of this description, wherein a more detailed description of the stem will not be necessary.
[0028] FIG. 8 shows a 4-speed (couplings of FIGS. 1 to 4 ) control circuit which is implemented by means of two 2-position 4-way spool valves with pressure control and spring return, namely 14 a (the inlet side cou-pled separately to the connections A 1 , R 1 and the outlet side sepa-rately to the connections A 2 , R 2 ) and 14 b (the inlet side coupled sepa-rately to the connections B 1 , R 1 and the outlet side separately to the connections B 2 , R 2 ). Each valve 14 a , 14 b is controlled via a pressure channel 16 a or 16 b , each closed by a 2-position 3-way spool valve 15 a or 15 b with electrical control and spring return.
[0029] FIG. 9 shows a 4-speed (couplings of FIGS. 1 to 4 ) control circuit, which is implemented by means of cartridge valves with pressure con-trol and spring return, namely 17 a (connection A 1 on the inlet side and connection A 2 on the outlet side), 17 b (connection A 1 on the inlet side and connections R 2 , 5 on the outlet side) and 17 c (connection A 2 on the outlet side, connections R 1 , 4 on the inlet side), as well as cartridge valves 18 a (connection B 1 on the inlet side and connection B 2 on the outlet side), 18 b (connection B 1 on the inlet side and connections R 2 , 5 on the outlet side) and 18 c (connection B 2 on the outlet side and con-nections R 1 , 4 on the inlet side). The pilot valve for each series 17 a - 17 c and 18 a - 18 c is a 2-position 4-way spool valve 19 a , 19 b with electrical control and spring return, their couplings corresponding to the couplings of FIG. 6 . The cartridge valves are placed in a separate frame which is connected for example to the motor, or they are integrated in a valve block which is placed in the harvester head and which also accommodates the other valves controlling the harvester head.
[0030] In FIGS. 5 to 9 , the connection R 1 is coupled to the channel 4 and the connection R 2 is coupled to the channel 5 , wherein the connections and valves coupled to the connections R 1 , R 2 simultaneously commu-nicate with the channels 4 , 5 and further with the valve 3 .
[0031] The invention is not limited solely to the above-presented embodiments used as examples, but it can be modified within the scope of the appended claims.
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A control coupling for a delimbing and cutting apparatus, provided for feeding means and for changing their feeding speed, and comprising at least two feed motors driven by a pressurized medium, each of the motors being intended to drive a feeding means which is intended to be placed against a tree trunk and to feed the tree trunk through said apparatus, a first channel, via which the pressurized medium can be supplied to the first feed motor and alternatively returned therefrom, and a second channel, via which the pressurized medium can be returned from the second feed motor and alternatively supplied to the same. Said feed motors are multi-capacity motors, wherein each motor has at least a first rotational capacity and at least a second rotational capacity as well as a first and a second basic connection for each capacity. The first basic connections of each motor are coupled together as a first connection , and the second basic connections of each motor constitute a second connection and a third connection, which are separate. The control coupling further comprises first valve means for coupling at least two different feeding speeds in operation, wherein the valve means are arranged to couple desired connections and channellings together.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of forming a nitrogen-doped porous graphene envelope, and more particularly to a method of forming a nitrogen-doped porous graphene envelope, the method including dissolving a nitrogen precursor in an organic precursor (a carbon precursor) and then vaporizing the resulting precursor to thus simultaneously synthesize the graphene envelope and perform nitrogen doping in a single step.
[0003] 2. Description of the Related Art
[0004] Ammonia (gas or liquid) or pyridine (liquid) including nitrogen is typically used as a gas or liquid precursor in order to dope carbonized substances with nitrogen. Typically, after carbonized substances, such as carbon nanotubes, graphite, or graphene, are synthesized, nitrogen compounds are added and high-temperature and high-pressure conditions are applied to perform nitrification (nitrogen doping). For example, Applied Surface Science 257 (2011) 9193-9198 by Geng et al. discloses that graphene, which is obtained by treating graphite oxide slurry at 1050° C., is treated at 900° C. in order to dope the surface of graphene with nitrogen. Thin Solid Films 520 (2012) 6850-6855 by Zhang, et al. discloses that a solution, which includes ethanol (70%) and ammonia (30%) mixed therein, is heated to 800° C. or more in order to synthesize nitrogen-doped graphene. As another example, Chemical Engineering Journal 156 (2010) 404-410 by Chen, et al. discloses that N 2 microwave plasma is applied with a frequency of 2.45 GHz at 50 to 1000 W to perform treatment under a 60 to 90 Torr condition to thus dope the surface of CNT with nitrogen.
[0005] The present invention provides a simple and economical process of simultaneously synthesizing graphene and performing nitrogen doping in a single step without incurring additional costs, instead of high-temperature, high-pressure, and high-cost processes performed in respective stages after graphene is produced.
CITATION LIST
Non-Patent Literature
[0006] (Non-patent Document 1) Applied Surface Science 257 (2011) 9193-9198
[0007] (Non-patent Document 2) Thin Solid Films 520 (2012) 6850-6855
[0008] (Non-patent Document 3) Chemical Engineering Journal 156 (2010) 404-410
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a method of simultaneously synthesizing a graphene envelope and performing nitrogen doping in a single step to form a porous graphene envelope on the surface of a substrate such as a commercial heterogeneous metal catalyst. Thereby, performance (activity) and durability of the substrate, such as the heterogeneous metal catalyst, are improved so as to prevent metal particles from being agglomerated and exfoliated even when the particles thereof are applied to a severe reaction process at a high temperature for a long period of time in the presence of acids or alkalis, and also to prevent the particles from being exfoliated and corroded even under an acidic or basic condition.
[0010] In order to accomplish the above object, the present invention provides a method of forming a nitrogen-doped porous graphene envelope, the method including: (S1) vaporizing an organic precursor and a nitrogen precursor to form the graphene envelope in a vaporizer; (S2) providing substrate particles in a reactor in which synthesis is to be performed and then heating the reactor to increase the temperature to a final reaction temperature; and (S3) supplying the organic precursor and the nitrogen precursor of step (S1) to the reactor of step (S2) using a carrier gas, and maintaining the reactor for a predetermined time.
[0011] The method may include: (S1) vaporizing an organic precursor and a nitrogen precursor to form a graphene envelope in a vaporizer; (S2) providing nanometal-supported particles or nanoparticle powder in a reactor in which synthesis is to be performed and then heating the reactor to increase the temperature to a final reaction temperature; and (S3) supplying the organic precursor and the nitrogen precursor of step (S1) to the reactor of step (S2) using a carrier gas and maintaining the reactor for a predetermined time. The nanometal-supported particles or nanoparticle powder may be a platinum-supported carbon black catalyst or catalyst powder.
[0012] Further, the method may include: (S1) vaporizing an organic precursor and a nitrogen precursor to form a graphene shell in a vaporizer; (S2) providing metal nanoparticles in a reactor in which synthesis is to be performed and then heating the reactor to increase the temperature to a final reaction temperature; (S3) supplying the organic precursor and the nitrogen precursor of step (S1) to the reactor of step (S2) using a carrier gas and maintaining the reactor for a predetermined time. The metal nanoparticles may be particles for catalyst reforming. The metal nanoparticles may be a metal-supported catalyst, and specifically nickel-supported alumina particles or powder.
[0013] Moreover, the method may include: (S1) vaporizing an organic precursor and a nitrogen precursor to form a graphene envelope in a vaporizer; (S2) providing silicon nanoparticles in a reactor in which synthesis is to be performed and then heating the reactor to increase the temperature to a final reaction temperature; and (S3) supplying the organic precursor and the nitrogen precursor of step (S1) to the reactor of step (S2) using a carrier gas and maintaining the reactor for a predetermined time. The silicon nanoparticles may be particles for a secondary battery electrode.
[0014] Step (S1)
[0015] Step (S1) may include vaporizing the organic precursor and the nitrogen precursor while a predetermined temperature and an appropriate gas atmosphere are maintained.
[0016] The organic precursor may be a liquid precursor selected from the group consisting of ethanol, methanol, acetylene, and acetone.
[0017] The nitrogen precursor may be pyridine.
[0018] The step (S1) may include vaporizing a precursor solution which includes the nitrogen precursor dissolved in the organic precursor. More specifically, pyridine, which is the nitrogen precursor, may be dissolved in ethanol, which is the organic precursor, and then vaporized. The mixing ratio of ethanol and pyridine may be adjusted in order to adjust the doping concentration of nitrogen. In the present invention, the concentration of a nitrogen precursor aqueous solution, such as pyridine, may be adjusted to control the incidence of defects of the graphene envelope, which is formed on the surface of the substrate, such as the platinum-supported carbon black catalyst. Accordingly, the porous graphene envelope may be formed on the metal particle surface.
[0019] The concentration of the nitrogen precursor in the precursor solution may be more than 0 v/v % and less than or equal to 20 v/v %. When an extremely high porosity is required, the concentration may be up to 50 v/v %. The incidence of defects of the shell (envelope) is increased as the concentration is increased, but when the concentration is more than 20 v/v %, the porosity is very high, and accordingly, the protection performance of the graphene envelope may be insufficiently exhibited.
[0020] In the present invention, in order to vaporize the precursor, a vaporizer including a quartz material may be manufactured and positioned in an oven, which is maintained at a predetermined temperature, and the temperature may be increased to vaporize the precursor while the carrier gas flows, to thus enable the vaporized precursor to flow into the reactor in which synthesis is to be performed. Typical examples of the material of the vaporizer include metal materials or glass (quartz or Pyrex). It may be preferable that glass be used as glass is a stable material, which is easy to check the properties and the remaining quantity of contents therein while being maintained at a constant temperature and which does not react with the precursor.
[0021] Step (S2)
[0022] Step (S2) includes heating the reactor, in which synthesis (a process of forming the porous graphene envelope on the substrate surface) is to be performed, to increase the temperature to the final reaction temperature.
[0023] The temperature of the reactor may be increased to 400 to 1100° C. during step (S2). The present invention has a merit in that the metal particles are capable of being coated at low temperatures (about 400° C.) due to the catalytic characteristic of the metal particles, which are a coating target, to thus significantly reduce processing costs.
[0024] The reactor may be positioned in a heating furnace, and may include a quartz material. The temperature of the heating furnace may be controlled to adjust the temperature of the reactor.
[0025] Step (S3)
[0026] Step (S3) may include supplying the precursor, which is vaporized during the step (S1), to the reactor of the step (S2) using the carrier gas, and maintaining the reactor for a predetermined time to thus form the nitrogen-doped porous graphene envelope on the surface of the substrate (the metal nanoparticles, the platinum-supported carbon black catalyst, or the silicon nanoparticles). It is preferable that the precursor, which is vaporized during the step (S1), be transported through the shortest path to the reactor for use in synthesis.
[0027] It is preferable that the temperature of a connection tube, through which the vaporizer is connected to the reactor, be maintained at around the boiling point of the vaporized precursor during the step (S3). This is configured in order to prevent condensation or congelation of the precursor, which is vaporized in the oven maintained at a predetermined temperature. The temperature of the connection tube may be maintained using a process of transporting the precursor to the reactor through a gas transportation path, around which a heating line is wound. The temperature of the heating line is maintained around the boiling point of the precursor.
[0028] The carrier gas may be an oxygen, hydrogen, argon, helium, or nitrogen gas.
[0029] In the step (S3), maintaining the reactor for a predetermined time, may be performed by maintaining the reactor for 10 sec to 30 min after the vaporized precursor reaches the synthesis reactor. During the present step, the vaporized precursor is allowed to flow to the reactor for a predetermined time, the supply of the reaction gas is stopped after a set time, and immediately, the carrier gas is allowed to flow, thereby precisely adjusting the exposure time of the coating target material to the gaseous precursor. This is because the shape of the graphene envelope depends directly on the exposure time. When the exposure time is short, namely, about 10 sec, a thin envelope having the minimum thickness may be manufactured, and the thickness of the envelope may be increased as the exposure time is increased.
[0030] Further, the present invention provides a method of manufacturing a platinum-supported carbon black catalyst, which has a nitrogen-doped porous graphene envelope, using the method of forming the nitrogen-doped porous graphene envelope.
[0031] Further, the present invention provides a method of manufacturing metal nanoparticles, which have a nitrogen-doped porous graphene envelope, using the method of forming the nitrogen-doped porous graphene envelope. The metal nanoparticles may be particles for catalyst reforming. The metal nanoparticles may be nickel-supported alumina particles.
[0032] The present invention also provides a method of manufacturing silicon nanoparticles having a nitrogen-doped porous graphene envelope using the method of forming the nitrogen-doped porous graphene envelope. The silicon nanoparticles may be for a secondary battery.
[0033] According to the present invention, a nitrogen-doped graphene envelope may be synthesized in a single step under a mild condition of normal pressure. Specifically, synthesis of the graphene envelope and nitrogen doping are performed simultaneously in a single step to form the porous graphene envelope on the surface of a substrate such as a commercial heterogeneous metal catalyst. Thereby, performance (activity) and durability of the substrate, such as the commercial heterogeneous metal catalyst, may be improved to prevent metal particles from being agglomerated and exfoliated even when the particles are applied to a severe reaction process at a high temperature for a long period of time in the presence of an acid or alkali, and also to prevent the particles from being exfoliated and corroded even under an acidic/basic condition.
[0034] Further, the present invention, by adapting a technology of simultaneously forming the graphene envelope on the surface of the substrate, such as the commercial heterogeneous metal catalyst, and performing nitrogen doping in a single step using the process of dissolving the nitrogen precursor in the carbon precursor and then vaporizing the resulting precursor may easily control the thickness, the porosity, and the incidence of defects of the carbon layer which is bonded to the substrate, such as the commercial heterogeneous metal catalyst. Therefore, there is a merit in that the amount of reaction active points on the surface of the substrate, which is exposed to the outside, is easily controlled. For example, when the graphene envelope is formed on a platinum-supported carbon black catalyst, many defects may be dispersed between carbon frames constituting the envelope to thus maintain the activity of the catalyst while protecting the metal particles under the envelope.
[0035] Moreover, the present invention has a merit in that formation of the graphene envelope on the surface of the substrate, such as the commercial heterogeneous metal catalyst, and nitrogen doping are performed simultaneously in a single step to thus simplify the process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0037] FIG. 1 shows the result of TEM analysis of a nitrogen-doped graphene envelope according to Example 2;
[0038] FIG. 2 shows the result of TEM analysis of a graphene envelope according to Comparative Example 1;
[0039] FIG. 3 shows the result of TEM analysis of a nitrogen-doped graphene envelope according to Example 5;
[0040] FIG. 4 is a graph showing the result of cyclic voltammetry of Comparative Example 2 (commercial catalyst);
[0041] FIGS. 5, 6, and 7 are graphs showing the results of cyclic voltammetry of catalysts synthesized in Example 1, 2, and 3;
[0042] FIG. 8 is a graph showing the result of cyclic voltammetry of a catalyst synthesized in Comparative
[0043] Example 1;
[0044] FIG. 9 is a comparative graph showing the result of the carbon dioxide reforming reaction of catalysts of Example 4 and Comparative Example 3; FIG. 10 shows the result of the charging and discharging test of an electrode for a secondary battery, which is manufactured using silicon nanoparticles of Comparative Example 4; and
[0045] FIG. 11 shows the result of the charging and discharging test of an electrode for a secondary battery, which is manufactured using silicon nanoparticles having a graphene envelope of Example 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] Hereinafter, preferred Examples will be described in order to give an understanding of the present invention. The following Examples are intended to illustrate the present invention but do not limit the spirit of the present invention. Further, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the present invention as set forth in the appended claims.
EXAMPLE 1
First Process of Forming (Applying) a Nitrogen-Doped Porous Graphene Envelope on a Commercial Platinum-Supported Carbon Black Catalyst
[0047] Ethanol (≧99.9%, Merck) was used as an organic precursor for forming a porous graphene shell (graphene envelope) on the surface of a commercial platinum-supported carbon black catalyst, and pyridine (99.8%, Aldrich) was used as a nitrogen precursor for forming pores or defects in the structure of the graphene shell (graphene envelope). Specifically, a precursor solution, which included pyridine dissolved in ethanol, was used.
[0048] The concentration of pyridine in the precursor solution was set to a volume ratio of 0.5 v/v %.
[0049] The quartz or Pyrex vaporizer (vaporizer volume of 150 ml), into which 50 ml of the precursor solution (ethanol including pyridine dissolved therein) was injected, was provided into the oven, which was maintained at a predetermined temperature, in order to vaporize the precursor for forming the graphene envelope. The temperature of the oven was maintained at 70° C. in order to vaporize ethanol.
[0050] The reactor for synthesis, which was used to form the graphene envelope, included the quartz material and had a tube shape having a diameter of 25 mm and a length of 300 mm, and the filter, which was made of the quartz material, was provided in the reactor to place the commercial platinum-supported carbon black catalyst therein. Nitrogen (70 sccm) was blown into the synthesis reactor through a bypass line, which did not pass through the vaporizer, for 30 min to remove impurities from the synthesis reactor. The commercial platinum-supported carbon black catalyst powder was placed on the filter, which was made of the quartz material, and vaporized ethanol (ethanol containing pyridine dissolved therein) was transported to the synthesis reactor, which was used to form the graphene shell (graphene envelope), using nitrogen (70 sccm) as the carrier gas. The temperature of the synthesis reactor was maintained at 400° C. and the reaction time was 30 sec. The reaction time was measured from the time when vaporized ethanol reached the synthesis reactor, and the temperature of the synthesis reactor was increased at a rate of 5° C/min from room temperature, and reached 400° C. at the time when vaporized ethanol reached the reactor. The reactor was left until 30 sec after the vaporized ethanol had reached the synthesis reactor to form (apply) a nitrogen-doped porous graphene shell on the commercial platinum-supported carbon black catalyst.
EXAMPLE 2
Second Process of Forming (Applying) a Nitrogen-Doped Porous Graphene Envelope on a Commercial Platinum-Supported Carbon Black Catalyst
[0051] The same process as Example 1 was performed, except that the concentration of pyridine was set to a volume ratio of 2 v/v %.
EXAMPLE 3
Third Process of Forming (Applying) a Nitrogen-Doped Porous Graphene Envelope on a Commercial Platinum-Supported Carbon Black Catalyst
[0052] The same process as Example 1 was performed, except that the concentration of pyridine was set to a volume ratio of 4 v/v %.
EXAMPLE 4
Process of Forming (Applying) a Nitrogen-Doped Porous Graphene Envelope on Metal Nanoparticles for Catalyst Reforming
[0053] The same process as Example 1 was performed, except that a metal-supported catalyst (nickel-supported alumina powder) for catalyst reforming was used as a substrate for applying the graphene envelope thereon.
EXAMPLE 5
Process of Forming (Applying) a Nitrogen-Doped Porous Graphene Envelope on Silicon Nanoparticles for a Secondary Battery Electrode
[0054] The same process as Example 1 was performed, except that the silicon nanoparticles for the secondary battery electrode were used as a substrate for applying the graphene envelope thereon.
COMPARATIVE EXAMPLE 1
Process of Forming (Applying) a Non-Porous Graphene Envelope Not Doped with Nitrogen
[0055] The same process as Example 1 was performed, except that only ethanol, to which pyridine for nitrogen doping was not added, was used as the precursor to synthesize the graphene envelope.
COMPARATIVE EXAMPLE 2
[0056] The commercial catalyst (Johnson Matthey Company, Hispec 4000, Pt 40 wt % on carbon black) was used as Comparative Example 2.
COMPARATIVE EXAMPLE 3
[0057] The alumina-supported nickel catalyst (Ni/Al 2 O 3 , Ni 5 wt %), on which the graphene envelope was not formed, was used as Comparative Example 3.
COMPARATIVE EXAMPLE 4
[0058] The silicon nanoparticles for the secondary battery electrode, on which the graphene envelope was not formed, were used as Comparative Example 4.
TEST EXAMPLE 1
Transmission Electron Microscopy (TEM) Analysis
[0059] The porous graphene envelope (the porous graphene shell formed on the surface of the metal particles of the commercial platinum-supported carbon black catalyst) according to Example 2, the graphene envelope according to Comparative Example 1, and the porous graphene envelope (the porous graphene shell formed on the silicon nanoparticles) according to Example 5 were analyzed using a transmission electron microscope, and the results are shown in FIGS. 1, 2, and 3 . From FIGS. 1, 2, and 3 , it can be confirmed that the thickness of the graphene envelope, which covers the surface of the platinum particles dispersed on the surface of the carbon black particles, is reduced as the concentration of added pyridine is increased. It can be confirmed that the porosity or defect of the graphene envelope is increased in proportion to the concentration of added pyridine.
TEST EXAMPLE 2
Evaluation of Electrochemical Performance Using Platinum-Supported Carbon Black Particles Having the Graphene Envelope
[0060] Electrochemical performance was evaluated using a potentiostat (BioLogic, SP-50) provided with an RRDE (rotating ring disk electrode). Saturated Ag/AgCl was used as a reference electrode, and calibrating was performed relative to a RHE (reversible hydrogen electrode). A glassy carbon disk (3 mm in diameter) and a platinum wire were used as a working electrode and a counter electrode, respectively. In the RRDE system, catalyst ink (0.2 mg Pt; a mixture of 2 mg catalyst, 5 μl Nafion solution (5 wt %, DuPont) and 1 ml ethanol) was loaded on the glassy carbon electrode to thus manufacture the working electrode. RRDE measurement was performed in the H 2 SO 4 solution (0.5 M) at 25° C. at a scan rate of 5 mVs 1 and a rotation rate of 1500 rpm.
[0061] Electrochemical performance was evaluated using the catalysts synthesized in Examples 1 to 3 and Comparative Example 1 and the commercial catalyst (Comparative Example 2) according to the aforementioned procedure, and the results are shown in FIGS. 4 to 8 . From the test results, it was confirmed that when the commercial catalyst (Johnson Matthey Company, Hispec 4000, Pt 40 wt % on carbon black) was used, the activity of the catalyst was reduced by about 30% after 1000 reaction cycles ( FIG. 4 ). This can be judged based on the observation that the platinum catalyst was gradually corroded, agglomerated, or exfoliated as the electrochemical reaction progressed. Meanwhile, it can be confirmed that the reduction in activity as the reaction progresses is insignificant due to the protection effect of the graphene envelope in Examples 1 to 3, in which the nitrogen-doped graphene envelope covers the surface of the commercial catalyst ( FIGS. 5 to 7 ). From FIGS. 5 to 7 , it can be confirmed that the reaction activity is reduced by about 12% after 1000 cycles in Example 1, the reaction activity is reduced by about 18% in Example 2, and the reaction activity is reduced by about 22% in Example 3. Meanwhile, it can be confirmed that the reduction in reaction activity is very insignificant, specifically about 5%, after 1000 cycles in Comparative Example 1, in which the number of defects is very low in the structure of the graphene envelope not doped with nitrogen ( FIG. 8 ). In Comparative Example 1, due to the graphene envelope the initial activity is very low. However, deactivation attributable to corrosion, exfoliation, and agglomeration of the catalyst is insignificant, thus only slightly reducing the activity of the reaction even after 1000 cycles due to the graphene envelope.
TEST EXAMPLE 4
Catalytic Reforming Reaction for Manufacturing Hydrogen Using Metal Nanoparticles for Reforming a Catalyst Having a Nitrogen-Doped Porous Graphene Envelope
[0062] The carbon dioxide reforming reaction of methane was performed using the catalyst to which the nitrogen-doped graphene envelope (using a solution including 0.5 v/v % of pyridine) was applied, according to Example 4, and the nickel-supported alumina catalyst (Ni/Al 2 O 3 , Ni 5 wt %) to which the graphene envelope was not applied, according to Comparative Example 3. The result is shown in FIG. 9 . In the carbon dioxide reforming reaction of methane, 0.2 g of the catalyst was placed in the quartz glass reactor, methane and carbon dioxides were blown at a flow rate of 1:1 together with a nitrogen carrier gas (CH 4 :CO 2 : N 2 =10:10:80) into the reactor, and the internal temperature of the reactor was maintained at 700° C. The composition of the gas exiting the reactor was analyzed using gas chromatography, and the conversion efficiencies of methane and carbon dioxide and the yield of hydrogen were calculated based on the analysis result. From FIG. 9 , it was confirmed that the long-term durability of the catalyst synthesized in Example 4 was excellent.
TEST EXAMPLE 5
Performance Test of a Secondary Battery Using Silicon Nanoparticles Having a Graphene Envelope
[0063] In order to manufacture the electrode, carbon-coated (graphene envelope-formed) Si nanoparticles (Example 5) and Si nanoparticles not coated with carbon (Comparative Example 4) were used after being heat-treated for 3 min using an anode material. Denka black was used as a conductive agent, and CMC (carboxymethyl cellulose) and SBR (styrene butadiene rubber) as a binder were mixed to manufacture the slurry. After the prepared slurry was uniformly applied on the copper foil and dried in an Ar atmosphere for 30 min, a coin-type (CR2032) half battery was manufactured in a globe box and 1M LiPF 6 was used as an electrolyte in order to measure electrochemical characteristics and battery performance. In order to evaluate the performance of the assembled half battery, the charging and discharging test was performed at a voltage in the range of 0.01 to 1.5 V vs Li/Li + using a constant-current/constant-voltage mode (CC/CV mode) of 0.2 c-rate. The results are shown in FIGS. 10 and 11 and Table 1.
[0064] As for the test results, when the carbon coating layer (graphene envelope) had a thickness of 10 nm or less and included less than ten layers of crystal defects, a very high effect was exhibited. Specifically, when carbon coating is not performed, an initial reversible efficiency (Initial Coulombic Efficiency (ICE)) is high, namely, 80% or more, but a capacity retention ratio is reduced to be less than 10% even after 50 cycles. This is typical in an anode to which silicon nanoparticles are applied. When the carbon coating layer is very thick or only graphene layers having a perfect crystal structure are formed, lithium ions do not effectively react with silicon to thus significantly reduce the initial capacity and the initial coulombic efficiency. On the other hand, when the coating thickness is very small, the initial coulombic efficiency and the initial capacity are increased, but the capacity retention ratio is rapidly reduced. The carbon layer (graphene envelope) applied using the method of the present invention has an appropriate thickness (graphene envelope thickness: 2 to 20 nm) and an appropriate number of crystal defects (the incidence of defects: 5 to 30%, the none-graphene region/the total surface area of the particle having the graphene envelope). Accordingly, a high initial coulombic efficiency of about 80% and a high initial reversible capacity of about 2800 mAh/g are ensured, and the capacity retention ratio is improved, being about 75% or higher.
[0000]
TABLE 1
1 st
Initial
Retention
Heat
reversible
coulombic
(%@50
treatment
capacity
efficiency
cycle)
Example 5
3 KW
2456.63
81.91
25.35
10 KW
2775.92
82.96
75.10
Comparative
3 KW
1894.34
82.17
75.19
Example 4
10 KW
2367.92
84.11
9.79
[0065] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed is a method of forming a nitrogen-doped porous graphene envelope. The method of forming the nitrogen-doped porous graphene envelope includes dissolving a nitrogen precursor in an organic precursor and then vaporizing the resulting precursor to thus simultaneously synthesize the graphene envelope and perform nitrogen doping in a single step.
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FIELD OF THE INVENTION
The invention relates to a tubular core of the type used for winding paper, such as newsprint, film and other sheet material. More specifically, the invention is directed to a tubular core assembly having mechanically interlocked end members for reducing the inside diameter of the ends of the tubular core.
BACKGROUND OF THE INVENTION
Tubes and cores are widely used in the film and paper industry for winding film and paper into roll form. These cores are usually made of paperboard and are formed by a spiral or convolute wrap process. Thus, one or more plies of paperboard are coated with adhesive and wrapped around a mandrel to seal each layer to the next in the structure. For lightweight uses, the tubes or cores are made of lightweight paperboard and may have only a few layers. However, for heavy duty uses, such as for winding and unwinding for newspaper and Rotogravure printing, the tubes are usually very long, for example up to about 10 ft. (3.08 m.) for U.S. Rotogravure printing and 10.5 ft. (3.22 m.), for European Rotogravure printing. In view of the large size, these tubes must be of very heavy or thick construction to be able to carry the weight of a large roll of paper.
In use on winding and unwinding equipment, the tubular cores are mounted on stub shafts or chucks of standard size. U-shaped metal end caps are typically inserted into the open ends of the tube to assist in more positive mounting of the paperboard cores on the chucks or stub shafts of the winding and unwinding equipment.
Many paperboard cores used in film and paper processes have a three-inch inside diameter and much of the commercially used equipment have chucks and stub shafts designed to cooperate with three-inch inside diameter cores. Because of this equipment design, equipment users are limited to use of the three inch inside diameter cores.
At times, printers and/or film manufacturers prefer to use a larger tubular core on equipment designed for use with a core of smaller diameter in order to improve both vibration and dynamic strength performance. For example, many conventional cores have a six-inch inside diameter and it is clear that the use of six-inch inside diameter core with equipment designed to support a core having a three-inch inside diameter can significantly impact vibration during the winding and unwinding process.
U.S. Pat. No. 4,875,636 to Kewin discloses a non-returnable newsprint carrier system in which the newsprint cylindrical core can be used without the need for metal end caps. The inside surfaces of the opposite end portions of the tubular core have substantially the same non-cylindrical configuration, profile and dimensions as the outside surfaces of the reel stub shafts of an offset printing press so that the tubular core and newsprint stub shaft will have a full profile fit in surface-to-surface contact over substantially the entire surface of the reel stub shafts inserted within the core during use thereof.
U.S. Pat. No. 4,874,139 to Kewin discloses tubular core assemblies which include an annular core insert member which may be made of a cellulosic material, permanently bonded to the inside end of a tubular paperboard core. The use of such an interior annular core insert can allow for the use of a smaller wall thickness paperboard tube. In practice, there is a problem with the annular core insert because it is fastened to the interior of the inside tube by an adhesive. The exterior of the core insert must have a tight fit with the interior of the core, inside the tube, to eliminate vibration and wobble in high speed winding and to try to keep the insert from breaking loose during sudden acceleration or deceleration of the unwind machine. Because of the relatively close tolerance fit between the annular core insert and the inside of the core, the adhesive, intended to bond the annular core insert to the core, is typically wiped out of the minimal space between the insert and the core during the axial insertion process. Moreover, unless the exterior surface of the annular core insert and the interior surface of the tube, are perfectly symmetrical and circular, gaps can be left between the two surfaces where no bonding occurs. Thus, in practice, the annular core inserts are seldom adhered securely to the tube and very seldom survive the winding operation, much less the unwinding operation.
The elimination of metal end caps for the mounting of cores on winding and unwinding equipment would be highly desirable. However, in practice the proposed systems of the prior art include various disadvantages as discussed above, including the poor bonding between interior annular core inserts and the ends of the tubular core and/or the need to reduce the diameter of inside portions of the tubular core in order to provide a tube with an inside surface having a profile matching the exterior profile of the reel stub shafts of winding and unwinding equipment. Moreover, there is no practical solution provided in the art for the recurring needs and desires of manufacturers to employ large diameter cores on equipment designed for use with smaller diameter cores.
SUMMARY OF THE INVENTION
According to the invention, a tubular core assembly includes a central paperboard core body having mechanically interlocked annular end members secured to each of its opposed ends for reducing the inside diameter of the ends. The inside diameter-reducing annular end members are secured to the central core body member in positive circumferential and axial locking relation. Because the inside diameter-reducing annular end members are positively engaged with both axial and circumferential surfaces of the central core body member, the invention provides a practical and readily available means for reducing the inside diameter of the ends of large cylindrical cores while preserving and/or enhancing the integrity of the large cylindrical core so that the large cylindrical cores can readily be used with winding and unwinding equipment designed for use for smaller cores. In addition, the inside surfaces of the annular end members can be configured and profiled to match the outside dimensions of conventional stub shafts or chucks of conventional winding and unwinding equipment.
The tubular core assembly of the invention includes an elongate hollow center cylindrical core body having a bodywall preferably formed by multiple wraps of a paperboard material and having opposed ends, a predetermined outside diameter, and a predetermined inside diameter. Annular end members, each having an exterior periphery, of which at least a portion defines the same outside diameter as the central core body, and which have a smaller inside diameter as compared to the central core body, are attached to each of the opposed ends of the central core body member in co-axial relationship therewith by integral mechanical interlocking means. The integral mechanical interlocking means comprise a plurality of axial grooves or notches in the central core body, each having a depth extending substantially through the bodywall thereof. A plurality of axially extending tongue members on each of the annular end members are received in the grooves of the central core body in interlocking relation therewith. The integral mechanical interlocking means provides for positive circumferential and axial engagement between the inside diameter-reducing annular end members and the central core body so that rotational motion applied to the annular end members is positively transferred to the central core body and so that axially inward force applied to the annular end members is directly transferred to the central core body with the result that the end members have improved rotational and axial load capabilities.
The inside diameter-reducing annular end members are readily formed from various cellulosic-based and/or polymer-based composite materials including wood particles or chips, wood pulp, paperboard, and/or liquid or solid polymers, preferably by conventional molding operations. The tubular core assemblies of the invention can be used without the need for metal end caps or inserts.
The inside diameter-reducing annular end members can have various exterior shapes and profiles according to various preferred embodiments of the invention. Because the annular end members reduce the inside diameter of the tube and increase the wall thickness at the ends of the completed assembly, these end members also provide increased strength to the ends of the tubular core assembly. The inside annular surfaces of the inside diameter-reducing end members can be provided with shapes and profiles matching the exterior profiles of conventional chucks and/or reel stub shafts of winding and unwinding equipment so that such chucks and/or reel stub shafts can be inserted into the core assemblies of the invention in surface-to-surface contact with the inside surface of the core assembly as disclosed in U.S. Pat. No. 4,875,636 to Kewin, which is hereby incorporated by reference. The tubular core assemblies of the invention can be used with conventional core plugs during shipping of empty cores and/or fully wound rolls of paper and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings which form a portion of the original disclosure of the invention:
FIG. 1 is an exploded perspective view of one end portion of one preferred tubular core assembly of the invention, the other end being identical; and
FIG. 2 is a cross-sectional side view of one end portion of a core assembly of the invention showing the inside diameter-reducing annular end member secured to one end of the central core body; and
FIG. 3 is a perspective view of one end of another preferred tubular core assembly according to the invention, a portion thereof being broken away to illustrate its construction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following detailed description, exemplary preferred embodiments of the invention are described to enable practice of the invention. It will be apparent that the terms used in describing the invention are used for the purpose of description and not for the purpose of limiting the invention to the preferred embodiments. It will also be apparent that the invention is susceptible to numerous variations and modifications as will become apparent from a consideration of the invention as shown in the attached drawings and described herein.
FIG. 1 illustrates an exploded perspective view of one end of a tubular core assembly of the invention. The opposed end of the tubular core assembly (not shown) is identical to the end shown in FIG. 1 as will be apparent. The tubular core assembly includes a central core body member 10 and an inside diameter-reducing annular end member 12. The central core body member 10 is defined by a cylindrical hollow bodywall 14 formed by multiple wraps of a paperboard material.
As illustrated in FIG. 1, the bodywall 14 is formed by a spiral wrapping process; however, the bodywall can also be formed of a single layer of plastic or similar material by a molding or extrusion process; or multiple layer wrapped tubular bodies can alternatively be formed by a conventional convolute wrapping process. In the preferred embodiments, the bodywall 14 will include multiple paperboard layers. Both the spiral wrapping process and the convolute wrapping process are well known to those skilled in the art. In general, such processes involve the wrapping of one or more adhesive coated plies around a mandrel to provide a tubular body. The thickness of the bodywall and the density of the paperboard ply used in the wrapping process are chosen to provide the desired strength in the resultant bodywall. For example, where the core is intended for light-duty or light-weight uses, the paperboard ply can have a light density and/or light weight and the bodywall thickness can be relatively low, for example, in the range of from about 0.125 inches to about 0.25 inches. On the other hand, for heavy-duty uses, a thicker bodywall, for example in the range of between about 0.5 inches and about 0.875 inches is needed and typically a heavy and/or thick paperboard ply material is used.
A plurality of grooves or notches 16 are provided in the annular ends of the bodywall for receiving matching, axially extending tongues or tenons 18 of the end members 12. Preferably, the grooves 16 extend entirely through the bodywall 14 of the central core body member 10 as shown in FIG. 1 although the notches or grooves 16 can be formed less than completely through the bodywall 14. In such instances, the grooves or notches 16 preferably extend substantially through the bodywall 14, i.e. the grooves 16 preferably extend more than 50 percent through the thickness of the bodywall 14. In this regard, it is important that rotational motion imparted to the end members 12 or to the central core body member 10 be fully transferred to the other member or members. Thus, extension of the grooves 16 preferably substantially through the bodywall 14 insures positive circumferential locking of the end member 12 into the central core body 10.
Returning to FIG. 1, the central core body member 10 also includes a plurality of tongue members 20 which are formed alternatively between the axial grooves 16 in the central core body member. The tongues 20 are profiled and configured to match grooves 22 formed in the inside diameter-reducing annular end member 12.
It will be apparent that the sizes and arrangements of the grooves and tongues shown in FIG. 1 can be widely varied. Thus, in FIG. 1, the grooves 16 are shown as having a smaller circumferential dimension, i.e. width, than the tongues 20 in the main body member 10. However, in another advantageous embodiment of the invention, the grooves 16 can have a grater circumferential dimension than the circumferential dimension of the tongues 20 in the central core body member. In such event, it will be apparent that the tongues 18 and grooves 22 on the inside diameter-reducing end members 12 will be modified to correspond to the dimensions of the tongues 20 and grooves 16 on the central core body member 10. Likewise, the tongues 20 and grooves 16 on the central core body member 10 can be configured to have identical circumferential dimensions with respect to one another.
Additionally, although the tongues 20 and grooves 16 in the central core body member 10 are each illustrated as having a substantially rectangular shape, it will also be apparent that the tongues 20 and grooves 16 can be beveled in either or both the axial direction or radial direction, or the tongues and grooves can be triangularly shaped to form a series of interlocking teeth, where desirable. However, the rectangular shaped tongues and grooves illustrated in FIG. 1 are preferred for ease of manufacture. In this regard, as indicated previously, the central core body member 10 is manufactured by a paperboard winding process. Typically, the paperboard tube is manufactured as a continuous member and is severed into tubes of the desired length during the manufacturing process. The ends of the individual tubes are thereafter treated, as by grinding or cutting, to form the grooves 16 in the ends of the paperboard tube.
Preferably, there are at least three and more preferably, four grooves 16, formed in the end of the central core body 10 as illustrated in FIG. 1. The use of at least three grooves ensures that the inside diameter-reducing end members 12 will be radially centered i.e., coaxially positioned, with respect to the central axis of the central core body member 10. More preferably, there are four, six or another even number of symmetrically oriented grooves 16, preferably four grooves, formed in the central core body member 10 in order to improve manufacturing efficiency. In this regard, pairs of opposed grooves arranged 180° with respect to each other can be cut using a single blade and a single cutting operation. Thus, it will be apparent that the four grooves 16 illustrated in FIG. 1 can be cut into the central core body member using only two cutting operations; one cutting operation employing a first blade for cutting the opposed top and bottom grooves 16, using a single pass of the blade across the annular end of the tube from top to bottom, and a second cutting operation using a second blade for cutting the two opposed side grooves 16 in a single pass.
The inside diameter-reducing end members 12 are formed, as indicated previously, by any of various well known processes, preferably by molding. Alternatively, the inside diameter-reducing annular end members 12 can be formed by grinding or cutting the annular ends of a paperboard tubular member to achieve the desired tongues 18 and grooves 22 on one end thereof.
Following formation of the central core body member 10 and the inside diameter-reducing annular end members 12, the two annular end members are joined to the central core body member 10 preferably employing any of various well known adhesive materials including latex or solvent-based and/or thermosetting adhesive materials. The adhesive materials are applied to the annular end surfaces of either, or both of, the central core body or the annular end members 12. Thereafter the end members are joined to the central core body and axial pressure is applied. Because the tongues and grooves of the central core body member, and the tongues and grooves of the inside diameter-reducing end members are inserted axially into each other, the adhesive material applied to the various tongues and grooves is forced into and maintained within the thus formed joint, resulting in even and permanent bonding of the end members to the central core body member.
In general, the use of tongues and grooves for mechanical interlocking of the inside diameter-reducing annular end members to the central core body member provides a number of significant benefits and advantages in the core assemblies of the invention. As indicated above, adhesive material is forced into, and not out of, the joint formed during the adhesive bonding process. In addition, the inside diameter-reducing annular end members are locked positively into the central core body member so that circumferential motion is positively transferred from one body member to the other and so that axially inward pressure on either or both of the inside diameter-reducing end members is positively transferred to the central core body member.
The central core body member 10 typically has an inside diameter of from a few inches, for example, three inches up to 6-7 inches or greater, preferably about 6 inches. The central core body member 10 generally has an extended length ranging from about 1 foot or more up to about 11 feet or greater, however, the benefits and advantages of the invention are most apparent when the entire-tubular core assembly has a length of greater than about five feet, in view of the known problems as to vibration and dynamic strength performance with such elongated tubular core bodies as discussed previously.
The inside diameter-reducing annular end members 12 typically have a longitudinal length based on the desired end use of the tubular core assembly and preferably will have a length which is about the same or greater than the chuck or reel stub shaft intended to be inserted into the tubular core assembly. Typically, the length of the inside diameter-reducing end members 12 will range from about 1 inch to about 18 inches or more.
FIG. 3 illustrates another preferred embodiment of the invention in which the inside-diameter reducing annular end member 12 is constructed to have only a portion of its exterior diameter the same as the exterior diameter of the central core body 14. In this embodiment, the two tongues 20 of the main core body 14 extend outwardly to and form a portion of the composite end face 30 of the core body assembly. The annular end member 12 includes two matching grooves which extend radially through only a portion 32 of the bodywall of the end member 12. As seen in the drawing the radial depth of the grooves in the end member is the same as the wall thickness of the bodywall of the central core body. Notched tongues 18 of the end member 12 are received in corresponding axially extending grooves in the central core body 14 which also extend radially fully through the entire bodywall of central core body 14.
As indicated previously, in a particularly preferred embodiment of the invention, the interior peripheral surface 24 (FIG. 1) of the inside diameter-reducing annular end members 12 can be profiled to match the exterior profile of a reel stub shaft used in winding and unwinding equipment as disclosed in U.S. Pat. No. 4,875,636. Thus, the interior surface of the inside diameter-reducing annular end members can include a first portion positioned at location 24a (FIG. 2) tapering radially outwardly in the axially outward direction, preferably at an angle of approximately 2° with respect to the longitudinal central axis of the tubular core assembly, and a second portion at location 24b extending axially outwardly from the first portion at location 24a and tapering radially outwardly at a second predetermined angle, preferably approximately 33° with the respect to the central axis of the tubular core assembly. In addition, the inside surface 24 can include one or more grooves for receiving a spline or the like on the exterior of a reel stub shaft of conventional winding or unwinding equipment. Such preferred profiled interior surfaces are discussed and illustrated in greater detail in U.S. Pat. No. 4,875,636, which has previously been incorporated herein by reference.
The core assemblies of the invention can also be used with conventional metal inserts for receiving stub shafts or chucks; however, as discussed above, such metal inserts are not necessary in preferred embodiments of the invention. As indicated previously, a conventional core plug can advantageously be incorporated into the annular opening of the inside diameter-reducing annular end members during shipping and storage of the core assembly bodies of the invention in order to protect the ends thereof. Such core plugs are generally known to those skilled in the art and exemplary core plugs are also disclosed in the previously mentioned U.S. Pat. No. 4,875,636.
The invention has been described in considerable detail with reference to its preferred embodiments, however, it will be apparent that numerous variations and modifications can be made without departing from the spirit and scope of the invention as described in the foregoing detailed specification and defined in the appended claims.
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A tubular core assembly for winding or unwinding of sheet material, such as newsprint or Rotogravure Print, is provided wherein the opposed ends of an elongate cylindrical core are provided with inside diameter-reducing annular end members. The inside diameter-reducing annular end members are mechanically interlocked with a central core body which is preferably formed by multiple wraps of a paperboard material. Mechanical interlocking is accomplished by a plurality of axial grooves in the bodywall of the central core body member and a plurality of axially extending tongue members on the annular end members which are received in the grooves of the central core body member in interlocking relationship therewith. Because of the mechanical interlocking relationship between the inside diameter-reducing annular end members and the central core body member, the inside diameter-reducing annular end members are secured to the central core body member in positive circumferential and axial locking relationship.
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BACKGROUND OF THE INVENTION
The present invention concerns a process for the production of a disintegrator roll of an open-end spinning apparatus, and a disintegrator roll manufactured by such a process.
DE 25 39 089 A1 discloses a disintegrating roll which has been equipped with a toothed active shredding-element, which displayed a substantial hardness in the top zone of the teeth, but in the foot zone a lesser hardness. In this way an ascertained winding of the toothed shredding-element on the body of the disintegrating roll could be assured. To this purpose, the point of each tooth is a separate element from the foot, and must be bound thereto, for example, by welding. This process is a very labor and time intensive procedure. For economic reasons, it cannot be allowed, that such a procedure can be a part of the manufacture of disintegrating rolls for open-end spinning apparatuses, since well over a hundred such rolls are required per open-end spinning machine.
In accord with another proposal offered by DE 29 04 841 A1, each tooth of the sawtooth shredding-element exhibits a plurality of zones of different hardness, whereby the hardness of the tooth diminishes in the direction from the tooth point to the foot. The tooth foot zone, contrarily, is not hardened, in order to allow for the necessary shaping of the sawtooth wire necessitated by the winding procedure. In order to be able to deform the ends of this sawtooth wire, so that the wire can be securely laid on the roll body, it is necessary to temper these wire ends after the hardening procedure, so that the hardening of the teeth will have no effect on wire ends. The disadvantage of this step is, that it is very difficult to restrict the hardening and subsequent heat treatment to specific areas.
OBJECTS AND SUMMARY OF THE INVENTION
A principal object of the present invention is to propose a process, which enables the wear area of the teeth of a sawtooth wire to be hardened to the greatest degree, preferentially, without simultaneously hardening the foot zone of the teeth. A further object is the creation of a process, which, essentially in a simpler and more certain manner, makes possible the installation of the shredding-element, especially of a sawtooth wire. An additional object of the invention is to create a disintegrating roll, which can be manufactured with the aid of the aforesaid process. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
This principal object is achieved by the sawtooth wire being converted into a shape, which essentially corresponds to the shape that the sawtooth wire is to assume on the shredding-element carrier, and the preshaped sawtooth wire being subsequently hardened. Due to the fact that the sawtooth wire is given its essentially final shape before it is mounted on the shredding-element carrier, the hardening, or the hardness provided for the shredding-element in connection with the installation of the shredding-element on a shredding-element carrier, is no longer of such importance, since no consideration need be given to a deformation during the laying of the shredding-element onto a shredding-element carrier.
Advantageously, the sawtooth wire is preshaped on a preshaping body, prior to hardening. In this manner, the sawtooth wire, when installed on the shredding-element, is subjected to no great stress as compared to the substantial deformation which otherwise would be required.
In a development of the process, provisions can be made, so that the sawtooth wire remains on a preshaping body during the hardening. Further, this preshaping body can be constructed by the shredding-element carrier itself.
Moreover, the ends of the sawtooth wire can be subjected to an grinding procedure.
Principally, the hardening of the shredding-element can be carried out in various ways. However, it has shown itself as being advantageous to harden the shredding-element by inductive heating independent of the shredding-element being sawtooth wire or a combination of needles and at least one saw tooth wire. In this way, the depth to which the hardening of the shredding-element is to be allowed is controllable.
The shredding-element exhibits a relatively small cross section. On this account it is advantageous if, in accord with a development of the invented process the formation of oxides, for instance mill scale, is prevented during the hardening process by hardening the shredding element in a protective gas.
Advantageously, the hardened shredding-element is subjected to a heat treatment for the avoidance of tensile stresses.
For the elimination of surface unevenness, such as the mill scale, it is advantageous to have the shredding-element blasted, for instance, by glass beads.
Since the material of the shredding-element becomes magnetic, while it is undergoing blasting, the shredding-element is advantageously demagnetized. Furthermore, the shredding-element can be deburred.
In spite of the hardening of the shredding-element, it is frequently desirable to further change the surface of the shredding-element which comes into contact with the to-be-opened single fibers, so that it is suited to the material to be worked. In an advantageous development of the invented process, a coating of the shredding-element can be provided.
In order to prevent the finally worked-up shredding-element from being out of round, the process can be improved in accord with the invention by a further grinding process performed in various manners. In particular, by a grinding treatment counter to the direction of the teeth of the saw tooth wire, the goal is advantageously gained wherein scale, which in the operation of the disintegrator roll can lead to non-uniform separation of fibers, is definitely removed.
The sawtooth wire, before it is brought into its shape, is a non-hardened wire. Thereby, the assurance is given that it permits itself to be brought into the desired shape. Particularly advantageous is the use of a shredding-element carrier of non-hardening material, preferably a low carbon steel, because in this way, the imparting of tension to the shredding-element carrier by the hardening of the shredding-element can be avoided.
In a further advantageous embodiment of the invention, provision is made, that the ends of the sawtooth wire, that is, both the wire start and the wire end piece, can be welded to the shredding-element carrier. Thereby, in a simple and secure way, it can prevent the sawtooth wire from loosening itself from the shredding-element carrier either during hardening or in operation. As to method of welding, essentially all known methods can be considered. In an advantageous development of the invention, the sawtooth wire is coated to better its abrasion resistance. This coating is done preferably by plasma deposition, for instance with titanium nitride. Thereby, it is especially favorable to operate with as low temperatures as possible, so that no hardening loss occurs in the hardened shredding-element wire by the heating of the wire.
With the aid of the previously described process, in accord with the invention, a disintegrating roll can be made with desired attributes.
The roll possesses a hardened shredding-element after it is shaped, that is, after the placement of the shredding-element on the shredding-element carrier. Further, this shredding-element can be, advantageously, an induction hardened shredding-element. By means of the use of a shredding-element wire and employing a lateral groove at the foot zone of the installed shredding-element carrier, the sawtooth wire can be especially securely fastened on the shredding-element carrier, wherein the sawtooth wire is laid in the groove. By means of the shaping of the material of the shredding-element carrier, the shredding element is pressed into the groove to make a form-fit connection.
The above described process, in accord with the invention, makes possible in a simple and secure manner, an exactly controlled hardening of the shredding-element. Any danger that the shredding-element will be damaged by this operation is absent, when the shredding-element is fitted onto the shredding-element carrier. Particularly, when the shredding-element points have been hardened by induction, it is possible by means of high frequency current to limit the hardening to the points of the shredding-element, while the foot part, held by the shredding-element carrier, remains in its original condition. High frequency hardening, nevertheless, is further advantageous, in that it so hardens those areas of the teeth, which form a hardness transition in each tooth that, even in the area of the tooth-foot, a hardness is attained, which strongly reduces the attrition in this area of the shredding-element. The shredding-element, or better, its teeth, also have an advantageous uniform rate of wear respectively from the tooth point to the tooth foot.
In this way, the disintegrating rolls can be made with an expectancy of long life, a wear resistant shredding-element, and moreover, operate without risks of breakage or damage to the roll.
Embodiment examples of the invention are explained in the following with the aid of drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a sawtooth wire which can be manufactured by the invented process in a perspective view;
FIG. 2 shows an invented disintegrator roll in profile view; and
FIG. 3 shows a portion sawtooth shredding-element wrapped on a disintegrator roll as well as a grinding wheel section in profile view.
DETAILED DESCRIPTION
Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are show in the figures. Each example is provided to explain the invention, and not as a limitation of the invention. In fact, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a further embodiment. It is intended that the present invention cover such modifications and variations.
Where open end spinning is concerned, it is necessary to reduce a sliver to individual fibers, which are then fed to an open-end spinning element (not shown) for the production of a continuous yarn. The separation of the fibers by combing from the forward progressing end of the sliver, is carried out with the aid of a disintegrator roll 1 enclosed in a housing 4 . To execute its designed purpose, the disintegrator roll 4 possesses a specifically designed shredding-element 2 (FIG. 2 ). To serve as a shredding-element 2 , a sawtooth wire 20 is employed ( FIGS. 1 to 3 ). On the other hand, there are shredding-elements which, besides one saw tooth wire 20 , exhibit still a second such sawtooth wire (not shown) and/or additionally a plurality of needles.
Because of the combing out of the forward progressing end of the sliver, the shredding-element 2 is subjected to a high degree of stress. For this reason, a hardening procedure has been provided for the shredding-element 2 . Such a hardening does indeed make the shredding-element 2 hard, but it also leads to the disadvantage that the shredding-element 2 is made brittle and can be damaged upon the deformation accompanying the fitting of the shredding-element 2 onto a shredding-element carrier 10 . Such damage especially occurs in the foot zone 200 ( FIG. 3 ) where fissures can occur.
The shredding-element 10 of the disintegrator roll 1 can be formed by the base body 100 of the disintegrator roll 1 . However, it is also possible to provide a ring (not shown), which, in a known manner, is held in place by clamps or the like.
In order to avoid the mentioned disadvantages and risks in accord with the process presented in the following, the flexible, unhardened sawtooth wire shredding-element, which does not yet exhibit any great hardness, is first brought into the essentially desired shape, which subsequently, in its installed condition, it will assume on the shredding-element carrier 10 . In this way, the desired shape is not brought to the to-be-achieved diameter d, but the spiral shape is additionally considered, which shape the sawtooth wire 20 will assume on the shredding-element carrier on the disintegrator roll.
Principally, the shaping of the sawtooth wire 20 can be done in different ways. Advantageously, however, the sawtooth wire 20 is wound on a shaping body 3 (FIG. 1 ), the diameter d of which is essentially just as large as the effective diameter D of the shredding-element carrier 10 for the disintegrator roll 1 . In this way, it is not required to shape the sawtooth wire in any important degree during its later installation on the shredding-element carrier 10 .
The final diameter d, which the sawtooth wire 20 should obtain by the shaping, is not necessarily identical with the outside diameter of the shredding-element carrier 10 . As a rule, the sawtooth wire 20 is not wound onto the outside circumference of the shredding-element carrier 10 , but rather is received in spiral grooving in this outside circumference of the shredding-element carrier 10 with the result, that the diameter d represents the diameter of this grooving. This is plainly seen in FIG. 2 in which this effective diameter d of the shredding-element carrier 10 is obviously less than the outside diameter D thereof.
After the sawtooth wire 20 has taken on its desired shape, it is subjected to a hardening procedure. Principally, it is not of great importance, which special hardening procedure is applied (for instance, flame-hardening). Nevertheless, experience shows that it is particularly advantageous, if the hardening of the shredding-element 20 is done by induction. In this process, the depth of the hardening can be exactly determined by a corresponding choice of the frequency of the alternating current.
Since priority is given to having a good hardening on such surfaces as come into contact with the fibers, high frequency currents are particularly well suited for this purpose.
For that reason, the frequency of the alternating current is chosen as high as possible, so that the hardening effect is limited especially to the points 201 of the teeth. In other words, the hardening is limited to the surface of the teeth of the shredding-element. This comes about at a frequency of the alternating current of at least 1000 kHz, and especially is the case within a frequency range of 1500 and 2000 kHz. The foot area 200 of the sawtooth wire 20 remains unhardened, that is, that area where the teeth are fastened, which is seen in the direction of the shredding-element carrier 10 .
The hardening of the sawtooth wire 20 can be carried out after the removal of the same from the preshaping body 3 . Principally, the preshaped sawtooth wire 20 is conducted through the induced high frequency field of a coil (not shown). In this procedure, the sawtooth wire 20 , in the surface area, particularly in the area of the teeth, is highly heated and, after leaving the field, is chilled.
The process, within the framework of the present invention, can be altered in various ways, especially through the substitution of individual features by equivalents or through other combinations of the features and/or equivalents. Thus, it is not required, that the hardening of the sawtooth wire 20 take place in an unsupported condition. Much more, the sawtooth wire 20 , during this hardening procedure, can still remain on the preshaping carrier 3 . This has the advantage, that the inductive hardening process can be limited in an especially simple and secure manner to the area of the tooth points 201 to the tooth footings 203 , whereby the foot area 200 of the sawtooth wire 20 retains, essentially, its original degree of hardness.
To avoid the manipulation of the sawtooth wire 20 in an already hardened condition, provisions can be made in a development of the described process, wherein the sawtooth wire 20 is laid onto the shredding-element carrier just before the carrying out of the hardening procedure and is secured thereon. Then, the so secured sawtooth wire 20 is subjected to a hardening procedure, especially the described induction hardening.
According to an advantageous development of the previously described process, the hardening of the shredding-element 2 can be carried out under the protection of an inert gas. In this way, the surface of the sawtooth wire 20 , which has been raised to a high temperature during the hardening process, is prevented from reacting with oxygen to form rust or scale, which can lead to undefined conditions and dimensioning of the teeth of the sawtooth wire 20 .
Independent of what kind of hardening has been employed, there is created, in accord with the above described process, a disintegrating roll 1 having a sawtooth wire 20 , which forms the shredding-element 2 . This sawtooth wire is preferably only hardened inductively, after it has assumed essentially its final shape, and especially after it has been secured to the shredding-element carrier 10 .
As part of the hardening procedure, there follows in the customary manner, a chilling of the sawtooth wire 20 by water, oil or the like. Thereby, inner stresses are created internally in the sawtooth wire 20 which can lead to fissuring. In order to avoid these, as soon as possible after the chilling, a heat treatment (tempering) is provided by means of which such stresses are relieved. In accord with a preferred improvement of the described process, the hardened sawtooth wire 20 during this tempering is brought principally to a temperature of about 130°. In this way, it is assured, that the steel from which the sawtooth wire 20 is made indeed loses the internal stresses, but not the hardness.
The sawtooth wire 20 which is on the shredding-element carrier 10 is, as a rule, subjected to a grinding procedure since it known from experience, that the sawtooth wire 20 installed on the shredding-element carrier 10 is generally out of round.
In accord with the embodiment depicted in FIG. 3 , the disintegrator roll 1 , now equipped with the sawtooth wire 20 is driven in the direction of the arrow f 1 , that is, in the direction of the rotation (arrow f 2 ), in which the disintegrator roll 1 turns during the spinning operation. The sawtooth wire 20 , which is driven by the disintegrator roll 1 during the grinding operation then moves contrary to the rotation of a grinding disk 5 , which is driven in the direction indicated by the arrow f 3 .
Not only the points 201 of the teeth, but also the ends of the sawtooth wire 20 affixed to the disintegrator roll 1 are subjected to the grinding procedure.
This operation seeks to prevent the ends of the sawtooth wire 20 fastened on the shredding-element 10 , from leading in a known manner to later problems with fiber transport within the housing 4 .
The hardened shredding-element 2 can still undergo a blasting operation in order to smooth its surface. This blasting can be done in customary procedures by means of blasting with sand, small glass globules or the like.
Since the shredding-element 2 is magnetized by the blasting procedure, the shredding-element 2 is advantageously demagnetized after this blasting procedure. This is done, as a rule, by the production of a corresponding magnetic counter field, whereby the shredding-element runs through the hysteresis loop with cyclic reduction of the maximal field strength.
In order to remove and round off protruding spikes and edges of the sawtooth wire 20 , it is advantageous if the sawtooth wire 20 is deburred. This can be carried out in known chemical procedures in a solution known as appropriate for this purpose, or also electrolytically with the aid of an acid solution.
If desirable, for acquiring certain surface characteristics, the shredding-element can also be coated, for instance, with a galvanically applied nickel plating. In doing this, it is also possible to embed diamond kernels in the nickel layer.
It is also possible to provide on a shredding-element carrier 10 a shredding element which possesses a sawtooth wire 20 as well as needles (not shown) in combination. Further, instead of a single sawtooth wire 20 , two such sawtooth wires 20 can be laid next to one another, whether the shredding-element 2 has auxiliary needles or not. Independent of the special design of a shredding-element 2 of a disintegrator roll 1 , the here described process can always be advantageously applied.
It will be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. It is intended that the present invention include such modifications and variations as come within the scope of the appended claims and their equivalents.
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A sawtooth wire to be laid in a groove of a shredding-element-carrier of a disintegrating roll of an open-end spinning apparatus is brought into a shape, which essentially represents that shape, which the sawtooth wire is to assume on the shredding-element carrier. The sawtooth wire is preshaped on a dummy body, the circumference of which predominately conforms to that of the shredding-element carrier, or the sawtooth wire is directly preshaped on the shredding-element carrier of the disintegrating roll. The preshaped sawtooth wire is subsequently hardened, preferably inductively with the aid of a high frequency alternating current with a frequency of more than 1000 kHz. In this manner, a disintegrating roll is made, the abrasion resistant shredding element of which, after the preshaping, i.e., after is securement on the shredding-element carrier, is a hardened shredding element.
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[0001] The present invention relates to a pharmaceutical fixed dose combination tablet comprising repaglinide and metformin. The present invention also provides a method of producing said tablet.
BACKGROUND OF THE INVENTION
[0002] Metformin disclosed in U.S. Pat. No. 3,174,901 is a long-acting biguanide antidiabetic that is mainly known for its antihyperglycaemic activity and is widely used in the treatment of non-insulin dependent diabetes mellitus (NIDDM). Its chemical name is N,N-dimethylimidodicarbon-imidic diamide having the following structure:
[0000]
[0003] Metformin is manufactured and supplied as hydrochloride salt form.
[0004] Metformin is freely soluble in water (Martindale, 33 rd Edition, page 332 (2002)). It is also known to be a poorly compressible substance. A poorly compressible substance is one that does not bind to form a tablet upon application of compression force. Therefore, such substances may require additional processing and special formulating before they can be compressed into tablets. With such substances, the additional processing necessary is usually a wet granulation step, as direct compression would not be effective. These substances may be formulated with binders or other materials that have high binding capacity (or that act as an aid to compressibility) such that the non-bonding properties of the non-compressible material are overcome. Other techniques to assist compression include having residual moisture in the blend prior to compression or having the non-compressible material in very low amounts in the tablet formulation. High-dose drugs, such as metformin, do not lend themselves to direct compression because of the relatively low proportion of diluent or compression aid in the tablet, poor powder flow and poor compressibility.
[0005] Repaglinide is i.a. disclosed in European patent application No. 0 589 874. It is a short-acting hypoglycemic antidiabetic with the chemical name (S)-2-Ethoxy-4-[2-[[3-methyl-1-[2-(1-piperidinyl)phenyl]butyl]amino]-2-oxoethyl]benzoic acid having the following formula:
[0000]
[0006] The solubility of the drug substance repaglinide is quite low (9 micro gram/ml in pH 5.0 buffer solution).
OBJECTS OF THE INVENTION
[0007] The mechanisms of action of repaglinide and metformin are considered to cooperate favourable in the treatment of type I and II diabetes mellitus.
[0008] Combination therapy of repaglinide with metformin is expected to show synergistic therapeutic efficacy in the treatment of type I and type II diabetes mellitus. As this assumption gets supported by an increasing amount of clinical data, there is an increasing desire for a fixed dose combination drug comprising the active ingredients repaglinide and metformin.
[0009] It was therefore an object of the present invention to provide a fixed-dose combination drug comprising repaglinide and metformin, said combination drug displaying the fast dissolution and immediate drug release profile combined with adequate stability.
[0010] Generally, a fixed-dose combination of drugs intended for immediate release is prepared by either making a powder mixture or a co-granulate of the two active ingredients with the necessary excipients, normally keeping the basic formulation of the corresponding mono-drug preparation and simply adding the second drug component.
[0011] With a combination of repaglinide and metformin, this approach was not feasible due to the fact that metformin has to be provided in a much higher quantity than repaglinide and due to the differences in solubility.
[0012] However, both repaglinide and metformin are chemical compounds difficult to handle. Therefore, an oral fixed dose combination drug which combines the features of pharmacologic efficacy, adequate drug stability and a reliable and robust method of manufacture has to overcome a number of technical problems. It is an object of the present invention to provide such a fixed dose combination drug.
[0013] It is an object of the present invention to provide a pharmaceutical composition that addresses the general challenges associated with the development of a pharmaceutical product, the specific challenges associated with the individual active compounds incorporated in the dosage form and also the challenges associated with bringing the active substances into combination.
[0014] A particular challenge associated with this combination is to ensure the bioequivalence of each active compound to the respective components when administered separately in spite of the biopharmaceutical problems associated with repaglinide and the different physical and chemical properties of both actives.
[0015] It is another object of the present invention to obtain a formulation of repaglinide and metformin with a size suitable for administration and acceptable to patients in spite of the fact that the composition of the invention shall contain a high amount of metformin (metformin is usually prescribed at 850 mg once or twice a day or at 500 mg three to four times a day). This considerable mass of metformin is to be combined in the same pharmaceutical dosage unit with repaglinide in smaller quantities than metformin (repaglinide is usually prescribed at 0.5 to 2 mg three to four times a day). Prior art teaches that such combination are associated with a large quantity of excipient in order to maintain an acceptable bioavailability (U.S. Pat. No. 6,074,670), what would result in a large tablet.
[0016] A further object of the present invention is to obtain a formulation which gives rise to high patient compliance, by reducing the number of unit forms of administration that need to be taken, such as tablets. Diabetes mellitus type II often requires treatment with more than one active substance. In addition, amongst type II diabetes, the prevalence of other disorders associated with insulin resistance (dyslipidaemia, hypertension), which frequently require additional pharmacological forms of treatment, is high. Patient compliance under such circumstances is quite a problem, because individual dosage units are necessarily quite large in view of the high amounts of active substances which need to be administered, and the practical limits as regards the mass of pharmaceutical compositions which can be administered to a patient as a single dosage unit.
[0017] An even further object of the present invention is to provide a pharmaceutical composition containing both active components, repaglinide and metformin, whilst maintaining a bioavailability of each of the two components equivalent to or superior to that obtained with repaglinide alone or metformin alone. The object of the present invention is to obtain a formulation wherein both products are bioequivalent or suprabioavailable compared to bioavailability of monotherapy.
[0018] Another object of the present invention is to provide a process for preparing the pharmaceutical compositions fulfilling the objectives listed above, such processes being able to be accomplished with a limited number of different steps and being inexpensive.
SUMMARY OF THE INVENTION
[0019] In accordance with the present invention, it has now been found that the solubility problem of the drug substance repaglinide could be overcome by using a granulate obtained by a spray drying (SD) process or by using the active triturate, which is a mixture of repaglinide
[0020] SD granulate and microcrystalline cellulose. Repaglinide SD granulate is the spray dried granulate of the mixture of repaglinide, Poloxamer 188, Povidone K 25 and meglumine.
[0021] Metformin hydrochloride is highly soluble in water and drug load of metformin is more than 80% w/w of the composition, so this formulation is too sensitive to the amount of moistening water for high shear granulation. The granulates manufactured by high share granulation have poor compressibility.
[0022] Repaglinide and metformin fixed-dose tablets which have good content uniformity, fast dissolution and enough hardness have been developed. Improvement of the repaglinide's content uniformity was investigated intensively; this problem was solved by the co-granulation of repaglinide active triturate and metformin using the fluidized bed granulation technique. For the enough hardness of the tablet, fluidized bed granulation is needed whereas direct compression and high-share granulation are not effective for improving the tablet properties. The amount of binder and microcrystalline cellulose (MCC) are also important for the properties. The moisture content of the granulate also has a big impact on the hardness.
DETAILED DESCRIPTION OF THE INVENTION
[0023] A first aspect of the present invention is a pharmaceutical tablet comprising repaglinide and metformin in a fast disintegrating tablet matrix [The term “disintegrating tablet matrix” refers to a pharmaceutical tablet base formulation having immediate release characteristics that readily swells and disintegrates in a physiological aqueous medium.]
[0024] The tablet preferably contains repaglinide in substantially amorphous form. [The term “substantially amorphous” refers to repaglinide comprising amorphous constituents in a proportion of at least 90%, preferably at least 95%, as determined by X-ray powder diffraction measurement].
[0025] Substantially amorphous repaglinide may be produced by any suitable method known to those skilled in the art, for instance, by freeze drying of aqueous solutions, coating of carrier particles in a fluidized bed, and solvent deposition on sugar pellets or other carriers. Preferably, however, the substantially amorphous repaglinide is prepared by the specific spray-drying method described hereinafter.
[0026] The other active ingredient metformin is generally supplied in its free basic form, although pharmaceutically acceptable salts may also be used. Preferred is the metformin hydrochloride with a specific particle size distribution, which is usually employed as a fine-crystalline powder, optionally in fine-milled, peg-milled or micronized form. For instance, the particle size distribution of metformin hydrochloride in the tablet, as determined by the method of laser light scattering in a dry dispersion system (Sympatec Helos/Rodos, focal length 100 mm) is preferably as follows:
[0000] d 10 : ≦20 μm, preferably 2 to 10 μm
d 50 : 5 to 100 μm, preferably 10 to 50 μm
d 90 : 20 to 150 μm, preferably 40 to 100 μm
[0027] The tablet generally contains 0.1 to 20 mg, preferably 0.5 to 10.0 mg, of repaglinide and 100 to 3000 mg, preferably 200 to 1000 mg, of metformin hydrochloride.
[0028] In an even preferred embodiment, the disintegrating tablet matrix comprises a binder, a filler, a disintegrant and, optionally, other excipients and/or adjuvants.
[0029] The tablet composition according to the present invention generally comprises 5 to 95 wt. %, preferably 10 to 80 wt. %, of active ingredients; 0 to 20 wt. %, preferably 3 to 10 wt. %, of dry binder; 0 to 10 wt. %, preferably 1 to 5 wt. %, of wet granulation binder; 0 to 95 wt. %, preferably 20 to 90 wt. %, of filler and 0 to 50 wt. %, preferably 1 to 10 wt. %, of disintegrant.
[0030] The binder is selected from the group consisting of dry binders and/or wet granulation binders. Suitable dry binders are, e.g., cellulose powder and microcrystalline cellulose. Specific examples of wet granulation binders are corn starch, polyvinyl pyrrolidone (Povidon), vinylpyrrolidone-vinylacetate copolymer (Copovidone) and cellulose derivatives like hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxyl-propylmethylcellulose.
[0031] The filler is preferably selected from anhydrous lactose, spray-dried lactose, mannitol, erythritol, sucrose, sorbitol, calcium phosphate, microcrystalline cellulose and lactose monohydrate.
[0032] Suitable disintegrants are, e.g., sodium starch glycolate, polacrilin potassium, Crospovidon, Croscarmellose, sodium carboxymethylcellulose and dried corn starch; sodium starch glycolate and polacrilin potassium being preferred.
[0033] The other excipients and/or adjuvants are, for instance, selected from carriers, lubricants, flow control agents, crystallization retarders, solubilizers, colouring agents, pH control agents, surfactants and emulsifiers, specific examples of which are given below. The excipients and/or adjuvants are preferably chosen such that a non-acidic, fast dissolving tablet matrix is obtained.
[0034] Other (optional) constituents may, for instance, be chosen from one or more of the following excipients and/or adjuvants in the amounts indicated:
[0000] 0 to 10 wt. %, preferably 0.1 to 5 wt. %, of lubricants;
0 to 10 wt. %, preferably 1 to 5 wt. %, of flow control agents;
0 to 10 wt. %, preferably 0 to 0.5 wt. %, of colouring agents;
[0035] The other excipients and adjuvants, if used, are preferably selected from diluents and carriers such as cellulose powder, microcrystalline cellulose, cellulose derivatives like hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxy-propylmethylcellulose, dibasic calcium phosphate, corn starch, pregelatinized starch, polyvinyl pyrrolidone (Povidone) etc.; lubricants such as stearic acid, magnesium stearate, sodium stearylfumarate, glycerol tribehenate, etc.; flow control agents such as colloidal silica, talc, etc.; crystallization retarders such as Povidone, etc.; solubilizers such as Pluronic, Povidone, etc.; colouring agents, including dyes and pigments such as Iron Oxide Red or Yellow, titanium dioxide, talc, etc.; pH control agents such as citric acid, tartaric acid, fumaric acid, sodium citrate, dibasic calcium phosphate, dibasic sodium phosphate, etc.; surfactants and emulsifiers such as Pluronic, polyethylene glycols, sodium carboxymethyl cellulose, polyethoxylated and hydrogenated castor oil, etc.; and mixtures of two or more of these excipients and/or adjuvants.
[0036] The tablets obtained release the active ingredients rapidly and in a largely pH-independent fashion, with complete release occurring within less than 15 minutes and release of the major fraction occurring within less than 5 minutes.
[0037] In accordance with the present invention, a substantially increased dissolution rate of the active ingredients is achieved. Normally, at least 70% and typically at least 90% of the drug load are dissolved after 30 minutes.
[0038] The tablets of the present invention tend to be slightly hygroscopic and therefore are preferably packaged using a moisture-proof packaging material such as aluminium foil blister packs, or polypropylene tubes and HDPE bottles which preferably contain a desiccant.
[0039] In a second aspect, the present invention relates to a method of producing the pharmaceutical tablet according to the present invention comprising the steps of:
(a) preparing a granulate by granulating and drying a mixture of repaglinide and metformin with a binder solution, using the fluidized bed granulation process, (b) mixing the granulate obtained in step (b) with a filler and a disintegrant, (c) blending the mixture obtained in step (c) with other excipients and/or adjuvants and (d) compression of the product obtained in step (d) into pharmaceutical tablets.
[0044] Repaglinide is preferably used in the form of a spray dried granulate or as an active triturate as mentioned hereinbefore; metformin is preferably used in the form of its hydrochloride salt with the specific size distribution as mentioned hereinbefore.
[0045] According to a further embodiment of the invention, the binder in step (a) is selected from the group consisting of dry binders and/or the group of wet granulation binders and is solved in purified water or a polar organic solvent, preferably ethanol or isopropanol. The solution thus obtained has a concentration of 0.1 to 30% by weight, preferably of 1 to 10% by weight.
[0046] Suitable dry binders are, e.g., cellulose powder and microcrystalline cellulose. Specific examples of wet granulation binders are corn starch, polyvinyl pyrrolidone (Povidon), vinylpyrrolidone-vinylacetate copolymer (Copovidone) and cellulose derivatives like hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxyl-propylmethylcellulose.
[0047] The total amount of dry binder is so chosen as to be 0 to 20 wt. %, preferably 3 to 10 wt. %, related to the final tablet formulation.
[0048] The total amount of wet granulation binder is so chosen as to be 0 to 10 wt. %, preferably 1 to 5 wt. %, related to the final tablet formulation.
[0049] According to an even further embodiment the moisture content of the granulate obtained in step (a) is controlled to be between 0.1 to 1.5% after drying.
[0050] According to an even further embodiment the filler in step (b) is selected from the group consisting of anhydrous lactose, spray-dried lactose, mannitol, erythritol, sucrose, sorbitol, calcium phosphate, microcrystalline cellulose and lactose monohydrate.
[0051] The total amount of filler is so chosen as to be 0 to 95 wt. %, preferably 20 to 90 wt. %, related to the final tablet formulation.
[0052] According to an even further embodiment the disintegrant in step (b) is selected from the group consisting of sodium starch glycolate, polacrilin potassium, Crospovidon, Croscarmellose, sodium carboxymethylcellulose and dried corn starch; sodium starch glycolate and polacrilin potassium being preferred.
[0053] The total amount of disintegrant is so chosen as to be 0 to 50 wt. %, preferably 1 to 10 wt. %, related to the final tablet formulation.
[0054] According to an even further embodiment the amount of disintegrant in step (b) is from 1 to 500 mg, preferably from 10 to 100 mg, per tablet.
[0055] According to an even further embodiment the other excipients and/or adjuvants in step (c) are selected from the group consisting of carriers, lubricants, flow control agents, crystallization retarders, solubilizers, colouring agents, pH control agents, surfactants and emulsifiers, specific examples of which are given below. The excipients and/or adjuvants are preferably chosen such that a non-acidic, fast dissolving tablet matrix is obtained.
[0056] The other excipients and adjuvants, if used, are preferably selected from diluents and carriers such as cellulose powder, microcrystalline cellulose, cellulose derivatives like hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose and hydroxy-propylmethylcellulose, dibasic calcium phosphate, corn starch, pregelatinized starch, polyvinyl pyrrolidone (Povidone) etc.; lubricants such as stearic acid, magnesium stearate, sodium stearylfumarate, glycerol tribehenate, etc.; flow control agents such as colloidal silica, talc, etc.; crystallization retarders such as Povidone, etc.; solubilizers such as Pluronic, Povidone, etc.; colouring agents, including dyes and pigments such as Iron Oxide Red or Yellow, titanium dioxide, talc, etc.; pH control agents such as citric acid, tartaric acid, fumaric acid, sodium citrate, dibasic calcium phosphate, dibasic sodium phosphate, etc.; surfactants and emulsifiers such as Pluronic, polyethylene glycols, sodium carboxymethyl cellulose, polyethoxylated and hydrogenated castor oil, etc.; and mixtures of two or more of these excipients and/or adjuvants.
[0057] The total amount of lubricant is so chosen as to be 0 to 10 wt. %, preferably 0.1 to 5 wt. %, related to the final tablet formulation.
[0058] The total amount of flow control agent is so chosen as to be 0 to 10 wt. %, preferably 1 to 5 wt. %, related to the final tablet formulation.
[0059] The total amount of colouring agent is so chosen as to be 0 to 10 wt. %, preferably 0 to 0.5 wt. %, related to the final tablet formulation.
[0060] According to an even further embodiment the hardness of the tablet obtained in step (d) is controlled to be between 20 and 300 N, preferably between 50 to 200 N.
[0061] For preparing the tablet according to the present invention, the tablet layer composition may be compressed in the usual manner in a monolayer tablet press, e.g. a high-speed rotary press in a bilayer or multilayer tabletting mode.
[0062] Although the monolayer tablet is the preferred form according to the present invention, it is also possible to prepare a bilayer or even multilayer, wherein the tablet layer composition may be compressed in the usual manner as mentioned above in a bilayer or multilayer tablet press.
[0063] For instance, the first tablet layer may be compressed at moderate force of 4 to 8 kN, whereas the main compression of first plus second layer is performed at a force of 10 to 300 kN, preferably 15 to 50 kN.
[0064] It was impossible to make tablets by the direct compression method due to the poor compressibility, even for a formulation which include 100 mg/tablet Povidone K25.
[0065] In the formulations according to the present invention, the moisture content of the granulate for tabletting should be between 1.5% and 3.0%. If it is lower than 1.5%, it is very difficult to make tablets due to poor compressibility. If it is higher than 3.0%, it is also very difficult due to poor flowability. Preferably, the moisture content should be between 1.8% and 2.5%.
[0066] In order to further illustrate the present invention, the following non-limiting examples are given.
EXPERIMENTAL PART
Example 1
[0067] Tablet containing 1.0 mg repaglinide and 650 mg metformin:
[0000]
Povidone K25
25.0
mg
Metformin HCl
650.0
mg
Repaglinide triturate
14.072
mg
Polacrilin potassium
30.0
mg
Microcrystalline cellulose
90.0
mg
Magnesium stearate
5.0
mg
Total
814.072
mg
Preparing Procedure:
[0068] Povidone K25 was dissolved in purified water (granulation liquid). Metformin HCl and repaglinide triturate were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screening machine with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and polacrilin potassium were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 2
[0069] Tablet containing 1.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 37.5 mg Metformin HCl 650.0 mg Repaglinide triturate 14.072 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 60.0 mg Magnesium stearate 5.0 mg Total 796.572 mg
preparing procedure according to Example 1
Example 3
[0070] Tablet containing 2.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 25.0 mg Metformin HCl 650.0 mg Repaglinide triturate 28.144 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 78.0 mg Magnesium stearate 5.0 mg Total 816.144 mg
preparing procedure according to Example 1
Example 4
[0071] Tablet containing 2.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 37.5 mg Metformin HCl 650.0 mg Repaglinide triturate 28.144 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 48.0 mg Magnesium stearate 5.0 mg Total 798.644 mg
preparing procedure according to Example 1
Example 5
[0072] Tablet containing 4.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 25.0 mg Metformin HCl 650.0 mg Repaglinide triturate 56.288 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 54.0 mg Magnesium stearate 5.0 mg Total 820.288 mg
preparing procedure according to Example 1
Example 6
[0073] Tablet containing 4.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 25.0 mg Metformin HCl 650.0 mg Repaglinide triturate 56.288 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 90.0 mg Magnesium stearate 5.0 mg Total 856.288 mg
preparing procedure according to Example 1
Example 7
[0074] Tablet containing 1.0 mg repaglinide and 500 mg metformin:
[0000]
Povidone K25
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
14.072
mg
Na-carboxymethylcellulose
25.0
mg
Microcrystalline cellulose
75.0
mg
Magnesium stearate
2.0
mg
Total
636.072
mg
Preparing Procedure:
[0075] Povidone K25 was dissolved in purified water (granulation liquid). Metformin HCl and repaglinide triturate were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and Na-carboxymethylcellulose were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 8
[0076] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000] Povidone K25 20.0 mg Metformin HCl 500.0 mg Repaglinide triturate 28.144 mg Na-carboxymethylcellulose 25.0 mg Microcrystalline cellulose 75.0 mg Magnesium stearate 2.0 mg Total 650.144 mg
preparing procedure according to Example 7
Example 9
[0077] Tablet containing 3.0 mg repaglinide and 500 mg metformin:
[0000] Povidone K25 20.0 mg Metformin HCl 500.0 mg Repaglinide triturate 42.216 mg Na-carboxymethylcellulose 25.0 mg Microcrystalline cellulose 75.0 mg Magnesium stearate 2.0 mg Total 664.216 mg
preparing procedure according to Example 7
Example 10
[0078] Tablet containing 1.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 20.0 mg Metformin HCl 650.0 mg Repaglinide triturate 14.072 mg Na-carboxymethylcellulose 25.0 mg Microcrystalline cellulose 75.0 mg Magnesium stearate 2.0 mg Total 786.072 mg
preparing procedure according to Example 7
Example 11
[0079] Tablet containing 1.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 50.0 mg Metformin HCl 650.0 mg Repaglinide triturate 14.072 mg Na-carboxymethylcellulose 25.0 mg Microcrystalline cellulose 75.0 mg Magnesium stearate 2.0 mg Total 816.072 mg
preparing procedure according to Example 7
Example 12
[0080] Tablet containing 1.0 mg repaglinide and 800 mg metformin:
[0000] Povidone K25 50.0 mg Metformin HCl 800.0 mg Repaglinide triturate 14.072 mg Na-carboxymethylcellulose 50.0 mg Microcrystalline cellulose 100.0 mg Magnesium stearate 2.0 mg Total 1019.072 mg
preparing procedure according to Example 7
Example 13
[0081] Tablet containing 1.0 mg repaglinide and 800 mg metformin:
[0000] Povidone K25 50.0 mg Metformin HCl 800.0 mg Repaglinide triturate 28.144 mg Na-carboxymethylcellulose 50.0 mg Microcrystalline cellulose 100.0 mg Magnesium stearate 2.0 mg Total 1033.144 mg
preparing procedure according to Example 7
Example 14
[0082] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000]
Hydroxypropylcellulose
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
28.144
mg
Na-carboxymethylcellulose
25.0
mg
Microcrystalline cellulose
75.0
mg
Magnesium stearate
2.0
mg
Total
650.144
mg
Preparing Procedure:
[0083] Hydroxypropylcellulose was dissolved in purified water (granulation liquid). Metformin HCl and repaglinide triturate were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and Na-carboxymethylcellulose were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 15
[0084] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000]
Hydroxypropylcellulose
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
28.144
mg
Crospovidon
25.0
mg
Microcrystalline cellulose
50.0
mg
Lactose
100.0
mg
Magnesium stearate
2.0
mg
Total
650.144
mg
Preparing Procedure:
[0085] Hydroxypropylcellulose was dissolved in purified water (granulation liquid). Metformin HCl, repaglinide triturate and lactose were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and Crospovidone were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 16
[0086] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000]
Hydroxypropylcellulose
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
28.144
mg
Croscarmellose
25.0
mg
Microcrystalline cellulose
50.0
mg
Lactose
100.0
mg
Magnesium stearate
2.0
mg
Total
650.144
mg
Preparing Procedure:
[0087] Hydroxypropylcellulose was dissolved in purified water (granulation liquid). Metformin HCl, repaglinide triturate and lactose were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and croscarmellose were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 17
[0088] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000]
Hydroxypropylcellulose
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
28.144
mg
Croscarmellose
25.0
mg
Microcrystalline cellulose
50.0
mg
Mannitol
100.0
mg
Magnesium stearate
2.0
mg
Total
650.144
mg
Preparing Procedure:
[0089] Hydroxypropylcellulose was dissolved in purified water (granulation liquid). Metformin HCl, repaglinide triturate and mannitol were charged into a suitable fluid bed granulator (e.g. WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and Croscarmellose were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 18
[0090] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000]
Hydroxypropylcellulose
20.0
mg
Metformin HCl
500.0
mg
Repaglinide triturate
28.144
mg
Croscarmellose
25.0
mg
Microcrystalline cellulose
50.0
mg
Calcium phosphate
100.0
mg
Magnesium stearate
2.0
mg
Total
650.144
mg
Preparing Procedure:
[0091] Hydroxypropylcellulose was dissolved in purified water (granulation liquid). Metformin HCl, repaglinide triturate and calcium phosphate were charged into a suitable fluid bed granulator (WSG-5: Powrex Co., Ltd.), briefly pre-mixed and granulated by spraying granulation liquid. Thereafter, the granulate was screened using a suitable screen with mesh size of ca 0.5 mm. Screened granulate, microcrystalline cellulose and Croscarmellose were mixed together using a suitable mixer. Then, magnesium stearate was added to the mixture and mixed using a suitable mixer (final mixture). The final mixture was compressed by a suitable tabletting machine.
Example 19
[0092] Tablet containing 2.0 mg repaglinide and 500 mg metformin:
[0000] Hydroxypropylcellulose 20.0 mg Metformin HCl 500.0 mg Repaglinide triturate 28.144 mg Croscarmellose 25.0 mg Microcrystalline cellulose 50.0 mg Calcium phosphate 100.0 mg Magnesium stearate 5.0 mg Total 653.144 mg
preparing procedure according to Example 18
Example 20
[0093] Tablet containing 3.0 mg repaglinide and 650 mg metformin:
[0000] Povidone K25 25.0 mg Metformin HCl 650.0 mg Repaglinide triturate 42.216 mg Polacrilin potassium 30.0 mg Microcrystalline cellulose 70.0 mg Magnesium stearate 5.0 mg Total 822.216 mg
Preparing procedure according to Example 1
|
The present invention relates to a pharmaceutical fixed dose combination tablet comprising repaglinide and metformin. The present invention also provides a method of producing said tablet.
| 0
|
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60/219,520 filed Jul. 20, 2000.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to a device for lifting a mower deck suspended from a riding mower, and more specifically, to a foot actuated deck lift mechanism for lifting a mower deck automatically from a cutting position to a transport position.
DESCRIPTION OF THE RELATED ART
[0003] There are a number of known devices for lifting a mower deck on a riding mower to a transport position. These devices typically include a hand actuated lift lever. U.S. Pat. No. 5,816,033 to Busboom et al. discloses a riding mower having an improved mower deck height control mechanism including an elongated deck height control lever pivotally movable from a lower position with respect to the frame means, to an upper position wherein, the mower deck is in its uppermost transit position. These types of deck lift arrangements require an operator to remove a hand from the drive controls or stop the mower to raise the deck to the transport position. Additionally, hand adjustment lift levers can require considerable force to raise a mower deck, particularly larger decks.
[0004] In U.S. Pat. No. 5,138,825 to Trefz et al., a pedal operating lifting system is provided for replacing conventional hand operating levers. The pedal also includes a locking mechanism located on the pedal mechanism for locking the deck in the uppermost position. In U.S. Pat. No. 5,351,467 to Trefz et al, a pedal operating lifting system is provided with unlimited adjustability within a range established by the maximum and minimum deck mower heights. The '825 and '467 patents disclose a pedal operated deck lifting system but do not include the advantages of the system disclosed by the present invention.
[0005] Accordingly, there is a need in the art for a mower deck lift mechanism that may be operated without the sole use of an operator's hands. Furthermore, there is a need for a mower deck lift assembly that may be easily attachable as an after market device addition to a riding mower, as well as a standard feature on a stock mower.
SUMMARY OF THE INVENTION
[0006] This invention provides a foot actuated mower deck lift device to lift a mower deck from a cutting position to a transport position without the sole use of the operator's hands.
[0007] More specifically, the invention is directed towards a lift mechanism that is hand and/or foot actuated for lifting a deck attached to a mower, and particularly, a mower deck attached to a riding lawn mower.
[0008] The present invention discloses a system that includes the cooperation of a lift handle with a foot pedal increasing mechanical system leverage and reducing the force required by the operator to engage the system. The present invention also can be operated solely by a foot pedal and without the use of the operator's hands. Finally, the present invention includes a locking transport position positively engaged by a lift pin incorporated into the lift lever.
[0009] According to the invention, the deck lift mechanism comprises a frame, a lift lever, inner and outer height adjustment plates, lift linkages, a front lift shaft, a rear lift shaft, shaft connecting linkages, and a pedal lever.
[0010] In accordance with an embodiment of the invention, the lift lever is pivotally coupled to a frame and has a pin movably attached thereto. A lift linkage has a first end pivotally coupled to the lift lever and a second end fixedly secured on a front shaft. A connecting linkage pivotally couples the front shaft to a rear shaft. Both the front and rear shafts are rotatably coupled to the frame. The pedal lever has a first end fixedly secured to the front shaft and a second free end for operation with the operator's foot.
[0011] In accordance with an aspect of this invention, it is desirable to provide a cutting system that permits the operator to change the cutting height while seated using an adjustment pin.
[0012] In accordance with another aspect of this invention, it is further desirable to provide a cutting system wherein the operator can raise the mover deck without the use of the operator's hands to a transport position and return the deck to that exact cutting position once the transport is completed.
[0013] In accordance with another aspect of this invention, it is further desirable for the lift assembly to be easily attachable as an after market device, in addition to being a standard stock feature.
[0014] These and other aspects of this invention are illustrated in the accompanying drawings, and are more fully disclosed in the following specification.
DETAILED DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is an elevation view of a riding mower incorporating the deck lift mechanism in a lowered cutting position;
[0016] [0016]FIG. 2 is an elevation view of a riding mower incorporating the deck lift mechanism in a transport position;
[0017] [0017]FIG. 3 is an isolated exploded view of the deck lift mechanism;
[0018] [0018]FIG. 4 is a perspective view of a pedal lever connected to a pedal and a deck lift lever;
[0019] [0019]FIG. 5 is a front view of the pedal lever and pedal;
[0020] [0020]FIG. 6 is a side view of the pedal lever of FIG. 5; and
[0021] [0021]FIG. 7 is a side view of a tightening plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] [0022]FIGS. 1 and 2 illustrate a foot actuated deck lift mechanism 10 according to the present invention. The deck lift mechanism 10 is shown in its intended operating position, attached to a riding mower, for lifting a mower deck 12 from a cutting position to a transport position. While the remaining components of a riding lawn mower are not shown in the appended drawings, it is expected that those skilled in the art will be intimately familiar with the omitted components, all which are generally conventional.
[0023] Referring now to FIG. 1, the deck lift mechanism 10 is shown in a lowered cutting position. FIG. 2 illustrates the deck lift mechanism 10 in a raised transport position. Provided in the deck lift mechanism 10 are a pair of height adjustment plates 16 , 18 for securing the deck 12 in the transport position and for positioning the deck at a plurality of particular vertical cutting positions 58 .
[0024] As shown in FIG. 3, the deck lift mechanism 10 includes a lift lever 14 , inner and outer height adjustment plates 16 , 18 , lift linkages 20 , a front lift shaft 22 , a rear lift shaft 24 , shaft connecting linkages 26 , and a pedal lever 28 .
[0025] Preferably, the deck lift mechanism 10 is actuated solely by an operator's foot using pedal lever 28 to raise the mower deck 12 to a transport position. Alternatively, the deck lift mechanism 10 may be raised to the transport position by the use of an operator's hand using lift lever 14 , or by the use of an operator's foot using pedal lever 28 assisting the hand using lift lever 14 .
[0026] The lift lever 14 is carried on the frame 29 of the vehicle and has an upper end positioned for engagement with the operator's right hand and a lower end pivotally coupled with the frame 29 . The lower end provides a peg member 30 formed integral with the lift lever 14 . The peg member 30 is pivotally received by an opening formed in the vehicle frame 29 . The peg 30 defines the axis about which the lift lever 14 pivots. The upper end angles into the operator's control area 32 to provide a handle for placement of the operator's hand.
[0027] As shown in FIG. 3, and illustrated by hidden lines in FIGS. 1 and 2, a spring assembly 34 is attached to the lift lever 14 between the upper and lower ends. The spring assembly 34 includes a pair of guides 36 , 38 , a spring 40 and a lift pin 42 . The upper guide 36 is generally shaped as an inverted L with a body portion and a top portion. The body portion of the upper guide 36 , is fixedly secured to the lift lever 14 by nut and bolt assemblies 44 . The lower guide 38 is welded to the lift lever at the bottom of the upper guide 36 . The spring 40 preferably is a compression spring and is axially positioned between, and restricted by, the guides 36 , 38 . The lift pin 42 is generally shaped as an inverted L. The upper end of the lift pin 42 is spaced at a distance from the lift lever handle 33 such that the operator's fingers can grasp the lift pin 42 while maintaining their palm on top of the handle 33 . The lower end of the lift pin 42 slidably extends through coaxially aligned openings 46 , 48 formed in the top portion of the upper guide 46 and in the lower guide 48 , and through the inside diameter of the spring 40 . A pin 50 is received in an aperature 51 in the lift pin 42 between the lower guide 38 and the bottom of the spring 40 . The pin 50 is longer than the outside diameter of the spring 40 and, therefore, carries the spring 40 upwards when the lift pin 42 is lifted upwards thereby compressing the spring 40 between the pin 50 and the top portion of the upper guide 36 .
[0028] As shown in FIG. 3, the preferred embodiment also provides a pair of height adjustment plates 16 , 18 for securing the deck 12 in a transport position and for positioning the deck at a plurality of particular vertical cutting positions. The inner adjustment plate 16 is welded to the frame 29 . The outer adjustment plate 18 is fixedly attached to the inner adjustment plate 16 by front and rear nut, spacer and bolt assemblies 52 , 53 . The spacers 54 maintain the adjustment plates 16 , 18 a fixed distance apart to provide a channel 56 between the adjustment plates 16 , 18 . Both adjustment plates 16 , 18 , have two rows of radially spaced apart height adjustment openings 58 at fixed intervals which provide the variety of cutting positions. The openings 58 in the adjustment plates 16 , 18 coaxially align and are positioned between the front and rear nut, spacer and bolt assemblies 52 , 53 . The forward most opening 60 provides the lowest cutting position and each subsequent opening incrementally increases the cutting height.
[0029] Referring again to FIG. 3, the lift lever 14 extends through the channel 56 formed by the adjustment plates 16 , 18 with the peg member 30 below, and the handle 33 above the adjustment plates 16 , 18 . The lift lever 14 radially moves along the channel 56 and is configured between the front and rear nut, spacer and bolt assemblies 52 , 53 .
[0030] As shown in FIGS. 1 and 2, the outer adjustment plate 18 is provided with an arcuate top rail 62 , uniformly distant from the peg member 30 upon which the bottom end of the lift pin 42 slides. A transport opening 64 for setting the deck into the transport position is formed by a contiguous recess, which extends through the top rail 62 into the outer adjustment plate 18 . The transport opening 64 is located rearward of the height adjustment openings 58 .
[0031] The lift pin 42 is biased against the top rail 62 by the spring 40 . When the lift pin 42 is positioned over the transport opening 64 , the spring 40 urges the lift pin 42 into the transport opening 64 thereby securing the deck 12 into the transport position. Preferably, the deck 12 is raised to a six-inch cutting height when in the transport position.
[0032] A height adjustment pin 66 , shown in FIG. 3, provides intermediate positioning of the deck 12 . The deck height is selected by inserting the height adjustment pin 66 through a coaxially aligned pair of height adjustment openings 58 to form a crossbeam through the channel. The lift lever 14 contacts and rests upon the height adjustment pin 66 under the force of gravity when setting the cutting height. For storage purposes and so that it does not get misplaced, the height adjustment pin 66 is attached to the outer height adjustment plate 18 by a wire, rope or chain.
[0033] A pair of laterally spaced lift linkages 20 include first ends pivotally coupled with the lift lever 14 , and second ends pivotally coupled with integral connection lever 68 fixedly provided on the front lift shaft 22 .
[0034] The front and rear lift shafts 22 , 24 are rotatably coupled to the frame 29 in any known manner. The lift shafts 22 , 24 are each provided with integral connection levers 70 . A pair of connecting linkages 26 are pivotally secured to the levers 70 on the front lift shaft 22 and the rear lift shaft 24 to form a parallel linkage, thereby pivotally coupling the front lift shaft 22 to the rear lift shaft 24 , such that rotation of the front lift shaft 22 is equally transmitted to the rear lift shaft 24 .
[0035] A pair of deck lift levers 72 are integrally provided on the front and rear lift shafts 22 , 24 . An opening 74 is provided in an outer end of each of the deck lift levers 72 . Chains 76 having an upper end attached to the openings 74 and a lower end attached to the deck 12 , support the weight of the deck 12 .
[0036] Springs 78 , preferably of the tension type, include a first end attached to the levers 70 on the rear lift shaft 24 and a second end attached to the frame 29 . The springs bias the rear lift shaft 24 towards the direction of rotation in which the deck 12 is lifted. The aggregate force of the springs 78 offsets a portion of the weight of the deck 12 to assist the operator when raising the deck 12 . Additional levers and springs can be provided to increase the biasing force.
[0037] As shown in FIGS. 4 and 5, the pedal lever 28 has a lower portion 80 , a middle portion 82 and an upper portion 84 . The middle portion 82 preferably angles towards the control area 32 from the lower portion 80 by forty-five degrees and the upper portion 84 preferably angles toward the control area 32 from the middle portion 82 by forty-five degrees for ergonomic operation by the operator's right foot.
[0038] The lower portion 80 is removably secured to the right front deck lift lever 72 . Particularly, a tightening plate 86 cooperates with the lower portion 80 to sandwich an intermediate section of the pedal lever 28 therebetween. Preferably, two groups of three openings 88 , 90 are provided, one group 88 in the tightening plate 86 and the other group 90 in the deck lift lever 72 as illustrated in FIGS. 4, 6 and 7 . The groups of openings 88 , 90 coaxially align for receiving nut and bolt assemblies. Two sets of the coaxially aligned openings are positioned above, and one set of the openings below, the deck lift lever 72 . Each group of the openings 88 , 90 are orientated as vertexes of an obtuse triangle. Each nut and bolt assembly is disposed adjacent the circumferential edge of the deck lift lever 72 , and preferably is connected thereto.
[0039] As shown in FIGS. 4 and 5, a pedal 92 is fixedly secured to an inward facing edge of the upper portion 84 . The pedal 92 is formed of a unitary piece of metal and includes upper and lower inwardly facing engagement surfaces 94 , 96 , and a top 98 , and left and right sides 100 , 102 . The upper engagement surface 94 is rectangular. The lower engagement surface preferably is trapezoidal wherein an edge 104 of the lower surface is disposed adjacent to the middle portion 82 of the pedal lever 28 . The engagement surfaces 94 , 96 slightly angle together to form an outwardly facing obtuse angle. The inward surface of both the upper and lower engagement surfaces 94 , 96 can be engaged with the operator's foot for operation of the deck lift mechanism 10 . Preferably, the inward surfaces have attached an abrasive material, or high friction material such as rubber, to reduce slippage of the operator's foot. The top 98 and left and right sides 100 , 102 perpendicularly extend outwardly form the upper engagement surface 94 to partially enclose the pedal lever upper portion 84 .
[0040] The operation of the preferred embodiment will now be discussed. To place the deck 12 in the transport position, the operator places their right foot on the pedal 92 wholly retaining their hands on the drive controls and remaining seated on the vehicle seat. As the operator depresses the pedal lever 28 with their foot, the foot and rear lift shafts 22 , 24 rotate causing the outer end of the deck lift levers 72 to radially rise upwards. The deck 12 , carried by the chains 76 attached to the deck lift levers 72 , is lifted upwards. Alternatively, the deck can be placed in the transport position by the operator moving the lift lever 14 backwards, or using a combination of the lift lever 14 and the pedal lever 28 .
[0041] Simultaneously, upon engagement of the pedal lever, the rotating front lift shaft 22 transmits movement to the lift lever 14 through the pair of lift linkages 20 . As the lift lever 14 pivots the lift pin 42 , carried by the lift lever 14 , radially moves rearward sliding atop the top rail 62 towards the transport opening 64 provided in the top rail 62 . Sufficiently depressing the pedal lever 28 moves the lift lever 14 , which carries the lift pin 42 where the potential energy of the spring 40 forces the biased lift pin 42 into the transport opening 64 . The lift pin 42 sufficiently extends into the transport opening 64 so as not to be inadvertently removed or jostled therefrom, yet require minimal lifting to be removed from the transport opening 64 . When fully inserted into the transport opening 64 , the lift pin 42 extends between ⅛ and 1½ inches therein, and preferably between ¼ and ¾ inch. The lift pin 42 fits within the transport opening 64 with little lateral play. When the lift pin 42 is within the transport opening 64 , the deck 12 is in the transport position corresponding to about a six-inch cutting height.
[0042] The deck can alternatively be placed in the transport position by the operator grasping the handle 33 with their right hand and pulling the lift lever 14 backwards, until the lift pin 42 reaches the transport opening. Similarly, the operator can simultaneously pull the handle 33 and depress the pedal lever 28 to place the deck into the transport position, which supports the deck at the desired cutting height.
[0043] To remove the deck 12 from the transport position to a cutting position, the height adjustment pin 66 is inserted into a pair of coaxially aligned openings 58 that correspond to the desired cutting height. Then, the operator places their palm on the handle 33 with fingers extending downward grasping the lift pin 42 . The operator applies moderate pressure to the pedal 92 and/or handle 33 to offset the weight of the deck 12 , thereby, reducing the force required to remove the lift pin 42 from the transport opening 64 . The operator closes their hand forcing the lift pin 42 upwards and out of the transport opening 64 . The lift lever 14 pivotally rotates forward under the weight of the deck 12 , partially offset by the operator, until contacting the height adjustment pin 66 , and consequently setting or re-setting the cutting deck position.
[0044] The cutting deck may be vertically adjusted for a plurality of cutting height settings. If the cutting deck is locked in its uppermost transport position, it may then be returned to the pre-selected cutting height set by the height adjustment pin once removed it is from the transport position.
[0045] Although the invention has been shown and described with respect to certain embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon reading and understanding of the specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the claims.
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An apparatus for lifting a deck of a vehicle, such as a lawn mower, by a foot actuated deck lift mechanism. The device includes a lift lever pivotally coupled to a frame and having a pin movably attached thereto. A lift linkage has a first end pivotally coupled to the lift lever and a second end fixedly secured on a front shaft. A connecting linkage pivotally couples the front shaft to a rear shaft. Both the front and rear shafts are rotatably coupled to the frame. The lift lever has a first end fixedly secured to the front shaft and a second free end for operation with the operator's foot. The deck is attached to the deck lift mechanism. A foot actuated deck lift mechanism, depressed by the operator's foot, and simultaneously causes the deck to rise and the lift lever to radially pivot. A pin attached to the lift lever rides atop adjustment plates. When the lift lever has pivoted a preset amount, an opening provided in the adjustment plates receives the pin. The pin then locks the deck at a height suitable for transporting the vehicle.
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This application is a continuation of application Ser. No. 10/380,846 filed on Apr. 14, 2003 now abandoned which designated the U.S.
FIELD OF THE INVENTION
This invention is in the field of water purification. More particularly, this invention describes a method and related apparatus to desalinate water by a high recovery reverse osmosis (high recovery RO) process. This novel high recovery reverse osmosis process comprises a sequence of unit operations which permits economical operation and high recovery of feedwater as purified product (up to 90% or greater) even when the feedwater contains a substantial amount of silica.
BACKGROUND OF THE INVENTION
There is increasing demand for purified water for various industries such as semiconductors, pharmaceuticals, and power generation. More frequently, these industries are located near centers of increasing population. These factors combine to put increased demands on available water supplies, and sophisticated water purification systems are needed to process feedwaters of declining quality (increasing salinity). Additionally, economic factors are demanding that water purification systems become less expensive to build and operate, and environmental factors are demanding that these systems utilize available feedwaters with greater efficiency and generate less waste. These demands can be met by providing improved water purification technologies and systems which economically process and recover a substantial fraction of feedwater as a purified product water, even in areas where the quality of the feedwater is declining.
The present invention provides for economical purification of feedwaters which contain significant concentrations (typically 30 ppm or greater) of silica by means of reverse osmosis (RO), and allows recovery of up to 90% or more of feedwaters as purified product without deposition of insoluble, amorphous silica within the reverse osmosis equipment.
Silica is ubiquitous in natural waters. The solubility limit of such silica in most waters is approximately 125 ppm. However, the chemistry of silica is complex; the actual solubility limit of silica in a particular water is variable and dependent upon numerous factors including temperature, pH, ionic composition, ionic strength, etc. When silica-containing waters are concentrated by means of conventional reverse osmosis and the relevant silica solubility limit is exceeded in the RO retentate, silica can precipitate and form “scale” on exposed surfaces of the system. RO system performance is then greatly degraded, and it is expensive and difficult to remove such scale once it has formed. For many natural waters with native silica concentrations of 30-80 ppm, the maximum practical recovery of purified water by conventional RO is limited to about 35-70%.
Former methods for achieving high recovery of silica-containing feedwaters as purified product by means of RO have relied on extensive and expensive pretreatment processing of feedwaters prior to RO, or alternatively on the addition of expensive “anti-scalant” chemicals. Such former preferred methods typically require adjusting the pH of the feedwaters to 10 or greater in order substantially to ionize silica and thereby maintain silica in solution. Levels of hardness in such feedwaters must first be reduced to very low concentrations, however, to prevent a different problem, namely deposition of mineral scale when the pH of the feedwaters is increased to relatively high pH levels. It is desirable also in such former methods to reduce the level of dissolved carbon dioxide in the feedwaters to reduce chemical usage needed for increasing the pH. Reference may be made to the work of Mavrov et al. (Desalination, 123 (1999) 33-43), and to U.S. Pat. No. 5,925,255 (Mukhopadhyay), which are incorporated herein by reference, for further discussions of such former methods.
The success of addition of “silica anti-scalant” chemicals to RO feedwaters is generally limited to applications producing RO retentates with not more than about 200-300 ppm silica. Thus high recovery (e.g., 90% or greater) of feedwaters containing significant concentrations of dissolved silica is generally not possible with silica anti-scalants. Reference may be made to Darton (Desalination, 124 (1999) 33-41), which is incorporated herein by reference.
SUMMARY OF THE INVENTION
A novel process and related apparatus for removal of silica from aqueous solutions is provided herein. In one aspect of the present invention, the pH of a silica-containing solution is adjusted to an acidic pH. The acidified solution is then processed through a reverse osmosis apparatus. In one embodiment, the acidified solution has pH between 1 and 6; preferably, the pH is between 2 and 5. The pH is adjusted with either mineral or organic acids. Preferably the acid is hydrochloric acid, sulfuric acid, gallic acid, ascorbic acid or combinations thereof.
In another aspect of this invention, silica-containing aqueous solution is subjected to a pretreatment process prior to the acidification step. The pretreatment process can include conventional reverse osmosis, softening, ion-exchange, flocculation, precipitation, absorption, nanofiltration, electrodialysis, electrodialysis reversal, microfiltration (membrane filtration), electrodiaresis, electrodeionization, filled cell electrodialysis, irradiation and combinations thereof. In yet another aspect of this invention, there is provided a process and apparatus for removal of silica from aqueous solutions. The process includes the steps of: (a) passing silica-containing solution through a pretreatment process to produce a first-treated solution; (b) adjusting the pH of the first-treated solution to an acidic pH to produce an acid-treated solution; and (c) passing the acid-treated solution through a reverse osmosis apparatus according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features of invention may be more fully understood from the following description when read together with the accompanying drawings.
FIG. 1 shows a schematic representation of a process according to this invention.
FIG. 2 schematically illustrates a simplified reverse osmosis apparatus for use in connection with this invention.
DETAILED DESCRIPTION
The present invention permits high recovery of purified water from feedwaters which contain significant concentrations of silica without deposition of silica-containing scale or formation of colloidal silica by first adjusting the pH of such feedwater into the acidic range, and then operating the RO process at acidic pH. The discovery of this invention is surprising in view of the prior art, particularly the publications of Iler which teach that colloidal silica is rapidly formed, and silica scale is rapidly deposited, from silicate solutions when the pH is lowered (reference may be made to R. K. Iler, “The Chemistry of Silica . . . ”, John Wiley & Sons, 1979, pp 83 ff). Without being limited by theory, we have found, contrary to what one would be led to believe by prior art teachings, that under acidic conditions (within an approximate pH range of 1-6), rates of polymerization and/or precipitation of silica from supersaturated solutions of silica (which are produced during RO as the result of concentration of acidic feedwaters which are not initially saturated in silica) are sufficiently slow so that operation of an RO process at high recovery is practical and economical. Former methods for achieving high recovery of silica-containing feedwaters as purified product water without silica deposition utilized equilibrium constraints imposed on polymerization and precipitation of silica at alkaline pH. Again, without being limited by theory, we believe that the present invention instead utilizes kinetic constraints imposed on polymerization and precipitation of silica by operation of an RO process at acidic pH. We therefore believe that the present invention is fundamentally distinct from and operates on different chemical principles than former methods based on comparison of their respective modes of operation.
The present invention does not consume relatively large quantities of base which are necessary to adjust and maintain feedwater at a strongly alkaline pH in former methods. Moreover, since the present invention operates under acidic conditions, extensive pretreatment of feedwater to remove hardness, carbon dioxide, and alkalinity to very low levels is also unnecessary. Growth and viability of many microorganisms present in natural waters is inhibited under acidic conditions, and biofouling concerns are thereby reduced. In an embodiment of this invention, the high recovery reverse osmosis process may be operated successfully on feedwaters which have received relatively minimal pretreatment(s) as compared with conventional methods. This provides economic advantages in terms of both lower equipment costs and lower operating costs.
The present invention is applicable to efficient purification of feedwaters which contain significant levels of natural silica, such as by way of example, groundwaters found in volcanic deposits. This invention is also applicable to treatment of partially-purified waters which still contain significant levels of silica, such as by way of example, from water softening, nanofiltration, electrodialysis and other operations well known in the art. This invention is also applicable to treatment of wastewaters which contain significant levels of silica, such as by way of example, retentates (brines) from conventional RO and nanofiltration operations.
FIG. 1 is a block diagram representing one embodiment of a process according to the present invention. In its simplest embodiment, the present invention may be utilized to process a feedwater directly. In this instance it would include the following sequence of unit operations:
In the foregoing sequence, the term “type 1 treatment” is understood to encompass those standard RO pretreatments prior to conventional RO which would be deemed appropriate and necessary for the particular feedwater at hand by one skilled in the art. Such standard RO pretreatments are those that are ordinary, and appropriate for feedwaters for conventional RO processing. Such standard “type 1” pretreatments might include, for example, simple media filtration, multimedia filtration, microfiltration, ultrafiltration, dechlorination, irradiation, and the like. The latter techniques are primarily physical in nature, and typically do not substantially alter the soluble chemical composition of the feedwater. The nature and amount of acid to be added to the feedwater to adjust the pH into a desirable acidic pH range (acidification) will be determined by the composition of each particular feedwater. In general the present invention operates successfully when feedwater pH is in the range of from about 1 to about 6, and more preferably in the range from about 2 to about 5. The present invention has been operated successfully using both mineral acids (e.g., hydrochloric acid; sulfuric acid), and organic acids (e.g., gallic acid; ascorbic acid) to establish the desired pH.
The reverse osmosis portion of the apparatus used in connection with the present invention is schematically illustrated in FIG. 2 . As seen in FIG. 2 , in its simplest form, the reverse osmosis portion of the high recovery reverse osmosis system comprises a reverse osmosis entrance conduit 12 , a reverse osmosis system 14 comprising reverse osmosis elements, a reverse osmosis retentate exit conduit 16 , and a reverse osmosis permeate exit conduit 18 . By selection of appropriate size and/or number of stages for the reverse osmosis system relative to the volume of acidic pH-adjusted feedwater being processed, one of ordinary skill in this art would understand how to control the concentration of the retentate thereby to adjust the content and recovery of retentate and permeate from the reverse osmosis system as desired.
In another embodiment, the present invention may be utilized to process feedwater which has been previously treated by methods which alter the chemical composition of feedwater, but which do not substantially reduce the amount of silica. In this embodiment, the present invention includes the following sequence of unit operations:
In the foregoing sequence, the term “type 2 treatment”is intended to include those unit operations which would alter the nature and/or the amounts of certain dissolved components in the feedwater without otherwise substantially altering the amount of dissolved silica in the feedwater. Such “type 2” unit operations would include by way of example, softening (as by means of zeolite softening; ion-exchange resin softening; etc.), partial ion-exchange, flocculation, precipitation, absorption, nanofiltration, electrodialysis, electrodialysis reversal, and the like. Additional unit operations which similarly process and affect the feedwater will be apparent to one skilled in the art. It will be apparent, for example, that a combination of a type 1 and a type 2 treatment could be used to pretreat a feedwater.
With certain feedwaters, pretreatment may be desirable to adjust concentrations of certain components of the feedwater which could otherwise adversely affect performance of the high recovery reverse osmosis process of this invention. Such components could be, by way of example, salts which would themselves precipitate and scale the system when concentrated above a certain limit, such as calcium sulfate; components that can promote or catalyze the precipitation of silica, such as magnesium, calcium, aluminum, iron, zinc, fluoride, phosphate ions, boric acid, and the like; and components that can promote precipitation of polymeric silica such as particulates, certain surfactants, polymers, and the like.
In yet a further embodiment, the present invention may be utilized to process a silica-containing wastewater. Such a wastewater may be processed directly, or may optionally be first subjected to a “pretreatment” as described above. In this embodiment the present invention would include the following sequence of unit operations:
(where in FIG. 1 , “Feedwater” is wastewater.)
One example of this embodiment is use of the high recovery reverse osmosis process to concentrate retentate from a nanofiltration operation. A second example is processing of retentate from a conventional RO operation by first treating such retentate by means of electrodialysis reversal (EDR) to provide a concentrated waste stream and a product stream which is substantially depleted of electrolytes. This EDR product stream, which may contain silica in approximately the same concentration as the original RO retentate, can be subsequently processed by high recovery reverse osmosis according to the present invention to provide a high recovery of water without deposition of silica in the system. Further examples include use of high recovery reverse osmosis to recover chemical and mechanical planarization (CMP) wastewater in semiconductor manufacturing operations, cooling tower wastewater (blowdown), and wastewaters to be further processed to comply with zero liquid discharge requirements. Additional examples of this embodiment will be apparent to those skilled in the art.
Again, without being limited by theory, we believe that the present invention utilizes kinetic constraints imposed on polymerization and precipitation of silica at acidic pH to facilitate efficient and stable operation of the high recovery reverse osmosis process while continuously maintaining a retentate stream that is supersaturated with respect to silica. Additional high recovery reverse osmosis process efficiencies, and increased stability of overall high recovery reverse osmosis operation, may be realized if the high recovery reverse osmosis process is periodically interrupted, and the high recovery reverse osmosis system is purged and cleaned in place (CIP) to remove potential silica nucleation sites which may be present. Such potential nucleation sites may be, by way of example, micro-colloidal silica particles, and other silica-containing particulates and deposits. A particularly effective CIP procedure for the high recovery reverse osmosis process includes the following sequence of operations: (1) switch the feed to the high recovery reverse osmosis process from the original feedwater to a cleansing water which is substantially depleted of silica and electrolytes (such as an accumulated portion of the high recovery reverse osmosis product water), and operate with this “clean” feedwater for a sufficient time to reduce the concentrations of silica and electrolytes in the retentate to be approximately the same as those in the “clean” feedwater; (2) add a sufficient amount of a base (such as sodium hydroxide, potassium hydroxide, ethanolamine, and the like) to the “clean” feedwater to raise the pH to 9-11, and soak, circulate, or recirculate this basic-adjusted cleansing water through the high recovery reverse osmosis system for a sufficient time to achieve equilibrium dissolution of any insoluble silica; (3) flush the system with the same basic-adjusted cleansing water used in step 2 above to reduce the concentration of silica in the retentate below its saturation limit at the operational, acidic pH; (4) add a sufficient amount of acid to the “clean” feedwater to reduce the pH back into the desired acidic pH-operating range for the high recovery reverse osmosis process; and, (5) resume high recovery reverse osmosis operation with the original silica-containing feedwater.
During recirculation of the basic CIP solution in step (2) above, silica concentration in the retentate stream may beneficially be monitored. If silica concentration in this recirculation stream exceeds the relevant silica solubility limit in “natural waters”—typically about 125 ppm at ambient conditions—then a portion of this retentate stream should be diverted, and this diverted volume replaced with “clean” feedwater. In this manner, silica concentration in the recirculating stream may be kept below the relevant natural solubility limit, and inadvertent precipitation of silica within the high recovery reverse osmosis system will be prevented when the pH of the recirculating solution is lowered as in step (4) above.
EXAMPLES
Example 1
In a laboratory batch RO experiment using a feedwater which approximates the composition of feedwater at an RO facility in Cape May, N.J. (approx. 60-70 ppm silica; Table 1 below), we performed a 7-fold concentration (85% recovery) of feed after adjusting the pH with 4300 ppm gallic acid, and obtained a clear permeate and a clear, stable retentate supersaturated with silica. The pH of both permeate and retentate was 3.9. The retentate contained 445 ppm silica as determined by the phosphomolybdate method (Hach Series 5000 Silica Analyzer). This silica concentration remained unchanged after 18 hours, thereby demonstrating the surprising stability of this supersaturated solution. After 186 hours under ambient laboratory conditions, the silica concentration in the retentate was still as high as 420 ppm, and the retentate remained clear.
TABLE 1
Composition of a well water (Cape May, NJ)
Ions
mg/L
Sodium:
387
Calcium:
18.9
Magnesium:
6.17
Potassium:
13.6
Chloride:
438
Bicarbonate:
286
Sulfate:
80
Silica:
67.4
pH:
7.1
Conductivity (uS/cm)
2048
Example 2
(a) The same simulated “Cape May, N.J.” feedwater used in Example 1 above was first treated with a weak acid cation exchange resin, and then sparged with nitrogen to displace carbon dioxide. This treated water, with a pH of 2.7, was then concentrated 15-fold (94% recovery) by RO. The permeate had a pH of 2.6 and a silica concentration of 1.2 ppm. The clear retentate had a pH of 3.4 and a silica concentration of 1084 ppm.
(b-e) The procedure of Example 2a was repeated, except that the silica concentration of the feed, the % recovery, and the pH of the treated feedwater immediately prior to concentration by RO were varied. Results for Examples 2a-2e are reported in Table 2 below.
TABLE 2
Feed
approx.
retentate
permeate
[SiO 2 ]
recovery
retentate
[SiO 2 ]
[SiO 2 ]
Ex.
(ppm)
(%)
pH
(ppm)
(ppm)
2a
69.0
94
3.4
1084
1.2
2b
75.2
94
3.3
1122
2.2
2c
71.3
92
5.0
845
1.7
2d*
71.3
92
7.7
278**
2.4
2e*
75.2
92
10.8
960
1.1
*Examples 2d and 2e are considered outside the scope of the present invention based on pH and are presented here for comparative purposes only.
**Example 2d retentate contained visible silica precipitate.
Example 3
Retentate from a conventional RO unit was demineralized by means of electrodialysis reversal (EDR) to give a brine waste and a product stream with the composition indicated in Table 3 below. The pH of this product stream was adjusted to 3.4 with HCl, and it was concentrated to approx. 95% recovery by high recovery reverse osmosis. Retentate from the high recovery reverse osmosis was clear and stable, had a pH of 4.5, and contained 786 ppm silica. The permeate was clear and contained 1.3 ppm silica (pH 3.3).
TABLE 3
Composition of an RO retentate after treatment by EDR
Ions
mg/L
Calcium
25.2
Magnesium
14.3
Sodium
83.2
Potassium
6.9
Bicarbonate
84.7
Sulfate
61.0
Chloride
124.0
Fluoride
0.4
Nitrate
3.5
Silica
41.6
TDS (mg/l)
444.8
Conductivity (uS/cm)
683.8
pH
5.6
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered illustrative and not restrictive, the scope of the invention being described by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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Processes and apparatus are disclosed for producing clear reverse osmosis retentates having silica concentrations which are substantially supersaturated in silica from feedwaters having silica concentrations, without substantial formation of alkali-soluble scale having substantial silica content in the associated reverse osmosis apparatus, by adjusting the pH of such feedwaters to an acidic pH range prior to reverse osmosis in accordance with this invention. Also disclosed are related processes and apparatus for periodically removing minor amounts of alkali-soluble scale having substantial silica content from the apparatus.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention concerns a method of interfacing mechanical and concrete components of a pump comprising a concrete volute, having an axial suction orifice in its lower part and a well in its upper part substantially coaxial with said suction orifice, coaxial upper and lower metal rings, which are fixed in respective recesses provided in the concrete of said well and of said suction orifice, respectively, a sealing ring removably attached to said lower ring, a metal cover having an edge removably attached to said upper ring, a vertical shaft supported axially and rotatably mounted on said cover, and a rotor attached to a lower end of said shaft and having a part facing said sealing ring with a small clearance between them.
2. Desription of the Prior Art
In volute pumps of routine sizes the volute is generally of metal, usually a casting. Beyond a certain size it may be more economical to make the volute from concrete, however, either using formwork, of wood for example, the outside shape of which corresponds to the inside shape of the spiral conduit of the volute, or using prefabricated concrete components which are assembled on site and which, once fitted together, form the volute. In either case concrete is cast around the formwork or the prefabricated components to form the infrastructure of the pumping station (and simultaneously forming the volute in the case where formwork is used).
The best manufacturing and positioning tolerances that can be achieved in civil engineering works are plus or minus 1 cm. These tolerances are incompatible with the tolerances for positioning the mechanical components of the pump, especially the tolerances for positioning the rotor of the pump relative to the stator. For example, the clearance between the sealing ring and the part of the rotor facing said sealing ring has to be in the order of 1 mm. Thus it is not possible to fix the sealing ring and the cover of the pump, which supports the shaft and the rotor, directly to the concrete, in the suction orifice and in the well of the volute, respectively. This is why, in known concrete volute pumps, the sealing ring and the cover are respectively fixed to a lower metal ring and an upper metal ring that have to be embedded in the suction orifice and in the well of the volute, respectively, at extremely precise position, the lower and upper rings forming the interfaces between the concrete volute and the mechanical components of the pump. To this end, during a first phase the lower ring is first positioned relative to the axis of the volute suction orifice and is then wedged approximately in terms of height and level (horizontality). In this position tie rods for anchoring the lower ring are embedded in the concrete.
During a second phase, and using the cover and the rotor of the pump as a jig, the lower ring is then wedged and finally adjusted relative to the geometrical axis of the pump, on the one hand, and the upper ring is wedged and then finally adjusted relative to the lower ring, on the other hand. During a third phase the lower and upper rings are definitely fixed to the concrete. These successive operations of adjusting and fixing the two rings entail masonry works that are also executed in stages, namely:
embedding the tie rods used to anchor the lower ring;
final fixing of the lower ring and finishing off with the inside wall of the volute suction orifice;
final fixing of the upper ring and finishing off with the inside wall of the volute well.
These successive operations entailing works of different kinds (masonry and mechanical adjustments) have the disadvantage of requiring repeated and alternating deployment of differently skilled workforces.
Also, in known concrete volute pumps the sealing ring and the cover are supported directly by the lower ring and by the upper ring, respectively. As a consequence of this, apart from the fact that the two rings have to be positioned in a precise manner (with a tolerance of 1 mm or better), they have also to be machined so as to have surfaces of an appropriate shape and with an appropriate surface finish to receive the sealing ring and the pump cover, respectively. These machining operations are relatively complex and costly, given that, here again, the machining tolerances are in the order of 1 mm or better and in that the two rings are relatively large. The diameter of the lower ring depends on the suction diameter of the pump rotor and that of the upper ring depends on the outside diameter of the rotor. To give an idea of the magnitudes involved, these diameters routinely vary between 1.5 m and 4 m.
An objective of the present invention is to propose a method executing, as a single operation and simultaneously, fitting of the lower and upper rings and the formation of mechanical support surfaces adapted to receive the removable components of the pump (sealing ring and cover), without it being necessary to call in specialists in other disciplines than mechanical engineering and without it being necessary to use precisely machined rings.
SUMMARY OF THE INVENTION
The present invention consists in a method of interfacing mechanical and concrete components of a pump comprising a concrete volute having an axial suction orifice in its lower part and a well in its upper part substantially coaxial with said suction orifice, coaxial upper and lower metal rings, which are fixed in respective recesses provided in the concrete of said well and of said suction orifice, a sealing ring removably attached to said lower ring, a metal cover having an edge removably attached to said upper ring, a vertical shaft supported axially and rotatably mounted on said cover, and a rotor attached to a lower end of said shaft and having a part facing said sealing ring with a small clearance between them, in which method said upper and lower rings are placed simultaneously in the respective recess, each ring is encapsulated with a hardenable resin which is shaped by means of a single mold having upper and lower molding surfaces coaxial with and spaced from each other at an axial distance corresponding to the vertical distance between said edge of said cover and said sealing ring so as to form, once said resin has set, upper and lower annular blocks of resin reinforced by said metal rings and having molded surfaces corresponding to said molding surfaces of said mold and respectively serving to support said cover and said sealing ring.
Other characteristics and advantages of the present invention will emerge more clearly from the following description given with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in vertical cross-section of a concrete volute pump.
FIG. 2 is a view in vertical cross-section of a jig usable to implement the method of the invention.
FIGS. 3 through 6 are views showing to a larger scale the respective details marked A, B, C and D in FIG. 2.
FIG. 7 is a view in vertical cross-section showing the jig from FIG. 2 installed in the volute of the pump.
FIGS. 8 and 9 are views respectively showing to a larger scale the details marked A and B in FIG. 7.
FIGS. 10 and 11 respectively show to a larger scale the details marked B and C in FIG. 7 and respectively illustrate the embedding of the upper and lower rings of the pump.
FIG. 12 is a view similar to FIG. 7 after embedding the upper and lower rings of the pump and following removal of the jig.
FIGS. 13 and 14 respectively show to a larger scale the details marked B and C in FIG. 12, after fixing the cover and the sealing ring respectively to the upper ring and to the lower ring of the pump.
FIGS. 15 and 16 show, to a larger scale than that of FIG. 2, another form of the lower part of the jig that is used to implement the method of the present invention when the sealing ring of the pump has a cylindrical shape.
FIG. 17 is a view similar to FIGS. 15 and 16 showing the cylindrical sealing ring fixed to the lower ring of the pump.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the pump essentially comprises a concrete volute 1 comprising an axial suction orifice 2 and a well 3 which is substantially coaxial with the suction orifice 2; a lower metal ring 4 and an upper metal ring 5 which are embedded in respective recesses 6 and 7 provided in the concrete walls of the suction orifice 2 and the well 3; a sealing ring 8 of metal, bronze for example, or plastics materials, removably attached to the ring 4; a metal cover 9, also known as the pump body backing member, removably attached to the ring 5; a shaft 11 which is supported axially and rotatably mounted on the cover 9 through the intermediary of bearings 12 and 13; and a rotor 14 which is fixed to the lower end of the shaft 11 and the lower part 14a of which faces the sealing ring 8 with a small clearance (approximately 1 mm) between it and the latter.
FIG. 2 shows a jig 15 that can be used for positioning and embedding the two rings 4 and 5 in the recesses 6 and 7, respectively. The jig 15 comprises a cylindrical barrel 15a to the ends of which are fixed, as by welding, for example, annular flanges 15b and 15c. The outside peripheral part of the lower surface of the flange 15b is machined to form a molding surface 15d (FIGS. 3 and 4) which is plane and perpendicular to the longitudinal axis 16 of the jig 15. Also, as shown in FIGS. 3 and 4, a cylindrical skirt 15e the diameter of which is smaller than the outside diameter of the flange 15b is welded to the lower surface of said flange concentrically with the axis 16.
Similarly, the outside peripheral area of the lower surface of the flange 15c is machined to form a molding surface 15f (FIG. 5 and 6) which is plane and perpendicular to the axis 16. As shown in FIGS. 5 and 6, the surface 15f can form part of a ring 15g welded to the edge of the flange 15c. The two molding surfaces 15d and 15f are coaxial with the axis 16 and spaced axially from each other by a predetermined distance corresponding to the vertical distance between the cover 9 and the sealing ring 8.
The ring 5 of the pump is removably attached to the flange 15b by various tension screws 17 such as that shown in FIG. 3, which pass freely through holes 18 in the flange 15b and are screwed into threaded holes 19 in the ring 5. The axes of the holes 18 are situated on a circle centered on the axis 16 of the jig 15. A gap e 1 of between one and a few centimetres is provided between the ring 5 and the flange 15b by means of a small number (three, for example) thrust screws 21 such as that shown in FIG. 4, which are screwed into threaded holes 22 in the flange 15b and bear against the upper surface of the ring 5. Sealing rings 23, of rubber, for example, are disposed around each of the screws 17 and 21. By choosing rings 23 having sufficient stiffness in the axial direction, the rings 23 could equally well serve as spacing rings between the ring 5 and the flange 15b, in which case the thrust screws 21 could be dispensed with.
Similarly, the ring 4 of the pump is removably attached to the outside ring 15g of the flange 15c by means of a number of tension screws 24 such as that shown in FIG. 5 which pass freely through holes 25 in the ring 15g and are screwed into threaded holes 26 in the ring 4. The axes of the holes 25 are situated on a circle centered on the axis 16 of the jig 15. A gap e 2 of between one and a few centimetres is provided between the ring 4 and the ring 15g by a few thrust screws 27 such as that shown in FIG. 6 and/or by sealing and spacing rings 28 disposed around each of the screws 24 and 27 (FIGS. 5 and 6).
After the rings 4 and 5 have been fixed to the flanges 15c and 15b, respectively, in the manner described above, the jig 15 is lowered through the well 3 of the volute 1 until the rings 4 and 5 are respectively level with the recesses 6 and 7 provided in the wall of the suction orifice 2 and in the wall of the well 3, respectively, as shown in FIG. 7. The jig 15 is disposed in such a way that its axis 16 coincides with the axis of the suction orifice 2 and so that the tie rods 29 used to anchor the ring 5 are positioned in the holes 31 provided for them (FIG. 7, detail A and FIG. 8). The jig 15 bears on the annular shoulder 7a of the recess 7 through the intermediary of screw jacks 32 such as that shown in FIG. 9, there being three screw jacks, for example, spaced by 120° at the edge of the flange 15b. Like the screws 21 and 17, the threaded parts of the anchor tie rods 29 and of the screw jacks 32 are protected by sealing and/or spacing rings 23 (FIGS. 8 and 9). The jig 15 is then adjusted in terms of height and levelled by means of the screw jacks 32. A sealing bead 33 (FIGS. 8 and 9) is laid between the lower end of the skirt 15e and the shoulder 7a of the recess 7. Rather than providing a sealing bead 33, the skirt 15e could be made of rubber or its lower edge could be fitted beforehand with a rubber sealing ring.
A resin mortar 34 is then cast into the holes 31 and into the recess 7 up to a level I (FIG. 10) such that the ring 5 is at least partially embedded in the resin mortar. The skirt 15e and the bead 33 prevent the resin mortar from flowing into the well 3. Resin mortar 34 is also cast into the recess 6 up to a level I' (FIG. 11) such that the ring 4 is at least partially embedded in the resin mortar. An annular retaining member 35 of L-shaped cross-section, the inside diameter of which corresponds to that of the suction orifice 2 and which is previously fixed to the annular shoulder 6a of the recess 6, prevents the resin mortar from flowing into the suction orifice 2.
After the resin mortar 34 has set, a hardenable resin 36 is cast into the recess 7 up to a level II (FIG. 10) and into the recess 6 up to a level II' (FIG. 11) such that the rings 4 and 5 are completely embedded and there are obtained two annular blocks of resin the upper surfaces of which are molded by the molding surfaces 15d and 15f, previously coated with an anti-adhesion agent. After the resin 36 has hardened, the screws 17 and 24 and the nuts of the anchor tie rods 29 are removed. Note that during the casting of the resin mortar 34 and during the casting of the resin 36 the screws 17, 21, 24, 27 and 32 and the threaded part of the anchor tie rods 29 were protected against contact with the resin mortar or the resin so that the screws 17 and 24 can be easily unscrewed to detach the jig 15 from the two rings 4 and 5. The jig 15 can then be lifted out of the well 3 of the volute 1.
The resin 36 is chosen to feature high hardness and a good surface state after removal of the mold, that is to say after removal of the jig 15. The resin 36 may be, for example, a CHOCKFAST ORANGE resin as manufactured by the PHILADELPHIA RESIN Corporation. The resin mortar may be, for example, a CHOCKFAST BLUE or CHOCKFAST RED mortar manufactured by the same Corporation. Following removal of the mold, there are obtained two annular blocks whose molded upper surfaces 37 and 38 (FIG. 12) are perfectly coaxial and spaced axially from each other by a predetermined distance corresponding to the vertical distance between the cover 9 and the sealing ring 8 of the pump. The sealing ring 8 is then laid onto the molded surface 38 of the resin block 36, the holes 39 in the ring 8 are aligned with the threaded holes 26 in the ring 4 and the ring 8 is fixed to the ring 4 by screws 41 as shown in FIG. 14. The assembly 9-14 is then lowered as a whole or in parts through the well 3 of the volute 1. The cover 9 comprises in its peripheral region 9a holes 42 the number of which corresponds to the total number of threaded holes 19 and anchor tie bolts 9 of the ring 5. Before the cover 9 is laid on the molded surface 37, the holes 42 are aligned with the anchor tie rods 29 and with the threaded holes 19 in the ring 5 and the threaded parts of the anchor tie rods 29 are then inserted through the corresponding holes 42 and the cover 9 is laid on the molded surface 37. The cover 9 is then fixed to the ring 5 by means of screws 43 which are screwed into the threaded holes 19 and by means of nuts which are screwed onto the anchor tie rods 29.
From the foregoing description it is clear that the two rings 4 and 5 of the pump are positioned and centered in an operation that is much simpler and much faster than previously by virtue of the use of the jig 15 and that the two rings 4 and 5 may be fixed at the same time, without calling in masons, by the mechanical engineers responsible for installing the mechanical components of the pump. Also, given that the sealing ring 8 and the cover 9 are no longer supported directly by the rings 4 and 5, respectively, but rather by the respective molded surfaces 38 and 37, the rings 4 and 5 no longer need to be accurately positioned relative to each other in the axial direction and no longer need to comprise machined parts; instead they may simply consist of cut or cast parts requiring no further finishing.
In the foregoing description the sealing ring 8 was in the shape of a flat ring. In some cases, however, the sealing ring is cylindrical and surrounds the lower part 14a of the rotor 14 of the pump concentrically, with a small radial clearance. In this case the lower part of the jig 15 may be modified as shown in FIG. 15. To the edge of the flange 15c is welded a cylindrical ring 15h coaxial with the axis 16 of the jig 15 (FIG. 2) and which has an outside diameter equal to the outside diameter of the sealing ring. The outside cylindrical surface of the ring 15h forms the molding surface 15f. The ring 15h is extended downwardly by a cylindrical skirt 15i which has an outside diameter slightly smaller than the inside diameter of the suction orifice 2 of the volute. The ring 4' of the pump is also of cylindrical shape and is removably attached to the ring 15h of the jig by tension screws such as the screw 44 shown in FIG. 15, that are screwed into threaded holes 45 in the ring 4'. A gap e 3 is provided between the rings 4' and the ring 15h by thrust screws such as the screw 46 shown in FIG. 15, there being three thrust screws spaced at angles of 120°, for example. Sealing rings 47 are placed around each of the screws 44 and 46. The rings 47 placed around the screws 44 may also serve as spacing rings, in which case the thrust screws 46 may be dispensed with.
After the jig has been positioned relative to the volute 1 as in the embodiment described above, a sealing bead 48 is placed between the cylindrical skirt 15i and the suction orifice 2 as shown in FIG. 16. A resin 36, for example the CHOCKFAST ORANGE resin previously mentioned, is then cast in the recess 6 in order to embed completely the ring 4'. At the same time the upper ring 5 of the pump is embedded in the way previously described. When the resin 36 has hardened, the screws 44 and 46 are removed and the jig 15 is lifted out through the well 3 of the volute as in the embodiment previously described. Removal of the mold leaves a cylindrical molded surface 38' (FIG. 17) adapted to receive the cylindrical sealing ring 8'. This comprises holes 49 that are aligned with the threaded holes 45 in the ring 4' and into which are inserted screws 51 for fixing the sealing ring 8' to the ring 4'.
It is to be understood that the embodiments described hereinabove have been given by way of illustrative and non-limiting example only and that numerous modifications may readily be proposed by those skilled in the art without departing from the scope of the present invention.
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A method of interfacing mechanical and concrete components of a pump comprising a concrete volute entails simultaneously placing two metal rings in recesses provided in a suction orifice and in a well of the volute of the pump. This is done using a jig having two molding surfaces spaced from each other by a predetermined axial distance and placed at a position near the rings. Each of the rings is embedded in a hardenable resin which is molded by the two molding surfaces on the jig. This forms two annular resin blocks having molded surfaces. These molded surfaces are used as respective support surfaces for a sealing ring and for a cover in which the rotor of the pump is rotatably mounted.
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This application is the national phase under 35 U.S.C. §371 of prior PCT International Application No. PCT/SE97/00484 which has an International filing date of Mar. 21, 1997 which designated the United States of America, the entire contents of which are hereby incorporated by reference.
FIELD OF INVENTION
This invention relates to the use of dextromethorphan, optionally encompassing salts, prodrugs and metabolites thereof, for the manufacturing of a medicament to be administered transdermally for achieving an antitussive effect and to methods of treating diseases being treatable with antitussive agents by transdermal administration of dextromethorphan, optionally encompassing salts, prodrugs and metabolites thereof.
BACKGROUND
Dextromethorphan, (+)-3-methoxy-17-methyl-9a,13a,14a-morphinan, is a synthetic opioid. Normally the hydrobromide of dextromethorphan is used pharmacologically, although other salts are not excluded. The preparation of (+)-3-methoxy-17-methyl-9a,13a,14a-morphinan was disclosed in U.S. Pat. No. 2,676,177 (SCHNIDER ET AL) and in Häfliger et al., Helv. Chil. Acta 39, 1956: 2053.
Clinically, in connection with tussometri dextromethorphan has shown a significant effect on reducing coughing frequency as well as intensity compared to placebo at a dosage of 40 mg perorally, an effect of the same order of magnitude as 60 mg codeine, see Mathys, Schweiz Med Wschr 1985;115: 307-11. However dextromethorphan has not shown any antitussive effect upon inhalation of 1-30 mg. Also demethylated metabolites, including dextrorphan, have shown cough suppressing effects, see Martindale, The Pharmaceutical Press, London, 1993: 746.
Dextromethorphan is a safe drug as concluded by Bem J. L., Peck R., Drug safety, 1992 (7): 190-199. Dextromethorphan has fewer side-effects than the other antitussive agents codeine and noscapine.
Dextromethorphan is rapidly converted in the liver into inter alia dextrorphan, which also has a clinical activity, see above, however on other receptors than dextromethorphan. Pharmacokinetic studies have shown that populations can be divided into two main groups based on their ability to metabolize dextromethorphan, the so called poor metabolizers and the extensive metabolizers, see e.g. J.-C Duché et al., “Dextromethorphan O-demethylation and dextrorphan glucoronidation in a French population”, Int J. of Clin Pharm, Therapy and Tox, 1993; 31(8):392-98, J. S. Marinac et al., “Dextromethorphan Polymorphic Hepatic Oxidation (CYP2D6) in Healthy Black American Adult Subjects”. Therapeutic Drug Monitoring, Raven Press New York, 1995; 17:120-124, and Chen et al., “Dextromethorphan: pharmacogenetics, and a pilot study to determine its disposition and antitussive effect in poor and extensive metabolisers”, Eur. J. Pharmacol 1990; 183(4):1573-74. Around 10% of the population are slow metabolizers of dextromethorphan and therefore more easily have side-effects, most often being fairly mild, such as drowsiness, confused speech, nausea and dizziness, although serious in case of overdosing, such as excitation, confusion and respiratory depression. The clinical implications of these findings are that different dosing regimes should be used for the individual patients. As this difference is related to the first-pass metabolism in the liver it is highly advantageous to avoid the first pass passage of the drug.
As metabolism following transdermal delivery of a drug is of much lesser extent than after oral delivery of the drug it is highly desirable to deliver dextromethorphan through the transdermal route.
When administered perorally dextromethorphan undergoes an extensive first-pass metabolism, i.e. the oral bioavailability is low meaning that fairly high doses need to be given. Absolute bioavailabilities have been reported as low as 3.8% in dogs, see Barnhart J. W., Massad E. N., “Determination of dextromethorphan in serum by gas chromatography”, J.
Chromatography 1979, 163: 390-395. Other reported values are 7% and 18%, see Dixon et al., Res. Commun. Chem. Pathol. Pharmacol., 1978;22:243).
The half-life of dextromethorphan is around 4-6 hours, which means that the plasma concentration-varies substantially during day and night unless dextromethorphan is delivered frequently, by peroral administration at least 3-4 times daily. Even then the sleeping pattern of the patient will be disturbed by cough attacks as the antitussive effect will not remain through a whole night. The sleeping pattern disturbance, as well as the other adverse effects mentioned above, are removed or reduced with the present invention being transdermally administered dextromethorphan as antitussive agent. The above transdermal administration can be used for human beings as well as animals.
PRIOR ART
Transdermal administration of dextromethorphan, but not as antitussive agent, is known, e.g. from U.S. Pat. No. 5,260,066 (CARLTON ET AL.) for cryogel bandages. Here dextromethorphan is administered only to sites of trauma, column 2, lines 59-60, whereas in the present invention dextromethorphan is only administered to intact skin. Further U.S. Pat. No. 5,260,066 just mentions dextromethorphan in a long listing of drugs. There are no examples showing administration of dextromethorphan. Further U.S. Pat. No. 5,260,066 does not even mention that an antitussive effect should be achieved. Supposedly this is not what is desired upon administration to sites of trauma
WO 91/15261 (MEDTRONIC) concerns iontophoretic devices which depend upon the physical activity of the patient and just mentions dextramethorphan on page 4, line 32-33, as a drug which could possibly be administered via said devices. Buth there are no examples showing that this is at all possible with said devices. Dextromethorphan is further not mentioned in the claims. Thus, WO 91/15261 simply concerns a very special device, requiring measurement of patient activity (page 4, lines 24-25, which means an activity sensor (page 11, lines 10-17). This is a non-useful device for administering dextromethorphan as the administration takes place once the patient starts coughing—which is too late. Thus, WO 91/15261 is in all respects an irrelevant and non-enabling reference. WO 91/15261 corresponds to U.S. Pat. No. 5,213,568 (LATTIN ET AL.) which thus also is a non-relevant reference.
WO 95/05416 (CYGNUS THERAPEUTIC SYSTEMS) discloses mucoadhesive devices for administration of drugs, inter alia dextromethorphan, to a body cavity, specifically to the oral cavity. It does not relate to transdermal administration.
U.S. Pat. No. 4,783,450 (FAWZI ET AL.), corresponding to WO 88/07871 (WARNER LAMBERT) discloses the use of lecithin for enhancing transdermal penetration. U.S. Pat. No. 4,645,502 (GRACE ET AL.) discloses a specific system for transdermal delivery of highly ionized fat insoluble drugs. WO 93/07902 (RICHARDSON-VICKS, INC.) discloses compositions for topical application comprising a drug and a non-ionic polyacrylamide. WO 93/07903 (RICHARDSON-VICKS, INC.) discloses compositions for topical application comprising a drug and a high molecular weight cationic polymer. EP 0 351 897 (THE PROCTER & GAMBLE COMPANY) discloses pharmaceutical compositions comprising a drug, a fatty acid and an alkane diol. EP 0 349 763 (BRISTOL-MYERS COMPANY) discloses a composition for trans-dermal administration comprising a drug and an imidazole derivative as penetration enhancer. U.S. Pat. No. 4,888,354 (CHANG ET AL.) discloses compositions for topical administration of drugs present in both free and acid addition salt form. U.S. Pat. No. 4,557,934 (COOPER) discloses topical compositions comprising a drug and 1-dodecyl-azacycloheptan-2-one as penetration enhancing agent In all these patent documents dextromethorphan is just mentioned in lengthy listings of drugs which theoretically might be included in the claimed compositions.
Anyhow there are nowhere in the above patent documents any examples of formulations including dextromethorphan as an antitussive agent. Thus use of transdermally administered dextromethorphan as an antitussive agent has neither been contemplated nor shown.
The only non-patent literature reference relating to transdermal delivery of dextromethorphan being known to the applicant is Mahjour et al., J. Controlled Release 14 (3); 1990:243-252. The contents thereof essentially corresponds to the above mentioned patent U.S. Pat. No. 4,783,450 (FAWZI ET AL.).
Hence the present invention, as further described below, is both new and inventive over prior art.
OBJECTS OF THE INVENTION
Disturbance of sleeping pattern and the other above mentioned disadvantages are removed or reduced when dextromethorphan is administered transdermally.
Accordingly, a first object of the present invention is to provide a device for transdermal administration use of dextromethorphan, optionally encompassing salts, prodrugs and metabolites thereof, for achieving an antitussive effect The administration can be to a human being or to an animal. The antitussive effect is for treating, including suppressing, any kind of irritant cough, such as, but not exclusively, non-productive and dry coughs.
A second object of the invention is to provide use of an antitussive compound comprising dextromethorphan for the manufacture of a composition to be administered transdermally for treating cough or conditions associated with cough.
A third object of the invention is to provide a method of treating diseases, in humans or animals, which are treatable with antitussive agents by administering dextromethorphan transdermally.
Other objects of the invention will become apparent to one skilled in the art, and still other objects will become apparent hereinafter.
SUMMARY OF THE INVENTION
The present invention relates to transdermal administration of dextromethorphan, optionally encompassing salts, prodrugs and metabolites thereof for achieving an antitussive effect. This effect is primarily achieved through the systemic effect of dext horphan. Anyhow other actions are not excluded.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1D are schematic drawings of different types of devices for transdermal delivery of drugs.
FIG. 2 is a diagram showing in vitro skin permeation of dextromethorphan from different solvents according to Example 3.
FIG. 3 is a diagram showing in vitro permeation of dextromethorphan through different membranes in accordance with Example 4.
FIG. 4 is a diagram showing in vitro release of dextromethorphan from different transdermal systems in accordance with Examples 5 and 6.
DETAILED DESCRIPTION OF THE INVENTION
Transdermal delivery of drugs can be achieved from topical products such as ointments or cremes or from transdermal devices. The present invention relates to administration via transdermal devices, which usually are called transdermal patches.
Devices usable as transdermal patches can be categorized in many different ways. A comprehensive categorization of transdermal devices is found in Steven Wick “Developing A Drug-In-Adhesive Design For Transdermal Drug Delivery”, Adhesives Age, 1995; 38(10):18-24, which hereby is incorporated by reference. Wick essentially divides transdermal devices into the below four main groups:
the reservoir type, in which the drug is placed in a liquid or a gel and delivered to the skin across a rate-moderating membrane;
the matrix type, in which the drug is placed within a non-adhesive polymeric material, typically a hydrogel or soft polymer;
the drug-in-adhesive type, in which the drug is placed within an adhesive polymer;
the multi-laminate type, which is similar to the drug-in-adhesive design but which incorporates an additional layer of pressure sensitive adhesive to cover the entire device and affix it to the skin.
The above four main types of transdermal devices are schematically illustrated in FIG. 1A-1D.
A fifth important type, not mentioned by Wick is the iontophoretic type, in which an electrical potential gradient is used for transferring the drug through the skin—see further e.g. Parminder Singh et al, “lontophoresis in Drug Delivery: Basic Principles and Applications”, Critical Reviews in Therapeutic Drug Carrier Systems, 1994; 11 (2&3):161-213.
The above split-up into groups is not very strict as variations and combinations of each may be envisaged. So may a multi-laminate type device encompass a device with many layers in a sandwich construction, such as the drug in one layer, excipients such as enhancers in a further layer, a membrane in another layer and an adhesive in still another layer. Or it could be composed of several drug-in-adhesive layers or combinations of the above layers.
The liquid or gel used in the above reservoir type device could be hydrophilic or lipophilic, such as water, alcohols, mineral oils, silicone fluids, various copolymers, such as ethylene vinyl acetate, vinyl acetate or polyvinyl alcohol/;polyvinyl pyrolidine. The reservoir may also include dyes, inert fillers, diluents, antioxidants, penetration enhancers, stabilizers, solubilizing agents and other pharmacologically inactive pharmaceutical agents being well known in the art.
The adhesives used are generally of three types, being the rubber type, encompassing inter alia polyisobutylenes, the acrylate type and the silicone type. The adhesives may be chemically modified, may have a wide range of molecular weights. To the adhesive could be added several types of excipients such as fillers, stabilizers, plasticizers, buffering agents, penetration enhancers, penetration retarders, solubilizing agents and other pharmaceutical ingredients being well known in the art.
Polymer films which may be used for making the rate-moderating membrane include, without limitation, those comprising low density polyethylene, high density polyethylene, ethyl vinyl acetate copolymers and other suitable polymers.
The backing layer serves the purposes of preventing passage of the drug or environmental moisture through the surface of the patch distant from the skin, and also for providing support for the system, where needed. The backing layer may be chosen so that the end product is appealing to the users, whether children, adults, elderly people or other customer groups. The backing layer is impermeable to the passage of dextromethorphan or inactive ingredients being present in the formulation and can be flexible or nonflexible. Suitable materials include, without limitation, polyester, polyethylene terephthalate, some type of nylon, polypropylene, metallized polyester films, polyvinylidene chloride and aluminium foil.
The release liner can be made of the same materials as the backing layer.
As will be clear further below the invention according to the present application encompasses administration of dextromethorphan via all hitherto known types of devices for transdermal administration. Mainly the above categorization will be adhered to in this application. Anyhow this does not exclude that transdermal devices which might fit better according to some other categorization also are included in the present invention.
It is well known in the art that the properties of the skin as such influence the penetration of the drug through the skin into the systemic circulation. It could thus be said that the skin controls the drug penetration rate. Anyhow as the skin as such is no part of the present invention the behaviour of the skin in connection with transdermal administration will not be discussed in detail. It is also well accepted in the art that when rate controlling properties are attributed to a transdermal device is meant properties associated with the release rate from the device as such. It is also evident that when a transdermal device is designed to exhibit a certain release performance the properties of the skin need be taken into consideration during the design process. The rate control ability is often a very important feature for a transdermal device in order to deliver the correct drug amount to the patient at the correct time. Thereby maximum efficacy is achieved while side effects are minimized. Many factors influence the rate control ability of a transdermal device. In the below Table 1 the most important such factors are listed and their influence in the respective device type is marked. A plus sign indicates that the influence is strong The absence of a plus sign does not exclude that the corresponding has at least some influence.
TABLE 1
Type of device
Drug-in-
Multi-
Factor
Reservoir
Matrix
adhesive
laminate
Polymer type(s)
+
+
+
+
Modification of the
+
+
+
polymer(s)
Activity, i.e. con-
+
+
+
+
centration, of drug
e.g. supersaturation
Additives in polymer(s)
Enhancer(s)
+
+
+
+
Cyclodextrine(s)
+
+
+
+
Retarder(s)
+
+
+
+
pH-adjustment
+
+
+
+
Solubilizer(s)
+
+
+
+
Emulsifier(s)
+
+
+
Membrane(s)
+
Hydrophilic
+
Lipophilic
+
Thickness
+
Pore size
+
Density
+
Chemical stabi-
+
+
+
+
lizer(s)
As a comparably high loading of dextromethorphan is needed for achieving the desirable therapeutic effect the reservoir type device and the multi-laminate type device, including several drug-containing layers, are presently considered to be the best modes for carrying out the present transdermal delivery of dextromethorphan.
It is also desirable to include, at least in some device types, one or more transdermal penetration enhancing substance(s) in order to increase the amount of dextromethorphan which may penetrate the skin and which eventually may reach the systemic circulation. Enhancers suitable in the present invention may be categorized in the below groups, although enhancers not belonging to any of these groups are not excluded.
alcohols, such as short chain alcohols, e.g ethanol and the like, long chain fatty alcohols, e.g. lauryl alcohols, and the like, and polyalcohols, e.g. propylene glycol, glycerine and the like;
amides, such as amides with long aliphatic chains, or aromatic amides like N,N-diethyl-m-toluamide;
amino acids;
azone and azone-like compounds;
essential oils, i.e. essential oils or constituents thereof, such as 1-carvone, 1-menthone and the like;
fatty acids and fatty acid esters, such as oleic acid, lauric acid and the like, further esters of fatty acids, such as isopropyl myristate, and various esters of lauric acid and of oleic acid and the like;
macrocyclic compounds, such as cyclopentadecanone and cyclodextrins;
phospholipid and phosphate compounds, such as phospholipids;
2-pyrrolidone compound,; and
miscellaneous compounds, like sulphoxides, such as dimethyl sulphoxides, and fatty acid ethers, such as Laureth-9 and polyoxylaurylether.
Combinations of enhancers from different groups in the above cathegorization may prove very useful and efficient.
For overviews of enhancers, see further e.g. G.C. Santus et al., “Transdermal enhancer patent literature”, Journal of Controlled Release, 1993;25:1-20 and Eric W. Smith et al., “Percutaneous penetration enhancers”, CRC Press Inc., 1995.
DETAILED DESCRIPTION OF THE INVENTION
The following examples are intended to illustrate but not to limit the scope of the invention, although the embodiments named are of particular interest for our intended purposes.
Materials and apparatus used in the examples
Materials
Dextromethorphan hydrobromide, Roche
Sodium hydroxide, Merck
b-cyclodextrine, Roquette
Hydroxypropyl-b-cyclodextrine, Janssen
Isopropyl myristate, Merck
Propylene glycol, Merck
Azone, Discovery Therapeutics Inc.
Ethanol 99.9%, De Danske Spritfabrikker
Ethyl acetate, Merck
Disodiumhydrogenphosphate, 2 H 2 O, Merck
Polycarbonate membrane 0.2 μm in pore diameter, Whatman
Polycarbonate membrane 0.6 μm in pore diameter, Whatman
Polyester membrane 0.2 μm in pore diameter, Whatman
Polyester membrane 0.6 μm in pore diameter, Whatman
Cotran 9702, 3M
Cotran 9711, 3M
Polyester film S 2016, Rexam Release
Polyester film Scotchpak 1220, 3M
Polyester film Scotchpak 1109, 3M
MA-24 Medical Grade Adhesive, Adhesives Research Inc.
ETA-2 Medical Grade Adhesive, Adhesives Research Inc.
Eudragit RL100, Röhm GmbH Chemische Fabrik
Eudragit NE 30 D, Röhm GmbH Chemische Fabrik
Plastoid E35H, Röhm GmbH Chemische Fabrik
Polyvidone 90, BASF
Durotak 387-2287, National Starch and Chemical B.V.
Apparatus
Franz diffusion cells
Coating equipment: RP Print Coat Instrument LTD., Type KCC 202 Control Coater System with vacuum bed and rods (100 and 400 μm)
UV-spectrophotometer
Drug Release Apparatus 5, paddle over disk, described in USP 23 p. 1797 HPLC-device:
LKB 2248 pump
LXB 2141 variable wavelength monitor
LKB 2221 integrator
LKB 2157 autosampler (20 μl injected)
Precolumn, 4 cm×4.6 mm i.d., packed with Nucleosil 5 C 18
Analytical column, 12 cm×4.0 mm i.d., packed with Nucleosil 5 C 18
The columns were eluted isocratically at ambient temperature with a mobile phase consisting of water-acetonitrile-acetic acid (600:400:1 v/v) with 0.02M potassium nitrate and 0.005M
1-octanesulfonic acid sodium salt. The flow rate was 1.2 ml/min and the column effluent was monitored at 280 nm.
EXAMPLE 1
Preparation of dextromethorphan base (in the following called dextromethorphan).
100 g of dextromethorphan hydrobromide was dissolved in 1000 ml of demineralized water. While stirring, the solution was heated to 60° C., until the solution was clear, and approximately 350 ml of sodium hydroxide (1M) was added (the addition of sodium hydroxide (1M) was stopped when precipitation no longer occurred) The precipitated mixture was refrigerated for at least 4 hours. The mixture was vacuum filtered and dried in a drying oven at 25° C. The resulting dextromethorphan passed the test of USP 23, p. 481.
EXAMPLE 2
Analysis of the receptor solutions described in Examples 3 and 4.
Quantitative determination of dextromethorphan in the receptor solution samples from the skin permeation studies in Example 3 and from the membrane permeation studies in Example 4 was done by the HPLC method described under Apparatus.
EXAMPLE 3
In vitro skin permeation studies from solutions of dextromethorphan.
Solution 1
A saturated dextromethorphan solution in demineralized water.
Solution 2
A saturated dextromethorphan solution in demineralized water containing 10 mg/ml of b-cyclodextrine.
Solution 3
A saturated dextromethorphan solution in demineralized water containing 10 mg/ml of hydroxypropyl-b-cyclodextrine.
Solution 4
50 mg dextromethorphan was dissolved in 5 ml isopropyl myristate.
Solution 5
50 mg dextromethorphan was dissolved in 5 ml propylene glycol.
Solution 6
50 mg dextromethorphan was dissolved in 5 ml propylene glycol containing 50 mg/ml of azone.
Solution 7
250 mg dextromethorphan was dissolved in 5 ml ethanol.
Solution 8
150 mg dextromethorphan was dissolved in 5 ml ethyl acetate.
In vitro permeation of dextromethorphan from the solutions 1, 2, 3, 4, 5, 6, 7 and 8 through dermatomed pig skin was investigated in Franz diffusion Cells.
Skin pieces with a thickness of approximately 765 μm were dermatomed from full thickness pig skin and mounted in glass diffusion cells with an available diffusion area of 1.8 cm 2 . Pig skin is a fully accepted model for human skin. The solutions were applied separately on the skin surfaces and the dermal sides were all exposed to 12.1 ml receptor solution consisting of a 0.05M phosphate buffer solution of pH 7.4 equilibrated to 37±1° C.
Permeation of dextromethorphan was followed by removing samples periodically and measuring the concentration by the HPLC method according to Example 2. The cumulative amount of dextromethorphan appearing in the receptor solution versus time is shown in FIG. 2 . An increase in the permeated amount of dextromethorphan is seen in the following order: Water, isopropyl myristate, propylene glycol, propylene glycol containing 5% azone, water containing 1% hydroxpropyl-b-cyclodextrine, water containing 1% b-cyclodextrine, ethanol and ethyl acetate used as solvents. The maximal observed flux of dextromethorphan is 21 μg/cm 2 /h and the range is from approximately 0.5 to 21 μg/cm 2 /h.
The results show that dependent on the used solvent it is possible to optimize the flux of dextromethorphan through the skin. Both by using ethanol and ethyl acetate and by addition of cyclodextrines, a remarkable increase in the fluxes is seen.
EXAMPLE 4
In vitro permeation studies across artificial membranes from solutions of dextromethorphan, imitating the reservoir type transdermal device.
Solution 9
50 mg dextromethorphan was dissolved in 5 ml propylene glycol.
Solution 10
50 mg dextromethorphan was dissolved in 5 ml ethanol.
In vitro permeation of dextromethorphan from the solutions 9 and 10 across 6 different types of artificial membranes was investigated in Franz diffusion cells.
Artificial membranes of the following types were studied: Whatman 0.2 μm PC (polycarbonate), Whatman 0.6 μm PC (polycarbonate), Whatman 0.2 μm PET (polyester), Whatman 0.6 μm PET (polyester), Cotran 9702 (ethylene vinyl acetate film) and Cotran 9711 (microporous polyethylene film). The membranes were mounted in glass diffusion cells with an available diffusion area of 1.8 cm 2 . Solution 9 was applied on the surface of all the above membranes while solution 10 only was applied on Cotran 9702 and Cotran 9711. The opposite sides of the membranes were all exposed to 12.1 ml receptor solution consisting of a 0.05M phosphate buffer solution of pH 7.4 equilibrated to 37±1° C.
Permeation of dextromethorphan was followed by removing samples periodically and measuring the concentration by the HPLC method according to Example 2. The cumulative amount of dextromethorphan appearing in the receptor solution versus time is shown in FIG. 3 . An increase in the permeated amount of dextromethorphan was seen in the following order of used membranes: Cotran 9702, Whatman 0.2 μm PC, Whatman 0.2 μm PET, Cotran 9711, Whatman 0.6 μm PC and Whatman 0.6 μm PET. The results show that it is possible to control the release rate of dextromethorphan through different membrane type. On this basis it is easy to produce a reservoir type device by sealing the membrane to a backing layer being impermeable to dextromethorphan and other components of the formulation.
EXAMPLE 5
Transdermal drug delivery systems with dextromethorphan or dextromethorphan hydrobromide as the active substances
System 1 (drug-in-adhesive type, acrylate)
2.5 g dextromethorphan was suspended in 20 g ETA-2 Medical Grade Adhesive to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, a polyester film, Scotchpak 1109, was laminated onto the dried drug gel. The resulting sheet was die-cut into patches which was kept at room temperature until use. The concentration of dextromethorphan was approximately 1.5 mg/cm 2 .
System 2 (drug-in-adhesive type, acryate)
5 g dextromethorphan was dissolved in 10 ml ethanol. The solution was added to 15 g Durotak 387-2287 to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, a polyester film, Scotchpak 1220, was laminated onto the dried drug gel. The resulting sheet was die-cut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 2 mg/cm 2 .
System 3 (multi-laminate type, waterbased acrylate)
2.4 g dextromethorphan hydrobromide was dispersed in a mixture of 3 g Eudragit NE 30 D and 45 g Plastoid E35H to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, an adhesive layer consisting of Plastoid E35H (wet layer=100 μm) coated on a polyester film, S 2016, was laminated onto the dried drug gel. The polyester film, S 2016, in contact with the drug gel was removed, and Scotchpak 1109 was laminated onto the drug gel as the backing The resulting sheet was diecut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 1 mg/cm 2 .
System 4 (drug-in-adhesive type, acrylate)
2.5 g dextromethorphan was suspended in 20 g Durotak 387-2287 to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, a polyester film, Scotchpak 1109, was laminated onto the dried drug gel. The resulting sheet was die-cut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 2 mg/cm 2 .
System 5 (drug-in-adhesive type waterbased acrylate)
2.4 g dextromethorphan hydrobromide was dispersed in a mixture of 3 g Eudragit NE 30 D and 45 g Plastoid E35H to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, a polyester film, Scotchpak 1109, was laminated onto the dried drug gel. The resulting sheet was die-cut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 1 mg/cm 2 .
System 6 (multi-laminate type, acrylate)
2.5 g dextromethorphan was dissolved in 10 ml ethanol. The solution was added to a mixture of 12.8 g Eudragit gel (50% Eudragit RL 100 swelled in ethanol), 12.8 g PVP gel (20% Polyvidone 90 swelled in ethanol) and 4 g propylene glycol to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer 400 μm). After drying at 80° C. for 10 minutes, an adhesive layer consisting of Plastoid E35H (wet layer 100 μm) coated on a polyester film, S 2016, was laminated onto the dried drug gel. The polyester film, S 2016, in contact with the drug gel was removed, and Scotchpak 1109 was laminated onto the drug gel as the backing The resulting sheet was die-cut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 0.5 mg/cm 2 .
System 7 (drug-in-adhesive type, polyisobutylene)
2.5 g dextromethorphan was suspended in 10 g MA-24 Medical Grade Adhesive to give the drug gel. The drug gel was solvent cast onto a polyester film, S 2016, by means of the coating equipment (wet layer=400 μm). After drying at 80° C. for 10 minutes, a polyester film, Scotchpak 1220, was laminated onto the dried drug gel. The resulting sheet was die-cut into patches which were kept at room temperature until use. The concentration of dextromethorphan was approximately 2 mg/cm 2 .
In vitro release studies according to Example 6 were carried out on the systems 1, 2, 3, 4, 5, 6 and 7 described above. The results of these studies are shown graphically in FIG. 4 .
The results show that different release profiles can be achieved from different types of devices.
EXAMPLE 6
In vitro release studies of the transdermal drug delivery systems according to Example 5.
The apparatus used was Apparatus 5, paddle over disk described under Apparatus. Patches of 7.1 cm 2 were applied to the disk assembly, using a suitable adhesive, with the release surface facing up. The dissolution medium used was 600 ml of 0.05M phosphate buffer pH 7.4 equilibrated to 32±0.5° C. Samples were withdrawn at 1, 2, 4, 8 and 24 hours, respectively.
The amount of dextromethorphan in the samples was determined by UV-spectrophotometry at 280 nm and the concentration of the respective systems was expressed in mg dextromethorphan per cm 2 .
A reservoir type device may be manufactured by heat sealing a membrane such as described in the above Example 4 to a backing containing the drug in a suitable vehicle.
A iontophoretic type device may be manufactured essentially according to embodiments disclosed in e.g. Parminder Singh et al, “Iontophoresis in Drug Delivery: Basic Principles and Applications”, Critical Reviews in Therapeutic Drug Carrier Systems, 1994; 11 (2&3):161-213. The administration of dextromethorphan is not disclosed in this reference. Anyhow it lies within the present invention to modify, using the disclosure in the present application, the embodiments according to said reference to become suitable for the administration of dextromethorphan.
The above examples show that it is possible to administer dextromethorphan and to control its release rate using all known types of devices for transdermal drug administration.
Some prodrug type derivatives of dextromethorphan can be used according to the present invention for obtaining the desirable antitussive effect Such derivatives may include other ethers in the 3-position than the methoxy-group. By modification in the 3-position compounds with favourable permeation rates through human and animal skin may be obtained. Upon permeation of stratum corneum dextromethorphan or dextrorphan may be generated through metabolic reactions. Other salts than the hydrobromide could be used as it is known that more lipophilic anions than bromide may generate ion-pairs with more favourable skin permeation rates.
It is evident that the above mentioned Examples may be modified to encompass also metabolites, different salts and prodrugs of dextromethorphan.
Various carriers and vehicles for dextromethorphan may be used in the transdermal administration. One such carrier is cyclodextrin, especially b-cyclodextrin. Dextromethorphan can be bound in the cavities of cyclodextrins to form so called inclusion complexes. Binding dextromethorphan to a cyclodextrin leads either to increased delivery rate or to decreased delivery rate depending on the dextromethorphan-cyclodextrine ratio.
It is within the present invention to add to the transdermal device substances being fragrances or other substances with agreeable smell in order to give the device a smell appealing to the user.
As the period of time from the first application of a transdermal device according to the present invention until a therapeutically effective serum level of dextromethorphan is achieved is in the order of up to 3 hours the complementary and concomitant use of another administration form may be of value. Oral, sublingual, buccal, nasal, pulmonary and rectal, and possibly other transmucosal, administration of dextromethorphan results in that the drug reaches the system more rapidly than through the transdermal route. As mentioned above said non-transdernal administration forms have the disadvantage of a lower bioavailability than the transdermal form of administration. Anyhow this disadvantage, and problems related thereto, may be temporarily tolerated if an antitussive effect is desirable in the period of time before the therapeutic effect is achieved from the transdermal device.
One suitable use of the mentioned forms of administration is to administer dextromethorphan through the oral, sublingual, buccal, nasal, pulmonary or rectal, or possibly other transmucosal routes approximately at the same time as the first transdermal device is applied. Thereafter new transdermal devices are applied to ensure the correct plasma level without further administration through the oral, sublingual, buccal, nasal, pulmonary and rectal, or possibly other transmucosal, route. The above concomitant use of different administration forms is especially useful in certain situations, such as, but not exclusively, some time prior to oral presentations, attendance to conferences and visits to theatres, concerts and church. It is thus feasible to market set of formulations including devices for transdermal administration as well as devices or formulations for oral, sublingual, buccal, nasal, rectal, pulmonary and rectal, and possibly other transmucosal, administration of dextromethorphan.
Another envisageable concomitant use according to the present invention is to apply a second transdermal device while a priorly applied first transdermal device is still adhered to the patient's skin while still delivering some amount of the drug. The utility behind this use is as follows. Suppose that the transdermal devices used deliver the drug during 36 hours. The first evening one such device is applied. The following evening the device still delivers the drug, though usually with a lower flux rate than earlier. If now this second evening a second transdermal device is applied while the first one is left on the skin the fluxes from the first and second device will add to a useful flux as the flux from the first device successively decreases while the drug from the second device only reaches the systemic circulation after some hours. By using transdermal devices in this way a more stable therapeutically effective plasma level of the drug during an extended period of time is achieved than if for example are used devices delivering for 24 hours and being replaced every 24 hours. Also other useful combinations of concomitantly used transdermal devices are envisageable.
As it might be advantageous that the cough now and then should be allowed to occur it might be desirable not to treat or prevent cough during too long continuous periods of time. It is within the present invention to administer dextromethorphan in such a way that a therapeutically effective systemic level of dextromethorphan prevails mainly during those periods of time during day and night when it is desirable that cough should be treated or prevented, and, consequently, in such a way that a less than therapeutically effective systemic level of dextromethorphan prevails mainly during those periods of time during day and night when it is not desirable that cough should be treated or prevented. The above object is achievable by applying the transdermal device at the appropriate time during day or night in combination with designing the device with the appropriate release profile.
Dosage
The maximal dose of dextromethorphan to be given perorally according to Martindale, “The Extra Pharmacopoeia”, London, 1993 is for adults 10 to 30 mg every 4 to 8 hours up to a maximum of 120 mg in every 24 hours.
Children aged 6 to 12 years may be given 5 to 15 mg perorally every 4 to 8 hours to a maximum in 24 hours and children aged 1 to 6 years 2.5 to 7.5 mg every 4 to 8 hours to a maximum of 30 mg in 24 hours. Similar peroral dosages are recommended in “Handbook of Non-prescription Drugs”, 10th ed., American Pharmaceutical Association, The National Professional Society of Pharmacists, Washington D.C., 1993.
The average hourly flux to be achieved from a transdermal formulation can be calculated from an average oral dosage of 60 mg in every 24 hours and a bioavailability of 25% in oral delivery. Assuming 100% bioavailability in using the transdermal route the average 24 hours transdermal dose should be 0.25×60 mg=15 mg, which corresponds to an hourly flux of (15×1000)/(30×24)=21 μg/cm 2 hour from a trans-dermal device with an area of 30 cm 2 . Recalculating to transdermal delivery corresponding to the maximum oral dosage of 120 mg in every 24 hours results in an hourly flux of 42 μg/cm 2 /hour from a transdermal device with an area of 30 cm 2 .
The area of a transdermal device being convenient for a patient to wear is in the range from 5 to 50 cm 2 . The corresponding patch loading should be at least 0.3-1.5 mg/cm 2 for a transdermal device with an area of 30 cm 2 . As the drug content of a transdermal device is never completely depleted during its application to a patient a higher loading than above must be anticipated, preferably 1-3 mg/cm 2 . The above indicated loadings in mg/cm 2 are to be considered as average loadings for an average size device. It is known that the driving force for the release of a drug from a transdermal device is related to the drug concentration, i.e. number of mg of drug/cm 3 . Therefore the above indicated loadings in mg/cm 2 are to be adjusted according to the actual areal size and thickness of the device in order to arrive at the desirable therapeutic effect.
Loadings for different sizes and types of devices for transdermal administration, taking into account different age groups and types of patients, range from about 0.1 mg/cm 2 to about 10 mg/cm 2 of dextromethorphan. The hourly flux rate of dextromethorphan ranges from about 1 μg/cm 2 /hour to about 100 μg/cm 2 /hour. The effective transdermally delivered amount of dextromethorphan is from about 0.05 mg/kg bodyweight to about 5 mg/kg bodyweight.
It should also be contemplated that a device for transdermal delivery during 8-12 hours would be clinically more relevant than a device for delivery during 24 hours. Such a device with limited release duration may be used for the periods with worst cough during daytime and during the night allowing the patient to cough the bronchi clean therebetween.
The mentioned device may either be taken off from the skin after 8-12 hours in order to stop further delivery, or be designed in such a way that its delivery drops to negligible or non-pharmacological levels after 8-12 hours. In this latter case the device may remain on the skin after 8-12 hours without the patient risking further delivery thereafter which facilitates the patient's handling of the device. Such devices are known per se, see eg U.S. Pat. No. 4,915,950 (MIRANDA ET AL.)—although not for delivery of dextromethorphan.
When dextromethorphan is administered in a transdermal device the latter should preferably be occlusive, which means that the device does not permit water to migrate outwardly from the patient. Thereby the hydration of the skin is increased which favours the penetration of dextromethorphan through the skin.
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The present invention is drawn to a device for the transdermal administration of dextromethorphan, (+)-3-methoxy-17-methyl-9a,13a,14a-morphanin, and salts, prodrugs and metabolites thereof, together with a pharmaceutically acceptable carrier, to a human being or animal in need thereof, to achieve an antitussive effect. The present invention is further drawn to a method of achieving an antitussive effect in a human being or animal which comprises transdermally administering dextromethorphan, (+)-3-methoxy-17-methyl-9a,13a,14a-morphanin, and salts, prodrugs and metabolites thereof, together with a pharmaceutically acceptable carrier.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to the field of computer vision, and more particularly, to a system and method for pattern identification of a learned image (or pattern) in a target image, wherein the learned image (or pattern) and the target image have linear features.
DESCRIPTION OF THE RELATED ART
[0002] Computer vision generally relates to the theory and technology for building artificial systems that obtain information from images or multi-dimensional data. As used herein “information” means anything that enables a decision to be fully and/or partially based. Exemplary computer vision applications include: controlling processes (e.g. an industrial robot or an autonomous vehicle), detecting events (e.g. for visual surveillance), organizing information (e.g. for indexing databases of images and image sequences), modeling objects or environments (e.g. industrial inspection, medical image analysis or topographical modeling), interaction (e.g. as the input to a device for computer-human interaction), etc. A subset of computer vision is machine vision, which is the application of computer vision to industry and manufacturing.
[0003] A goal of computer vision is to make a computer “see”. In order to make a computer “see” in an unconstrained environment an extraordinary amount of computational power, perhaps on the order of 10 15 operations per second likely is needed. Even if such a speed was possible in a commercial computer vision system, it is difficult to perform rapid visual searches in unconstrained, natural environments.
[0004] To make search and recognition tasks tractable in commercial computer vision, designers typically limit the task's visual complexity. This may be done in a variety of example, the vision system may be set up to view and recognize only one or a small class of objects. Second, the presentation (position, orientation, size, view, etc.) of these objects is strictly controlled. Thus, the object variability is limited to the point that the vast majority of variables are eliminated and the search and can be implemented with reasonable cost in terms of both computing time and money.
[0005] For example, when packaging ice cream, the vision system must recognize a package lid from a small class of lids (e.g., Vanilla, Chocolate, Raspberry, etc.). To reduce visual complexity, a designer will typically use a uniform light source and present the various lids in a plane parallel to the camera's sensor to eliminate perspective distortions.
[0006] Computer vision systems generally lack the knowledge needed to constrain and interpret a general visual search (e.g., an uncontrolled environment). Therefore, practical computer vision search requires the designer to drastically restrict what the vision system sees and to add a priori knowledge about what it will see so that it can interpret the result. Thus, a major drawback to computer vision in real world applications is the time, money and specialized knowledge needed for such applications to be adequately performed.
[0007] The evolution of computer vision in the last twenty years was driven by improvements in hardware and algorithms. A variety of computer vision methods have been developed for image detection (also referred to herein as pattern recognition). These techniques include, for example, using binary images to represent gray scale images, normalized grayscale correlation, blob analysis, geometric based search and recognition, contour based search, affine invariant constellation based recognition, corner detection, salient icon detection, scale invariant feature transform, etc.
[0008] Limitations with these various techniques include, for example: requiring uniform lighting, applying a threshold value to the image, multiple objects in an image can confound blob distributions, difficult or impossible to recover object orientation from projections, computational intensive, time intensive, a variety of templates for the same image, constrain the parts seen by a machine vision system, not practical for uncontrolled environments, etc.
SUMMARY
[0009] A strong need exists in the art of computer vision for improving visual search to handle wider variations in target presentation, lighting, and size (e.g., scale). As the vision system becomes more robust to object variation, the need to restrict the system's view by positioning and lighting is reduced, and the development time and costs to put a priori knowledge into the system are reduced. Rather than laboriously testing every possible match of a template (part model) to any possible view (location, orientation and scale) of an object, aspects of the present invention relates to a system and method for finding straight lines in learned images and target images and use the straight lines as salient features or icons to determine if a learned image matches a target image or vice versa.
[0010] One aspect of the present invention relates to a method for matching a learned object with a target object, the method comprising: providing at least one learned object and at least one target object, wherein the learned object and the target object include at least one line segment; selecting at least one line segment from at least one learned object; determining the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object; determining if the learned object matches the target object based at least in part on the step of determining the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object.
[0011] Another aspect of the present invention relates to a method for matching a learned object with a target object, the method comprising: providing at least one learned object and at least one target object, wherein the learned object and the target object have a plurality of contour points, wherein contour points having a curvature below a certain threshold value are grouped together to form at least one line segment; extracting at least one line segment from the learned image; determining the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object; and determining if the learned object matches the target object based at least in part on the step of determining the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object.
[0012] According to an aspect of the invention, the at least one line segment selected in the step of selecting at least one line segment has a plurality of contour points.
[0013] According to an aspect of the invention, the plurality of contour points are detected using an edge detection algorithm.
[0014] According to an aspect of the invention, the step of determining the amount of translation, rotation and scaling for the learned object utilizes a transform matrix.
[0015] According to an aspect of the invention, the transform matrix includes a position, an orientation and a scale of the target image.
[0016] According to an aspect of the invention, the transform matrix includes a quality of fit between the learned object and the target object.
[0017] According to an aspect of the invention, the quality of fit between the learned object and the target object is determined by summing the Euclidian distances between corresponding contour points in the learned image and the target image.
[0018] According to an aspect of the invention, tracking a target image and outputting a control signal to one or more electrical devices based on the determination if the learned object matches the target image.
[0019] According to an aspect of the invention, fitting an analytical line using linear regression for at least one line segment in the target image.
[0020] According to an aspect of the invention, the analytical line is determined by calculating a midpoint of the line segment, wherein the midpoint is an average of a beginning end point and an ending endpoint for the line segment.
[0021] Another aspect of the present invention relates to a method for matching a learned object with a target object, the method comprising: a) providing at least one learned object and at least one target object, wherein the learned object and the target object have a plurality of contour points, wherein contour points having a curvature below a certain threshold value are grouped together to form at least one line segment; b) extracting at least one line segment from the target image, wherein the selected line segment corresponds to a longest line segment of the target image; c) extracting at least one line segment from the learned image, wherein the selected line segment corresponds to a longest line segment of learned image; d) determining a transformation hypothesis that maps the learned image to the target image; e) selecting a next longest line segment from the learned image and the target image; f) determining if the learned object matches the target image based at least in part on the step of determining a transformation hypothesis that maps the learned image to the target image.
[0022] According to an aspect of the invention, if the learned object does not match the target object, another learned image is selected and steps c) through f) are repeated.
[0023] According to an aspect of the invention, wherein the step of determining if the learned object matches the target object is determined by calculating a ratio of the lengths of the corresponding line segments of the learned image and the target image.
[0024] According to an aspect of the invention, verifying a match between the learned image and the target image.
[0025] According to an aspect of the invention, the match is determined by calculating a distance along a gradient direction from a contour point to a target edge point for each of the contours associated with the learned image.
[0026] According to an aspect of the invention, tracking a target image and outputting a control signal to one or more electrical devices based on the determination if the learned object matches the target image.
[0027] Another aspect of the present invention relates to a method for training a computer vision system to recognize a reference shape, the method comprising: providing a reference shape; extracting line segment information from one or more contour points in the reference shape by grouping contour points having a curvature at or near zero as a line; and storing the line segment information in a computer readable form.
[0028] According to an aspect of the invention, the line segment information includes at least one from the group consisting of: an endpoint, a midpoint, a line angle or a line length for the one or more line segments.
[0029] According to an aspect of the invention, the line segment information includes at least one contour point.
[0030] According to an aspect of the invention, the line segment information includes a vector from the midpoint for each of the one or more line segments to a reference point.
[0031] According to an aspect of the invention, the computer readable form is a database.
[0032] According to an aspect of the invention, the reference shape is provided from an electronic computer aided design file.
[0033] Another aspect of the present invention relates to a program stored on a machine readable medium, the program being suitable for use in matching a learned object with a target object, wherein when the program is loaded in memory of an associated computer and executed, causes extracting at least one line segment from a learned image and a target image, wherein the selected line segment corresponds to a longest line segment of the image; determining a transformation hypothesis that maps the learned image to the target image; selecting a next longest line segment from the learned image and the target image; and determining if the learned object matches the target image based at least in part on the step of determining a transformation hypothesis that maps the learned image to the target image.
[0034] According to an aspect of the invention, the program further includes tracking a target image and outputting a control signal to one or more electrical devices based on the determination if the learned object matches the target image.
[0035] Another aspect of the invention relates to a method for learning an object, the method comprising: providing an object in electronic form, wherein the object includes at least one linear feature formed by a plurality of contour points; extracting at least one icon from the object, wherein the icon includes at least one end point associated with the linear feature, wherein the icon has a size determined by a distance between an end contour point and the one end point, wherein the end contour point is an outermost contour point from a series of contour points having a curvature below a curvature threshold value in from the one end point.
[0036] According to an aspect of the invention, the at least one icon is scale and rotation invariant.
[0037] According to an aspect of the invention, the at least one icon is extracted for all linear features of the object having a segment length above a length threshold value.
[0038] According to an aspect of the invention further includes fitting an analytic line on the line segment using linear regression for representation of the icon.
[0039] According to an aspect of the invention, the analytic line utilizes the end point associated with the linear feature and the end contour point.
[0040] According to an aspect of the invention, storing information related to the at least one icon in a database of icons.
[0041] According to an aspect of the invention, the at least one icon is stored for all linear features of the object having a segment length above a length threshold value.
[0042] According to an aspect of the invention, the information includes a length associated with at least one icon.
[0043] According to an aspect of the invention, the information includes a scale associated with at least one icon.
[0044] According to an aspect of the invention, the information includes an icon angle, wherein the icon angle is the relation between the icon and a reference point in the object.
[0045] Another aspect of the invention relates to a method for matching a learned object with a target object, the method comprising: providing at least one learned icon in electronic form, wherein the learned icon is associated with a learned object, wherein the learned icon includes at least a learned icon length and an angle; providing a target object in electronic form; selecting a first learned icon; extracting a first target icon from the target object; determining the amount of translation, rotation, and scaling needed to transform the first learned icon to have one or more lines substantially the same size as the first target icon; and determining if the learned object matches the target object based at least in part on the step of determining the amount of translation, rotation, and scaling needed to transform the first learned icon to have one or more lines substantially the same size as the first target icon.
[0046] According to an aspect of the invention, the first learned icon has a length larger than other icons associated with the learned object.
[0047] According to an aspect of the invention, the amount of translation is determined by aligning a midpoint associated with the first learned icon with a midpoint associated with the first target icon.
[0048] According to an aspect of the invention, the amount of rotation is determined by aligning the first learned icon to overlay the first target icon.
[0049] According to an aspect of the invention, the amount of scaling is determined by dividing the length of the first learned icon by the length of the first target icon.
[0050] According to an aspect of the invention, the step of determining the amount of translation, rotation and scaling for the learned object utilizes a transform matrix.
[0051] According to an aspect of the invention, the transform matrix includes a quality of fit between the learned object and the target object.
[0052] According to an aspect of the invention, the quality of fit between the learned object and the target object is determined by summing Euclidian distances between corresponding contour points in the learned image and the target image, wherein the contour points are linear features associated with each of the learned image and the target image.
[0053] According to an aspect of the invention further including outputting a control signal to one or more electrical devices based on the determination that the learned object matches the target image.
[0054] Another aspect of the invention is related to a method for matching a learned object with a target object, the method comprising: providing at least one learned object, wherein the learned object has a plurality of contour points, wherein contour points having a curvature below a certain threshold value are grouped together to form a learned icon, wherein the learned icon has a first end point and a second end point; providing a target object in electronic form; selecting at least one learned icon; extracting a first target icon from the target object; determining the amount of translation, rotation, and scaling needed to transform the learned icon to have a size and shape that corresponds to the target icon; and determining if the learned object matches the target object based at least in part on the step of determining the amount of translation, rotation, and scaling needed to transform the learned icon to have a size and shape that corresponds to the target icon.
[0055] Other systems, devices, methods, features, and advantages of the present invention will be or become apparent to one having ordinary skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
[0056] It should be emphasized that the term “comprise/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.”
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] The foregoing and other embodiments of the invention are hereinafter discussed with reference to the drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Likewise, elements and features depicted in one drawing may be combined with elements and features depicted in additional drawings. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0058] FIG. 1 is an exemplary image in accordance with aspects of the present invention.
[0059] FIGS. 2-4 illustrate exemplary contours in accordance with aspects of the present invention.
[0060] FIGS. 5-9 illustrate an exemplary method in accordance with aspects of the present invention.
[0061] FIGS. 10A-10D illustrate exemplary translation, rotation and scaling transformations in accordance with aspects of the present invention.
[0062] FIGS. 11A-11F illustrate an exemplary method in accordance with aspects of the present invention.
[0063] FIG. 12 illustrates an exemplary learned image and learned image icons.
[0064] FIGS. 13-16 illustrate an exemplary method in accordance with the aspects of the present invention.
[0065] FIGS. 17 and 19 illustrate edge extraction straight lines in accordance with aspects of the present invention.
[0066] FIG. 20 is an exemplary application in accordance with aspects of the present invention.
[0067] FIGS. 21-24 are exemplary methods in accordance with aspects of the present invention.
[0068] FIGS. 25-32 are exemplary applications in accordance with aspects of the present invention.
[0069] FIG. 33 is a block diagram of a system in accordance with aspects of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0070] The present invention is directed to a system and method for pattern identification of learned image (or learned pattern) in a target image, wherein the learned image and the target image have linear features. This application is based on a doctoral thesis entitled “Visual Search For Objects With Straight Lines”, submitted by the inventor of the subject application in January 2006 to the Department of Electrical Engineering and Computer Science of Case School of Engineering, the entirety of which is incorporated by reference as if fully rewritten herein.
[0071] Referring to FIG. 1 , an exemplary image 10 is shown. Image 10 may be a digital image, a portion of an object or image, an electronic representation of an image, etc. As shown, image 10 is a digital image of an outdoor scene. It may be desirable for a machine to determine the precise location and/or orientation of one or more items (or patterns) in this scene. This information may be used in any desirable manner, so that a controller, a device, or other electronic device may properly interact with software that is capable of detect optical objects in order to facilitate controlling, assembly and/or processing information related to the item.
[0072] For example, it may be desirable to find a target 12 (e.g., a stop sign) located within this image. The ability to locate and/or track the target 12 may be useful for a variety of applications. For example, autonomous vehicle guidance, providing “sight” to electronic equipment, etc.
[0073] Image 10 may include one or more items within the image. In FIG. 1 , image 10 includes target 12 , buildings 14 , persons 16 , a street 18 , a tree 20 , a traffic sign 22 , etc. Each item includes a variety of contours 30 . In general, contours 30 may be thought of as being an ordered list of edge point coordinates that describe a boundary of an item or pattern located in the image, including both internal and external boundaries. In FIG. 1 , contours 30 are indicated along the outside of the target 12 , as well as, within the text of target 12 . One of ordinary skill in the art will readily appreciate that image 10 includes a variety of objects, each of these objects generally has a contour. For purposes of clarity, contours associated with each of these objects are not shown.
[0074] Generally, the present invention “trains” on target 12 so that the invention will know the pattern of the item for which it is searching. During the training process, the present invention is given, or creates, a “pattern image,” and the system trains on the pattern image. During the searching process, the present invention searches a “scene image” in an effort to locate the pattern that was used to train the system. For purposes of clarity, “pattern image”, as used herein, means the image used in training (also referred to herein as a “learned image”), and “scene image” means the target image that is being searched for a pattern image (also referred to herein as a “target image”).
[0075] FIG. 2 illustrates contour 30 that has been extracted, for example, from a pattern image during the training process and/or from a computer aided design file (e.g. CAD drawing). Referring to FIG. 2 , contour 30 includes a plurality of contour points 32 , which lie along contour 30 . Index point 34 (located at (x 0 , y 0 )), which is a contour point, is selected, and two reference points, back point 36 (located at (x 1 , y 1 ), and “behind” index point 34 by a constant k and front point 38 (located at (x 2 , y 2 ), and “in front of” index point 34 by a constant k (not shown)) are selected. Variable k controls the locality of the curvature measurement. In one embodiment, k represents the number of contour points that separate back point 36 from index point 34 , which is the same as the number of contour points separating front point 38 from index point 34 . A smaller value for k gives very local curvature measurements, while a larger value for k gives more global measurements.
[0076] In one embodiment, indices of front point 38 and back point 36 may be selected automatically. In general, they are separated from index of index point 34 by k (i.e., each is k data points away from index point 34 ). The index of front point 38 is smaller than the index of index point 34 by k, while the index of back point 36 is larger than the index of index point 34 by k. For example, if (x 0 , y 0 ) is at index 100 , then back point 36 is the point at index 90 , and front point 38 is at index 110 (for k=10).
[0077] Generally, k is chosen based upon the severity of the curves in the pattern contours and based upon the number of contour points that are used to represent the contour. Generally, a smaller k may be preferred, but k typically should not be too small. A k of 10 is sufficient in most standard applications.
[0078] Stick vector 40 , which is a vector that connects back point 36 and front point 38 , has a direction representing the direction of “crawl;” that is, the direction from back point 36 to front point 38 . Stick vector 40 has an angle of 60 relative to the horizontal axis.
[0079] In another embodiment, an additional back point (not shown) and an additional front point (not shown) may also be used. In general, these points may be indexed with a value greater than k. These points may be used to define an additional stick vector (not shown), which may provide additional information regarding contour 30 .
[0080] Line 42 connects index point 34 and back point 36 , while line 44 connects index point 34 and front point 38 . Angle θ 2 represents the angle between stick 40 and line 44 . A distance h represents a contour curvature measure for a contour point (e.g., index point 34 ). The distance h is the shortest distance from index point 34 to stick 40 . For example, for an appropriate k value, a value of h=0 indicates that the stick is falling on a straight line.
[0081] The “crawling” process described above is set forth in U.S. Pat. No. 7,006,964, which is hereby incorporated by reference as if fully rewritten herein. The present invention utilizes aspects of the crawling process and utilizes line (straight) segments, which conventionally were believed to be useless for visual search because they contain only limited, one-dimensional information. In one aspect of the invention, the end points of the line segments are utilized for object identification. As discussed in detail below, an end point of a line segment is a unique (salient) point in an image. The end point is also scale and rotation invariant.
[0082] Referring to FIG. 3 , a rectangle 100 is illustrated within an area A. The area A may be a viewing area, a memory, or any other suitable medium capable of representing one or more images. The rectangle 100 has four straight line segments 102 , 104 , 106 , and 108 . Each of the line segments 102 , 104 , 106 and 108 have ends, in most cases, and have an angle, which is simply the angle of the line with respect to some external coordinate system (discussed below). The length of the line segment (solid line) provides its scale and the center point of the line gives its location. A straight line has true and stable angle and scale that define a “characteristic” or “canonical” angle and scale.
[0083] For example, each of the four lines that make up a rectangle is bounded by two corners. Each bounded line gives position, orientation, and scale information, as shown in FIG. 3 , to direct attention and recognize the rectangle shape regardless of the location, angle, and size of the rectangle in the image, with respect to a given reference point 110 , as shown in FIG. 4 .
[0084] An exemplary method in accordance with the present invention is depicted by FIGS. 5-10 . A simple pattern in the form of a synthetic rectangle 100 is used to illustrate aspects of the invention. The rectangle pattern 100 that is to be learned is shown in darker gray. A goal is to “train” on this shape and search for it in another image as illustrated in FIG. 6 . The shape (e.g., rectangle 100 ) in FIG. 5 has translated, rotated and scaled by unknown factors to end up as it looks in FIG. 6 ( 150 ). As shown in FIG. 7 , a coordinate system 160 is added to the rectangle 100 .
[0085] Straight-line segments 102 , 104 , 106 and 108 from the reference shape (also referred to as the learned image) are extracted as shown in FIG. 8 utilizing the crawling procedure discussed below. The following information is then saved for each line segment and/or image icon: contour points, end-points, center point, line angle, and line length. A vector from each line's center point to an object reference point (user-defined coordinate system center) may also be saved. In order to search for a target image (e.g., the rectangle 150 ), line segments for this shape (pattern) (e.g., line segments 152 , 154 , 156 and 158 ) are extracted, as shown in FIG. 9 . The extracted information is saved. Note, no reference point has been established in the target image at this juncture.
[0086] In order to match the learned object with the target object (pattern), the amount of translation, rotation, and scaling needed to transform the learned object such that its lines overlap (or its contours) the lines of the target (unknown) object are computed. The coefficients of the transform matrix give the position, orientation, and scale of the target object. In addition, the quality of the fit from learned to target is a measure of recognition and may also be saved in the transform matrix.
[0087] Referring to FIG. 10A , consider just the top line 106 in the trained object 100 and the longer top line 156 in the target object. To bring these two lines into alignment (1) the center of the trained object's line 106 is translated to center of the target object's line 156 (as shown in FIG. 10B ); (2) the trained object's line 106 is rotated to match the angle of the target object's line (as shown in FIG. 10C ), and (3) scale (stretch, in this case) the trained object's line (contour) to completely overlap with the target object's line (as shown in FIG. 10D ).
[0088] If a trained-line center point is given coordinates x p , y p , its length is l p , and its angle θ p , and for a target-line x s , y s , 1 s , θ s , the transformation coefficients are:
[0089] δx=x p −x, Translation in x
[0090] δy=y p −y s . Translation in y
[0091] δ0=θ p −θ s . Rotation
[0092] δs=l p /l s . Scale
[0000] The transformation coefficients form the hypothesis for recognition and location. If we apply these coefficients to the lines from the trained object (learned object) then match the lines in the target object, this validates the hypotheses that (a) the target object is a transformed version of the learned object (recognition), and (b) that the proposed transform is correct (location).
[0093] Instead of using only the straight lines in the reference (the trained pattern) and target for hypothesis verification, a set of contour points in reference and target objects are matched. This may be conceptually thought of as “overlaying” the reference object's contour points onto the target object. The quality of the fit or match quality is computed by summing the Euclidian distances between corresponding reference and target contour points. The match scores are transformed so that high match values indicate a better match, as this is used to from match scores such as correlation coefficients. Note that only few points from the contours are needed to quickly verify if a valid match based on the transform (hypothesis) from the pair of straight lines is found. In the above example, if we choose corresponding lines between the pattern and the target just to illustrate the idea. If the two lines are not corresponding lines, then the verification procedure produces low match score and a new line from the target is examined. That is, a new hypothesis (transform) is generated and verified, and so on until a high match score is found.
[0094] Only one straight line segment is generally needed from the learned image (also referred to herein as a reference pattern) to compute the transform and to find and match target objects. As shown in FIG. 6 , the example target rectangle 150 has four straight lines (e.g., 152 , 154 , 156 and 158 ), any one of which can direct the “visual attention” to find the object in its new location, angle and scale. As with human vision, important features (straight lines in this method) are quickly extracted and then a second stage sequentially tests for matching patterns.
[0095] Another more complex pattern (object) being recognized and located is illustrated in FIGS. 11A-11F . In this example, the single straight line 200 is the focus of our “attention”, as illustrated in FIG. 11A . Several hypotheses (transforms) 202 are generated and rejected, as illustrated in FIGS. 11B-11E , before a hypothesis is verified, as shown in FIG. 11F . As seen from the Figures, attempts to find the line 200 are made on various line segments of the target image. The hypothesis is rejected until the proper line segment 200 is found in the target image.
[0096] If a reference pattern (object) has N straight lines (also referred to herein as “icons”) and the scene image has a M straight lines (lines belong to object(s) we want to recognize and locate, plus noise lines), then the cost for using one reference line as a hypothesis is 0(M) and for using all reference lines is 0(N×M). If we train on K object, then the computation cost for each hypothesis is 0(M×K) and the total computation cost is 0(N×M×K). These costs assume no prior knowledge of the transformation between two compared lines. However, we often do have a priori information that limits the range of transformations. For example, if we know that the target objects will only vary in scale with in a range of 0.5 to 2.0, then many possible pairs of line matches (transformations) can be immediately eliminated. Another way to reduce the number of hypotheses is to use additional information about the lines, such as the color difference on each side of a line, or the angle between lines. These require additional assumptions about the objects and images, but can greatly reduce the number of hypothesis that we need to test and hence the computation time.
[0097] A typical pattern contains 500 to 5000 contour points. Experimentally it has been found that 10 to 100 contour points are sufficient for rapid verification using aspects of the present invention. Once a pattern with high verification score is found then all pattern contour points are considered for final verification. The cost of the worst case scenario for rapid verification is 0(100) calculations, which is very fast and on the order of few micro seconds with modern computers.
[0098] As used herein, the gradient angle of straight line is the average gradient angle of contour points that make up that line segment. The gradient angle may be computed from the direction of the image intensity gradient at each contour point. Thus a line angle based on gradient information can range from −π to π. Without gradient information, it is difficult to determine the “direction” of the line so angles range from only −π/2 to −π/2. Thus, gradient information is generally needed in order to get the correct angle for the transformation hypothesis. Otherwise, there is a need to test the hypothesis for 2 angles θ and θ+π, which effectively doubles the search time.
[0099] As stated above, only one line segment from a pattern is generally needed to search for matching target objects. However, if the corresponding line in the target is occluded or corrupt, then no match may be found. It has been found that for practical purposes, using five lines from the reference pattern provides robust results. The criterion for choosing these five lines is simply to pick the five longest lines in the reference pattern. The rationale for this approach is that longer lines provide more accurate transformations. With five lines, we have sufficient redundancy to make this method robust.
[0100] An end point of a line is a unique (salient) point in an image. An end point is scale and rotation invariant point. The size of a line segment provides a true scale (size) of that point and the orientation angle provides the angle of the point. Therefore, we can extract image patches (also referred to as icons) centered at the end point, the size of the image patch is the scale (the line length) or a factor of the line length. The angle of the line is the orientation for which the patch is extracted. The image patch becomes rotation and scale invariant patch. Learned object (pattern) comprises lines and patches. During the search phase, the image patches of the learned object are compared for similarity with image patches of unknown object(s). Matched pairs suggest that the end points are corresponding point. A verification process is then performed. This method allows for fast recognition of multiple learned objects.
[0101] FIG. 12 shows a pattern and examples of image patches. Each patch (also referred to herein as “icon”) (e.g., A-F) corresponds to a line segment extracted from the learned image (e.g. Panera sign). Each patch can be converted into a vector with means such as principle component analyses. Indexing techniques can be used to match an image patch with a data base of image patches that belongs to trained objects.
[0102] Thus, aspects of the present invention relate to methods that can perform practical visual searching using straight line segments provided in a target image and a learned image in a fast and highly accurate manner.
[0103] In one aspect, Curvature-Based Straight Line Extraction (CBSLE) is utilized to extract straight lines from images. One of ordinary skill in the art will appreciate that any method of extracting lines from images may be used in accordance with aspects of the present invention. However, the CBSLE method has been shown to be very efficient for detecting linear patterns and/or features in images.
[0104] The CBSLE method is now discussed in detail. The curvature at a point on a curve is defined as the change in tangent, θ, with respect to distance, s, along the curve:
[0000]
K
=
δθ
δ
s
[0000] A contour point is considered to belong to a straight line if its curvature value is near zero or the osculating circle's radius, 1/K, is large. A measure of curvature may be computed by the perpendicular distance, h, between a contour point and a virtual line (called a “stick”) that spans between “before” and “after” points as shown in FIGS. 13-15 . The number of contour points between the chosen contour point and the “before” and “after” points is the same, and is called the “span”. h is a scale dependent measure of curvature on quantized curves. It approximates the analytic definition of curvature as the span distance decreases. Quantization and noise in digital images prevents the use of small spans (scales). Instead, aspects of the present invention allow the span to be a free parameter that sets the scale of measure, where larger spans “average out” more details of the digital curve.
[0105] Adjacent contour points with small curvature are grouped to form straight-line segments. The points in each straight-line segment are then fitted to an analytic straight line (y=mx+b) using linear regression. Each straight line segment consists of its individual edge points and an equation (y=mx+b) where the slope, m, is the orientation of the line. The mid-point of the segment is the average value of the segment's end points, and is taken as the line position.
[0106] An exemplary computation for h is as follows:
[0000] δ x i :=x l+span −x i −span δ yi :=y i+span −y i−span
[0000] δ x i :=x l+span −x l δ y l i :=y i+span −y i
[0000] ø i :=atan2└δ xi ,(−δ y ) i ┘ λ i :=atan2 └δxl i ,(−δ y l ) i ┘
[0000] α i :=0 i −λ i side_length i :=√{square root over ((δ xl i ) 2 +(δ yl i ) 2 )}{square root over ((δ xl i ) 2 +(δ yl i ) 2 )}
[0000] h i :=side_length i ·sin(α i ) h i is the h value for a contour point at index i.x i y i is the contour point being tested for belonging to a straight line.
[0107] If we approximate a small contour segment with circular arc then, as shown in FIG. 16 , then:
[0000]
(
s
2
)
2
+
(
R
-
h
)
2
=
R
2
[0108] Solving for R:
[0000]
R
=
1
8
·
s
2
+
4
·
h
2
h
[0109] Then the curvature k is equal to:
[0000]
k
=
8
·
h
s
2
+
4
·
h
2
This shown that in the limit, h is sufficient to computer curvature.
[0110] An exemplary algorithm to extract line segments using the h method is as follows:
[0000]
Step I
Extract contours using an edge detector such as [Canny, 1986]
Select a span, n, to set the scale of measure
Select a threshold value for calling a curve straight
Loop: “crawl” each contour in the object
Loop: for every contour point cp i in a contour
Get cp i−n , cp i+n
Compute h, as above
If h < threshold value
Mark cp i ,
End
End
Step II
Loop: for every contour in the object
Loop: for every contour point marked in Step I
Collect and save connected marked points as a single
line segment.
End
End
Loop: for each line segment
First and last points are the ends of the segment
Average of first and last points are the center (location) of the
segment
Least square fit points in the segment to compute m, b for y =
mx + b.
Compute average gradient angle of all contour points (line
orientation)
End
[0111] The following information is then available for each line segment in the image:
[0112] Pend_a=the first end point of line segment (from the direction of crawl)
[0113] Pend_b=the last end point of line segment (from the direction of crawl)
[0114] Pcenter=the center of line segment=(Pend_a+Pend_b)/2.
[0115] P i =contour points in this line segment
[0116] AveGradAngle=the average angle of contour points −π to π.
[0117] The AveGradAngle is generally computed from the slope of the line and the direction of the intensity gradient along the line. The slope provides angle defined from −πi/s to π/2 but AveGradAngle has a range −π to π. AveGradAngle is generally needed to get the proper transform coefficients. FIGS. 17 and 18 are exemplary illustrations of line segments being extracted from images using the CBSLE algorithm.
[0118] The “span” value is the number of contour points (pixels) to go “backward” or “forward” from a contour point that is being examined for curvature. The length of the span (the number of pixels in the arc) sets the scale of measurement. As the length of the span increases, details—higher spatial frequencies—of the curve are generally lost. In a sense, the span acts as a low pass filter to reduce digital noise and to set the scale of measurement. Longer span values will cause the algorithm to miss short line segments, and shorter span values will increase the number of short line segments found in a slowly curving contour. In practice, a span of three pixels (7 contour points from beginning to end of the contour segment) has been found to work with most contours. Changing the span value effects the locations of the ends of a line segment. FIG. 19 shows how the straight line segments “slide” as the span value varies.
[0119] Once the crawling process is completed, hypothesis generation is performed. A straight line segment (the reference line) from the reference pattern (also referred to as the learned image) is compared to target lines from the target pattern or scene. The transformation required to match the reference line to the target line is the hypothesis that the reference line and target line represent the same line feature in an object or pattern that has been translated, rotated and scaled. The hypothesis is nearly an affine transform.
[0120] The following is exemplary transformation code fragment used to generate the hypothesis:
[0000] // COMPUTING SCALE // Scale is scene line-length divided by pattern line -length. scale = aSceneLine.length / aPattLine.length; //COMPUTE ROTATION rotation = aPattLine.trueTheta − aSceneLine.trueTheta; // //COMPUTE TRANSLATION translationX = aPattLine.xmid − aSceneLine.xmid; translationY = aPattLine.ymid − aSceneLine.ymid; // COMPUTING SCENE PATTERN LOCATION // Translate the mid-point-pattern to mid-point-scene, rotate about the scene // mid-point and compute where the scene pattern point is. SceneRefX = (xref translationX − aSceneLine.xmid)*cos(rotAngle) − (yref − translationY − aSceneLine.ymid)* sin(rotAngle) + aSceneLine.xmid; SceneRefY = (xref − translationX − aSceneLine.xmid)*sin(rotAngle) + (yref − translationY − aSceneLine.ymid)*cos(rotAngle) + aSceneLine.ymid; // Scale it. SceneRefX = (SceneRefX − aSceneLine.xmid)*scale + aSceneLine.xmid; SceneRefY = (SceneRefY − aSceneLine.ymid)*scale + aSceneLine.ymid; The above steps can be reduced as follows: scale = aSceneLine.length/aPattLine.length; //Scale rotation = aPattLine.trueTheta − aSceneLine.trueTheta; //Rotation // Compute translation double costrans = cos(rotation) * scale; double sintrans = sin(rotation) * scale; double X = (xref − aPattLine.xmid); double Y = (yref − aPattLine.ymid); xScene = X*costrans − Y*sintrans + aSceneLine.xmid; yScene = X*sintrans + Y*costrans + aSceneLine.ymid;
During the search phase for the target object, the hypothesis generating algorithm selects (attends to) a line from the reference pattern (starting with the longest straight line of the pattern) to compare to a line from the scene (also starting with the longest line). This comparison suggests a transformation hypothesis that could map the reference pattern to the target pattern. Then this hypothesis is verified and accepted or rejected, as discussed below. If rejected, another hypothesis is generated and verified, and so on until the hypothesis is accepted.
[0121] In current implementation, the only constraint applied during hypothesis construction is the length of the line. This is done first by starting the hypothesis generation from the longest lines and working towards shorter lines, and second, if the ratio of the lengths of the reference and target lines is outside expected range, then that line is skipped. These two constraints are quite minimal. Stated another way, the methods disclosed herein generally assume very little about the structure of the reference and target patterns. Adding constraints to selecting line pairs could greatly reduce the number of hypotheses that have to be verified, but at the expense of assuming more about the objects being recognized and located. Some other exemplary constraints that could help reduce the number of hypotheses include:
1. In color images, use the average color difference across the line as a “label” or tag for selecting lines for hypothesis generation. This is probably a trick used by human vision. 2. Create a line profile (graph of gray-level pixel values) that is the perpendicular bisector of the straight line. Find the extremum (brightest point) in the profile and use the distance between the straight line and the extremum (along the line profile) as a “label” or tag for selecting line pairs for hypothesis generation. The extremum could be computed by any of the methods suggested by [Brady & Kadir], [Tuytelaars &Van Gool], or [Tell & Carlsson]. 3. In analogy with search methods proposed by Schmid, Lowe, and Brady, use the entire line profile (as described in 2. above) as the “descriptor” or “key” to use for searching in a data base for matching lines.
[0125] An object is defined purely as contours (connected sets of edge points) at initial location, angle and size (scale, uniform scale). When an object translates, rotates, or changes in size, only its contours move. This is unlike other methods that use image areas to define an object.
[0126] The verification module takes a transformation hypothesis and applies it to the reference pattern to overlay the pattern on the target edge image. The edge image, as computed by the Canny operator, has only edge points, not contours (connected sets of edge points). The verification then computes the match in the fit of the transformed contour points and the target image edge points. A high match score supports the hypothesis that the target pattern is a transformed version of the reference pattern.
[0127] The verification process in pseudo code is as follows:
[0000] Set a distance threshold, n (typically 6 or 7) Match Score = 0 Initialize a Score LUT, of size n Loop: For all points, p, in the reference contours Find the distance along the gradient direction, d, from contour point, p, to a target edge point. If d n then Match Score += Score LUT(n) End
The values of the Score LUT (Look-Up Table) are empirically determined, typically:
[0000] Distance, d Resulting Score 1 1.00 2 0.99 3 0.98 4 0.94 5 0.90 6 0.86 7 0.80
The scores fall off more rapidly as d increases in the LUT. The Match Score thus is larger, the closer the distance between the reference object's contour points and the target's edge points. The Match Score is generally scaled by dividing it by the total number of points in the reference object's contour points, to give a percent match.
[0128] Aspects of the present invention relate to initially using a small number of pattern contour points—about 10% is sufficient—to quickly test for a possible match. Once a possible match is found (a match score above 80%), the verification is repeated on the entire set of contours to get a more accurate score for this reference object and transformation hypothesis. One of ordinary skill in the art will readily appreciate less than the entire set of contours may be used to determine a match and/or verification.
[0129] A final step is used to exactly match the location and scale of the transformed pattern with the target pattern. While the angle estimate is precise due to the least squares line fit, the location has about 5 pixel error and the scale has about 10% error. To reduce this error to a fraction of a pixel, I use a simple hill climbing approach to “zero in” on the location and scale. The hill climbing method searches for a higher match score by stepping left, right, up and down by 2.5 pixels and by enlarging and reducing (scaling) by 5%. If a better position and scale is found, the step size for the position and scale are halved and the search repeated until no improvement is found. This very quickly reaches a match that is within 0.078 pixel in position (less than 1/10 of a pixel) and within 0.078% of the best scale.
[0130] FIG. 20 shows verification attempts and the closest match, which then has to be “zeroed in” by the hill climbing algorithm. In fact, comparing the intersection points of two pairs of lines from the reference pattern and corresponding target lines would eliminate the need to hill climbing.
[0131] FIG. 21 illustrates an exemplary method 300 in accordance with aspects of the present invention. The method 300 is useful for matching a learned object with a target object. At step 302 , at least one learned object and at least one target object are provided, wherein the learned object and the target object include at least one line segment. One of ordinary skill in the art will appreciate that the learned object may be previously learned and stored in any suitable electronic format. At step 304 , at least one line segment from at least one learned object is selected. At step 306 , the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object are calculated. At step 308 , it is determined if the learned object matches the target object.
[0132] FIG. 22 illustrates an exemplary method 350 for matching a learned object with a target object. At step 352 , at least one learned object and at least one target object is provided, wherein the learned object and the target object have a plurality of contour points. The contour points having a curvature below a certain threshold value are grouped together to form at least one line segment. At step 354 , at least one line segment is extracted from the learned image. At step 356 , the amount of translation, rotation, and scaling needed to transform the line segment of the learned object to have one or more lines substantially the same size as lines on the target object is determined or otherwise calculated. At step 358 , a determination is made as to whether the learned object matches the target object.
[0133] FIG. 23 illustrates an exemplary method 400 for matching a learned object with a target object. At step 402 , at least one learned object and at least one target object is provided, wherein the learned object and the target object have a plurality of contour points, wherein contour points having a curvature below a certain threshold value are grouped together to form at least one line segment. At step 404 , at least one line segment from the learned image is extracted, wherein the selected line segment corresponds to a longest line segment of learned image. At step 406 , at least one line segment is extracted from the target image, wherein the selected line segment corresponds to a longest line segment of the target image. At step 408 , a transformation hypothesis is determined that maps the learned image to the target image. At step 410 , a determination is made to see if there are any other line segments to inspect. Generally, the next longest line segment from the learned image and the target image is selected. If the determination result is positive, steps 404 through 410 are repeated. If the determination is negative, at step 412 , a determination is made if the learned object matches the target image. If the learned object matches the target object the method 400 terminates at step 416 . If the learned object does not match the target object another learned object is selected and steps 404 through 410 are repeated.
[0134] FIG. 24 illustrates another exemplary method 450 for learning an object. The method 450 includes at step 452 providing an object in electronic form, wherein the object includes at least one linear feature formed by a plurality of contour points. At step 454 , at least one icon is extracted from the object. The icon generally includes at least one end point associated with the linear feature. The icon generally has a size determined by a distance between an end contour point and the one end point, wherein the end contour point is an outermost contour point from a series of contour points having a curvature below a curvature threshold value in from the one end point. The icon is scale and rotation invariant. At least one icon is extracted for all linear features of the object having a segment length above a length threshold value. An analytic line may be fit on the line segment using linear regression for representation of the icon. The analytic line may utilize the end point associated with the linear feature and the end contour point. At step 456 , information extracted and/or otherwise calculated that is related to the icon(s) may be stored in a database of icons.
[0135] An application of aspects of the present invention is illustrated in FIG. 25 . The top four images are from the same scene and the bottom two images are from different scenes. The images are taken at different distances from the stop sign and to show a range of sizes (scales) from 1.0 to 2.3. The stop sign in the top left image is used as the reference (training) pattern (scale=1.0). This pattern is 78×78 pixels, but any size is suitable. The illustrated images are 640×480 pixels. These scenes have many objects with lots of straight lines. In these busy images, the algorithm recognizes and locates the stop sign.
[0136] FIG. 26 shows a similar exemplary type of street scene as in FIG. 25 , but for a “Talbots” sign. The reference pattern size is 280×142 pixels and the scene images are 640×480 pixels. The “Talbots” signs have a size range from 1.0 to 0.52 times. The learned object is the top left image. The algorithm recognizes and locates the “Talbots” sign.
[0137] FIG. 27 shows the back of a truck, moving on the highway in a foggy day. This test demonstrates the feasibility to use this algorithm in an unmanned vehicle convoy. The algorithm “locks” onto the writing on the truck and tracks it. The scale range for these images was from 1.0 to 0.55. The pattern size for these images is 231×135 pixels.
[0138] FIG. 28 shows images of label on a package of CD-R disks. The label images show some translation and rotation but mostly changes in scale. This test shows that, using this algorithm, you can teach on one type of label and search for similar label but on different product with a different size. Three independent patterns from the label were trained and searched on the entire image. There are very few straight lines in these images but the algorithm performed well.
[0139] FIG. 29 shows lanes on the highway. This Figure illustrates how the CBSLE algorithm might be used for lane tracking. The straight line extractor takes 41 milliseconds on these 640×480 images (using a 2 GHz, Pentium III laptop). This means this algorithm could be used to track lanes at about 20 images (samples) per second.
[0140] FIG. 30 shows labels on various bottles. The algorithm has no difficulty recognizing the logo, even though the bottles in the first three images are physically larger than in the last three. Using this algorithm could eliminate the need to train on individual product types.
[0141] FIG. 31 illustrates an image of a metal bracket, as it might be presented on a conveyer belt. The algorithm successfully locates the bracket regardless to its orientation angle and size.
[0142] FIG. 32 shows logos representing different countries on a pamphlet. The algorithm can be trained on one or more of the countries (e.g. if the algorithm is trained on the “France” logo), the algorithm is capable of finding the France logo even though there are many other similar and straight line rich patterns in the image.
[0143] As a practical contribution, the aspects of the present invention may be used in a wide variety of application including, for example, autonomous guidance of vehicle convoy by having successive vehicles lock on a pattern on the back of the preceding vehicle; guide vehicles by finding the straight edges in road marking at the middle and at the edge of the road; and applications wherein a closed-loop guidance and/or control system is utilized that requires a fast searching algorithm.
[0144] FIG. 33 illustrates an exemplary feedback system 500 that may be used in accordance with the aspects of the present invention. The system 500 may include an optical input device 502 (e.g., a CCD camera) and/or an electronic storage device 504 for providing a learned image and/or a target image to a processor 506 . The output of the devices 502 , 504 may be input to a processor 506 that has computer code that is functional to carry out the desired functionality. The processor 506 may generate a control signal to a controller 508 (e.g., programmable logic controller) that may be used to control one or more electronic devices 510 (e.g., vehicle navigation system, tracking system, etc.). A feedback signal may be generated by the electronic device 510 to the controller 508 and/or processor 506 in order to control the particular application in which the invention is being applied.
[0145] Specific embodiments of an invention are disclosed herein. One of ordinary skill in the art will readily recognize that the invention may have other applications in other environments. In fact, many embodiments and implementations are possible. The following claims are in no way intended to limit the scope of the present invention to the specific embodiments described above. In addition, any recitation of “means for” is intended to evoke a means-plus-function reading of an element and a claim, whereas, any elements that do not specifically use the recitation “means for”, are not intended to be read as means-plus-function elements, even if the claim otherwise includes the word “means”. It should also be noted that although the specification lists method steps occurring in a particular order, these steps may be executed in any order, or at the same time.
[0146] Computer program elements of the invention may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). The invention may take the form of a computer program product, which can be embodied by a computer-usable or computer-readable storage medium having computer-usable or computer-readable program instructions, “code” or a “computer program” embodied in the medium for use by or in connection with the instruction execution system. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium such as the Internet. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner. The computer program product and any software and hardware described herein form the various means for carrying out the functions of the invention in the example embodiments.
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Disclosed is method of visual search for objects that include straight lines. A two-step process is used, which includes detecting straight line segments in an image. The lines are generally characterized by their length, midpoint location, and orientation. Hypotheses that a particular straight line segment belongs to a known object are generated and tested. The set of hypotheses is constrained by spatial relationships in the known objects. The speed and robustness of the method and apparatus disclosed makes it immediately applicable to many computer vision applications.
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FIELD OF THE INVENTION
This invention relates to a sliding contact guide for a power transmission utilizing an endless, circulating, flexible power transmission medium. It relates, for example, to a guide in a chain drive transmission, in which a chain transmits power from a driving sprocket to a driven sprocket, or to a guide in a belt drive transmission, in which a belt transmits power from a driving pulley to a driven pulley.
BACKGROUND OF THE INVENTION
In general, as shown in FIG. 9 , a chain or belt transmission device for valve timing in an internal combustion engine, or for transmitting rotational power in another drive mechanism, includes a chain or belt CH, which transmits power from a driving sprocket or pulley S 1 to one or more driven sprockets or pulleys S 2 . The transmission includes a pivotally mounted, movable sliding contact guide Ga, which cooperates with a tensioner, and a fixed sliding contact guide Gb. The movable guide and the fixed guide are attached to a frame E of the engine or other drive mechanism by suitable pins P or by bolts, or similar mountings. The guides make sliding contact with the chain or belt CH, and prevent vibration of the chain or belt both in the plane of its traveling path (which is usually vertical), and in the transverse direction. The pivoting guide Ga cooperates with a tensioner T to maintain tension in the chain or belt.
FIG. 7 , is an exploded side view of a movable guide (i.e., a tensioner lever) 30 for use with a chain, as disclosed in Japanese Patent No. 3253951. FIG. 8 is bottom plan view of the guide. The guide 30 comprises a guide body including a shoe 31 on a surface of which chain CH travels in sliding contact. A plate-receiving portion 32 is provided on a back of the shoe 31 , and extends along the longitudinal direction of the guide. The plate-receiving portion and the shoe are integrally molded as a unit from a synthetic resin. A reinforcing plate 40 , composed of a rigid material, is fitted into a slot 32 a in an edge of the plate-receiving portion. This slot opens in a direction facing away from the shoe, and extends along the longitudinal direction of the guide. The plate-receiving portion 32 is provided with a mounting hole 32 b adjacent one end thereof, for mounting the guide body on a frame of an engine, or other machine. A mounting hole 41 is provided adjacent one end of the reinforcing plate 32 at a position such that it comes into register with the mounting hole 32 b when the reinforcing plate 40 is fitted into slot 32 a . This allows the guide body and reinforcing plate to be fastened together on a pivot means such as a mounting bolt, a mounting pin or the like.
Since the shoe 31 and the plate-receiving portion 32 are integrally molded as a unit from a synthetic resin, it is not necessary to provide a separate shoe. Thus, the number of parts, and the number of production steps are reduced. Further, since the reinforcing plate 40 is received in slot 32 a in the plate-receiving portion 32 the strength of the guide in its pivoting direction is increased, and its bending rigidity, toughness and strength are significantly improved. The use of this type of guide has increased rapidly due to the demand for low cost and high reliability.
However, in order to increase the strength of the guide, it is necessary to increase the thickness in the reinforcing plate. The increase in thickness results in an undesirable increase in the weight of the reinforcing plate and in the overall weight of the guide. Moreover, when reinforcing plates are formed by punching a rolled metallic sheet or by molding a fiber-reinforced resin, production difficulties are encountered when increased plate thickness is desired. Furthermore, some regions in the reinforcing plate require higher strength than others. For example the region surrounding the mounting hole, and the region adjacent the part that contacts the plunger of a tensioner, require higher strength than other regions. However, it was not easy to vary the strength of a conventional reinforcing plate to meet the requirements for added strength only in the regions where additional strength is needed. Accordingly, to meet these regional strength requirements, it was conventional practice to make the entire reinforcing plate thicker, and the result was an increase in the weight of the reinforcing plate and in the overall weight of the guide body.
Accordingly a general object of the invention is to solve one or more of the above-mentioned problems of conventional sliding contact guides. Another object of the invention is to provide a sliding contact guide having enhanced strength without increasing the weight guide. Still another object is to provide a simple way to control strength distribution in a guide, according to the strength requirements of respective regions of the guide body.
BRIEF SUMMARY OF THE INVENTION
The sliding contact guide in accordance with the invention comprises an elongated shoe composed of synthetic resin, an elongated plate-receiving portion, and a reinforcing plate. The shoe has front and back sides and a surface extending longitudinally on the front side for sliding contact with a flexible power transmission medium. The elongated plate-receiving portion, which is also composed of synthetic resin, is integrally molded as a unit with the shoe on the back side thereof. The plate-receiving portion extends longitudinally along the back side of the shoe and has a longitudinally extending slot. The slot has opposed walls disposed in perpendicular relation to the transmission medium-contacting surface. A body mounting hole extends through the plate-receiving portion adjacent one end of the guide and intersecting the slot. The reinforcing plate, for reinforcing the guide, fits in the slot and has opposite surfaces respectively in opposed relationship to the opposed walls of the slot, and a through hole in register with the body mounting hole. In accordance with the invention, at least one of the opposite surfaces of the reinforcing plate has a concavo-convex shape.
The concavo-convex shape can be formed by bends along lines extending parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe. Alternatively, the concavo-convex shape can be formed by at least one bend extending substantially parallel to the direction of elongation of the shoe. At regions requiring increased strength, the bend lines can be closer together than the bend lines in other regions.
The materials, which form a guide body in the invention, are not significantly limited. However, since the sliding contact surface of the guide body functions as a shoe, the materials of the guide body are preferably so-called engineering plastics such as polyamide resin and the like, having high durability and superior lubricating properties. Suitable materials include nylon 6, nylon 66, all aromatic nylons and the like. Furthermore, fiber reinforced plastics may be used alone, or in combination with other materials, depending on requirements such as bending strength and the like.
Provided that the materials of the reinforcing plates have sufficient bending rigidity and strength, they are also not limited significantly. However, the materials of the reinforcing plates are preferably iron-based metals such as cast iron, stainless steel and the like, non-ferrous metals containing aluminum, magnesium, titanium or the like as the main component, engineering plastics such as polyamide resin, fiber-reinforced plastics, and the like.
By virtue of the concavo-convex shape of the reinforcing plate, the plate has an improved load-supporting capability over that of a conventional reinforcing plate composed of the same material. The sliding contact guide exhibits a significantly higher strength compared to that of a flat reinforcing plate having the same thickness.
When the concavo-convex shape is formed by bend lines parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe, the guide has improved strength to withstand loads exerted in the direction perpendicular to its shoe, for example impact loads exerted by the plunger of a tensioner cooperating with the guide.
On the other hand, when the concavo-convex shape is formed by one or more bend line extending in the longitudinal direction of the reinforcing plate, higher strength is exerted in longitudinal directional, so that the guide is better able to withstand longitudinal loads, such as vibration due to the pivoting of the guide or the like.
The density of the concavo-convex portions of the reinforcing plate can be varied by selecting the spacing of the bend lines, and accordingly the strength of the plate can be selectively enhanced in regions where larger loads are applied, such as the portion engaged by a plunger of the tensioner, or the portion surrounding the mounting hole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view showing a movable guide according to a first embodiment of the invention;
FIG. 2 is a bottom plan view of the movable guide shown in FIG. 1 ;
FIG. 3 is an exploded view of a cross-section of the movable guide taken on the plane —III—III— in FIG. 1 , the exploded view also showing a mounting pin;
FIGS. 4( a ), 4 ( b ) and 4 ( c ) are bottom plan views, corresponding to FIG. 2 , of guides in accordance with further embodiments of the invention, showing alternative shapes for the reinforcing plate;
FIG. 5 is an exploded perspective view showing a mova0ble guide according to still another embodiment of the invention;
FIG. 6 is a cross sectional view taken on plane —VI—VI— in FIG. 5 ;
FIG. 7 is an exploded side view of a conventional movable guide
FIG. 8 is a bottom plan view of the conventional movable guide shown in FIG. 7 ;
FIG. 9 is an elevational view showing sliding contact guides in the valve timing transmission of an internal combustion engine; and
FIG. 10 is a bottom plan view corresponding to FIG. 2 , showing bend lines near the ends of a reinforcing plate that are closer together than the bend lines in a central portion of the plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 , a plastic movable guide 10 is formed by incorporating a reinforcing plate 20 into a guide body in the direction of the arrow.
This guide body is a plastic body integrally molded as a unit from synthetic resin, and comprises a shoe 11 having a surface on one side for sliding contact with a traveling chain, and a plate-receiving portion 12 provided on the back side of the shoe 11 and extending along the longitudinal direction of the guide. The guide body includes a flange 12 f formed at an edge of the plate-receiving portion 12 remote from the shoe 11 , and a boss 12 c having a mounting hole 12 b for pivotally mounting the guide body on the frame of an engine, or other machine incorporating a flexible transmission medium. The plate-receiving portion 12 has truss-shaped reinforcing ribs 12 e , and a slot 12 a opening at flange 12 f , facing away from the shoe, and extending along the longitudinal direction of the guide.
To reinforce the guide body, a reinforcing plate 20 , having a mounting hole 21 , is fitted into the slot 12 a . Holes 22 are locking holes for engagement with locking pieces 12 g of the guide body when the reinforcing plate 20 is inserted into the guide body, in order to secure the reinforcing plate 20 to the guide body.
A plunger-receiving portion 12 d is provided adjacent the pivoting front-end portion of the guide body for engagement with the plunger of a tensioner. The shape of the plunger-receiving portion 12 d is not limited especially. For example, to prevent the plunger from becoming dislodged from the plunger-receiving portion 12 d by transverse vibration, a protruding portion (not shown) is preferably formed at the edge of the flange 12 a , for preventing transverse shift of the plunger.
With the reinforcing plate 20 fitted into it, the movable guide is attached to the frame of an engine, or other machine, by a mounting pin or mounting bolt such as the shoulder bolt 13 shown in FIG. 3 . The mounting bolt has a pivot portion 13 A which is received in the holes 12 b and 21 of the guide body and reinforcing plate, respectively. The mounting bolt not only establishes a pivot, but also assists holes 22 and locking pieces 12 g in fastening the guide body 10 and the reinforcing plate 20 together.
The reinforcing plate 20 is molded in a bent shape by pressing a metallic rolled sheet using a wave-shaped mold such that the bending lines of the plate are parallel to the walls of slot 12 a , but transverse to the shoe, as shown in FIG. 1 . The thickness of the material from which the reinforcing plate is formed is approximately one-half the width in the slot 12 a . However, by virtue of the concavo-convex configuration of the reinforcing plate, it can fill the slot 12 a as can be seen in FIG. 2 . The reinforcing plate, bent as shown in FIGS. 1 and 2 , can withstand large loads directed in the pivoting direction of the guide, and the guide exhibits a strength that is the same as or greater than that of a flat reinforcing plate having a thickness the same as the slot width.
Although the reinforcing plate 20 was molded into a bent shape by pressing a rolled metallic sheet, the concavo-convex shape on the surface of the reinforcing plate can be also obtained by a die casting process, using a die casting mold having a concavo-convex shape. A fiber-reinforced resin can also be formed into the concavo-convex shape
The concavo-convex shapes of the surface of the reinforcing plate are not limited to the shape shown in FIG. 2 . Alternatively, a wave type shape such as shown in FIG. 4( a ) can be adopted. Likewise, a bent shape, as shown in FIG. 4( b ), having no longitudinally extending flat portions can be used. As a further alternative, a shape in which ribs 20 a are formed on both surfaces of a reinforcing plate, as shown in FIG. 4( c ), may be used. In the embodiments shown in FIGS. 2 and 4( a ) to 4 ( c ), a regular concavo-convex shape is formed, in which the bends are disposed at equal intervals. However, a more dense configuration of bend lines can be used to enhance the strength of the reinforcing plate. Thus, the concavo-convex shape in portions positioned at regions where a large load is applied, such as a region near the tensioner receiving portion 12 d , and/or a region near the boss 12 c , can be formed with a bend line density greater than that in other regions of the reinforcing plate formed than in other regions so that the strength of the guide can be selectively improved.
The embodiment shown in FIGS. 5 and 6 , is substantially the same as the embodiments of FIGS. 1–4( c ) except that the reinforcing plate 20 is formed so that the bending lines extend along the longitudinal direction of the reinforcing plate, and enhances the strength on the load in the longitudinal direction of the guide.
In the embodiments described so far, each of the guides is a movable guide, supported for pivotal movement on a mounting pin, bolt or the like. However, the invention can be applied to a fixed guide attached to a frame of an engine or the like by two mounting pins or bolts.
The most important advantages of the invention may be summarized as follows.
First, the concavo-convex shape of the reinforcing plate, provides the plate with an improved load-supporting capability. The sliding contact guide exhibits a significantly higher strength compared to that of a flat reinforcing plate having the same thickness. As a result the weight of the guide can be decreased, which contributes to improved fuel economy in the case of an engine.
When the concavo-convex shape is formed by bend lines parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe, the guide has improved strength to withstand loads exerted in the direction perpendicular to its shoe, for example impact loads exerted by the plunger of a tensioner cooperating with the guide.
On the other hand, when the concavo-convex shape is formed by one or more bend line extending in the longitudinal direction of the reinforcing plate, higher strength is exerted in longitudinal directional, so that the guide is better able to withstand longitudinal loads, such as vibration due to the pivoting of the guide or the like.
The density of the concavo-convex portions of the reinforcing plate can be varied by selecting the spacing of the bend lines, and accordingly the strength of the plate can be selectively enhanced in regions where larger loads are applied, such as the portion engaged by a plunger of the tensioner, and/or the portion surrounding the mounting hole. Thus, the bend lines can be formed close together at and near the ends of the reinforcing plate, and farther apart in the central portion of the plate as shown in FIG. 10 .
The sliding contact guide according to the invention can be produced simply by changing the molds, dies or the like used to reproduce the reinforcing plate. Thus, production cost is not increased. Moreover the material cost is reduced. Therefore, the invention has significant industrial value.
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In a sliding contact guide for a flexible power transmission medium such as a chain or belt, the guide body includes a shoe and a plate-receiving portion integrally molded as a unit from a synthetic resin. A reinforcing plate is inserted into a slot in the plate-receiving portion. A surface of the reinforcing plate is of a concavo-convex shape. The concavo-convex shape enhances the strength of the reinforcing plate without increasing the overall weight of the guide. By controlling the spacing of the bend lines forming the concavo-convex configuration, the strength of the guide can be controlled in accordance with strength requirements for different regions of the guide.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mooring devices and more particularly pertains to a new spring loaded mooring device for attaching a mooring device or other type of supporting device to a dock or the like.
2. Description of the Prior Art
The use of mooring devices is known in the prior art. More specifically, mooring devices heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art mooring devices include U.S. Pat. No. 4,899,680; U.S. Pat. No. 4,297,963; U.S. Patent Des. 321,470; U.S. Pat. No. 3,473,505; U.S. Pat. No. 849,023; and U.S. Patent Des. 273,176.
In these respects, the spring loaded mooring device according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of attaching a mooring device or other type of supporting device to a dock or the like.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of mooring devices now present in the prior art, the present invention provides a new spring loaded mooring device construction wherein the same can be utilized for attaching a mooring device or other type of supporting device to a dock or the like.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new spring loaded mooring device apparatus and method which has many of the advantages of the mooring devices mentioned heretofore and many novel features that result in a new spring loaded mooring device which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art mooring devices, either alone or in any combination thereof.
To attain this, the present invention generally comprises an eyelet with an annular configuration and residing within a first plane. It should be noted that the eyelet has a predetermined diameter. Note FIGS. 7-9. Also included is a linear rod having a first end connected to an outer edge of the eyelet. The rod extends from the eyelet along a line which resides in a second plane that forms an angle ranging from 1 degree to 90 degrees with the first plane. As shown in the Figures, the rod has a length which is about twice the diameter of the eyelet. Next provided is a linear cross bar with a length about 1/2 that of the rod. The cross bar is coupled at a central extent thereof to a second end of the rod. Further, the cross bar resides within the second plane. Ideally, the cross bar includes a pair of flared, sharpened spurs each integrally mounted to ends of the cross bar and extending perpendicularly therefrom in parallel with the eyelet. In the preferred embodiment, the eyelet, rod, and cross bar are formed of a rigid metal with a constant circular cross-section. Finally, a plate is provided with a planar circular configuration. A concentric aperture is formed in the plate for being slidably received on the rod. Associated therewith is a coil spring encompassing the rod between the eyelet and the plate for urging the plate against the cross bar.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new spring loaded mooring device apparatus and method which has many of the advantages of the mooring devices mentioned heretofore and many novel features that result in a new spring loaded mooring device which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art mooring devices, either alone or in any combination thereof.
It is another object of the present invention to provide a new spring loaded mooring device which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new spring loaded mooring device which is of a durable and reliable construction.
An even further object of the present invention is to provide a new spring loaded mooring device which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such spring loaded mooring device economically available to the buying public.
Still yet another object of the present invention is to provide a new spring loaded mooring device which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new spring loaded mooring device for attaching a mooring device or other type of supporting device to a dock or the like.
Even still another object of the present invention is to provide a new spring loaded mooring device that includes an eyelet with a rod having a first end connected thereto. A cross bar is coupled at a central extent thereof to a second end of the rod. A spring mechanism is adapted for being urged toward the cross bar with a recipient surface situated therebetween.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIGS. 1 & 2 are illustrations of the prior art associated with the present invention.
FIGS. 3A & 3B are a perspective views of the hook embodiments of the present invention.
FIG. 4 is a perspective view of the fishing pole supporting embodiment of the present invention.
FIG. 5 is a side view of the lazy susan embodiment of the present invention in use.
FIG. 6 is a perspective view of the embodiment of the present invention shown in FIG. 5.
FIG. 7 is a front view of the mooring embodiment of the present invention.
FIG. 8 is a side view of the mooring embodiment of the present invention.
FIG. 9 is a cross-sectional view of the present invention taken along line 9--9 shown in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 through 9 thereof, a new spring loaded mooring device embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
The present invention, designated as numeral 10, includes an eyelet 12 with an annular configuration and residing within a first plane. Note FIGS. 7-9.
Also included is a linear rod 14 having a first end connected to an outer edge of the eyelet. The rod extends from the eyelet along a line which resides in a second plane that forms an angle ranging from approximately 1 degree to approximately 90 degrees with the first plane. As shown in the Figures, the rod has a length which is about twice the diameter of the eyelet.
Next provided is a linear cross bar 16 with a length about 1/2 that of the rod. The cross bar is coupled at a central extent thereof to a second end of the rod. Further, the cross bar resides within the second plane. Ideally, the cross bar includes a pair of flared, sharpened spurs 17 each integrally mounted to ends of the cross bar and extending perpendicularly therefrom in parallel with the eyelet.
In the preferred embodiment, the eyelet, rod, and cross bar are formed of a rigid metal with a constant circular cross-section, as shown in FIG. 9.
Finally, a plate 18 is provided with a planar circular configuration having a diameter slightly less than that of the eyelet. A concentric aperture is formed in the plate for being slidably received on the rod. Associated therewith is a coil spring 20 encompassing the rod between the eyelet and the plate for urging the plate against the cross bar.
By this structure, the cross bar may be inserted between a pair of adjacent planks. Thereafter, the cross bar is rotated and maintained in place by way of the plate and spring. The eyelet, or supporting means, may thus be secured to the planks which may constitute a portion of a dock, fence, table or the like.
In various alternate embodiments shown in FIGS. 3-6, the supporting means may take alternate forms such as a hook 22 for hanging a plant or the like on a fence. Note FIG. 3A. FIG. 3B shows a similar embodiment being used in conjunction with a cinder block or the like. As shown in FIG. 4, the supporting means includes an angled tube 24 for releasably receiving a fishing pole and securing the same to a dock. Lastly, the supporting means may further take the form of a lazy susan 28 for being secured on a table.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A device is provided including an eyelet with a rod having a first end connected thereto. A cross bar is coupled at a central extent thereof to a second end of the rod. A spring mechanism is adapted for being urged toward the cross bar with a recipient surface situated therebetween.
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RELATED APPLICATION
This application is a Divisional of U.S. patent application Ser. No. 11/461,651, filed Aug. 1, 2006, now U.S. Pat. No. 8,362,135, which claims the benefit of U.S. Provisional Application No. 60/704,625, filed Aug. 2, 2005, the entire teachings of which are incorporated herein by reference.
BACKGROUND
Lime plasters have a history that spans thousands of years. Historically, lime was used to plaster floors at least as early as 9,000 B.C. Lime plaster was used in Imperial Rome, 13 th -century England, 11 th -century Mayan cities, Japan, Germany, India, Southeast Asia, Central America and Colonial America.
Ancient lime plasters, renders, stuccos, and washes formed of lime have lasted to this day through history giving building lime an exceptional track record. Lime lasts a long period of time, making it an excellent medium for long term repairs and maintenance.
SUMMARY
Described herein are improved compositions for the long term restoration and repair of lime plasters, as well as for other structures and materials, such as ceramics, wood, and stone. Also disclosed are methods for using those compositions in assembly and new construction, as these methods are not limited to restoration and repair procedures. Two surfaces are bonded using a two-step procedure, wherein a conditioner composition is applied and then an adhesive composition is applied to the surface. An advantage of embodiments of these compositions is that they are less toxic and more environmentally safe compared to other construction adhesives.
For example, a method for adhering a plaster composition to a structure, e.g., a support structure such as a wooden lath or masonry (such as brick, terra cotta blocks, cement blocks or stone), is carried out by administering, e.g., by applying, injecting, spraying, painting, a conditioner composition into a gap between the plaster and the support structure, the conditioner composition comprising a polymer having the Chemical Abstracts registry number (CAS No.) 222414-16-6 (such as the commercially available RHOPLEX 1834 acrylic emulsion, which includes 47±0.05% solids, and has a pH of 9.3-10.2, a density of about 8.8 lbs/gal at 25° C. and a glass-transition temperature of 13° C. from Rohm & Haas of Philadelphia, Pa., USA), or similar acrylic emulsion, and administering, e.g., by applying, injecting, spraying, painting, an adhesive composition into the gap, the adhesive composition comprising RHOPLEX 1834, or similar acrylic emulsion among other modifiers.
In some embodiments, the method further comprises creating ports (i.e., bores) in the plaster through which the conditioner composition and the adhesive composition are injected. The plaster is brought toward the support structure (before or after injection of the adhesive composition) such that the adhesive composition can penetrate both into the plaster and into the support structure; and the position of the plaster relative to the support structure is maintained by a fastener, e.g., a screw, passed through the plaster and into the support structure.
The composition of the conditioner includes a polymer-containing emulsion such as RHOPLEX 1834, or similar acrylic emulsion. In various embodiments, the conditioner also includes water and/or isopropanol. For example, the conditioner composition includes: approximately 45 volume-percent RHOPLEX 1834, or similar acrylic emulsion; approximately 45 volume-% water; and, approximately 10 volume-% isopropanol. The adhesive composition optionally includes a polymer having the Chemical Abstracts registry number (CAS No.) 253351-13-2 (such as the commercially available RHOPLEX 1950 acrylic emulsion, which is about 63% solids, has a pH of about 5.0, a viscosity of about 150 cps at 25° C., a density of about 8.7 lb/gal at 25° C., and a glass-transition temperature of about −50° C., and which is also from Rohm & Haas of Philadelphia, Pa., USA), or similar acrylic emulsion. For example, the adhesive composition for use with plaster, metal and glass includes an adhesive foundation containing• approximately 60 volume-percent RHOPLEX 1834, or similar acrylic emulsion; and, approximately 40 volume-percent RHOPLEX 1950, or similar acrylic emulsion.
In another embodiment, a more-rigid adhesive for use in bonding ceramic tile includes RHOPLEX 1834, or similar acrylic emulsion, and RHOPLEX 1950, or similar acrylic emulsion, at a ratio of approximately 2 parts RHOPLEX 1834, or similar acrylic emulsion, and 1 part RHOPLEX 1950, or similar acrylic emulsion; this more-rigid formulation (2:1) is suitable in this context because ceramic tile applied to cement board has very little flexibility. The ratio can be increased to 90-100 volume-percent RHOPLEX 1834, or similar acrylic emulsion; and, 10-0 volume-percent RHOPLEX 1950, or similar acrylic emulsion, to make it less flexible if the situation calls for it. In yet another embodiment, the ratio of RHOPLEX 1834, or similar acrylic emulsion, and RHOPLEX 1950, or similar acrylic emulsion, is approximately 2:3. In a highly flexible embodiment that can be used, e.g., to bond wood structures, the ratio of RHOPLEX 1834, or similar acrylic emulsion to RHOPLEX 1950, or similar acrylic emulsion, is approximately 1:2; the bonding of wood to wood requires this increased flexibility to accommodate the natural flexibility and movement of wood.
The method includes a step of adding a thickener composition to the adhesive foundation to form the adhesive composition, the adhesive composition having a viscosity that is higher than that of the adhesive foundation. For example, the thickener composition and the adhesive foundation are mixed at concentrations in the following ranges: approximately 80 to 85 volume-% base adhesive composition; and, approximately 15 to 20 volume-% thickener composition. The thickener serves an important function in this adhesive system. On its own, the thickener is a high-viscosity material (i.e., a thick gel). Added to the mixture of acrylic emulsions, the thickener allows the mixed adhesive to function with two different viscosities. When at rest (subjected to low shear rates), the adhesive has high viscosity similar to that of shaving cream. When injected under pressure (high shear rates), the adhesive will flow easily, demonstrating low viscosity. This property (referred to as thixotropy) is of great advantage in vertical applications.
In a method of adhering a plaster or other substrate to a support structure, a conditioner is injected and allowed to set for 2, 5, 10, 15, 20, 30 minutes depending upon conditions (e.g., as temperature drops or as humidity rises, the conditioner can be allowed to set for a longer period of time); and then no later than ½ hour after the injection of the conditioner, the adhesive is applied. In one embodiment, the adhesive composition is delivered to the surfaces 10 minutes after the delivery of the conditioner composition. These techniques likewise apply to many other adhesive applications, including but not limited to new assemblies, new and existing construction, restoration, and repair.
Also disclosed is an adhesive foundation. For example, the adhesive foundation in this embodiment includes approximately 60 volume-% RHOPLEX 1834, or similar acrylic emulsion; and, approximately 40 volume-% RHOPLEX 1950, or similar acrylic emulsion. In another example, the adhesive composition contains: an adhesive foundation including approximately 60 volume-% RHOPLEX 1834, or similar acrylic emulsion and approximately 40 volume-% RHOPLEX 1950 or similar acrylic emulsion; and a thickener composition including approximately 16.8 volume-% of a polymer having the Chemical Abstracts registry number (CAS No.) 37325-11-4 (such as that known as ACRYSOL ASE-60 thickener, which includes 28% solids, and has a pH of 3.5, a specific gravity of 1.054 at 25° C., a viscosity of 10 mPa·s, and a glass-transition temperature of 13° C. from Rohm & Haas of Philadelphia, Pa., USA), or similar acrylic emulsion; and, approximately 81.9 volume-% water; and a weak or strong base in sufficient quantities to ensure the transformation of the ASE-60, or similar acrylic emulsion/water mixture into the “thickener gel”. In particular embodiments, the base can be ammonium hydroxide, potassium hydroxide, or morpholine (C 4 H 9 NO, CAS No. 110-91-8) at approximately 1 volume-% or less in the adhesive. In the formulation described above, the adhesive composition includes: approximately 80 to 85 volume-% adhesive foundation; and, approximately 15 to 20 volume-% thickener composition.
A kit for adhesive use contains the following items and/or compositions:
a) a first container containing a conditioner composition, the conditioner composition including:
i) approximately 45 volume-% RHOPLEX 1834, or similar, acrylic emulsion; ii) approximately 45 volume-% water; and iii) approximately 10 volume-% isopropanol,
b) the second container containing an adhesive composition, the adhesive composition including:
i) an adhesive foundation including:
a) approximately 60 volume-% RHOPLEX 1834, or similar, acrylic emulsion; and b) approximately 40 volume-% RHOPLEX 1950, or similar, acrylic emulsion; and
ii) a thickener composition including:
a) approximately 16.8 volume-% ACRYSOL ASE-60, or similar acrylic emulsion, thickener; and b) approximately 81.9 volume-% water; and c) a weak or strong base in sufficient quantities to ensure the transformation of the ASE-60, or similar acrylic emulsion/water mixture, into the “thickener gel” added to the adhesive foundation at a volume of approximately 15%-20% of the adhesive foundation.
A variety of advantages can be obtained via use of the compositions and methods described herein. The adhesive composition after setting is water resistant and provides a deep, strong bond between surfaces, even when used to bond dirty, gritty and/or friable surfaces, i.e., under conditions where many other types of adhesives are ineffective. The set adhesive composition remains flexible under cold conditions and maintains its structure and adhesion of the surfaces on a near-permanent basis in warm conditions. The use of the conditioner (primer) enhances the ability of the adhesive to bond in unfavorable circumstances, such as uneven or dirty surfaces, described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the stabilization of historic plaster.
FIG. 2 shows a masonry bit for drilling into the plaster.
FIG. 3 shows a dispersal device for delivering the conditioner composition.
FIG. 4 shows a screw and a washer used to bring the plaster into contact with the lath.
FIG. 5 shows the drilling of injection ports through the plaster.
FIG. 6 shows the delivery of conditioner composition through the ports.
FIG. 7 shows the injection of adhesive composition into the ports.
FIG. 8 shows the temporary clamping of the plaster into soft contact with the laths.
FIG. 9 shows the cleaning of exposed surfaces after the adhesion.
FIG. 10 shows the infrared spectrum for RHOPLEX 1834.
FIG. 11 shows the infrared spectrum for RHOPLEX 1950.
FIG. 12 shows the infrared spectrum for ACRYSOL ASE-60.
FIG. 13 shows the overlay of infrared spectra for RHOPLEX 1834, RHOPLEX 1950, and ACRYSOL ASE-60.
DETAILED DESCRIPTION
Specifically described in the foregoing text are methods for repairing, restoring, and preserving the integrity of historical and ornamental plasters, such as lime plasters, gypsum plaster, and Portland cement plaster, as well as additional structures and materials. These methods can likewise be used for new assembly, wherein original structures are constructed from newly manufactured materials. Additional materials that can be bonded via these methods include ceramic tile, vinyl tile, linoleum tile, wood, stone, leather, paper, metal, glass, terra cotta, brick, natural or synthetic fibers, fabric, foam, (such as foam made of polyurethane, polystyrene, or similar material), etc., and for other general repair or new assembly. The following description is particularly focused on the example of repairing lime plasters, though the same techniques are to be used with the repair and assembly of other materials.
Lime plasters have properties that make them excellent candidates for repair. Because lime crystallizes over an extended time frame, lime plasters are considered young at 100 years, and plaster may have had many decades to cure before repair is carried out. Additionally, lime plaster is flexible (relative to gypsum plaster or Portland cement plaster) and resistant to water damage. On exteriors, the outer-most layer is considered a sacrificial layer and is maintained with regular lime washes or treatment with limewater. With maintenance, historic plaster can last forever.
In either an interior or exterior repair context, an important factor is the compatibility of materials and building systems. This compatibility between the original material and the repair material is particularly important in an extreme environment. When the interior of the building has a wide range of environmental changes, e.g., humidity or temperature fluctuations, the compatibility issue becomes critical.
When in-kind replacements are the appropriate method of plaster repair, the repair material should have the same hardness, or be softer than the historic fabric, so that any loss of material comes from the repair and not from the original fabric.
Limestone is burned in a kiln to form quicklime (CaO) and then hydrated to form lime putty (building lime) [Ca(OH) 2 ]. The building lime is then allowed to cure by exposure to CO 2 (e.g., atmospheric) to form calcium carbonate (CaCO 3 ). Building limes are used to fabricate lime plasters, mortars, and washes.
The conservation of historic plasters is accomplished through the application of consolidates to friable areas and/or adhesive reattachment by injecting the conditioner and adhesive compositions between the plaster and its lath.
This lime plaster restoration procedure is determined, e.g., by the amount of separation of plaster from laths in the interior or exterior of a dwelling or other structure. If the plaster forms the ceiling of a room, and if the plaster separates from laths over time, then the plaster is likely to crack and sag, thereby causing the ceiling to droop downward. This phenomenon can occur with wall surfaces as well.
The stabilization of historic plaster 12 , as shown in FIG. 1 , includes the following four stages: (1) drilling injection ports 14 through the plaster 12 or through the wood laths 16 and inspecting the gap between the plaster 12 and the laths 16 ; (2) injecting a conditioner composition from a sprayer 24 (as shown in FIG. 6 ) into the gap 20 between the plaster 12 and the laths 16 , priming both surfaces; (3) injecting an adhesive composition 18 into the gap 20 ; and, (4) bringing the plaster 12 back toward the laths 16 , e.g., by clamping the plaster 12 to the laths 16 (using the screws 32 and washers 34 of FIG. 4 ) and tightening to insure “soft” contact between the adhesive composition 18 , the plaster 12 , and the lath 16 . In one embodiment, the steps are performed in the order listed above; alternatively, plaster 12 can be clamped before the injection of the conditioner composition and before the adhesive composition is applied into the gap 20 .
In stage (1), identified above (and illustrated in FIG. 5 ), injection ports (holes) 14 are drilled through the plaster 12 with a 3/16-inch masonry bit 22 (illustrated in FIGS. 2 and 5 ); the ports 14 can have, e.g., a diameter of 3/16 inches (4.8 mm). A measuring device or other object (e.g., an awl, or a screwdriver) can then be inserted through a port 14 , and one can measure the distance it travels before striking the lath and thereby gauge the size of the gap between the plaster and the lath. When selecting drilling sites for a vertical wall crack or a ceiling crack, one can commence by drilling 1.5 to 2 inches (approximately 3.8 to approximately 5.1 cm) away from the crack, every other lath or spaced approximately 2.75 to 3 inches (approximately 7.0 to approximately 7.6 cm) apart vertically (or laterally on a ceiling) along the entire length of the crack 23 . More or fewer injection sites can be used, depending on the severity of displacement. At greater distances of displacement between the two surfaces, a greater number of injection ports are used; i.e., the degree of displacement is directly correlated with the number of injection ports.
In stage (2), shown in FIG. 6 , a conditioner composition 26 is delivered, e.g., by injection, through the ports using a dispersal device 24 , e.g., a high-quality garden sprayer, to consolidate the fine dust and dirt found on the surfaces to be adhered. The conditioner composition 26 comprises the following ingredients:
(a) approximately 45 volume-% RHOPLEX 1834, or similar acrylic emulsion; and (b) approximately 45 volume-% water; and (c) approximately 10 volume-% isopropanol (99%).
“Similar” acrylic emulsions for use in the conditioner (and adhesive) composition will promote conditioning (and adhesive) properties similar to (or substantially the same as) those promoted by the RHOPLEX 1834 acrylic emulsion. Compositions that are substantially the same can also share the same chemical constituents as RHOPLEX 1834 acrylic emulsion, have the same polymer type, include approximately the same solids content, have approximately the same viscosity, and/or have approximately the same glass transition temperature. On the other hand, one example of a difference in a polymer that is nevertheless “substantially the same” can be, e.g., in polymer chain length. For example, the acrylic emulsion can be various copolymers formed from a mixture of monomers comprising at least two monomers selected from (C 1 to C 8 ) alkyl(meth)acrylates, (meth)acrylic acid, and styrene, as described in U.S. Pat. No. 6,423,805, which is incorporated herein by reference in its entirety. References herein to other emulsions and polymers that are “substantially the same as” recited commercial products and polymers having particular CAS numbers likewise share common properties, such as those noted above (including +/−20% variance of the physical properties, such as adhesive strength, of the referenced compositions, such as RHOPLEX 1834 or 1950 acrylic emulsions).
The conditioner composition 26 prepares the surfaces of the plaster 12 and the laths 16 (e.g., by consolidating dirt and grit and by reducing friability of the matrices at the surfaces) to allow the adhesive composition (in stage 3) to better grip both surfaces and to draw acrylic chains into the matrices of the plaster and lath surfaces, thereby promoting a deep bond.
In stage (3), illustrated in FIG. 7 , an adhesive composition 18 , which includes an adhesive foundation thickened with a thickener composition, is injected into the ports 14 ten minutes after the injection of the conditioner composition in stage (2). An embodiment of the adhesive foundation comprises the following ingredients:
(a) approximately 60 volume-% RHOPLEX 1834 or similar acrylic emulsion; and (b) approximately 40 volume-% RHOPLEX 1950 or similar acrylic emulsion.
In the adhesive composition, the RHOPLEX 1834, or similar, acrylic emulsion is comparatively more rigid than the RHOPLEX 1950, or similar, acrylic emulsion. Accordingly, increasing concentrations of the less-rigid RHOPLEX 1950, or similar, emulsion increases the flexibility of the adhesive composition, thereby improving the flexible bonding capability of the adhesive composition. The adhesive composition initially is milky white, though it dries to a translucent, e.g., “water white” appearance. RHOPLEX 1950 emulsion (binder) is described in U.S. Pat. No. 6,613,832, which is incorporated herein by reference in its entirety.
Before use, the adhesive foundation is mixed with a thickener composition at an approximate ratio, e.g., of 80 to 85% adhesive foundation to 15 to 20 volume-% thickener composition. An embodiment of the thickener composition comprises the following ingredients:
(a) approximately 16.8 volume-% ACRYSOL ASE-60, or similar acrylic emulsion, thickener (an acid-containing acrylic emulsion copolymer); (b) approximately 81.9 volume-% water; and (c) a weak or strong base in sufficient quantities to ensure the transformation of the ASE-60, or similar acrylic emulsion/water mixture into the “thickener gel.”
The ACRYSOL ASE-60, or similar acrylic emulsion, thickener is alkali-activated so when the base is added, the thickener composition takes the form of a gel that can serve as a thickener when combined with the adhesive foundation.
After the adhesive foundation and the thickener are mixed to form the adhesive composition 18 to the approximate viscosity of shaving cream, the adhesive composition 18 can be injected through the ports 14 in the plaster 12 using a caulk gun 30 or other delivery device, employing approximately one handle squeeze of the gun 30 per port 14 (or approximately 0.5 ounce adhesive per injection site). The adhesive composition 18 flows from the caulk gun 30 under pressure into the gap 20 between the plaster 12 and the lath 16 and then stays in place. Both the conditioner composition and adhesive composition penetrate up to 1, 2, 5, 10, 20 or 50 mm into the surfaces to be bonded. The conditioner composition can be applied at a pressure, e.g., of 10, 25, or 50 pounds per square inch, while the adhesive composition can be applied at a pressure, e.g. l of 25, 50 or 100 pounds per square inch.
Use of the conditioner composition and use of the water-borne acrylics in the adhesive composition allow for the formation of a soft bond shoulder (i.e., without a sharply defined border for acrylic penetration into the surfaces). For comparison, when traditional epoxies are used as consolidants, the epoxies cure in a manner that allows them to soak into the porous surfaces developing a “hard” or well-defined shoulder. This shoulder often becomes an area of future failure. In contrast, water borne acrylics, such as those described herein, cure (coalesce) via water evaporation leaving a less-defined, flexible edge, which is less prone to being a source of future fracture. Other chemistries, such as epoxies compounded to be soft, urethanes, and silicones, yield excellent results as well. Acrylics are our method of choice; the acrylics are pulled along, penetrating deeper into the plaster and wood/masonry lath matrices, with the water. Because the speeds of penetration and evaporation are slow, a diffuse border is formed between the areas of no acrylic and the areas completely filled with acrylic (i.e., there is a gradual change in acrylic concentration as one enters deeper into the structures to be bonded). Unlike “film” adhesives, the acrylic conditioner/adhesive compositions described herein penetrates to a substantial depth into the plaster and wood/masonry lath matrices (e.g., up to 1/16 inch, ⅛ inch or even ¼ inch), depending on the porosity of the matrices and on the amount of material applied.
The porosity of the materials being “glued together” has a direct effect on the degree to which the conditioner and adhesive penetrates the two surfaces. This adhesive coalesces by releasing water into the porous structure of the material and thereby evaporates. The greater the three-dimensional texture and porosity of a material, the greater the surface area for adhesion, and the more pores the adhesive can penetrate. Wood, pottery, and ceramic tiles are excellent examples of porous surfaces where the adhesive is able to form a deep, penetrating purchase. In particular embodiments, at least one of the materials to be bonded is porous. For example, as smooth as glass tiles are, they can be bonded to a porous material.
In stage (4), shown in FIG. 8 , the plaster 12 is temporarily clamped into soft contact with the laths via screws inserted through 2-inch plastic washers 34 and then through the ports 14 in the plaster 12 and then to the laths, into which they are screwed, e.g., with a hand or power screwdriver 36 . The screws 32 are tightened until the plaster is drawn to a distance from the laths within the tolerance of the thickened acrylic-emulsion adhesive composition 18 (as much as 3/16 inch, preferably 1/32 to 1/16 inch) to adhere to and penetrate into both surfaces. As previously noted, stage (4) can be performed either before or after injection of the conditioner composition and injection of the adhesive composition into the gap between the plaster and the laths.
Finally, exposed surfaces can be cleaned with warm water and a soft sponge, 38 (as shown in FIG. 9 ). The adhesive is allowed to cure for a minimum of 24 hours. The washers or braces are then removed. Dried adhesive can be removed with a putty knife or metal window scraper. Drill holes and cracks can be filled with a material, such as plaster or joint compound.
The repair adhesive for plaster must be able to bond in difficult circumstances because the conditions encountered in re-establishing the bond between historic plaster and lath are adverse. These properties make the adhesive well suited for any type of adhesive task. In easy-to-bond circumstances it will function particularly well and outperform others. Whether easy or difficult conditions exist for bonding, the adhesive composition bonds by penetrating the matrices and consolidating the surfaces, thus allowing the adhesive to achieve complete attachment.
In addition to the use of these compositions and methods for adhering plaster to wood lath, brick or terra cotta block the compositions and methods can similarly be used to repair like materials, as well as to adhere different materials to each other (both structural and non-structural), such as plaster to plaster, wood to wood, glass to glass, metal to metal, plaster to wood, synthetic tile to plywood, ceramic tile to drywall, glass tile to cement board, metal to plaster, and wood to metal, foam to foam, foam to wood, foam to metal, foam to glass, fabric to fabric, fabric to most any other porous material, as well as many other unlike material uses.
In another application, where the adhesive is used to bond ceramic tile to a substrate, such as cement, the surfaces of the tile and substrate to be bonded are first cleaned. The conditioner composition is then applied (e.g., sprayed) onto both surfaces. After a ten-minute set time, (whereby the conditioner penetrates or soaks into the substrate), an even layer of the adhesive composition is spread using a ⅛-inch notched spreader on one surface. The tile is then set in place on the substrate and secured in place. The exposed surface of the tile and the surrounding area can then be cleaned with warm water and a soft sponge. The adhesive is then allowed to cure for at least 24 hours. If the tile is installed on a floor, a 72-hour cure should be provided to afford full strength of the bond. Because the adhesive is water-based, a longer setting period may be needed for particularly large or less porous tiles. After the adhesive has set, grout can be filled around the edges of the tile, as desired.
In another embodiment, where a wood bond is repaired, the surfaces to be bonded are again cleaned first. The conditioner is sprayed or brushed onto both surfaces. After a ten-minute set time, a thin layer (e.g., approximately 1/16-inch thick) of adhesive is applied to one surface. The two surfaces are then clamped or braced into soft contact (e.g., with mechanical fasteners or adjustable straps). The exposed surfaces can then be cleaned with warm water and a soft sponge, and the bond is allowed to cure for 24 hours.
In describing embodiments of the invention, specific terminology is used for the sake of clarity. For purposes of description, each specific term is intended to at least include all technical and functional equivalents that operate in a similar manner to accomplish a similar purpose. Additionally, in some instances where a particular embodiment of the invention includes a plurality of system elements or method steps, those elements or steps may be replaced with a single element or step; likewise, a single element or step may be replaced with a plurality of elements or steps that serve the same purpose. Moreover, while this invention has been shown and described with references to particular embodiments thereof, those skilled in the art will understand that various other changes in form and details may be made therein without departing from the scope of the invention.
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Improved compositions for the restoration, repair and assembly of materials include (a) a conditioner composition including a polymer that matches or is substantially the same as that to which Chemical Abstracts registry number (CAS No.) 222414-16-6 is assigned (commercially available as RHOPLEX 1834 acrylic emulsion) and (b) an adhesive composition that also includes a polymer that matches or is substantially the same as that to which CAS No. 222414-16-6 is assigned. Adhesive composition can also include a polymer that matches or is substantially the same as that to which CAS No. 253351-13-2 (commercially available as RHOPLEX 1950 acrylic emulsion) is assigned. First, the conditioner composition is injected into a gap between the two structures to be adhered. Next, the adhesive composition is injected into the gap. In one embodiment, the compositions are used to restore and repair historic plaster ceilings and walls.
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BACKGROUND OF THE INVENTION
[0001] The present embodiments relate to wireless communication systems and, more particularly, to operation of a communication system in which a user equipment (UE) communicates with a base station (eNB) equipped with a large number of antennas.
[0002] With Orthogonal Frequency Division Multiplexing (OFDM), multiple symbols are transmitted on multiple carriers that are spaced apart to provide orthogonality. An OFDM modulator typically takes data symbols into a serial-to-parallel converter, and the output of the serial-to-parallel converter is frequency domain data symbols. The frequency domain tones at either edge of the band may be set to zero and are called guard tones. These guard tones allow the OFDM signal to fit into an appropriate spectral mask. Some of the frequency domain tones are set to values which will be known at the receiver. Among these are cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), and demodulation reference signals (DMRS). These reference signals are useful for channel measurement at the receiver. Cell-specific reference signals as well as channel state information reference signals are not precoded and are generated by a pseudo-random sequence generator as a function of the physical cell ID. In Releases 8 through 10 of the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS), which was designed for conventional point-to-point communication, the cell ID is not explicitly signaled by the base station (called eNB) but is implicitly derived by the UE as a function of the primary synchronization signal (PSS) and secondary synchronization signal (SSS). To connect to a wireless network, the UE performs a downlink cell search to synchronize to the best cell. A cell search is performed by detecting the PSS and SSS of each available cell and comparing their respective signal quality, for example, in terms of reference signal received power (RSRP). After the cell search is performed, the UE establishes connection with the best cell by deriving relevant system information for that cell. Similarly, for LTE Release 11 the UE performs an initial cell search to connect to the best cell. To enable multi-point CoMP operation, the connected cell then configures the UE by higher-layer signaling with a virtual cell ID for each CSI-RS resource associated with each respective base station involved in the multi-point CoMP operation. The UE generates the pseudo-random sequence for each CSI-RS resource as a function of the virtual cell ID.
[0003] Conventional cellular communication systems operate in a point-to-point single-cell transmission fashion where a user terminal or equipment (UE) is uniquely connected to and served by a single cellular base station (eNB or eNodeB) at a given time. An example of such a system is Release 8 of the 3GPP Long-Term Evolution. Advanced cellular systems are intended to further improve the data rate and performance by adopting multi-point-to-point or coordinated multi-point (CoMP) communication where multiple base stations can cooperatively design the downlink transmission to serve a UE at the same time. An example of such a system is the 3GPP LTE-Advanced system. This greatly improves received signal strength at the UE by transmitting the same signal to each UE from different base stations. This is particularly beneficial for cell edge UEs that observe strong interference from neighboring base stations.
[0004] Most UEs which communicate with a single eNB are configured with a single CSI-RS resource. Other UEs may be configured for CoMP where multiple eNBs coordinate with each other in servicing the UE. In particular, DL transmission from multiple adjacent eNBs is coordinated to avoid or cancel inter-cell interference. This effectively reduces interference and boosts the signal-to-noise ratio at the UE. One example of CoMP transmission is joint processing, where data for a single UE might be transmitted from multiple adjacent eNBs. A UE receiving CoMP transmission, therefore, needs to be configured with multiple CSI-RS resources in order to measure respective channels of multiple eNBs. In this case, each CSI-RS resource is separately configured by higher layer RRC signaling including the CSI-RS antenna port number, a CSI-RS resource index, periodicity and offset of the CSI-RS transmission, and relative transmit power of the CSI-RS.
[0005] FIG. 1 shows an exemplary wireless telecommunications network 100 . The illustrative telecommunications network includes base stations 101 , 102 , and 103 , though in operation, a telecommunications network necessarily includes many more base stations. Each of base stations 101 , 102 , and 103 (eNB) is operable over corresponding coverage areas 104 , 105 , and 106 . Each base station's coverage area is further divided into cells. In the illustrated network, each base station's coverage area is divided into three cells such as 104 a , 104 b , and 104 c . A handset or other user equipment (UE) 107 is shown in cell A 104 a . Cell A is within coverage area 104 of base station 101 . Base station 101 transmits to and receives transmissions from UE 107 over channel 108 . UE 107 is configured with CSI-RS resources to measure channel 108 from eNB 101 . UE 107 may also receive transmissions from eNB 102 . UE 107 is configured by higher layer RRC signaling with separate CSI-RS resources in order to measure channel 109 from eNB 102 .
[0006] Base stations 101 and 102 configure UE 107 for periodic uplink Sounding Reference Signal (SRS) transmission. Base station 101 estimates channel quality from the SRS transmissions. For downlink (DL) data transmission, UE 107 measures the DL wireless channel from DL reference signals and reports Channel State Information (CSI) to the eNB. The eNB uses the CSI report to perform DL link adaptation and scheduling to determine data transmission schemes to the UE, including time/frequency resource assignment, modulation, and coding schemes.
[0007] The DL reference signals used by UE 107 may be Cell-specific Reference Signals (CRS) or Channel State Information Reference Signals (CSI-RS) in LTE. The CSI-RS resource configuration includes a number of CSI-RS antenna ports, a CSI-RS resource index, periodicity of CSI-RS transmission, and relative transmit power of the CSI-RS. CSI is reported in the form of a set of recommended MIMO transmission properties to the eNB. CSI includes a Channel Quality Indicator (CQI), precoding matrix indicator (PMI), and rank indicator (RI). RI indicates the number of data layers that the UE recommends the eNB to transmit. PMI is the index to a recommended precoding matrix in a predetermined codebook known to the eNB and the UE. CQI reflects the channel quality that the UE expects to experience if the recommended RI and PMI are used for data transmission. The time and frequency resources that can be used by the UE to report CSI are controlled by the eNB. The UE is semi-statically configured by higher layers to periodically feedback different CSI components (CQI, PMI, PTI, and RI) on the Physical Uplink Control Channel (PUCCH). Different PUCCH modes can be configured for CSI feedback.
[0008] FIG. 2 illustrates CSI-RS resources in a physical resource block (PRB) pair that can be configured for a UE using 2Tx, 4Tx, and 8TX MIMO, respectively, for an OFDM system with a normal cyclic prefix (CP). These CSI-RS resources allow the UE to perform channel estimation. The number of CSI-RS resources varies according to the antenna configuration. For each channel that the UE needs to measure, one of the available CSI-RS configurations is specified to the UE by higher layer signaling. FIG. 3 is similar to FIG. 2 and illustrates CSI-RS resources in a physical resource block (PRB) pair that can be configured for a UE using 2Tx, 4Tx, and 8TX MIMO, respectively, for an OFDM system with an extended cyclic prefix (CP).
[0009] The difference between a physical antenna and an antenna port is herein described for the multi-vendor LTE system. Different eNB vendors may deploy different numbers of physical antennas at their eNB products. Furthermore, the number of physical antennas for different types of base stations may be different. For example, a macro base station designed for wide area coverage may deploy a large antenna array, while a small form-factor base station (e.g. a pico- or femto-cell base station) that is designed to cover a relatively small area may deploy a small number of physical antennas. In order to limit standardization efforts while allowing sufficient implementation flexibility for eNB vendors, LTE has adopted the “antenna port” concept. An antenna port is a reference signal on which the wireless propagation channel property experienced by one signal can be inferred by another signal. As such, an antenna port is uniquely determined by a reference signal from which the UE can measure the associated channel. Hence, if two physical antennas are used to transmit the same reference signal, they appear to a UE as one antenna port. In this case, the UE is not able to differentiate between these two physical antennas. The mapping between physical antennas and antenna ports is determined by the eNB and may be transparent to the UE. Therefore, the UE can differentiate between different antenna ports, because they are associated with different reference signals, but it cannot differentiate between different physical antennas.
[0010] While the preceding approaches provide steady improvements in interference measurement and Channel State Information reporting for wireless communications, the present invention is directed to further improvements. Accordingly, preferred embodiments described below are directed toward this as well as improving upon the prior art.
BRIEF SUMMARY OF THE INVENTION
[0011] In a preferred embodiment of the present invention, there is disclosed a method of operating a wireless communication system. In one embodiment, measurement and feedback of channel state information from a UE to a base station equipped with a large number of transmit antennas is disclosed. The method includes transmitting a plurality of channel state information reference signal (CSI-RS) sub-resources and a plurality of mode configuration signals to a remote transceiver. The method further includes receiving independent channel state information (CSI) signals according to the mode configuration signals for the respective sub-resources.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0012] FIG. 1 is a diagram of a wireless communication system of the prior art;
[0013] FIG. 2 is a diagram of the prior art illustrating CSI-RS resources that may be configured for a UE to measure a channel using 2Tx, 4Tx, and 8Tx MIMO with a normal cyclic prefix (CP);
[0014] FIG. 3 is a diagram of the prior art illustrating CSI-RS resources that may be configured for a UE to measure a channel using 2Tx, 4Tx, and 8Tx MIMO with a normal cyclic prefix (CP);
[0015] FIG. 4 is a diagram illustrating amplitude and phase scaling of a signal from a physical antenna to an antenna port;
[0016] FIG. 5 is a diagram of a base station having multiple antennas for azimuth and elevation beamforming; and
[0017] FIG. 6 is a block diagram showing operation of a user equipment and a base station according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Communication of downlink control information from a base station (eNB) to a user equipment (UE) for Long Term Evolution (LTE) with backwards compatibility to legacy systems is essential for operating a coordinated multi-point (CoMP) LTE wireless communication system. This control information specifies the location of respective data signals for the UE within received subframes. Accordingly, embodiments of the present invention employ both localized and distributed transmission of control information to improve communication from the eNB to the UE as will be described in detail.
[0019] Some of the following abbreviations are used throughout the instant specification.
[0020] CCE: Control Channel Element
[0021] CQI: Channel Quality Indicator
[0022] CRS: Cell-specific Reference Signal
[0023] CSI: Channel State Information
[0024] CSI-IM: Channel State Information Interference Measurement
[0025] CSI-RS: Channel State Information Reference Signal
[0026] CoMP: Coordinated Multiple-Point transmission
[0027] DCI: DownLink Control Information
[0028] DL: DownLink
[0029] DMRS: Demodulation Reference Signal
[0030] eICIC: Enhanced Inter-cell Interference Coordination
[0031] eIMTA: Enhanced Interference Mitigation
[0032] eNB: E-UTRAN Node B or base station or evolved Node B
[0033] EPDCCH: Enhanced Physical Downlink Control Channel
[0034] E-UTRAN: Evolved Universal Terrestrial Radio Access Network
[0035] feICIC: Further Enhanced Inter-cell Interference Coordination
[0036] HARQ: Hybrid Automatic Repeat Request
[0037] ICIC: Inter-cell Interference Coordination
[0038] IRC: Interference Rejection Combining
[0039] JT: Joint Transmission
[0040] LTE: Long Term Evolution
[0041] MIMO: Multiple-Input Multiple-Output
[0042] MRC: Maximum Ratio Combining
[0043] PCFICH: Physical Control Format Indicator Channel
[0044] PDCCH: Physical Downlink Control Channel
[0045] PDSCH: Physical Downlink Shared Channel
[0046] PMI: Precoding Matrix Indicator
[0047] PRB: Physical Resource Block
[0048] PUCCH: Physical Uplink Control Channel
[0049] PUSCH: Physical Uplink Shared Channel
[0050] QAM: Quadrature Amplitude Modulation
[0051] RE: Resource Element
[0052] RI: Rank Indicator
[0053] RRC: Radio Resource Control
[0054] SCID: Scrambling Identification
[0055] SIB 1 : System Information Block Type 1
[0056] SNR: Signal to Noise Ratio
[0057] TDD: Time Division Duplex
[0058] UE: User Equipment
[0059] UL: UpLink
[0060] VRB: Virtual Resource Block
[0061] ZP-CSI-RS: Zero-power Channel State Information Reference Signal
[0062] Scheduling in a wireless network is achieved by the base station (eNB in LTE) transmitting downlink control information to mobile terminals (UE in LTE). In a cellular wireless network, a base station may need to schedule transmissions to multiple mobile users at the same time. As a result, the base station needs to transmit downlink control information to different users simultaneously. It is also possible that the base station may transmit different types of control information to a UE simultaneously, such as common control information and UE-specific control information.
[0063] In LTE, downlink control information bits are carried in a Downlink Control Information (DCI) format. A DCI is channel encoded, modulated, and transmitted in a specific physical transmission channel over an air interface. In a legacy system, DCI formats are transmitted by the Physical Downlink Control Channel (PDCCH). A PDCCH is transmitted in the legacy PDCCH region. Different DCI formats are used for different scheduling purposes. DCI can be used to transmit common control information to all users in a cell, UE-specific downlink control information to schedule PDSCH data transmission to a UE, or UE-specific downlink control information to schedule uplink data transmission from the UE to the eNB.
[0064] Table I below is a relation between DCI formats and corresponding downlink transmission modes. The DCI formats are UE-specific, monitored by UEs, and scrambled by C-RNTI.
[0000]
DL Mode
DCI format
Transmission scheme
Mode 1
DCI 1A
Single antenna port with cell-specific
reference signal (CRS) port 0
Mode 2
DCI 1
Transmit diversity
Mode 3
DCI 2A
Open-loop spatial multiplexing
Mode 4
DCI 2
Closed-loop spatial multiplexing
Mode 5
DCI 1D
Single-layer multiuser MIMO with CRS
Mode 6
DCI 1B
Single-layer closed-loop precoding with CRS
Mode 7
DCI 1
Single-layer beamforming with demodulation
reference symbol (DMRS) port 5
Mode 8
DCI 2B
Dual-layer spatial multiplexing with DMRS
ports 7-8
Mode 9
DCI 2C
8-layer spatial multiplexing with DMRS
ports 7-14
Mode 10
DCI 2D
Coordinated Multi-Point communication,
8-layer spatial multiplexing with DMRS
ports 7-14
[0065] FIG. 4 illustrates the principle of amplitude and phase scaling in the elevation domain of a signal from a panel of physical antennas 400 to a UE antenna port 402 . Here, a panel comprising Q physical antenna panels 400 are cross phased and applied to beam shaping circuits prior to signal transmission. The signal is multiplied by respective weights w 1-Q,0 for +45″ polarization and by respective weights w 1-Q,1 for −45″ polarization. Both weighted signals are transmitted by Q respective antennas such that in phase signals in an elevation direction of a particular UE are reinforced, thereby improving a received signal-to-noise ratio. It is noted that with conventional antenna technologies, co-phasing is typically performed in the analog domain by phase shifting. Therefore, coefficients w i,j (i=1 . . . Q, j=0,1) are complex variables with power equal to 1, performing phase rotation only. The UE sees a logical received signal 402 as a single antenna port rather than Q separate physical antennas. As a result of using the antenna port concept, an LTE system standardizes a fixed number of antenna ports while allowing different eNB vendors to use an arbitrary number of physical antennas.
[0066] Recent advances in radio frequency (RF) and integrated circuit (IC) design have made significant improvements in advanced eNB antenna deployments possible. In particular, 3-dimensional beamforming and high-order MIMO according to embodiments of the present invention are possible. Typical eNB antenna deployment for 3GPP LTE may include an array of cross-polarized or co-polarized antennas that are spaced apart in the azimuth domain. For 3-dimensional beamforming, each antenna includes an integral number of sub-elements arranged in a vertical configuration to achieve a desired elevation pattern and overall gain in the elevation domain by co-phasing. When these vertically arranged sub-elements are individually and adaptively controlled in the digital domain, the antenna array adapts transmissions in both azimuth and elevation to allow much more flexible antenna pattern shaping, adaptive beamforming, and adaptive cell shaping.
[0067] Referring to FIG. 5 , there is a diagram of a base station having multiple antennas for azimuth and elevation beamforming. The system maps Q physical antennas 500 into B antenna ports 502 . Weight signals w N,M,B are phase and amplitude scale factors for each antenna panel of the Q physical antennas. Subscript N represents the physical antenna panel, M represents the corresponding antenna port in the azimuth direction, and B represents the corresponding antenna panel in the elevation direction. Each antenna panel is individually controlled for azimuth and elevation beamforming. This permits more efficient communication between the eNB and the UE by minimizing inter-cell interference and improving the SNR at the UE. Individual control, however, requires an increase in antenna ports from 1, 2, 4, or 8 of LTE legacy systems to 16, 32, 64, or even more for large antenna deployments. This also requires new DL reference signal design and configuration as well as a new channel state information (CSI) feedback mechanism.
[0068] A new CSI-RS design is disclosed in copending application Ser. No. 14/222,553 (TI-73611), filed March 2014, and incorporated herein by reference in its entirety. A UE configured with one CSI process to measures a DL channel of a single eNB is configured with one CSI-RS resource. This CSI-RS resource is associated with two CSI-RS sub-resources, denoted sub-resource 1 and sub-resource 2. As an exemplary use case, CSI-RS sub-resource 1 is used by the UE to report CSI for antenna panels, and sub-resource 2 is used to report CSI to the virtual MIMO array. Each CSI sub-resource is independently configured by higher layer RRC signaling with a set of parameters that may include some or all of the number of CSI-RS antenna ports, CSI-RS resource index, CSI-RS subframe periodicity and offset, and the ratio of energy-per-resource-element (EPRE) of CSI-RS relative to relative PDSCH transmission power ρ. In one embodiment, the EPRE ratio ρ is configured for the CSI-RS resource but not configured for each sub-resource. In another embodiment, the EPRE ratio ρ is configured for one CSI-RS sub-resource but not configured for the other CSI-RS sub-resource.
[0069] The number of CSI-RS antenna ports for each CSI-RS sub resource k (k=1,2) is equal to a corresponding number of CSI-RS antenna ports in LTE Rel. 11 (e.g. 1, 2, 4, or 8). The total number of CSI-RS antenna ports of the CSI-RS resource (N t ) is a function of the number of CSI-RS antenna ports of both sub-resource 1 (N t,1 ) and sub-resource 2 (N t,2 ). In one embodiment, N t =N t,1 ×N t,2 , corresponding to a square antenna array. The CSI-RS resource index for each CSI-RS sub-resource k (k=1,2) is equal to a corresponding CSI-RS resource index in LTE Rel. 11 and is dependent on the number of CSI-RS antenna ports (N t,k ) configured for the corresponding CSI-RS sub-resource k (k=1,2). The CSI-RS subframe periodicity and offset are separately configured for CSI-RS sub-resource 1 and sub-resource 2. Furthermore, the subframe periodicity of one sub-resource may be an integer multiple of the other sub-resource periodicity. For example, sub-resource 1 may be used to measure the CSI of sub-elements within one antenna panel, and sub resource 2 may be used to measure CSI between various antenna panels.
[0070] Turning now to FIG. 6 , there is a diagram showing communication between user equipment (UE) 600 and a base station (eNB) 620 according to the present invention. UE 600 may be a cell phone, computer, or other wireless network device. UE 600 includes a processor 606 coupled to a memory 604 and a transceiver 610 . Processor 606 may include several processors adapted to various operational tasks of the UE including signal processing and channel measurement and computation. The memory stores application software that the processor may execute as directed by the user as well as operating instructions for the UE. Processor 606 is also coupled to input/output (I/O) circuitry 608 , which may include a microphone, speaker, display, and related software. Transceiver 610 includes receiver 612 and transmitter 614 , suitable for wireless communication with eNB 620 . Transceiver 610 typically communicates with eNB 620 over various communication channels. For example, transceiver 610 sends uplink information to eNB 620 over physical uplink control channel PUCCH and physical uplink shared channel PUSCH. Correspondingly, transceiver 610 receives downlink information from eNB 620 over physical downlink control channel PDCCH and physical downlink shared channel PDSCH.
[0071] Base station 620 includes a processor 626 coupled to a memory 624 , a symbol processing circuit 628 , and a transceiver 630 via bus 636 . Processor 626 and symbol processing circuit 628 may include several processors adapted to various operational tasks including signal processing and channel measurement and computation. The memory stores application software that the processor may execute for specific users as well as operating instructions for eNB 620 . Transceiver 630 includes receiver 632 and transmitter 634 , suitable for wireless communication with UE 600 . Transceiver 630 typically communicates with UE 600 over various communication channels. For example, transceiver 630 sends downlink information to UE 600 over physical downlink control channel PDCCH and physical downlink shared channel PDSCH. Correspondingly, transceiver 630 receives uplink information from UE 600 over physical uplink control channel PUCCH and physical uplink shared channel PUSCH.
[0072] Once communication is established with eNB 620 , transceiver 610 receives an uplink (UL) grant in a downlink (DL) subframe. Transceiver 610 uses the CRS or CSI-RS in one or more of the DL subframes to create a CSI measurement report that is transmitted to eNB 620 in a subsequent UL subframe. The CSI reports may be periodic on the PUCCH or aperiodic on the PUSCH. CSI feedback for CSI-RS sub-resource 1 and sub-resource 2 are preferably independently configured by higher layer RRC signaling to include all or a subset of Rank Indicator (RI), Precoding Matrix Indicator (PMI), and Channel Quality Indicator (CQI) parameters. For example, CSI-RS sub-resource 1 may be configured to feedback PMI 1 to inform eNB of co-phasing information of sub-elements within one antenna panel, reflecting channel information in the elevation domain. CSI-RS sub-resource 2 may be configured to feedback RI, PMI, and CQI, where RI indicates the number of beamforming layers in the horizontal domain. As another example, CSI-RS sub-resource 1 may be configured to feedback RI and PMI, while CSI-RS sub-resource 2 may be configured to feedback PMI and CQI. As yet another example, sub-resource may be configured for a wideband report, while sub-resource 2 is configured for a subband frequency-selective report.
[0073] Periodic CSI feedback on the PUCCH for CSI-RS sub-resource 1 and sub-resource 2 are independently configured with their respective feedback periodicity and/or offset. For example, a CSI report for sub-resource 1 may be configured with a large feedback periodicity for less frequent CSI reports, while a CSI report for sub-resource 2 may be configured with a smaller feedback periodicity for more frequent CSI reports. This may be desirable when the channel correlation between antenna sub-elements within one array panel is highly correlated and temporarily more stable, especially as user equipment do not move quickly in the vertical domain. The feedback periodicity for CSI sub-resource 2 can be configured with a larger periodicity when needed to more efficiently follow the channel variation of the UE moving in the vertical domain. Feedback offset for CSI sub-resource 1 and sub-resource 2 may be configured to be the same, so that CSI for sub-resource 1 and CSI for sub-resource 2 may be reported in the same subframe. This increases the feedback overhead and may be difficult for PUCCH formats 1, 1a, 1b, 2, 2a, and 2b, which each have a maximum 11-bit CSI payload. PUCCH format 3, however, has a maximum 22-bit CSI payload and may be preferable for this configuration. Feedback offset for CSI sub-resource 1 and sub-resource 2 may also be configured to be different so that CSI for sub-resource 1 and sub-resource 2 are reported in different subframes. Since this does not increase the feedback overhead, PUCCH formats 2, 2a, 2b, and 3 may be used. Finally, CSI sub-resource 1 and sub-resource 2 may be configured with different reporting priority. In the event two CSI reports for the two respective sub-resources collide in the same subframe, CSI for the CSI-RS sub-resource with the highest priority is reported while CSI for the CSI-RS sub-resource with the lower priority is dropped.
[0074] For aperiodic CSI feedback, it is preferable that one UL grant should trigger concurrent CSI reports for sub-resource 1 and sub-resource 2 in the same UL PUSCH subframe to provide eNB with full channel information in both horizontal and vertical domains. It is also preferable that the bit sequence of the CSI report for sub-resource 1 precede the bit sequence of the CSI report for sub-resource 2. However, it is possible that an UL grant may trigger CSI feedback for only one sub-resource. In one embodiment of the present invention, when a 1-bit CSI trigger is used, a logical 0 indicates no CSI report is transmitted, and a logical 1 indicates a CSI report for CSI-RS sub-resource 1 and sub-resource 2. In another embodiment of the present invention, when a 2-bit CSI trigger is used, a logical 00 indicates no CSI report is transmitted, a logical 01 indicates a CSI report for CSI-RS sub-resource 1, a logical 10 indicates a CSI report for CSI-RS sub-resource 2, and a logical 11 indicates a CSI report for CSI-RS sub-resource 1 and sub-resource 2. This advantageously provides selected CSI reports for CSI-RS sub-resources having the same or different reporting times. For instance, when the UE moves slowly in the vertical domain but quickly in the horizontal domain, it is not necessary for the eNB to always trigger CSI feedback for both dimensions at the same time. Therefore, the eNB may trigger CSI feedback for the sub-resource corresponding to the horizontal domain without triggering CSI feedback for the sub-resource corresponding to the vertical domain.
[0075] Still further, while numerous examples have thus been provided, one skilled in the art should recognize that various modifications, substitutions, or alterations may be made to the described embodiments while still falling with the inventive scope as defined by the following claims. Other combinations will be readily apparent to one of ordinary skill in the art having access to the instant specification.
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A method of operating a communication system is disclosed. The method includes transmitting a plurality of channel state information reference signal (CSI-RS) sub-resources and a plurality of mode configuration signals to a remote transceiver. The method further includes receiving channel state information (CSI) signals according to the mode configuration signals for the respective sub-resources.
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BACKGROUND OF THE INVENTION
This invention relates to textile marking devices and more particularly to a fabric shademarking device.
As is well known in the garment industry, it is desirable to stamp identifying indicia, ordinarily sequential numbers, along the backside of the fabric web as it is being spread on a spreading table by a fabric spreading apparatus. The purpose of doing this is so that when a stack of cloth parts are cut out from the layers of spread fabric, the pieces of a single layer can be identified and combined together to form a single garment to eliminate any possibility of variations in the color shade of the fabric from layer to layer.
Numerous attempts have been made to produce successful shademarkers. Some such attempts are described in U.S. Pat. Nos. 3,902,413 (Powell et al.), 3,951,397 (Rice) and 3,939,766 (Darwin). In the shademarker described in U.S. Pat. No. 3,939,766, the shademarker consists of a frame which carries printing wheels having a series of indicia printing elements on the peripheries thereof, and which are rotated by movement of the fabric in engagement with the printing wheels. A mechanism is provided for applying ink only to a selected printing element so that all of the printing elements engaged the fabric but only the selected element imprints its image thereon. Means are further provided for rotating the printing wheel in synchronism with the mechanism for applying the ink so that the printing element which is to be inked may be manually selected. The cloth as it passes through the shademarker, which incidentally is mounted on the fabric spreader, passes over an anvil roller on one side of the fabric while a pair of printing wheels press against the fabric on the side opposite from the anvil roller to imprint the shademarking indicia. The motion of the fabric through the shademarker rotates the printing wheels and the inking mechanism as well as an ink roller which inks the inking mechanism.
There are several problems with this type of shademarker. The first problem arises in that a substantial amount of tension is introduced into the fabric because of the fact that the fabric as it passes through the shademarker and onto the spreading table is being used as the motivating force for rotating the printing wheels. This can cause the fabric to be distorted in the spread if it is a loosely woven fabric such as a knit, for example. Another problem is that the tension can produce smearing in the imprinting of the shademarking indicia. Still another problem is that the tension produced in the fabric by means of its contact with the anvil roller and printing wheels may be unevenly distributed across the width of the fabric thereby producing a nip or tuck in the fabric prior to its passing through the printing section of the shademarker. This can result in an interruption in the printed image which renders it unrecognizable.
SUMMARY OF THE INVENTION
The above and other disadvantages of prior art shademarking devices are overcome by the present invention of an improved fabric shademarker of the type which is mounted on a fabric spreading machine and which has at least one inked, rotatable printing cylinder having raised characters on its circumferential surface and an opposed impression cylinder with the fabric web being imprinted with selected characters across its width from the printing cylinder as the fabric web is fed between the printing cylinder and the impression cylinder during the spreading operation. The improvement of the invention comprises means for synchronizing the rotation of the printing cylinder with the rotation of the impression cylinder and raised pads on the circumferential surface of the impression cylinder, each of the raised pads being positioned to mate with at least one corresponding raised character on the printing cylinder. By this mechanism, the tension introduced along the longitudinal edges of the fabric web because of the impression and printing cylinders is equalized. This is due to the fact that the slack portions of the fabric web will drape between the raised pads and the taut portions of the fabric web will span the chord between the circumferentially adjacent raised pads.
In one preferred embodiment of the invention, the means for synchronizing the rotation of the printing and impression cylinders is motorized and drives the impression and printing cylinders, without regard to the force of the cloth fabric as it is being spread, so as to feed the fabric web through the shademarker. This is in contrast to the prior art shademarkers in which the movement of the cloth itself as it was being spread forced the rotation of the impression and printing cylinders. By this means, no tension is introduced into the fabric and smearing of the printed characters on the fabric is substantially reduced. This motorized means also drives the spreader itself to further reduce any tension which might otherwise be introduced into the fabric. In a particular preferred embodiment, the raised characters on the printing cylinder and the raised pads on the impression cylinder are arranged in corresponding helixes to thereby cause any taut or slack portions in the fabric to be moved transversely with the ultimate effect being that the tension across the web is equalized. The raised characters or the raised pads are preferably resilient. In the preferred embodiment, the spacing between the impression cylinder and the printing wheels is controllable to take into account different fabric web thicknesses. Furthermore, by controlling the spacing between the impression roller and the printing wheels, the fabric may be paid out more or less quickly.
In order to allow the fabric web to be initially fed between the impression cylinder and the printing cylinders, the impression cylinder is pivotally mounted in the shademarker so that it can be swung from a closed position, closely adjacent the printing cylinder, to an open position, away from the printing cylinder. Timing belt means are provided for maintaining the synchronization between the impression cylinder and the printing cylinder when the impression cylinder is swung between the closed and open positions so that upon being swung back from an open position to a closed position, the raised pads of the impression cylinder will still be mated with the corresponding raised characters of the printing cylinder.
It is therefore an object of the present invention to provide a shademarker attachment for a fabric spreading machine which does produce a nip in the fabric during the shademarking processing without putting tension or distortion to neither axis of the fabric.
It is another object of the invention to provide a shademarker attachment for a spreading machine which equalizes the tension in the fabric web during the shademarking operation.
It is still another object of the invention to provide a shademarker for a fabric spreading machine which is motorized to produce no tension in the fabric both transversely and longitudinally as the fabric is spread and simultaneously shademarked.
The foregoing and other objects, features and advantages of the invention will be more readily understood upon consideration of the following detailed description of certain preferred embodiments of the invention, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view with portions broken away of the shademarker and spreading apparatus according to the invention;
FIG. 2 is a diagrammatic perspective view of the printing cylinders, impression cylinders, inking roller and inker of the embodiment depicted in FIG. 1;
FIG. 3 is a vertical view of the left side of the shademarker according to the invention depicted in FIG. 1;
FIG. 4 is a vertical, sectional view, with portions broken away taken generally along the line 4--4 in FIG. 3;
FIG. 5 is a vertical, sectional view, with portions broken away taken generally along the line 5--5 in FIG. 3;
FIG. 6 is a vertical, sectional view, with portions broken away taken generally along the line 6--6 in FIG. 4;
FIG. 7 is a vertical, sectional view, with portions broken away taken generally along the line 7--7 in FIG. 5;
FIG. 8 is a sectional view taken generally along the line 8--8 in FIG. 6;
FIG. 9 is a vertical, diagrammatic view of the printing cylinder, impression cylinder, inking cylinder and ink roller of the shademarker embodiment depicted in FIG. 1;
FIG. 10 is an enlarged, vertical, sectional view, with portions broken away, of the indexing mechanism for positioning the raised characters on the printing cylinders with respect to the inking roller of the shademarker according to the invention depicted in FIG. 1;
FIG. 11 is a diagrammatic, sectional view, taken generally along the line 11--11 in FIG. 9;
FIG. 12 is a horizontal, sectional view, with portions broken away taken generally along the line 12--12 in FIG. 3; and
FIG. 13 is a vertical, sectional view, taken generally along the line 13--13 in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to FIGS. 1 and 3, the invention is supported in a spreader carriage 10 which is composed of a vertical left side plate 12 and a vertical right side plate 14, which are held in a spaced apart position by crossbar supports 16. The spreader moves along on wheels 18 and 19 rotatably mounted in the side plates 12 and 14, respectively. The wheels 18 roll on a rail 20 mounted on a horizontal and planar spreading table 22. The side plate 14 has rubberized wheels 19 which are rotatably supported by it and which roll along the flat surface of the table 22. The spreading table 22 can extend for any length such as a length of fifty feet, for example. The width of the table 22 is slightly larger than the spreader 10 to accommodate the width of a bolt of cloth 26. The bolt of cloth 26 is carried on an axle 28 which is rotatably supported at each end on a pair of rollers 30 mounted at the upper end of an upright leg 24 attached to each of the side plates 12 and 14.
Because the position of the shademark 10 is fixed with respect to the width of the spreading table 22 due to the fact that the wheels 18 ride on side rails 20, it is sometimes necessary to shift the bolt 26 transversely in order to properly align it and center it in the shademarker and on the table 22. Referring now more particularly to FIGS. 1 and 13, a mechanism for accomplishing this is disclosed. A cylindrical race 36 is mounted on the left end of the axle 28 between the bolt 26 and the rollers 30. A lever arm 34 is pivotally mounted at one end to the vertical leg 24 and carries a forked pair of rollers 35 at its other end. The rollers 35 are captured by race 36. A threaded shaft 32 having a knob at one end is rotatably mounted in the vertical leg 24. Its other end is threadably engaged in the mid-portion of the lever arm 34. By manually turning the shaft 32, the lever arm 34 may be rotated clockwise or counterclockwise as viewed in FIG. 13. This has the effect of moving the cylindrical race, together with the axle 28, transversely with respect to the shademarker. This allows the bolt 26 to be adjustably centered within the shademarker.
In order to propel the shademarker 10 along the spreading table 22, an electric motor 38 is coupled through a right angle and reduction gear assembly 40 which has an output shaft 41 on the opposite side of the side plate 12 from the motor 38 and the reduction gear assembly 40. A V belt pulley 42 is mounted on this shaft 41. The pulley 42 is connected to a pulley 44 by means of a V belt 46. The pulley 44 is mounted on one of the wheels 18. The motor 38 is reversible so that power transmitted to the wheel 18 by means of the pulleys 42 and 44 can thereby drive the spreader 10 in either direction along the spreading table. The motor is controlled by a pair of swing arms 48 which are pivotally mounted on the side plate 12 and which are pivotally connected at their free ends to a horizontal shaft 50 which is mounted in sliding blocks 52 attached to the side of the side plate 12. A double ended rising cam 54 is mounted on the shaft 50 to operate a pair of microswitches 56 and 58 attached to the side plate 12. When one of the arms 48 is rotated in the counterclockwise direction to shift the horizontal bar 50 the right, as viewed in FIG. 1, the rising end of the cam 54 operates the switch 58 which causes the motor 38 to rotate in the proper direction to drive the shademarker 10 to the right as viewed in FIG. 1. Conversely, when the swinging arm 48 is rotated in the clockwise direction, to shift the bar 50 to the left as viewed in FIG. 1, the rising end of the cam 54 closes the switch 56 to cause the motor 38 to drive the shademarker to the left as viewed in FIG. 1. A double ended spring 60 mounted on the side plate 12 causes the shaft 50 to center the cam 54 between the switches 56 and 58 in the absence of any force acting on the swinging arms 48.
The shademarking device of the present invention is carried by the spreader 10 and is operable to print identifying indicia on the backside of the fabric as it leaves the bolt 26 but before it is spread on the table 22. The shademarker is capable of having the indicia changed for each successive layer of cloth.
In leaving the bolt of cloth 26, the fabric web 62 is passed toward the right hand side of the spreader 10, as viewed in FIG. 3, and passes underneath a rear top roller 64. It thereafter passes over and around a forward top roller 66 and down between an impression cylinder 68 and an upper, units printing cylinder 70 and a lower, tens printing cylinder 72. The arrangement of the impression cylinder 68 with respect to the printing cylinders 70 and 72 is that the impression cylinder is to the right of the fabric web 62, as viewed in FIG. 3, and the printing cylinders 70 and 72 are to the left of the web 62, as viewed in FIG. 3. After leaving the tens printing cylinder 72, the web 62 passes between a pair of lower or bottom rollers 76 and 78. The web is thereafter dropped, tensionlessly, to the table 22 as the spreader 10 moves along the table. As will be explained in greater detail hereinafter, the impression cylinder 68 and the printing cylinders 70 and 72 are driven by the motor 38 to pull the web 62 through the shademarker so that the web 62 which falls between the rollers 76 and 78 has substantially no longitudinal tension exerted on it. It is paid out in synchronism with the speed of the spreader 10 as it moves along the table 22. As will be explained hereinafter, the printing cylinders 70 and 72 each have a plurality of bands 80 of raised printing characters 82. These bands extend around the cylinders circumferentially and are spaced apart along the length of the cylinders, that is transversely across the width of the shademarker. Each band 80, as mentioned above, is made up of a plurality of raised characters 82 in segments. The characters constitute a sequence of indicia such as a sequence of numbers around the band 80. Individual characters are selectively inked by raised pads 86 spaced about the circumference of an inking transfer cylinder 84 spaced approximately parallel to the impression cylinder 68 and on the opposite side of the printing cylinders 70 and 72 from the impression cylinder 68. The rotational orientation of the cylinders 70 and 72 may be selectively altered, as will be explained in greater detail hereinafter with respect to the location of the raised inking transfer pads 86 on the inking transfer cylinder 74, so that individual characters on the printing cylinders 70 and 72 may be selectively inked to the exclusion of the remaining raised characters on the printing cylinders 70 and 72.
Ink is applied to the raised inking transfer pads 86 by means of an ink roller 88 which is positioned adjacent to the inking transfer cylinder 84. The ink roller 88 constitutes a permanent supply of ink. All of the rollers and cylinders 64 - 78, inclusive, and 84 and 88 all extend parallel to each other and are horizontal with respect to the table 22. They also extend transversely across between the sideplates 12 and 14 and are rotatably supported between them.
Referring now more particularly to FIGS. 4 and 9, it will be seen that the raised character band 80 of the units cylinder 70 is staggered axially from the raised character band 80 of the tens cylinder 72 so that the band 80 of the cylinder 70 is slightly to the left of the band 80 of the cylinder 72 as viewed in FIG. 4. This allows the numerical indicia on the band 80 of the cylinder 72 to be printed in the left column on the fabric web 62, that is the tens place, and the character from the band 80 on the cylinder 70 to be printed in the right hand column on the web 62, that is the units column. For convenience in the illustration, as viewed in FIG. 11, the numerical indicia imprinted on the web 62 is 00. Any numerical combination could be imprinted, however, and typically the numerical indication would be the number of the layer stacked on the table 22. As viewed in FIG. 11, the left hand character band 80 is the character band mounted on the cylinder 70 whereas the character band 80 appearing to the right in the Figure is the band which is mounted on the cylinder 72. It will be appreciated that when the numbers are imprinted on the fabric, their order will appear to be reversed.
Referring now more particularly to FIG. 10, the means by which the characters 82 may be indexed relative to the impression cylinder 68 and the inking cylinder 84 will be described. It will be understood that the same mechanism is used for rotating the cylinders 72 and 70 and, therefore, only a single description will be given for the mechanism for indexing the cylinder 72, it being understood that like components will be designated by primed numerals for the cylinder 70. The cylinder 72 is mounted on a rotational shaft 90 which is co-axially mounted at its left end within a cylindrical sleeve 92. Sleeve bearings 94 at opposite ends of the interior of the sleeve 92 reduce the friction between the shaft 90 and the sleeve 92. Next to the plate 95, in a direction away from the cylinder 72, is mounted a first toothed gear 96. Adjacent this gear 96 is a smaller diameter gear 98 and next to the gear 98 is a spacer ring 100. The spacer ring 100 bears against one side of a bearing race and bearing assembly 102 which is held within a collar 104 mounted in the side plate 12. The bearing race 102 is retained within the collar by means of a circular clip or retaining ring 106 mounted in the outward end of the collar 104. The sleeve 92 is supported within the bearing race 102 on a circular, flanged sleeve 108. The sleeve 108 has a plurality of circumferentially spaced transverse holes 110 which receive a spring-loaded pin 114 mounted in a circular member 112 at the end of the shaft 90. By rotating the shaft 90 through the use of the member 112, the pin 114 may be selectively aligned with any one of a plurality of the holes 110. This fixes the angular orientation of the cylinder 72 with respect to the gears 96 and 98 mounted on the sleeve 92. As will be explained in greater detail hereinafter, this also indexes the characters 82 mounted on the circumferential surface of the cylinder 72 with respect to the impression cylinder 68 and the inking transfer cylinder 84 because all of these various cylinders are interconnected by means of gears. A retaining nut 116 on the outer end of the sleeve 92 bears against the sleeve 108 at the end of the shaft 90 to hold the whole assembly rigidly between the side plates 12 and 14. Furthermore, the retaining nut 116 is used to time the blade cylinders 72 and 70 to the remainder of the mechanism.
Referring now more particularly to FIGS. 4, 5, 6 and 8, the gearing connections between the various rotative elements will now be described. The gear 96 of the printing cylinder 72 meshes with a gear 118 of the inking transfer cylinder 84. The corresponding gear 96' of the printing cylinder 70 also meshes with the gear 118 but does not mesh with the gear 96. The gear 98 of the printing cylinder 72 meshes with a gear 120 mounted on a synchronous registration shaft 122 used in conjunction with the impression cylinder 68, as will be explained in greater detail further in this application. The impression cylinder 68 has a gear 124 mounted on its end which is closest to the side plate 12 and which meshes with the gear 96 and 96'. As best viewed in FIGS. 6 and 8, the gear 96 meshes with a gear 126 and the gear 120 meshes with a gear 128. The gears 126 and 128 are mounted on a single shaft 130 via one revolution clutches, clockwise and counterclockwise respectively. This facilitates driving the printing unit in one direction only, regardless of the linear direction of motion of the spreading unit in reference to the table. To prevent freewheeling of the two printing cylinders 70 and 72 together with the impression cylinder 68 upon fast stopping of the spreader shademarker, an electric brake with its two halves mounted to the side blade 12 and cylinder 70 respectively when energized absorbes the rotary energy of the printing unit. By controlling the clutch 131 the drive from the shaft 531 may be selectively engaged and disengaged. The shaft 130 is rotatably mounted in the side plate 12 and the end of the shaft 130 which is on the side of the side plate 12 opposite from the gears 126 and 128 has a pulley 132 mounted on it. The pulley 132 is driven by a belt 134 whose other end is entrained around a pulley 136.
Referring now more particularly to FIG. 12, it can be seen that the pulley 136 is the output pulley from a variable speed mechanism 138. The variable speed mechanism 138 includes, in addition to the pulley 136, a pulley 142 having V-shaped plates and whose effective diameter may be varied by the adjustment of a lever arm through a knob 140. By turning the knob 140, the effective diameter of the pulley 142 may be continuously varied. A belt 144 is entrained around the pulley 142 and around a pulley 146 connected through a electrically operated clutch 148 to the output shaft 41 of the reduction gear assembly 40. Thus, the operator can, by appropriate electrical signals to the clutches 148 and 131, cause the printing cylinders and impression cylinder and inking cylinder, as well as the ink roller, to all be rotatably driven by the motor 38 at a speed which is adjustable by means of the knob 140 so that the shademarking mechanism can be placed in synchronism with the speed of the spreader carriage 10.
It should also be noted that the inking transfer cylinder 84 is mounted on a shaft 150, together with the gear 118. At the opposite end of the shaft 150 from the gear 118 is mounted a gear 152 which meshes with a gear 154 mounted on the ink roller 88, all as best viewed in FIG. 4. Thus, all of the rotatable elements of the shademarker are driven by the motor 38 rather than by being rotated by the force of the cloth web moving through the shademarker as it is being spread.
To this point, the shademarker of the present invention is not wholly unlike the shademarker described in U.S. Pat. No. 3,939,766 (Darwin) except that the present shademarker is power driven whereas the Darwin shademarker is operated by the force of the fabric web moving through the shademarker. As pointed out above, one problem with some prior art shademarkers is that the fabric web in passing through the shademarker acquires a nip across the width of the fabric due to uneven tension on the longitudinal edges of the fabric web. This problem is avoided in the present invention by having bands 156 spaced axially along the length of the impression cylinder 68. The bands encircle the impression cylinder and have a plurality of raised pads 158. The locations of the pads 158 about the circumference of the impression cylinder 68 are selected to coincide with the point where the raised characters 82 of the printing cylinder band 80 will press against the fabric web 62. Thus, as the fabric web passes between the printing cylinders 70 or 72 and the impression cylinder 68, it is contacted primarily by being pressed between the raised characters 82 and corresponding raised pads 158 on the bands 156. The indexing mechanisms for rotating the printing cylinders 70 and 72 with respect to the inking transfer cylinder 84 are so dimensioned that the raised characters 82 will also fall into alignment with at least one of the raised pads 158 on a particular band 156.
The means by which this mechanism eliminates the uneveness and longitudinal tension of the fabric web is that as a particular longitudinal edge of the fabric web is drawn taut in passing over the impression cylinder 68, it will span the chord between the circumferentially adjacent pads 158. As the longitudinal edge grows slack it will tend to drape between circumferentially adjacent pads 158. The net effect of this operation is that the longitudinal tension on both edges will eventually even out. With a convention impression cylinder or anvil roller as it is sometimes called in some shademarkers, there is no provision made for taking up such slack and it is cumulatively built up into a nip which finally grows to such a size that it makes a fold, thereby interrupting the shademarking imprintation on the fabric web. In the preferred embodiment of the invention, the pads 158 take a modified helical pattern, as is best viewed in FIG. 5 and FIG. 11. In this embodiment, the raised characters 82 must also have a helical arrangement. The helical arrangement of the raised characters 82 and the raised pads 158 is with respect to the longitudinal axis of the cylinders 70, 72 and 68. That is, the pads tend to follow a helix which encircles the cylinders. In other embodiments, other patterns may also be used, such as a herring bone pattern. It is only necessary that the pattern taken by the pads of the raised characters on the printing cylinders be opposite in direction from the pattern used for the raised pads on the impression cylinder. The purpose of either of these two patterns is to have the effect of "walking" the uneveness of the fabric web from the center of the fabric web to the outside edge, thereby accelerating the equalization of the tension in the longitudinal edges of the fabric web.
The means by which the raised characters 82 are selectively inked is best illustrated in FIG. 9. The inking transfer cylinder 84 has two raised portions 86 which are spaced 180° apart. By selectively setting the angular orientation of the printing cylinders 70 or 72 with respect to the inking transfer cylinder 84, a selected raised character may be thereby placed into circumferential alignment with one of the raised pads 86. The printing cylinders 70 and 72 have three sets of numbers spaced about their circumference, in the staggered pattern as described above. The ratio of the rotational speeds of the printing cylinders 70 and 72 with respect to the inking transfer cylinder 84 is that the printing cylinders will make three complete revolutions for each two complete revolutions of the inking transfer cylinder 84. In this way, the printing cylinders 70 and 72 may be adjusted, as described above, so that a parituclar raised character will always fall in alignment with one of the raised pads 86 on the inking transfer cylinder 84 so that only that raised character is inked. It is this inked character which will then be printed upon the fabric web 62 as it passes between the impression cylinder 68 and the printing cylinders 70 and 72. The pads 86, as mentioned above, also contact the ink roller 88 with each complete revolution thereby acquiring sufficient ink to be transferred to the raised characters 82. The amount of ink which is transferred is carefully controlled so that smearing is avoided.
To allow the web 62 to be initially threaded between the printing cylinders 70 and 72 and the impression cylinder 68, the impression cylinder is rotatably mounted between a pair of swing arms 69 which are pivoted at their lower ends to the side plates 12 and 14. This allows the impression cylinder 68 to be moved between a closed position, closely adjacent to the printing cylinders 70 and 72, and an open position, away from the printing cylinders 70 and 72.
Toggle linkages 174 connected at one end to the swing arms 69 and at their other ends to a shaft 176 which is rotatable by means of handles 178 at either end is used to swing the impression cylinder into the closed position and open position. A microswitch 180 mounted on the side plate 14 is contacted by the swing arm 69 when the impression cylinder is in the closed position. The switch 180 is connected to the controls for the spreader carriage 10 so that the carriage cannot be accidentally operated in the shademarking mode when the impression cylinder is in the open position. It should be noted that the degree to which the impression cylinder 68 is pressed into engagement with the printing cylinders 70 and 72 is adjustable by means of adjusting the length of the toggle 174. The characters 82 or the pads 158 are preferably resilient. Because of this resiliency, the rate at which the fabric is fed between the impression cylinder and the printing cylinders may be controlled in some degree. By squeezing the impression cylinder 68 closer to the printing cylinders 70 and 72, the rate of fabric feed may be increased. This increase in rate takes place with the elastic deformation of the characters 82 or the pads 158. Conversely, by not pressing the impression cylinder 68 into close engagement with the printing cylinders 70 and 72, the feed rate of the fabric may be slowed. In this way, the slight differences in the rate of feed due to different thicknesses in the fabric web 62 may be compensated.
In order to retain the alignment of the pads 158 with the raised characters 82 when the impression cylinder 68 is swung away from engagement with the printing cylinders in order to initially feed the fabric between the printing cylinders and the impression cylinder, the synchronization shaft 122 has a pulley 160 at its end which is nearest the side plate 14, in which that end is rotatably mounted. The corresponding end of the impression cylinder 68 also has a pulley 162. As best viewed in FIG. 7, a timing belt 164 is entrained around the pulleys 162 and 160 and passes over an idler pulley 166 rotatably mounted at the bottom of the swing arm 69. Slack in the belt 164 is taken up by a pulley 168 which is rotatably mounted on an L-shaped leg 170 which is pivotally mounted to the side plate 14 and which is biased by a spring 172, one end of which is attached to the free leg of the member 170 and the other end of which is attached to the side plate 14.
The terms and expressions which have been employed here are used as terms of description and not of limitations, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible within the scope of the invention claimed.
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A fabric shademarker of the type which is mounted on a fabric spreading machine and which prints identifying indicia such as numerals on the reverse side of the fabric as it is spread, layer by layer, on a spreading table and which is characterized by the improvement of means for synchronizing the rotation of the printing and impression cylinders and further in that the impression cylinder has raised pads spaced along its circumferential surface which mate with corresponding raised characters on the printing cylinder so that tension, which would otherwise be introduced along the longitudinal edges of the fabric web which is being spread because of the unequal friction exerted on the fabric by the impression and printing cylinders, is equalized due to the fact that the slack portions of the fabric web drape between the raised pads on the impression cylinder and the taut portions of the fabric web span the chord between the circumferentially adjacent raised pads on the impression cylinder with the net tension thereby being averaged to zero. In the preferred embodiments of the invention, the pads on the impression cylinder and the raised characters on the printing cylinders are arranged in corresponding helixes. The impression cylinder, printing cylinder, and inking cylinders are all driven by motorized means which also drive the spreader so that the fabric is spread tensionless.
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RELATED APPLICATIONS
This application claims rights under 35 USC §119(e) from U.S. Application Ser. No. 61/299,652 filed Jan. 29, 2010, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to the use of nuclear quadrupole resonance for the detection of molecules and more particularly to the use of balanced transmission lines as a sensor to detect molecules such as explosives, narcotics and other molecules of interest.
BACKGROUND OF THE INVENTION
In the early 1900s, not long after Einstein published his equations on thermal equilibrium, individuals realized that there were likely to be resonances at very low frequencies for atoms and molecules and that these resonances would occur because if one emits a photon of exactly the correct frequency, the material will absorb this photon, store it for some amount of time and then get rid of the absorbed energy. It is has been found that in nature the molecules which absorb such energy always fall to a lower energy state.
One of the ways for the material to emit energy is through spontaneous emission where a photon of exactly the same energy that is impinging on the material is thrown off in a random direction at random times.
The second way of getting rid of the energy absorbed by the material is through process of stimulated emission in which a photon arrives at exactly the appropriate energy, gets near the molecule, stimulates the molecule and when the molecule drops to the lower energy state it emits a photon that is exactly in phase with the original photon.
The energy that is thrown off either in spontaneous emission or stimulated emission results in an exceedingly narrow spectral line. In fact the line is generally considered to be a single line that exists at a given wavelength or frequency. It is noted that the material only has one choice assuming that the material is pumped at its lowest energy state, raising the energy within the molecule such that the only way that it can release its energy is to emit a photon of that exact energy.
Nuclear quadrupole resonance has been utilized in the past to detect the presence of specific molecules, including explosives. Explosives generally involve the use of nitrogen or nitrogen bonded with other elements. When nuclear quadrupole resonance was utilized in the past, it was used to detect the presence of molecules due to the molecular elements that are bonded together such that the molecules absorb energy at for instance as many as eight different energy levels or spectral lines. It turns out that at least three of the energy levels tend to be prominent, although in some materials there are upwards of all eight energy levels for one bond. If one has many bonds there may be many dozens of spectral lines. In order to detect the presence of a molecule one usually is looking to pump energy right at the top of one of the spectral lines and look for energy coming back at the same frequency.
As part of the subject invention, it has been found that the spectral lines of interest especially for explosives are in the 100 KHz to 10 MHz range. A particularly interesting explosive is called RDX which has a spectral line in the 3 to 4 MHz range, as does sodium nitrate.
However if one is seeking to detect stimulated or emission or spontaneous emission at 3 MHz, the wavelength of the returns is incredibly long, in some cases corresponding to the size of a building. Moreover, the photons that are emitted in either spontaneous or stimulated emission represent very little energy. For instance, a red photon carries an energy of about 3.5 electron volts, with detectable radiation being one or two millionths of 3.5 electron volts. The result is that photons emitted from the molecules are virtually undetectable. One of the reasons is that in order to detect single photons one is faced with thermal background that overwhelms the detection process. In order to achieve any type of result, one pumps large numbers of photons into the target material such that for every milliwatt second an extraordinary number of photons are involved.
If the photons are at the appropriate frequency they are absorbed and only when the frequency exactly corresponds to a resonance line does the molecule start absorbing the photons. Thus it is quite important that the frequency source utilized in the nuclear quadrupole resonance measurements be extremely precise and stable.
If one performs a frequency sweep, the emission that comes back is on the order of 1% of the energy that impinges on the molecule.
It is noted that prior nuclear quadrupole resonance techniques can be likened to looking into a headlight to find a 1% response.
As a result, a pulsed coil prior art nuclear quadrupole resonance detection of molecules requires upwards of 100 kilowatts of energy coupled to a very high Q tuned coil having for instance a Q of 80 or better. If there is any offset in terms of the frequency of the incident radiation or if the coil tuning was not precise, then any emissions from the molecule will be lost in the clutter.
First and foremost in the prior art pulsed coil nuclear quadrupole resonance techniques, it was only with difficulty that one could in fact detect any response. One of the reasons is because the coil exhibits a large dwell time after which one looked for a response.
If one did not wait, the incoming radiation would swamp the detectable results. In order to eliminate this problem, those in the past used a pulsed source and then waited for a response after the trailing edge of the pulse. Prior systems thus pumped pulsed energy into a coil with the target material at the center of the coil. Thereafter the material would absorb energy and then the prior systems would listen for the spontaneous decay.
The problem with spontaneous decay is that at thermal equilibrium a spontaneous photon happens only once for every two million stimulated photons. Thus, in terms of detecting spontaneous decay, one is at an extremely difficult power disadvantage. Secondly, the spontaneous decay might happen over several tens of milliseconds which means that the instantaneous power levels at any point in time are very low. For spontaneous decay using a pulsed coil nuclear quadrupole resonance, the problem is that one is working with very few photons and further they are stretched out over time. This means that one has to use huge amounts of power to overcome these problems, often in the nature of kilowatts of energy. Moreover, because one is looking at very low signal strength the coil is made with a very high Q. This means that the coil couples well with the environment, that in turn means that the coil picks up a great deal of background noise.
Pulsed coil nuclear quadrupole resonance detection systems have been marginally cost effective and their power density has exceeded human safe limits.
More specifically, taking RDX as an example, the bandwidth of the RDX resonance is about 400 hertz. This means that the associated decay time or relaxation time is on the order of 2.5 milliseconds. If one were to sweep the frequency through the resonance as one approaches the resonant frequency, what happens is that one excites the nucleus of the nitrogen atom. When the nucleuses are excited they go into an upper state and then as one sweeps by the frequency there is a population inversion in these nuclei at which time they start to decay.
If one utilizes a long CW pulse what would happen is that one would see a periodicity of absorption and emission. When the CW pulse is turned on, the molecule goes into the excited state but then relaxes through stimulated emission. What would happen utilizing a CW signal is that one would see a series of absorptions and emissions that would occur every 2.5 milliseconds.
For RDX, assuming a pulsed coil system, one must use a pulse width of about half a millisecond because the pulse has to decay down fast enough so that the spontaneous emission can be observed.
Thus in the past a relatively short pulse of CW energy was used to enable listening for the response. However, in order to be able to detect the response at all, a very high Q coil was required. High Q coils have an excessive relaxation time. As a result, in order to provide for the ability to listen when driving a very high Q coil at half a millisecond one has to have other circuitry to quench the coil as fast as possible so as to be able to listen to the return, typically in terms of a little hiss that comes off after irradiation with the pulse.
Thus, in the prior systems one had to have exceedingly large kilowatt sources of 3 MHz energy in order to obtain enough of a response, and then had to pulse the source so as to be able to stop it and quench it in time to be able to detect the minuscule response that would occur.
Having the high Q coil further was complicated by the fact that one could not frequency sweep a sample because the high Q coil resonates at only one frequency.
This for instance precludes the ability to distinguish between the detection of multiple spectral lines to be able to distinguish the spectral response of the target molecules from the spectral responses from uninteresting molecules.
Also, when using a high Q coil one has to use an exceedingly large amount of shielding to make the system safe for use around people, as well as having to actively quench the coil.
Moreover, when pumping 1 kilowatt into a coil, the presence of the system is very easy to detect. Thus, terrorists could avoid screening knowing that such a detection system was in operation.
Note that the pulsed coil system detects spontaneous not stimulated emissions. Spontaneous emissions are not coherent and one obtains the square root of the power coming back.
Thus, in the past it has been virtually impossible to, provide a workable system that would reliably and safely detect dangerous amounts of explosive material hidden on a human.
SUMMARY OF INVENTION
Rather than using the high power noise-prone pulsed coil system for detecting nuclear quadrupole resonance lines due to spontaneous emission, in the subject system stimulated emission is sensed. For stimulated emissions, the energy produced by the molecule is not spontaneous and it is not happening randomly. Rather, the emission that is seen in the stimulated emission is coming back exactly in phase with the incident radiation, namely a coherent response.
In the subject system a low power swept frequency source is used in combination with a probe in the form of a terminated balanced transmission line in which molecules including explosives, narcotics and the like that are located between the transmission line elements are detected. In the subject system the result of the absorption of the milliwatt/watt energy is picked off with a directional coupler or circulator so as to eliminate the transmitted energy from swamping the received energy. What is seen is the 1% stimulated emission coherent result that is exactly in-phase with the transmitted signal. It is the coherent in-phase relationship that permits integrating the weak signals into a detectable result.
As a result of utilizing the directional coupler the transmitted signal is rejected. Moreover, the utilization of a balanced transmission line essentially has a zero Q, thus eliminating the background noise associated with the high Q coils. Moreover, since the transmission line is not resonant at any one frequency, a sample can be frequency swept or simultaneously irradiated with signals at multiple frequencies. Additionally, there is no frequency limit to the sweep frequency since there are no tuned circuits involved.
In one embodiment, the energy is step wise swept so as to be able to correlate the result with spectral lines of a known molecule while being able to reject returns from molecules having other spectral lines.
It has been found for explosives such as TNT, RDX and PETN and other molecules of interest that sweeping between 100 KHz and 10 MHz is enough of a sweep to discriminate against non-target materials. For instance, while one might be looking for the spectral lines associated with RDX, one would also like to be able to ignore the spectral lines of for other materials, or for that matter glycine which is present in a great many biologic materials.
The subject system is typically operated at between 200 milliwatts up to 10 watts, making the system much safer than the high power kilowatt pulsed coil nuclear quadrupole resonance systems. Moreover, quenching is unnecessary.
For robust detection of the stimulated emission, more than one spectral line can be considered as an indicator of the molecule. For instance, for RDX one might wish to look at two or three of the RDX spectral lines. If it turns out that glycine is present, and if in fact one of the RDX spectral lines share a spectral line with the glycine, then one could ignore the overlapping spectral line.
While scanning network analyzers can be utilized as frequency sources for the subject invention, due to the fact that the transmission line does not discriminate from one frequency to the next, it is possible to connect multiple frequency sources in parallel to feed the transmission line resulting in simultaneous evaluation of several frequencies.
It is also possible to use a pseudo-random number code pattern so that the system would be difficult to jam. Moreover, the low power system is hard to detect, obscuring the fact that any scanning is going on at all.
In one embodiment while one could scan from 100 KHz to 10 MHz, this type of scanning procedure wastes a large amount of time and is not necessarily beneficial. If one is only looking for specific resonance lines, the scanning can be scheduled to appropriately frequency hop, thus dramatically reducing scanning time.
Note in the subject system that no single detection of a spectral line is used to declare the presence of the target material. Rather, the system desirably requires multiple hits in order to declare the presence of the target material.
It is also noted that the subject system looks at the stimulated emissions, as opposed to the spontaneous emissions, primarily because the spontaneous emissions are perhaps one two millionth of the power of the stimulated emissions. This is important because, as mentioned above, in determining the presence of a target molecule, one is seeing only 1% of the incident energy being returned.
Further, RDX resonances have a bandwidth of approximately 400 hertz, which as mentioned above, results in a decay time or relaxation time of about 2.5 milliseconds. Assuming a stepped sweep approach, the nucleus of the atoms making up the molecules are excited and when they go into the upper state, there is a population inversion in these nuclei, with the stimulated emission occurring immediately thereafter. Note that the stimulated atoms that have been inverted relax coherently such that there is a coherent response back to the probe. Because of the 2.5 millisecond relation time stepped sweeps would have to be adjusted accordingly.
Since there is no coil involved, one does not have to use quenching and since one uses a directional coupler to ignore the transmitted signal, one does not, have to stop and listen in order to get adequate readings.
Moreover, in one embodiment of the subject invention, a cancellation algorithm is utilized in which the transmission line is observed without a sample between the transmission line elements during a calibration sweep. Thereafter, any material that is between the transmission line elements has results that are subtracted from the calibration sweep results. Thus, if there are any peculiarities in the analyzer or transmission lines, these peculiarities are subtracted out. As a result, steady state noise is nulled out.
The reason for the use of the transmission line is that it focuses all the energy between the two balanced leads or elements. Because a balanced transmission line is the world's worst antenna by design it does not leak energy to the environment, unlike a coil. Concomitantly, the transmission line does not receive interference from the environment, making the subject system an extremely quiet system.
The system is implementable in a number of different forms such as providing two spaced apart transmission line elements to either side of a gate or portal through which an individual is to pass. Such a portal may be an airport security checkpoint. Moreover, two pieces of copper pipe or copper tape may be placed on opposing walls down a corridor to form the transmission line, or the balanced transmission lines can be placed on a road to detect the passage of target material between the transmission line elements. Additionally, the transmission line could for instance be configured as opposed guard rails.
Considering for instance that a terminated balanced line contains two elements, one element is called a plus element and the other is called a minus element. The magnetic flux lines are in a plane perpendicular to the axis of the elements. In one configuration, a large area can be covered using a number of side-by-side plus/minus lines. For instance, these lines could be laid out in a carpet at an airport to track people carrying explosives on their person. Thus, one can monitor the transmission lines to be able to tell where someone carrying explosives is walking and to be able to track their path.
It will be appreciated that the subject system, by avoiding the high Q coil, also avoids the large amount of shielding necessary for public safety or the safety of those operating the equipment. Also, as mentioned above, there is no need to actively quench any part of the probe in order to be able to listen to the relatively small returns from the irradiated sample.
Rather than having to run a kilowatt into a coil, in the subject invention successes have been reported at a 200 milliwatt level with excellent signal to noise ratios. Thus, there is the ability to operate at a 30 dB lower power levels than a pulsed coil. This means that the entire system can be run at low power. The result is that the subject system does not interfere with magnetic media or people's safety and is very hard to detect any distance away from the test site. Thus, even standing a few feet beside the balanced transmission line one is not able to detect it. As a result, a person would not know that he or she is being monitored. Also, if a pseudo-random hopping, schedule is utilized, detection of the presence of such a system is virtually impossible.
As will be appreciated, the conductors for the transmission lines could be for instance as large as a two inch pipe, or could in fact be flat transmission line elements. It is also noted that the termination resistance is equal to the impedance of the transmission line. In one embodiment, the space between the elements is about 2.5 to 3 feet, such that one could conveniently paint conductive stripes on opposing sides of a corridor, with the impedance being controlled by how tall the stripes are and how far apart the stripes are. For a corridor-sized installation one might have a conductive stripe on either side of the corridor that is 11 feet long and about a foot tall. Also with larger areas one needs more power to create the flux density required. Thus if one considers a 12 foot long probe, this requires about 36 times as much power as a miniature probe. It is the power density (watts/meter^2) that remains constant.
Regardless, one can obtain adequate results in a corridor type situation with between 7 and 10 watts of power into the probe.
The amount of power required is dependant on how much material one is trying to detect and also the flux density that one is trying to excite it with, as well as how much integration time is available.
Small amounts of explosives can be carried on the person in the persons clothing, swallowed, or can even be surgically implanted, which would be virtually undetectable through a physical examination of the person and also through standard X-ray techniques. Thus for the creative or diligent terrorist, it may be of interest to provide pockets of the explosive within the body of the individual that could not be readily detected by present techniques.
It is noted that the maximum flux density given two spaced apart conductors is on a line between the two conductors, with the minimum being outside the transmission line. As one proceeds to the edge of the conductors, one obtains more flux density. However, the flux density does not very significantly in a direction normal to the plane between the two transmission line elements so it is possible to get reasonable coverage for a human sized object or even a truck sized object above the transmission line. Note that the transmission line impedance can typically be between 100 and 1,000 ohms which is not critical. The critical component is the flux density, with the critical flux density being approximately 1 watt per meter 2 .
With a flux density of less than 1 watt per meter 2 , the signal-to-noise ratio is less for the same integration time. If the flux density is greater than 1 watt per meter 2 , then the signal-to-noise ratio is improved because of the coherent signal. The result of the coherency is that the signal-to-noise ratio improves linearly with how much integration time is utilized.
Integration time refers to the collection of the results of multiple stimulated emissions over time. As a general rule, one has to dwell on the target material for whatever is the inverse of the particular bandwidth involved. Bandwidths in the subject case are on the order of a 100 to 500 hertz which results in dwell times of between 1 and 5 milliseconds.
Of course, as mentioned above, one need not frequency hop in 1 to 5 millisecond intervals because there is no reason why one cannot monitor multiple lines simultaneously or even feed the lines with parallel-outputted frequency generators. In short if one were using three signal generators coupled to the same transmission line, one. Could sense three different spectral lines simultaneously.
Since the subject system can sample multiple frequencies simultaneously this is considerably different from the pulsed coil nuclear quadrupole resonance systems that tend to tune a coil for a specific frequency because of the need for the high Q. Thus, in the subject system one can track the results over the entire bandwidth utilizing the same balanced transmission line probe.
As a result, the subject system is capable of detecting an entire class of explosives, whether they are people-born or vehicle-born. Moreover, the subject system may detect contraband such as narcotics, with many narcotics having very specific nuclear quadrupole resonance signatures. This includes cocaine and heroin.
It will be appreciated that for some complex organics the spectral lines tend to be larger, such as those associated with glycine. Glycine, even in its usual 5% concentration for dietary supplements, for instance, can be distinguished by recognizing the glycine spectra and subtracting out the nuclear quadrupole resonance signature. As a result, if it turns out that one of the spectral lines happens to be right on top of the molecule of interest, the subject system provides way to discriminate against the non-target molecules.
Another application is to be able to detect explosives in shipping containers. In such cases one has an incredibly long integration time available, for instance weeks during which the inspection can take place.
Another different application for the subject technique is in the production of molecular compounds. Explosives for instance have a certain composition which involves a very specific ratio of the molecular components. It has been found that the subject technique can be used to verify the specific percentage ratio of the components in the test sample, so that one can non-destructively inspect materials during production without damaging it.
It has been found that the detected spectral lines are one-to-one correlatable with the ratio of the molecular constituents in a compound so that the measurements are a very accurate prediction of the actual ratio of the elements in the compound.
Moreover, it has been found that the stability of the frequency source and its accuracy is important with respect to the stability of the oscillators involved, with the aforementioned cancellation requiring suitably stable oscillators.
With suitably stabilized oscillators in the form of for instance multiple network analyzers, one can digitally synthesize multiple frequencies simultaneously. Fast-Fourier transforms are then used to sort out the frequencies. In this case one piece of hardware can generate multiple frequencies simultaneously. This cuts down the time that the specimen has to be between the elements of the balanced transmission line, thus for instance to be able to detect somebody who is running with explosives.
For stepped frequency sweeps, one can allocate 5 milliseconds per frequency. If one is analyzing 10 spectral lines then one is doing so in 50 milliseconds. However, the problem is that there may be 40 or 50 different prominent explosives, all with different spectral lines, and hundreds of compounds that have spectral lines in the same region. Thus instead of processing 10 spectral lines, one might have to process 1 , 000 spectral lines. At 50 hertz, this corresponds to a dwell time of 0.5 seconds and necessitates synthesizing all frequencies of interest simultaneously.
In summary, stimulated emissions due to nuclear quadropole resonance are detected utilizing a terminated balanced transmission line and a directional coupler, thus to detect explosives, contraband, narcotics and the like that exist between the transmission line elements. In one embodiment, a stepped frequency generator is utilized to provide a scan between 100 KHz and 10 MHz. In another embodiment, parallel frequency sources are coupled to the transmission line, either embodiment permitting correlation with expected spectral lines, with the frequency sources being low power so as to not create a safety hazard and so as not to interfere with radiation sensitive devices such as film or electronic circuits that are in the vicinity of the balanced transmission line probe.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the subject invention will be better understood in connection with the Detailed Description, in conjunction with the Drawings, of which:
FIG. 1 is a diagrammatic illustration of the detection of an explosive hidden on an individual as the individual walks through a balanced transmission line coupled to an explosive/contraband detection unit that utilizes nuclear quadrupole resonance in which, in one embodiment, RDX spectral lines are detected to ascertain the presence of an explosive;
FIG. 2 is a graph showing the spectral signatures of a number of potential explosive materials indicating for RDX and HMX, a spectral signature in a 3-4 MHz range, with TNT indicating a spectral signature in the sub 1 MHz range as well as ammonium nitrate and potassium nitrate, with tetryl having a signature in the 3-4 MHz range and with urea nitrate having a spectral signature not only in the sub 1 MHz range but also in the 2-3 MHz range, noting that sodium nitrate has a very close spectral signature to one of the spectral lines of glycine;
FIG. 3 is a diagrammatic illustration a prior art pulsed coil nuclear quadrupole resonance system illustrating the use of high power pulses and a high Q coil in which the system has a transmit-receive switch, the cycling of which depends on coil quench time;
FIG. 4 is a diagrammatic illustration of the subject system illustrating a stepped network analyzer functioning as a frequency source for generating a number of stepped frequencies which are amplified by a low power amplifier to less than 10 watts in one embodiment, with the amplifier being coupled to a balanced transmission line probe in which the transmission line is terminated in a load and in which a directional coupler is utilized to detect the stimulated emission from a material under test, unimpeded by the output power applied to the transmission line;
FIG. 5 is a block diagram of the subject system in which transmissions at various stepped frequencies are applied through a 24 bit digital-to-analog converter to a circulator that functions as a directional coupler, with the output of the circulator being converted by a 24 bit A-D converter to correlate the returns with raw correlated data from a library, the output of the hardware-implemented correlator provided to a microcontroller for detecting the existence of a particular material present at the probe; Note that this system can be used to test several simultaneous frequencies simultaneously.
FIG. 6 is a diagrammatic illustration of an embodiment of the subject invention in which explosives detection includes the use of parallel foil strips on opposing walls of a hallway that function as a balanced transmission line probe for detecting target materials carried by a person walking down the hallway;
FIG. 7 is a diagrammatic illustration of the utilization of a grid of balanced transmission lines for the location of a target material carried for instance by an individual who traverses the grid;
FIG. 8 is a diagrammatic illustration of the use of the subject system as a nuclear quadrupole resonance component ratio detector for detecting the ratio of molecular components in material proceeding down a production line to detect component ratios in a non-destructive environment on the fly as the material passes between the balanced transmission line probe elements;
FIG. 9 is a diagrammatic illustration of a shipboard container inspection system utilizing the subject system in combination with a mesh radio network to report incidents to a cargo control room; and,
FIG. 10 is a block diagram of parallel-connected frequency generators coupled to a terminated balanced transmission line.
DETAILED DESCRIPTION
Referring now to FIG. 1 , an individual 10 may be carrying on his or her person some contraband or explosives 12 which may for instance may be secreted in his or her underwear, or could even be surgically implanted. One such explosive is RDX and it is the purpose of the subject invention to be able to detect explosives in as little quantity as 75 grams which is approximately about a fifth of a cup. Terrorists and the like are using more and more sophisticated ways of secreting explosives and/or contraband and a physical examination of the individual may not yield the presence of such explosives or contraband. Not only may the explosives or contraband be surgically implanted in the individual, they may be swallowed in bags and be held internally in the gut until such time as their “removal”.
Present systems for detecting such explosives or contraband such as back scatter X-rays are not effective to detect such secreted items and the use of higher power radiation is counterindicated for safety reasons.
On the other hand, as shown in FIG. 1 , an explosive or contraband detection system 14 utilizes nuclear quadrupole resonance in which swept frequencies are applied to a balanced and terminated transmission line 16 embedded in a screening gate or housing 18 in which the elements of the balanced transmission line 20 and 21 as well as load 23 are embedded in the gate. The balanced transmission line has no frequency to which it is tuned, such that the application of signals for instance between 100 KHz and 10 MHz may be applied due to the non-tuned nature of the probe which is comprised of elements 20 , 21 and 23 .
As will be seen, the power necessary to detect nuclear quadrupole resonance is in general below 10 watts and often as little as 200 milliwatts, due to the subject explosives/contraband detection system which, inter alia, utilizes a directional coupler in the form of a circulator to cancel out the transmitted energy while receiving only the stimulated emission from the molecules in the target sample.
As used herein, the target sample 12 includes molecules having a particular recognizable spectrographic signature in which the spectral lines of the sample are recognizable when compared with the spectral lines generated through stimulated emission of all of the remaining molecules that surround the target sample.
For instance, glycine which is common in the human body has spectral lines that are distinguishable for instance from RDX spectral lines, with glycine in essence forming a background spectral signature which is to be distinguished.
While the subject invention will be discussed in terms of explosives, it is understood that the material under test may be molecules of any type having a known spectral signature. This includes contraband such as narcotics and other types of drugs such as heroin and cocaine which, due to the subject system in one embodiment involving stepped and swept frequency transmission enables one to eliminate the spectral signatures of non-target materials while being able to single out the spectra of target materials.
Referring to FIG. 2 , what is shown is a spectral chart for common explosive materials such as RDX, HMX, PETN, TNT, ammonium nitrate, potassium nitrate, tetral, urea nitrate and sodium nitrate, also as compared with the spectra of glycine.
What will be seen is that all of these materials have spectra between about 100 KHz and about 5 MHz, which spectra are detectable by the subject system. For instance, if one detects spectra of RDX in the 3-4 MHz band, this is clearly distinguishable from the glycine spectra which lie below 1.5 MHz.
Likewise one can distinguish PETN from RDX as well as being able to distinguish HMX from RDX due to the offset of the spectra of HMX in the 3-4 MHz band from the spectra of RDX.
Since the subject system detects stimulated emission from all of the molecules in the sample between the balanced transmission lines, it is possible through correlation processing to be able to provide a probability of a match between the spectral lines of the target material as opposed to the spectral lines due from molecules that are not target materials and which constitute background.
Referring now to FIG. 3 , what will be seen in the prior art pulsed coil nuclear quadrupole resonance system is the utilization of a high Q coil 20 which is driven from a frequency generator 22 , the output of which is amplified by an amplifier 24 to the 1 kilowatt level. The signal from the amplifier is switched via a transmit/receive switch 26 and is applied to the coil during a pulsed sequence, with switch 26 being returned to the receive position at which point the high Q coil 20 is coupled to a low noise amplifier 26 , to an analog-to-digital converter 28 and thence to a computer 30 for measuring the spontaneous emission response from material under test 32 .
In short, since the system described in FIG. 4 measures the spontaneous emission of the material under test and since in order to generate, enough spontaneous emission high power was deemed to be necessary, the system of FIG. 4 is clearly not usable around human beings for safety reasons.
Moreover, in order to be able to eliminate the effect of the transmitted power with respect to the relatively low power of the receive signal, it was necessary to be able to quench high Q coil 20 so as to be able to see the return from the material under test. The quench time, τ Q is problematic with respect to providing realtime measurements. It has been found that it is important to be able to provide circuitry to be able to quench high Q coil 20 in order to increase the pulse repetition frequency. However, the quench time when utilizing a high Q coil is problematic as mentioned above.
Moreover, the utilization of a high Q coil is problematic because it also collects background, which background can oftentimes obscure the results.
On the other hand and referring now to FIG. 4 , a balanced transmission line probe 40 is coupled to a power amplifier 42 which amplifies a frequency generator 44 output, in one embodiment provided by a stepped network analyzer. The transmission line is terminated by a terminating load 46 .
When a material under test 48 is placed between the balanced transmission line elements 50 and 52 , it has been found that the stimulated emission from the material under test can be sensed utilizing a directional coupler 54 coupled to a low noise amplifier 56 which is in turn coupled back to the network analyzer 44 that detects the very low level stimulated response of the material under test. It is noted that network analyzer 44 is coupled to a computer 58 such that the returned signal can be processed and an alarm 60 activated if the material under test has a spectral signature match to that of a target material.
While it is possible to generate only one frequency corresponding to one the major spectral line of the target sample, it is useful to be able to scan frequencies for instance f 1 -f n in order to obtain the spectral lines of whatever materials might be between the elements of the balanced transmission line. Because the balanced transmission line has a Q of zero, not only is it possible to couple a wide frequency range of signals to the transmission line, the Q of zero also means that there is very little outside interference with respect to the signals that exist interior to the transmission line.
Moreover it has been found that while the flux densities vary at various positions between the transmission line elements, at least in the plane of the transmission line elements, locating a material under test above or below the plane of the transmission line elements does not materially affect the readings.
Referring to FIG. 5 , in one embodiment an memory card (such as a SXDX 62 gigabyte card) having a 30 MB per second transfer rate may be utilized to generate the 100 KHz to 10 MHz signals that are coupled to probe 64 utilizing a 24 bit digital-to-analog converter 66 to which is applied a PN code 68 in one embodiment.
The utilization of a pseudo-random code is for defeating jamming, with the pseudo-random code being similar to that utilized in GPS systems for this purpose.
The input to the probe and the output from the probe are coupled to a circulator 70 which, as described above, completely eliminates the effect of the transmitted signal on the received signal, thereby to eliminate the problems of having to quench a high Q coil.
The output of circulator 70 is applied to a 24 bit analog-to-digital converter 72 , with the receive PN code being applied to a hardware implemented correlator 74 that correlates the received stimulated emission information with raw correlator data 76 such that if there is a high correlation between the raw correlator data and the received data, microcontroller 78 may be used to drive memory card event log 80 and also provide an operator interface 82 alarm condition indicator.
Note that in terms of the generation of stepped frequency signals, a library 84 may be utilized that carries the spectral signatures of many types of target molecules. This results in the ability to generate a large variety of very narrow frequency signals which are applied to probe 64 .
It will be appreciated that the frequency stability of the signal generator in the form of a network analyzer such as shown in FIG. 4 is critical due to the narrow nature of the spectral lines that are generated by the nuclear quadrupole resonance phenomena and the requirement of coherence.
Referring now to FIG. 6 , in one embodiment, an explosive contraband detection system 90 may be coupled to a balanced transmission line probe 92 which includes elements 94 and 96 embedded foil strips in hallway walls 98 and 100 , with elements 94 and 96 terminated in a resistance load 102 . In this case an entire hallway may be monitored for the presence of target molecules whether carried by a person or in some other conveyance as it transits down a hallway.
Referring to FIG. 7 , it is possible to provide a grid of balanced transmission lines here shown at 110 to include pairs of transmission lines for instance vertical pairs 112 and 114 indicated by the plus and minus nomenclature for the particular transmission line. Likewise, a crossing or transverse transmission line structure may include transmission lines 116 and 118 . By monitoring the results on the various transmission lines one can localize the target molecule as illustrated at 120 as being at position x n y m This kind of grid, whether on the floor or surrounding a building can track the presence of explosives or contraband materials and therefore determine the track or path of the individual or conveyance which is transporting these materials.
For this particular embodiment the detection of explosives in for instance the north/south direction here illustrated at 122 is correlated with at explosive detection in east/west direction here illustrated at 124 to provide location.
Referring now to FIG. 8 , one of the important characteristics of the subject system is that the molecular component ratio can be detected on the fly in a production line environment to provide non-destructive testing. Here a nuclear quadrupole resonance component ratio detector 130 is utilized with a balanced transmission line probe 132 to, for instance, detect the molecular composition of a drug 134 in pill form as the pills pass through the balanced transmission line probe. It has been found that by sweeping the frequency of the signals to the balanced transmission line probe one can detect not only the spectral lines of the various components in question, but also can detect the ratio of the target components.
Thus, rather than having to perform destructive tests in order to ascertain the constituents of a product being manufactured, one can non-destructively detect the component ratios utilizing the subject nuclear quadrupole resonance system.
Referring to FIG. 9 , another embodiment of the subject system is the ability to track the contents of cargo containers that may either be placed shipboard or on other modes of conveyance in which, as illustrated, a cargo container 140 may be provided with internal balanced transmission lines 142 terminated as illustrated at 144 and coupled, for instance, to an explosive detection system 146 of the subject nuclear quadrupole resonance variety. If for instance the containers contain explosives or contraband, here illustrated at 148 , whether these materials are initially placed in the container or later clandestinely placed into a sealed container, their presence can be detected as illustrated at 146 by an explosives detector. Through the use of a mesh network 148 , the detected results can be communicated from explosives detector 146 and a co-located transmitter 150 which is part of a self establishing mesh network 152 aboard a ship to the cargo control room. Mesh network 152 includes one or more repeaters 156 which relays the information from transmitter 150 to a receiver 158 in the cargo control room.
It is noted that when monitoring containers, due to the length of time on board ship, the integration times available for the sensing of the stimulated emissions are dramatically increased. This long integration time can accommodate lower power detection. What this means is that an exceedingly robust system is available for detecting the relatively minute simulated emissions, with integrating occurring over a long period of time, thanks to the fact that the containers are in transit for substantial periods of time. While this embodiment of the subject system has been described in terms of shipboard containers, any kind of container monitoring on conveyances is within the scope of the subject invention.
It is also possible for instance to utilize the subject system to detect contraband or explosives in trucks that pass through a portal. This is possible due to the relatively thick skin depths associated with metal containers that permit penetration of low frequency signals so that the transmission line carried signals can penetrate well into the containers. Thus, the subject system may be utilized to detect not only person-carried contraband and explosives, but also truck or vehicle-carried contraband or explosives, as for instance they proceed through a portal or checkpoint.
Referring now to FIG. 10 , while the subject system has been described in terms of stepped frequency production, it is possible to use a parallel-connected set of frequency generators 170 , 172 and 174 , the outputs of which are summed at 176 and applied to a balanced transmission line 178 having elements 180 and 182 through a circulator 184 . It is also possible to synthesize multi frequency signals digitally. The output of circulator 184 is applied to a network analyzer or receiver 186 that, inter alia, enables correlations between spectral lines found at the various frequencies to target molecule spectral lines, whereupon signals representative of the presence of the target molecule may be applied to an alarm 188 .
Thus, whether or not stepped frequencies are utilized, or whether a number of parallel-connected frequency sources are utilized, the result of being able to scan spectral lines of target and non-target molecules can be quickly scanned.
While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications or additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.
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Stimulated emissions due to nuclear quadropole resonance are detected utilizing a terminated balanced transmission line and a directional coupler for the detection of explosives, contraband, narcotics and the like that exist between the transmission lines, with either a stepped frequency generator utilized to scan between 100 KHz and 10 MHz, or wherein parallel fixed frequency sources are coupled to the transmission line, thereby to permit correlation with expected lines, with the frequency sources being low power so as to not create a safety hazard and so as not to interfere with radiation sensitive devices such as film or electronic circuits that are in the vicinity of the balanced transmission line.
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BACKGROUND OF THE INVENTION
[0001] The present invention involves a process of coating a non-woven fiber glass mat with foam or froth on the same wet process line used to make the mat, as an intermediate step in the mat manufacturing process, and the foam coated fiber glass mat products that result. These coated mats have many uses, but are especially useful as a facing on a gypsum wallboard for exterior application and on which stucco is applied.
[0002] Fibrous non-woven mats are often formed into a wet mat from an aqueous dispersion of fibers such as glass and/or synthetic organic fibers can include other fibers such as cellulose fibers, ceramic fibers, etc. and can also include particles of inorganic material and/or plastics. Usually a solution of urea formaldehyde resin, usually modified with a thermoplastic polymer, or one of many other known resin binders is applied to a the wet non-woven web of fibers and then, after removing excess binder and water, the bindered web is dried and heated further to cure the urea formaldehyde resin or other resin binder to form a non-woven mat product. A typical process is disclosed in U.S. Pat. Nos. 4,112,174 and 3,766,003, the disclosures of which are hereby incorporated herein by reference.
[0003] The fiber glass mat (Johns Manville's 7502 Mat—2 lb./100 sq. ft.) made using a binder of urea formaldehyde performed good in the process disclosed in U.S. Pat. No. 4,647,496 to make a faced insulating gypsum board, also disclosed in that patent, but the mat was not as strong as desired which caused process breakouts adding to production costs. This mat was also more rigid than desired which made it difficult to fold around the edges of the board and also irritated the hands and arms of the workers handling and installing the insulating board product. Further, when the faced insulated gypsum board was cut, the dust from the mat was excessive and further irritated those it contacted, particularly if the workers bare arms, etc. were sweaty and exposed to the dust. Skin abrasion and irritation was also a problem for those handling the mat and the faced board when not wearing gloves and long sleeve shirts.
[0004] To address the inadequate strength problem a small portion of polyester, polyethylene terathalate (PET), fibers were used in place of an equal amount of glass fibers and the urea formaldehyde resin binder was replaced with an acrylic binder containing a small amount of a stearylated melamine. This improved the strength adequately and also improved the handling characteristics of the mat somewhat, i.e. the mat is more friendly to those handling and installing the mat or board, but the acrylic bound mat is more expensive and less fire (flame) resistant. Such mats are disclosed in U.S. Pat. No. 5,772,846. While the mats disclosed by this latter reference have substantially improved “hand” and cause very little abrasion or discomfort in handling, the cost is higher, the mat is less flame resistant than the mat disclosed in U.S. Pat. No. 4,647,496 and further improvement is still desired by some users.
[0005] There still exists a need for a nonwoven fiber glass mat that has better flame resistance, lower cost and good handlability (flexibility and non abrasive/non irritating to the skin).
BRIEF SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a foam or froth coated nonwoven fibrous mat useful as a facer on gypsum insulating board of the type described in U.S. Pat. No. 4,647,496 having one or more of improved handling characteristics, improved flame resistance, improved flexibility and product that produces less, or less irritating, dust when the faced gypsum board is cut than the mats used heretofore for facing insulating gypsum board.
[0007] It is a further object of the present invention to provide flexible mats containing a major portion of less expensive chopped glass fibers that can be used for facing gypsum wall board and other products.
[0008] It is a further object to provide a low cost method of making a foam faced fibrous non-woven mat on a wet process line without having to coat a dried mat either in-line or off-line and without having to dry the mat a second time.
[0009] The present invention includes a method of making a foam coated fibrous non-woven mat where the fibers are preferably, but not necessarily, bonded together with a conventional mat binder comprising using a wet process to form a wet non-woven web from a low concentration aqueous slurry followed by partially dewatering the mat, preferably, but not necessarily, adding an excess of aqueous resin binder, removing some but not all of the binder, then applying an aqueous foam or froth having a high air content and a high blow ratio, onto the top of the wet mat in-line, and then heating the mat to remove the water, and preferably to cure the binder, and set the foam coating. The aqueous foam slurry contains a foam that breaks down fairly quickly such that the mat has enough permeability to allow drying air to penetrate the mat. The foam coating will hold the non-woven fibrous web together adequately for some applications, but it is preferred to use a conventional binder in a conventional manner to give the non-woven finished mat greater strength. The aqueous foam is foam having a blow ratio of at least 15, preferably at least 25, and most preferably between 15 and 30, a viscosity of at least 200 centipoise, preferably at least 500 centipoise, and have rapid heat breaking and non-draining characteristics.
[0010] The present invention also includes the mats made by the above process, or a different process wherein foam is applied to wet mat in-line, comprising a non-woven fibrous mat with the fibers bound together with a resinous binder and having a dry foam coating on one surface of the mat, the dry foam coating preferably being permeable to allow the mat to breathe and to allow later coatings to penetrate the foam coating. The foam layer may penetrate into the non-woven fibrous mat a distance that is a small fraction of the total thickness of the mat. This mat is very useful as a facer for many products, particularly gypsum wallboard and insulating boards of various kinds. The foam coating ties up the fibers preventing loose fibers from or fiber ends from getting on people handling and/or installing the product faced with the foam coated mat and causing irritation and/or itching. The foam forming the foam coating on the mat can contain fire retardant or intumescent material, adhesives, colorants and/or other materials for changing the appearance or performance of the mat surface.
[0011] The present invention also includes laminates comprising a base layer such as gypsum wallboard or insulating boards, fiberglass blanket, plywood or other wood product having adhered thereto a foam coated fibrous non-woven mat as described above.
[0012] Preferably the inventive mat for facing the insulating gypsum board has a basis weight within the range of about 1.5 and about 3, preferably within the range of about 1.8-2.5 pounds per 100 square feet, most preferably about 2.2-2.4 pounds per 100 sq. ft. Preferably the binder content of the dried and cured mats is within the range of about 15 wt. percent and about 25 wt. percent, most preferably about 20-25 wt. percent, based on the weight of the finished mat. Preferably the inventive mat contains a major portion of glass fibers, but can also contain a minor portion of polymer fibers, such as PET polyester fibers, cellulosic fibers like wood pulp, and ceramic fibers, bound together with a minor portion of a conventional modified urea formaldehyde binder. Other conventional binders can be used instead of the modified UF binder such as a phenolic resin, a melamine formaldehyde, a furfuryl alcohol, a latex containing a mixture of a cross linked vinyl chloride acrylate copolymer having a glass transition temperature as high as about 113 degrees F., preferably about 97 degrees F., and a small amount of a stearylated melamine and other conventional mat binders.
[0013] When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond that so long as the advantages of the invention are realized. Practically, there is rarely the time or resources available to very precisely determine the limits of all the parameters of ones invention because to do would require an effort far greater than can be justified at the time the invention is being developed to a commercial reality. The skilled artisan understands this and expects that the disclosed results of the invention might extend, at least somewhat, beyond one or more of the limits disclosed. Later, having the benefit of the inventors disclosure and understanding the inventive concept and embodiments disclosed including the best mode known to the inventor, the inventor and others can, without inventive effort, explore beyond the limits disclosed to determine if the invention is realized beyond those limits and, when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein. It is not difficult for the artisan or others to determine whether such an embodiment is either as expected or, because of either a break in the continuity of results or one or more features that are significantly better than reported by the inventor, is surprising and thus an unobvious teaching leading to a further advance in the art.
DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic of a conventional wet mat process line having a curtain coater binder applicator and a foam applicator, for practicing the present invention.
[0015] [0015]FIG. 2 is a schematic cross section of a portion of the process line of FIG. 1 showing the binder application portion and the foam application portion according to the present invention.
[0016] [0016]FIG. 3 is a schematic cross section of a portion of the process line of FIG. 1 showing the binder application portion and another embodiment of a foam application portion according to the present invention.
[0017] [0017]FIG. 4 is a schematic cross section of a portion of the process line of FIG. 1 showing the binder application portion and a still further embodiment of a foam application portion according to the present invention.
[0018] [0018]FIG. 5 is a schematic cross section of a portion of the process line of FIG. 1 showing the binder application portion and a still further embodiment of a foam application portion according to the present invention.
[0019] [0019]FIG. 6 is a partial plan view of the system shown in FIG. 5 taken along lines 6 - 6 showing how foam applying nozzles are positioned.
DETAILED DESCRIPTION OF THE INVENTION
[0020] It is known to make reinforcing nonwoven mats from glass fibers and to use these mats as substrates in the manufacture of a large number of roofing and other products. Any known method of making nonwoven mats can be used in this invention, such as the conventional wet laid processes described in U.S. Pat. Nos. 4,129,674, 4,112,174, 4,681,802, 4,810,576, and 5,484,653, the disclosures of each being hereby incorporated herein by reference. In these processes a slurry of glass fiber is made by adding glass fiber to a typical white water in a pulper to disperse the fiber in the white water and to form a slurry having a fiber concentration of about 0.2-1.0 weight %, metering the slurry into a flow of white water to dilute the fiber concentration to 0.1 wt. percent or less, and continuously depositing this mixture onto a moving screen forming wire to dewater and form a wet nonwoven fibrous mat. This wet nonwoven mat is then conveyed through a binder application where an aqueous resinous binder is applied in excess, the surplus is removed by suction and the wet, bindered mat is then dried and the binder cured to form a nonwoven mat product.
[0021] The method of the present invention comprises a modification to the binder application portion of otherwise conventional mat making processes by adding a second applicator for applying a foam coating. Most nonwoven mat processes and forming machines are suitable for modification and use with the present invention, but preferred are the wet laid nonwoven mat processes and machines wherein an aqueous slurry containing fibers is directed onto a moving permeable screen or belt called a forming wire to form a continuous nonwoven wet fibrous mat.
[0022] [0022]FIG. 1 is a schematic of a preferred wet laid system for practicing the invention. Fibers 5 are fed continuously at a controlled rate into a pulper 1 along with a conventional whitewater through a pipe 7 , also continuously and at a controlled rate. An agitator 3 in the pulper 1 mixes and disperses the fibers in the whitewater. The resultant concentrated fibrous slurry flows continuously through a pipe 9 into an optional pump 11 that pumps the concentrated slurry into a fiber slurry holding tank 13 . The concentrated fiber slurry is preferably metered continuously from the holding tank 11 with a valve 14 and into a metered flow of deaired whitewater 27 to form a diluted fibrous slurry. The valve 25 meters a correct rate of deaired whitewater to the pulper 1 via pipe 7 and a correct rate of deaired whitewater 27 to form the diluted fiber slurry. The diluted fibrous slurry flows into pump 15 and is pumped to the mat forming machine 17 , which can be of any width and typically is wide enough to make a finished mat 12 feet wide or wider. Alternative forming methods for making the body portion of the nonwoven mat include the use of well known paper or board making processes such as cylinder forming, dry forming or air laid, etc.
[0023] The preferred processes for the production of mats of the present invention are those known processes using mat forming machines 17 like a Hydroformer™ manufactured by Voith-Sulzer of Appleton, WS, or a Deltaformer™ manufactured by North County Engineers of Glens Falls, N.Y. In these machines, the diluted fiber slurry flows horizontally against an inclined moving permeable belt or forming wire (not shown) where the fiber is collected and builds up in a random pattern to form a wet fibrous mass 28 while the whitewater passes through the forming wire becoming somewhat foamy (due to contained air) and is transported to a deairing tank 21 via pipe 19 . The wet fibrous mass 28 is dewatered to the desired level with a suction box 29 to form a wet fibrous web 30 . The foamy whitewater removed is piped through pipe 32 to the deairing tank 21 , preferably via the pipe 19 .
[0024] This wet nonwoven fibrous web 30 , the body portion, is then preferably, but not necessarily, transferred to a second moving screen 33 and run through a dual application section 31 where first an aqueous binder mix is applied to the mat in any one of several known ways. An aqueous binder is pumped at a controlled rate from a binder mix holding tank 45 via a controlled rate pump 46 such that more binder than is needed is fed through a pipe 37 to a binder applicator such as a curtain coater 35 where the binder slurry is applied in excess to the wet web 30 . Other types of conventional applicators can be used to apply the binder in a known manner.
[0025] The aqueous binder mix is prepared by feeding one or more aqueous resin binders 52 at a desired rate to a binder mix tank 47 having an agitator 49 therein to mix the aqueous binder(s) 52 to form a binder mix. Fibers or particles, such as microfibers, pigments, filler, etc., can also be added to the binder mix tank 47 . The binder mix or slurry is then pumped to the binder holding tank 45 with a metering pump 53 and pipe 55 . A metering pump 46 pumps binder mix, mixed with returned excess binder via line 43 from suction boxes 39 and 41 , through line 37 to the binder applicator 35 and speeds up and slows down the pumping rate with the speed of the mat line or windup 59 . The resin content in the binder mix and the degree of vacuum in the suction boxes 39 and 41 are varied to control and obtain the desired binder resin content of the mat in a known manner.
[0026] The binder mix can be prepared continuously or in batches as is well known. When prepared continuously, all ingredients of the mix are carefully metered in known ways to insure that the desired composition of the finished mat is maintained.
[0027] When the aqueous binder mix is applied to the wet nonwoven web 30 (FIG. 2), the binder mix will saturate the wet nonwoven fibrous mat. Preferably, excess aqueous binder slurry is applied using the curtain coater 35 , such as supplied by North County Engineers of Glens Falls, N.Y., but other known methods of application and equipment that will also handle the particles and/or fibers in the binder and that will apply this at the rate required to the top of the wet body portion of the mat will work.
[0028] As shown in FIG. 2, the binder mix flows over a lip of an inclined surface 38 of a curtain coater type of the binder applicator 35 and onto the wet web 30 . As shown, the aqueous binder mix flows into the wet web 30 also coating at least portions of the fibers in the body portion 30 and the excess aqueous binder portion flows out of the wet web 30 , through the permeable belt 33 and into a first suction box 39 . The binder saturated web 30 A is then run over a second, or more, suction box 41 while still on the moving permeable belt 33 to remove excess binder to form a wet, bindered nonwoven web 30 B containing the desired amount of aqueous binder. The excess binder mix that is removed is returned to the binder mix tank 47 , and/or to the binder holding tank 45 , via pipe 43 .
[0029] A second applicator, a foam applicator 48 is mounted just downstream from of the second suction box 41 , but above the permeable belt 33 and the wet, bindered web 30 B, in a similar manner as the binder applicator 35 . The foam applicator 48 can be any foam coater applicator, but preferably is a conventional pipe slot applicator 48 . An aqueous foam according to the present invention is prepared in foam generator 54 using a high shear type mixer such as a pinned drum mixer or foam generator available from Gaston Systems, Inc. of Stanley, N.C., or Lessco Company of Dalton, Ga., or any suitable equivalent foam generator for this purpose and forced to the foam applicator 48 through line 50 which divides into multiple lines 26 that enter the foam applicator 48 spaced along and around the pipe slot applicator 48 . A positive displacement pump 56 , which can be any type of positive displacement pump, pumps an aqueous foam precursor into the foam generator 54 and the high shear action inside the foam generator 54 produces foam 24 whose pressure due to expansion forces the foam through the lines 50 and 26 into the applicator 48 where it is extruded through a slot 50 onto the top surface of the moving wet, bindered web 30 B to form a foam coating 40 and a foam coated, bindered, fibrous web 42 . The rate of foam extrusion through the slot 50 is controlled by the pumping rate of the positive displacement pump 56 . The foam applicator 48 can have an optional foam smoothing lip 51 adjacent the downstream side of the slot 50 for purposes of controlling the height of the foam layer 40 and for smoothing the top surface of the foam layer 40 .
[0030] As can be seen, the foam penetrates the top of the wet, bindered web. 30 B slightly. The type of foam used is carefully selected and controlled to prevent the foam from penetrating further into the wet, bindered web 30 B. Foam coating has an advantage, because of its very high viscosity under low shear, i.e. it sits on top of the wet web without excessive penetration after application. The aqueous binder in the bindered web 30 B also helps prevent deeper penetration by the foam. The application rate of foam to the wet, bindered web 30 B, and thus the thickness of the foam layer or coating 40 , is controlled by the controlling the speed of the permeable belt 33 and the rate of foam pumped to the foam applicator 48 by the foam pump 54 .
[0031] The foam coated, wet, bindered web 42 is next transferred to a moving conventional permeable, oven belt (not shown) in a known manner and run through an oven 57 to dry the wet web 42 and to cure (polymerize) the polymeric based resin binder which bonds the fibers together forming the finished inventive foam coated fibrous mat 58 which can be wound into a roll 59 using conventional mat winding equipment. The mat is heated to temperatures of up to about 500 degrees F. in an oven, depending on the type of binder used and/or the nature of the foam on the surface, but other types of dryers and heaters can be used also such as sequential can dryers, a honeycomb oven roll and other ovens used in the art of manufacturing fibrous, non-woven mats.
[0032] Preferrably the foam is applied to a wet, bindered web to produce a foam coated binder bound fibrous mat, but the binder is optional. Foam can be applied to a wet web containing no binder in which case the fibers are held together by the foam layer on one surface of the mat while the opposite portion of the mat contains no added binder. Nevertheless, the resultant mat has enough strength to enable it to be wound up and unwound for use in making a mat faced laminate. In this latter case, the foam, wet gypsum mix, or other base laminate material penetrates the unbound fiber portion of the mat and bonds the fibers together while also bonding the mat to the base layer.
[0033] The fibers, or fibers and particles, in the web portion of the mats of the present invention preferably constitute about 40-80 wt. percent of the total weight of the mat and the foam coating on the mat amounts to about 5-35 wt. percent of the mat. The resin binder content of the mats can vary greatly, but usually is about 10-30 wt. percent of the foam coated mats of the present invention. A preferred coated mat of the present invention contains about 70+/−5 wt. percent fibers, about 20+/−3 wt. percent binder holding the fibers together and about 10+/−5 wt. percent foam coating.
[0034] Preferably, the majority of the fibers are glass fibers and most preferably all the fibers are glass fibers, but this invention is equally applicable to ceramic, natural, like wood pulp, manmade cellulosic fibers and polymer fibers and to nonwoven webs made from mixtures of any combination of these types of fibers. While the majority of the fibers are glass fibers in the preferred body portion, all or any portion of non-glass fibers can also be included, such as man made or natural organic fibers like Nylon™, polyester, polyethylene, polypropylene, cellulose or cellulose derivatives, etc.
[0035] The fibers used in the nonwoven mat should be at least 0.25 inch long or longer, more preferably at least one-half inch or three-quarters inch long and most preferably at least about one inch long, but mixtures of fibers of different lengths and/or fiber diameters can be used as is known. It is preferred that these fibers be coated with a silane containing size composition as is well known in the industry.
[0036] The glass fibers can be E, C, A, T, S or any known type glass fiber of good strength and durability in the presence of moisture and mixtures of lengths and diameters. Fibers of any diameter can be used, but the preferred fibers are K 137 (about 13 micron average diameter) or M 137 (about 16 micron average diameter) and 117 K or M 117 E glass fibers available from Johns Manville International, Inc. of Denver, Colo., but most commercially wet chop glass fiber products are be suitable. A substantial advantage of the present invention is that it enables the use of larger fiber diameters, which are less expensive, while producing a faced product that has a surface that is “user friendly” and non abrasive. Larger fiber diameters have caused irritation problems in past facer products causing the industry to shift to more costly, smaller diameter fibers like H or G fibers (about 10 or 9 microns average diameter).
[0037] The binder used to bond the fibers together can be any conventional binder capable of bonding the fibers together. A wide variety of binders are used to make nonwovens with urea formaldehyde (UF), acrylic resin, melamine formaldehyde (MF), polyester, acrylics, polyvinyl acetate, and urea formaldehyde and melamine formaldehyde binders modified with polyvinyl acetate and/or acrylic being typically used.
[0038] The foam used to make the foam coating of the two layered mat should not penetrate substantially into the aqueous resin binder slurry, but could penetrate slightly. The foam should have a very high blow ratio (or low cup weight, i.e. grams per liter), the density of the foam precursor divided by the density of the wet froth or foam, forming a very dry froth. The blow ration should be at least 12 and preferably at least 25, most preferably about 15-30 such as 15-18. The foam must be extremely non-draining, for example when a one liter Imhoff cone is filled with the wet froth or foam and allowed to stand for 16 hours, less than 5 millimeters and preferably less than 2 millimeters of liquid should collect in the bottom of the cone. The foam should be rapid breaking when exposed to heat due either to the nature of the resin in the foam or the amount of inert fillers in the foam, and not form an impermeable film during drying. The foam, when it breaks during drying, should have a viscosity of at least 200 centipoise and preferably at least 500 centipoise, with a viscosity in the range of about 200 to about 600 being preferred, so that the broken foam does not penetrate too far into the fibrous web substrate. One suitable foam is TN-599 available from B. F. Goodrich of Brecksville, Ohio. Another suitable foam is used in the following example.
[0039] The type of foam should be selected according to the parameters provided above and the rate of application should be controlled such that the permeability of the foam coated mat is at least 150-200 cubic feet per minute per square foot (CFM/sq. ft.). More preferably the permeability of the foam coated mat is at least 350 and most preferably at least 500 CFM/sq. ft. Where the foam is applied by continuous extrusion, such as in FIGS. 2 and 3, the foam should be applied at a velocity that approximates the linear speed of the wet web for best results. The importance of permeability in the foam coated mat is to allow penetration of the material being used to adhere the foam coated surface to another medium, such as an adhesive used to bond a scrim, decorative facing or other material to the foam coated surface of the mat. Another important consideration in certain applications such as when used to face certain insulation media is that the permeability allows the product to “breath”, i.e. to pass air or other gases through the mat facer. Lower permeability can be preferred if drying is done by can or impingement ovens, rather than with a through air oven.
[0040] [0040]FIG. 3 shows another embodiment of applying foam to the wet mat according to the present invention. This embodiment is the same as the embodiment shown in FIG. 2 except for the binder applicator used. In this embodiment, a foam extruder 70 is used, such as a Zimmer Variopress foam applicator available from J. Zimmer Maschinenbau Ges. GmbH of Klagenfurt, Germany. The foam 72 , as described above, enters the Variopress foam applicator 70 from above after being pumped in the manner described in the description of FIG. 2 above. The foam 72 flows by gravity down through the foam applicator housing 71 and into two counter rotating gears 73 , 74 , which pump the foam at a desired and controlled rate through an extrusion die 75 and onto the wet, bindered mat 30 B to form the foam coating 42 . The gear 73 rotates clockwise and the gear 74 rotates counter clockwise. The speed of rotation of the gears 73 , 74 , is variable and can be changed to deliver the desired rate of foam onto the wet, bindered mat 30 B according to the linear speed of the wet, bindered mat 30 B and the desired coating thickness or foam loading of the foam coating 42 . The Variopress foam applicator can be raised and lowered in any suitable manner to optimize the application of the foam onto the wet, bindered mat 30 B. The Variopress foam applicator 70 preferably spans completely across the width of the mat 30 B, but need not if only a portion of the width of the mat 30 B is to be coated with foam.
[0041] [0041]FIG. 4 shows a still further embodiment of applying a foam layer onto a wet, bindered non-woven web or mat 30 B. This embodiment is similar to the embodiments described in FIGS. 2 and 3, except that the foam is applied using a different device. In the embodiment shown in FIG. 4 the foam applicator 78 is a counter clockwise rotating perforated drum 79 , such as a Zimmer MAGNOROLL™ available from Zimmer, Machinery of Spartanburg, S.C. 29304. The perforated drum 79 is made from a 16H perforated metal screen available from Stork Screens of America of Charlotte, N.C. 28269. The screen used has hexagonal shaped holes that are preferably so close together that foam dots formed on the wet, bindered mat 30 B from foam extruded through the hexagonal holes flow together to form a continuous layer 42 of foam, although it is also permissible for some applications if the foam hexagonal dots do not quite flow together.
[0042] The perforated drum 79 , extending entirely or partially across the width of the web 30 is supported with an axle 80 which can be moved up or down to move the outer surface of the drum 79 closer to or further away from the wet web 30 B, and can also be moved up-line or down-line to optimize the position the foam application in a known manner. A roller 81 , supported on a movable shaft 82 , is positioned on the interior of the drum 79 near the bottom of the drum 79 and rotates, preferably counterclockwise to force the foam 83 through the holes as they rotate to the bottom of the perforated drum 79 to form the foam layer 42 on the wet web 30 B. Foam 83 is pumped in a controlled rate in a known manner as described above to, and distributed along the bottom portion of the perforated drum 79 , by a manifold 84 and rectangular nozzle 85 . Instead of using the roller 81 to force the foam through the perforated drum 79 a doctor or wiper blade or a contacting slot or feed nozzle can be used as is well known in the art of coating with a perforated drum.
[0043] [0043]FIG. 5 shows a preferred method of applying a foam coating in-line to a wet non-woven fibrous web 30 , preferably a wet, bindered non-woven fibrous web 30 B. The system of FIG. 5 is similar to the systems of FIGS. 2, 3 and 4 described above except that the foam applicator is a plurality of nozzles 88 , 89 mounted above the wet web 30 , preferably mounted above the wet, bindered web 30 B. Foam is pumped in the method described above to a known manifold (not shown) which distributes the foam evenly to a plurality of nozzles 88 , 89 where the foam 90 is sprayed downwardly on the top surface of the wet web 30 or preferably onto the wet, bindered web 30 B to form the foam layer 42 . The foam 90 exits the nozzles 88 , 89 at a velocity that does not disturb the fibrous structure of the wet web 30 or the wet, bindered web 30 B. Preferably the nozzles are spaced apart in two staggered rows as shown in FIG. 6 to provide even coverage of foam application onto the wet web 30 or the wet, bindered web 30 B. The nozzles 88 , 89 are mounted on a rack (not shown) in a known manner that allows the nozzles to be moved up and down and up-line and down-line to permit optimization of the foam application to produce the desired foam layer 42 . The preferred nozzles are Spraying Systems nozzles 8002 available from Spraying Systems Company, of Wheaton, Ill., with the foam being applied to the nozzles at a pressure of about 40 psi, but other nozzles can provide different coating weights and application widths. It is important to note that the nozzles are not generating the foam but merely spraying prepared foam delivered to the nozzles.
EXAMPLE 1
[0044] A wet web was formed in a conventional wet process on a laboratory wet former simulating a Voith Hydroformer™ line as used and disclosed in U.S. Pat. Nos. 4,637,496 and 5,772,846 using M 117 glass fibers one inch long. A fiber slurry was prepared in a well known manner by adding one inch long E glass type M 117 wet chop glass fiber from Johns Manville International, Inc. having a silane containing chemical sizing on the surface, as is well known, to a known cationic white water containing Natrosol™ thickening agent available from Aqualon, Inc. of Wilmington, Del., and a cationic surfactant C-61, an ethoxylated tallow amine available from Cytec Industries, Inc. of Morristown, N.J., as a dispersing agent to form a fiber concentration of about 0.8 weight percent. After allowing the slurry to agitate for about 5 minutes to thoroughly disperse the fibers, the slurry was metered into a moving stream of the same whitewater to dilute the fiber concentration to a concentration averaging about 0.05 to 0.06 weight percent before pumping the diluted slurry to a headbox of a pilot scale model of a Voith Hydroformer™ where a wet nonwoven mat was continuously formed.
[0045] The wet mat was removed from the forming wire and transferred to a second carrier wire running under a curtain coater binder applicator where an aqueous binder slurry was applied to the mat. The aqueous binder was a modified urea formaldehyde resin binder. This aqueous binder was made by adding adding to an aqueous urea formaldehyde resin, Georgia Pacific 2928 UF resin latex containing 54-56 wt. percent solids, about 7.5 wt. percent, based on the urea formaldehyde solids, of Duraset™ 827, available from Franklin International of Columbus, Ohio, and about 5 wt. percent of hexamethylene tetramine as a cross-linking agent.
[0046] The bindered mat was run over a suction box to remove excess binder and then was run under a pipe slot foam applicator where a foam was applied to the top surface. The foam precursor was an inorganic filled latex, UniBond™ 0946, available from UniChem™ Company of Haw River, N.C. The foam precursor had a total solids content of 30 percent and an unfoamed viscosity of 560 centipoise. The foam precursor was converted into a foam on a laboratory LESSCO™ foam unit to a blow ratio of about 30. This produced a stable, wet foam that produced less than two millimeters of liquid in the bottom of an Imhoff cone when allowed to stand for about 16 hours. The foam coated mat was then passed through an air dryer where it was dried and heated to about 350 degrees F. to cure the modified urea formaldehyde binder.
[0047] The resultant foam coated mat had a basis weight of 2.48 pounds per square (100 square feet). The basis weight of the fibrous mat substrate was about 2.32 pounds per square. The LOI of the foam coated mat was 27.4 weight percent while the LOI of the dry bindered substrate was 23.2 percent of the substrate or 21.7 percent of the foam coated mat. The foam content of the mat was about 5.7 weight percent. The other properties of the foam coated mat were as follows:
[0048] Dry tensile strength—106 pounds per 3 inch width
[0049] Hot wet tensile strength—66 pounds per 3 inch width
[0050] Air permeability of uncoated bindered mat—770 CFM
[0051] Air permeability of foam coated mat of example—550 CFM
EXAMPLE 2
[0052] Another wet web was formed in the same conventional wet process on a laboratory wet former simulating a Voith Hydroformer™ line as used and disclosed in U.S. Pat. Nos. 4,637,496 and 5,772,846 as used in Example 1. A fiber slurry was prepared in a well known manner by adding 0.75 inch long E glass type K 117 wet chop glass fiber from Johns Manville International, Inc. having a silane containing chemical sizing on the surface, as is well known, to a known cationic white water containing Natrosol™ thickening agent available from Aqualon, Inc. of Wilmington, Del., and a cationic surfactant C-61, an ethoxylated tallow amine available from Cytec Industries, Inc. of Morristown, N.J., as a dispersing agent to form a fiber concentration of about 0.8 weight percent. After allowing the slurry to agitate for about 5 minutes to thoroughly disperse the fibers, the slurry was metered into a moving stream of the same whitewater to dilute the fiber concentration to a concentration averaging about 0.05 to 0.06 weight percent before pumping the diluted slurry to a headbox of a pilot scale model of a Voith Hydroformer™ where a wet nonwoven mat was continuously formed.
[0053] The wet mat was removed from the forming wire and transferred to a second carrier wire running under a curtain coater binder applicator where an aqueous binder slurry was applied to the mat. The aqueous binder was a modified urea formaldehyde resin binder. This aqueous binder was made by adding to an aqueous urea formaldehyde resin, Georgia Pacific 2928 UF resin latex containing 54-56 wt. percent solids, about 7.5 wt. percent, based on the urea formaldehyde solids, of Duraset™ 827, available from Franklin International of Columbus, Ohio, and about 5 wt. percent of hexamethylene tetramine as a cross-linking agent.
[0054] The bindered mat was run over a suction box to remove excess binder and then was run under nozzles spraying foam as shown in FIG. 5 above where a foam was applied to the top surface. The nozzles were 8002 nozzles available from Spraying System Company of Wheaton, Ill. The nozzles were spaced about 3-3.5 inches apart with the bottom of the nozzles being about 6.5 inches above the to surface of the wet, bindered mat. The foam precursor was the same inorganic filled latex, 914-661-97-75 available from Noveon, Inc. of Cleveland, Ohio. The foam precursor had a total solids content of 35 percent and an unfoamed viscosity of 560 centipoise. The foam precursor was converted into a foam on a laboratory LESSCO™ foam unit to a blow ratio of about 10-15. This produced a stable, wet foam that produced less than two millimeters of liquid in the bottom of an Imhoff cone when the cone was filled with one liter of foam and allowed to stand for about 16 hours. The foam had a line pressure of about 40 psi to the nozzles and was applied at a rate to produce a dry foam addition of about 0.7 oz./sq. yd. The rate of foam addition to the web per unit area can be increased or decreased by changing the line speed, changing the foam pressure or by using larger or more application nozzles.
[0055] The foam coated mat was then passed through an air dryer where it was dried and heated to about 350 degrees F. to cure the modified urea formaldehyde binder.
[0056] The resultant foam coated mat had a basis weight of 2.7 pounds per square (100 square feet). The basis weight of the fibrous mat substrate was about 2.23 pounds per square. The LOI of the foam coated mat was 21 weight percent while the LOI of the dry bindered substrate was 16.1 percent of the substrate or 13.3 percent of the foam coated mat. The foam content of the mat was about 4.9 weight percent. The other properties of the foam coated mat were as follows:
[0057] Dry tensile strength—65 pounds per 3 inch width
[0058] Hot wet tensile strength—27 pounds per 3 inch width
[0059] Air permeability of uncoated bindered mat—659 CFM
[0060] Air permeability of foam coated mat of example—338 CFM
[0061] Thus it can be seen that while the foam coating reduced the permeability of the mat about 21 percent, the foam coating did not substantially reduce the permeability of the bindered mat and thus did not greatly inhibit its drying in an air dryer. This is important because if it were to substantially reduce the permeability, for example by about 50-75 percent or more, the line speed would have to be slowed substantially, increasing the manufacturing cost substantially.
EXAMPLE 3
[0062] Example 2 was duplicated except for the type of foam used and the basis weight of the finished mat which in this example was 1.3 pounds per/100 sq. ft. Also, a non-foam coated, bindered mat of the same kind as the bindered mat used to make the foam coated mat was made as a control. In this example a fluorpolymer was used. The fluorpolymer used was Sequapel NRL available from Omnova Solutions of Chester, S.C. The properties of fluorpolymer foam coated mat and the control mat were as follows:
[0063] Control mat LOI—27.6 percent
[0064] Foam coated mat LOI—29.1
[0065] Amount of foam addition-about 1.5 wt. percent of finished mat
[0066] Permeability of control mat—643
[0067] Permeability of foam coated mat—620.
[0068] Dry tensile strength of control mat—87.1 lbs./3 in. width
[0069] Dry tensile strength of foam coated mat—73.1 lbs./3 in. width
[0070] Hot wet tensile of control mat—40.3 lbs./3 in. width
[0071] Hot wet tensile of foam coated mat—33.9 lbs/3 in. width
[0072] The foam coated mat was tested for repellency to a 50 percent concentration in water isopropyl alcohol using an accepted test and the foam coated mat passed the test while the control mat failed badly.
[0073] This inventive method of foam coating on-line in a wet forming mat process completely eliminates the need for the more costly off-line foam coating process currently being used. It also produces mats in which the foam coating prevents shedding of fibers from the face that is exposed after laminating to intermediate products or used to face products like gypsum board, insulation boards or blankets. It also presents a friendly surface, reducing abrasion or irritation caused by frequent handling of current glass mat faced products, particularly in hot, humid conditions. Further, this inventive method can also be used to coat the surface of a mat with a fire retardant or intumescent coating, a heat activating adhesive coating or other adhesive coating, colored coatings and other functional coatings by incorporating the functional ingredient(s) in the foam precursor or wet foam in a known manner. Incorporating the functional ingredient in the foam coating instead of the mat as was often the done in the past requires less functional ingredient further reducing the manufacturing cost.
[0074] The foam coated mats can be bonded to a gypsum wall board, insulating boards of various types and combustible substrates, like a wood product such as hardboard, particle board, chip board, oriented strand board or plywood. With gypsum board, the wet gypsum mix can be formed against the uncoated surface of the foam coated mat to bond to the fibrous web. In the case of combustible substrates the foam coated mat can be adhered with any known adhesive fire resistant adhesive with the uncoated web of the mat against the combustible material.
[0075] While the preferred embodiments of the invention have been disclosed in detail, other embodiments within the described invention and having other functional additives known or obvious to those skilled in the art are considered to be part of the present invention and are intended to be included in the invention claimed below.
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A new foam coated nonwoven fibrous mat having properties particularly suited for a facer on gypsum wallboard, laminates made therefrom and the method of making the mat is disclosed. The mat preferably contains a major portion of glass fibers and a minor portion of a resinous binder. The foam coating is permeable and reduces fiber dust and abrasion experienced in the past with relatively coarse, relatively inexpensive glass fibers in the mat. Contrary to previous methods, the foam coated fibrous mat is made in-line on a wet mat forming production line by applying a wet foam binder onto a wet, fibrous web followed by drying and curing in-line.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part and claims the benefit of U.S. patent application Ser. No. 11/425,424, filed Jun. 21, 2006, which is incorporated herein by reference.
BACKGROUND OF INVENTION
The present invention relates generally to a window in a vehicle, and in particular to a mounting assembly for a vehicle window.
For some automotive vehicles, customers are offered an option—for certain windows on the vehicle—to have fixed glass or a window that can open. The windows that can open typically have a window pane that slides in guide channels between inner and outer portions of a seal in a window opening. The opening and closing motion may be driven by a hand crank, a so-called manually opening window, or by a motor, a so-called power window. For the fixed glass configuration, the window pane is typically bonded in place over the window opening with urethane and encapsulated with a rubber weatherstrip surround.
The look of the window for a fixed glass window, then, is different from the look of the window in the same vehicle when a moving window option is chosen. Moreover, the shape of the window pane is different for the two, requiring two different shaped pieces of glass, one for each type of construction. This also requires a different door/vehicle body construction for fixed and moving glass systems. Thus, the application of two different mounting techniques for fixed and moving window options in a particular vehicle is undesirable, since it does not allow a particular vehicle to have a common appearance for the different window options, and it requires a different construction for the window pane and structure.
In order to overcome these drawbacks, some have employed a window pane and door construction for a movable window—whether or not the window pane is meant to be fixed. For the movable window configurations, the usual manual or power window mechanisms (also called regulators) are employed. For a fixed window, most of the manual window mechanism is installed. The window pane is also installed and mounted to the manual window mechanism. Then, the mechanism is used once at the assembly plant to move the window pane into the full up (closed) position, and is locked in this position. No window crank handle is put on the inside of the door so it can never be rolled down. This gives the customer a fixed glass window while maintaining the same look of vehicles whether they have a fixed window, manually opening, or a power opening window. Moreover, the same window pane and essentially the same door construction can be employed for all of the configurations. However, this one time use of the manual regulator assembly includes most of the components necessary for a manually opening window, such as a cable system, clutch drive mechanism, long rails for guiding the window to its full up and down positions, etc. So this configuration adds significantly to the weight, number of parts, complexity and cost of the more conventional fixed window.
SUMMARY OF INVENTION
An embodiment contemplates a window mounting assembly for mounting a window pane between an inner and an outer portion of a window sealing assembly of a window opening in a vehicle. The assembly may comprise a cam support configured to mount to a vehicle structure, a window support cam and a cam lock. The window support cam may be mounted to the cam support and pivotable about a cam axis, with the window support cam having a lobe portion extending away from the cam axis and a peripheral window support surface for supporting a lower edge of the window pane. The cam lock may include a ratchet gear rotationally fixed to the window support cam and a ratchet arm configured to selectively prevent the lobe portion of the window support cam from rotating in a direction that allows the window pane to drop.
An embodiment contemplates a window mounting assembly for mounting a window pane between an inner and an outer portion of a window sealing assembly of a window opening in a vehicle. The assembly may comprise a cam support configured to mount to a vehicle structure, a window support cam and a cam lock. The window support cam may be mounted to the cam support and pivotable about a cam axis, with the window support cam having a lobe portion extending away from the cam axis and a peripheral window support surface for supporting a lower edge of the window pane. The cam lock may include a tension spring having a first end and an opposed second end, with the first end connected to the window support cam adjacent to the lobe portion and the second end fixed relative to vehicle structure at a location that will create a pivot inflection point for the window support cam such that when the window support cam is rotated to a first side of the inflection point the lobe portion will be pulled down away from the window pane and when the window support cam is rotated to a second side of the inflection point the lobe portion will be pulled up toward the window pane to thereby support a lower edge of the window pane.
An embodiment contemplates a method of fixedly mounting a window pane in a window opening of a vehicle window frame, the method comprising the steps of: mounting a window mounting assembly to a vehicle structure adjacent to the window opening; sliding the window pane into run channels of the vehicle window frame; mounting a lower edge of the window pane onto a peripheral support surface of a window support cam of the window mounting bracket assembly; rotating a cam lobe of the window support cam into contact with the lower edge of the window pane until the window pane slides upward through the run channels into a fully closed position; and locking the window support cam, against rotation allowing the window pane to lower, as the window pane is lifted into the fully closed position.
An advantage of an embodiment is that the window mounting bracket assembly allows for the use of the same window pane, same sealing assembly, and same door in white for both movable and fixed windows, while not incurring the unneeded extra expense, parts, assembly time and weight of a manual window regulator for a fixed window.
An advantage of an embodiment is that, while the window pane acts as a fixed window (in a fixed window application), the window mounting bracket assembly still allows for variation in build tolerances and adjustment of the window pane, should servicing needs require this. Moreover, when service of the window pane is needed, the window mounting bracket assembly can be reused.
An advantage of an embodiment is that seal set that occurs over time is accounted for to assure a good seal between the window pane and the sealing assembly.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a partially schematic perspective view of a portion of a vehicle window assembly.
FIG. 2 is a section cut, on an enlarged scale, taken along line 2 - 2 in FIG. 1 , but without the run channel shown.
FIG. 3 is a schematic elevation view of a portion of a door and window assembly.
FIG. 4 is a schematic, side view of a window mounting bracket assembly.
FIG. 5 is a schematic elevation view of the window mounting bracket assembly.
FIG. 6 is a schematic elevation view of a portion of a door frame.
FIG. 7 is a schematic elevation view of a bracket support plate and fasteners.
FIG. 8 is a perspective view of a window mounting bracket assembly according to a second embodiment.
FIG. 9 is another perspective view of the window mounting bracket according to the second embodiment.
FIG. 10 is a schematic elevation view of a window and support cam according to a third embodiment.
DETAILED DESCRIPTION
FIGS. 1 and 2 illustrate a vehicle window assembly, indicated generally at 20 , that includes a window frame 22 defining a window opening 24 . Extending along the window frame 22 around the window opening 24 is a sealing assembly 26 . The sealing assembly 26 includes a window seal 28 (also called a weatherstrip) having an inner portion 30 facing into the vehicle and an outer portion 32 facing outward from the vehicle, with a gap 31 defined between them. The window frame 22 also includes window run channels 34 , within which portions of the sealing assembly 26 are mounted. The window run channels 34 retain and guide a window pane 36 in the gap 31 , while allowing the window pane 36 to slide up and down. The vehicle window assembly 20 illustrated in FIGS. 1 and 2 allows for use of the conventional manual and power window regulators as well as a window mounting bracket assembly 40 , which will be discussed relative to FIGS. 3-7 .
FIGS. 3-7 illustrate the vehicle window assembly 20 as part of a vehicle door assembly, indicated generally at 42 . While this embodiment illustrates a window frame 22 defining a window opening 24 in the door assembly 42 , the present invention can be employed anywhere on a vehicle where there is an option between a fixed window and a moving window, such as, for example a rear door on an extended cab pickup, a van sliding door, or a back light of a pickup truck.
A door frame 44 of the door assembly 42 includes three slotted mounting holes 46 located below the window opening 24 . Each slotted mounting hole 46 may include a larger diameter upper portion 48 and a smaller diameter lower portion 50 . Although three holes 46 are shown in this embodiment, other numbers may be employed instead, if so desired.
The window mounting bracket assembly 40 includes a bracket support plate 52 , having three mounting fasteners 54 extending therefrom and located so that each one aligns with a respective one of the slotted mounting holes 46 . Each mounting fastener 54 includes a head 56 that is small enough to be received through a respective one of the upper portions 48 , but is large enough that it cannot slide through the corresponding lower portion 50 . While fasteners and holes are illustrated as a means for mounting the support plate to vehicle structure, other means of mounting may be employed instead, if so desired.
A cam shaft 58 extends through the bracket support plate 52 and is centered about a cam axis 60 . The cam shaft 58 also includes a cam rotation feature 61 .
A window support cam 62 is mounted on the cam shaft 58 and is spaced from the bracket support plate 52 by a spacer 64 . The window support cam 62 includes a peripheral support surface 66 for supporting a lower edge 38 of the window pane 36 . The shape of the peripheral support surface 66 may be a semi-cylindrical concave surface for receiving and centering the window pane 36 relative to the window support cam 62 . This surface may have a different shape, if so desired. The window support cam 62 includes a cam lobe 68 , where the peripheral support surface 66 extends farther from the cam axis 60 than at other locations along the peripheral support surface 66 .
The window mounting bracket assembly 40 also includes a cam lock 70 . The cam lock 70 can be inserted between the bracket support plate 52 and the window support cam 62 to lock the two together so they cannot rotate relative to each other. With the cam lock 70 removed, the window support cam 62 can rotate relative to the bracket support plate 52 , particularly when driven by the cam rotation feature 61 .
The installation procedure for installing a fixed window configuration with the window mounting bracket assembly 40 will now be discussed. The window mounting bracket assembly 40 is assembled. The bracket support plate 52 is attached to the door frame 44 (which may be a door inner panel) by mounting the heads 56 of the mounting fasteners 54 in the upper portions 48 of the three slotted mounting holes 46 and sliding the plate 52 down. The heads 56 are now trapped in the lower portions 50 of the holes 46 .
The window pane 36 is then loaded into the window frame 22 by sliding it up in the window run channels 34 between the inner and outer portions 30 , 32 of the window seal 28 . The lower edge 38 of the window pane 36 is mounted in the peripheral support surface 66 of the window support cam 62 while the support cam 62 is oriented so that it is at or near its lowest position (i.e., the cam lobe 68 is not extending upward). Then, the window support cam 62 is rotated (using the cam rotation feature 61 , if desired) to rotate the cam lobe 68 upward, thus pushing the window pane 36 into its full up (closed) position. The cam lock 70 is then inserted into the mounting bracket assembly 40 to lock the support cam 62 in position and thus lock the window pane 36 permanently in the fully closed position. This also holds the mounting fasteners 54 in the lower portion 50 of the slotted mounting holes 46 so the heads 56 cannot slide out of the upper portions 48 of the mounting holes 46 .
FIGS. 8 and 9 illustrate a second embodiment of the window mounting bracket assembly 140 . Since this embodiment is similar to the first, similar element numbers will be used for similar elements, but employing 100-series numbers. The window mounting bracket assembly 140 includes a bracket support plate 152 , having three support arms 174 extending therefrom, with a mounting fastener 154 supported by and extending from each arm 174 and located so that each fastener 154 aligns with a respective one of the slotted mounting holes (shown in FIG. 6 ).
A cam shaft 158 extends through the bracket support plate 152 and is centered about a cam axis 160 . The cam shaft 158 is supported at its other end by a shaft support plate 172 . A cam rotation feature 161 is included on the cam shaft 158 . A window support cam 162 is also mounted on the cam shaft 158 and is rotationally fixed relative to the cam shaft 158 and the cam rotation feature 161 . The window support cam 162 includes a peripheral support surface 166 for supporting a bearing member 176 that can slide up and down on clip supports 178 extending from the bracket support plate 152 . A glass clip 180 is also mounted on the clip supports 178 and can be pushed up into contact with a lower edge of the window pane (shown in FIGS. 3 and 4 ). The glass clip 180 may include a slot 182 for receiving and supporting the lower edge of the window pane. The window support cam 162 includes a cam lobe 168 , where the peripheral support surface 166 extends farther from the cam axis 160 than at other locations along the peripheral support surface 166 .
The window mounting bracket assembly 140 also includes a cam lock 170 . The cam lock 170 includes a ratchet gear 184 that is mounted on the cam shaft 158 and rotationally fixed relative to the window support cam 162 . The cam lock 170 also includes a ratchet arm 186 that is pivotally mounted on the bracket support plate 152 and can pivot into contact with teeth on the ratchet gear 184 . The ratchet arm 186 is oriented relative to the gear 184 so that, when in contact, the ratchet arm 186 will only allow rotation of the ratchet gear 184 —and hence the window support cam 162 —in one direction (counterclockwise as seen in FIG. 8 ). A cam spring 188 is connected at one end to the ratchet arm 186 and connected at the opposite end to the bracket support plate 152 at a location that will cause the cam spring 188 to be in tension, biasing the ratchet arm 186 into contact with the ratchet gear 184 .
The installation procedure for installing a fixed window configuration with the window mounting bracket assembly 140 will now be discussed. Preferably, the window mounting bracket assembly 140 comes to a vehicle assembly plant in a shipped position with the window support cam 162 rotated so the cam lobe 168 extends away from the vertical position. The window support cam 162 may be held in this shipped position by securing the cam rotation feature 161 relative to the bracket support plate 152 .
Then, the bracket support plate 152 is attached to the door frame. This may entail attaching the three mounting fasteners 154 to the slotted mounting holes in the door structure. The window pane is loaded into the window frame by sliding it up in the window run channels between the inner and outer portions of the window seal. The same door-in-white assembly, with the same window run channels and window seal are used for vehicles with power windows, manual window, or, in this case, a fixed window pane. The lower edge of the window pane is mounted in the slot 182 of the glass clip 180 , providing one central support to hold the bottom of the window pane.
Then, the cam rotation feature 161 is released from the bracket support plate 152 and is rotated clockwise (as seen in FIG. 9 ). This will cause the window support cam 162 to rotate, pushing the cam lobe 168 into the bearing member 176 . As the window support cam 162 is rotated further, the cam lobe 168 will push the bearing member 176 into the glass clip 180 , which, in turn, pushes upward on the window pane. This pushes the window pane into its full up (closed) position. As the window support cam 162 rotates to push the window pane up into its closed position, the ratchet gear 184 rotates with the cam 162 . The ratchet arm 186 slides along the gear teeth as the cam 162 is rotating counterclockwise (as seen in FIG. 8 ), but engages the teeth to prevent rotation in the other direction. Thus, the window pane ends up locked in its closed position by the cam lock 170 .
Even though the cam lock 170 provides a positive lock of the cam position, the engagement of the ratchet arm 186 to the ratchet gear 184 allows the cam to be rotated further if the portion of the seal along the upper edge of the window pane gives over time. In addition, if repair or replacement of the window pane is needed, one may pivot the ratchet arm 186 away from the ratchet gear 184 (against the bias of the cam spring 188 ), releasing the window support cam 162 . The cam lobe 168 can then be moved out of the way. With the cam lobe 168 pivoted away, the window pane can be removed and replaced.
FIG. 10 illustrates a third embodiment of the window mounting bracket assembly 240 . Since this embodiment is similar to the first, similar element numbers will be used for similar elements, but employing 200-series numbers. In this embodiment, the window support cam 262 may mount to and pivot relative to the door frame 244 , with a cam axis 260 being defined as the location the cam 262 pivots relative to the door frame 244 .
A cam spring 288 has a first end 290 that mounts to the window support cam 262 near the cam lobe 268 and a second end 292 that mounts to the door frame 244 . The second end 292 is oriented relative to the cam axis 260 such that, when the window support cam 262 is rotated a certain amount in the counterclockwise direction (a pre-installation position shown in FIG. 10 with solid lines), the cam spring 288 will tend to pull the cam further in that direction, and when the cam 262 is rotated a certain amount in the clockwise direction (an installed position shown in FIG. 10 with phantom lines), the cam spring 288 will tend to pull the cam further in this opposite direction. At the inflexion point between the pull in the opposite directions, the orientation of the first end 290 relative to the second end 292 causes the cam spring 288 to be in tension and extending directly over the cam axis 260 .
The installation of the window pane 236 will now be discussed. The window support cam 262 is moved to the pre-installation position where it will be held by the cam spring 288 so that the cam lobe 268 is away from the lower edge 238 of the window pane 236 . The window pane 236 is then loaded into the window frame 222 by sliding it up in the window run channels between the inner and outer portions of the window seal 228 . A glass clip 280 , which may include a window support slot, is located between the window support cam 262 and the lower edge 238 of the window pane 236 and the window support cam 262 is rotated clockwise (as seen in FIG. 10 ) past the inflection point for the cam spring 288 , causing the cam lobe 268 to press against the glass clip 280 , which in turn pushes up on the window pane 236 . The cam spring 288 is sized so that it provides enough force to hold the window pane 236 in its closed position—thus, the cam spring 288 acts as a cam lock for this embodiment. Since the window pane 236 is held by the tension in the spring, a significant range of build variation can be accommodated. Also, the cam spring 288 will accommodate seal set over time and maintain the window pane 236 securely in the upper portion of the window seal 228 .
As an alternative, the second end 292 of the cam spring 288 , the window support cam 262 , and the glass clip 280 may be mounted on a support bracket that attaches to door structure, similar to the other embodiments, if so desired.
While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
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The invention concerns a window assembly in a vehicle having a window pane that is fixed in a window frame that is also used for movable windows, and a method for mounting the fixed window pane in the window assembly. The method may include: mounting a window mounting assembly to a vehicle structure adjacent to the window opening; sliding the window pane into run channels of the vehicle window frame; mounting a lower edge of the window pane onto a peripheral support surface of a window support cam of the window mounting assembly; rotating a cam lobe of the window support cam into contact with the lower edge of the window pane until the window pane slides upward into a fully closed position; and locking the window support cam, against rotation allowing the window pane to lower, as the window pane is lifted into the fully closed position.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a National Stage of PCT International Application Serial Number PCT/FR2013/051885 filed Aug. 5, 2013, which claims priority under 35 U.S.C. §119 of French Patent Application Serial Number 12/57632, filed Aug. 6, 2012, the disclosures of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
It is often desirable to increase the resolution of an image. For example, certain imagers, such as terahertz (THz), infrared (IR) or low cost imagers may capture low-resolution images. By increasing the resolution of one or more of the low-resolution images, the image quality can be improved.
A super-resolution image may be reconstructed from a plurality of low-resolution images of a same scene. For example, the images may correspond to a sequence of frames of a video stream captured by an imager. By combining the visual information from multiple images, the total amount of visual information can be increased in the super-resolution image. Indeed, because each low-resolution image is in some way different from the others, it contributes some unique information that is absent from the other images.
A method of generating a super resolution image based on multiple low-resolution images generally involves up-scaling one of the low-resolution images, and then modifying the pixel values of the up-scaled image based on pixel values taken from the low-resolution images.
However, there is a technical problem in accurately selecting the pixel values to be used for this pixel modification. Indeed, the selected pixel values should correspond to pixels having positions in their respective images that accurately match the position of the pixel to be adjusted. Any miss-match between the pixel positions will result in added noise and thus a reduced image quality.
One technique that has been proposed for matching the pixel positions is to estimate the motion of objects from the differences between the low-resolution images. However, such motion estimation is difficult and complex to perform, and can be imprecise, particularly in the case of objects that make non-continuous or non-uniform movements.
US patent application N°US2009/0110285 describes a method of super-resolution image reconstruction that does not rely on motion estimation directly. Instead, the method compares pixel values of pixels surrounding a target pixel with pixel values of pixels surrounding pixels in the target pixel's neighborhood in neighboring images.
While the technique described in this US patent application provides an alternative to performing motion estimation, it has a number a drawbacks, for example in terms of complexity, and the resulting image quality.
There is thus a need in the art for an improved method and device for performing high-resolution image reconstruction.
2. Description of the Related Art
The present disclosure relates to a method and device for performing super-resolution image reconstruction, and in particular to a method and device for generating a super-resolution image from one or more low-resolution images.
SUMMARY
It is an aim of embodiments of the present disclosure to at least partially address one or more needs in the prior art.
According to one aspect, there is provided a method of generating a super-resolution image by a processing device, the method comprising: up-scaling an input image to generate an up-scaled image; and modifying the pixel value of a first pixel of the up-scaled image by: generating a similarity value for each of a plurality of candidate pixels in said input image and/or in one or more further input images, the candidate pixels being chosen based on the position of said first pixel in said up-scaled image, the similarity value being generated by evaluating the similarity of a group of surrounding pixels of each of said candidate pixels with a group of surrounding pixels of said first pixel; selecting a first subset of said candidate pixels based on said similarity values; and generating the modified pixel value of said first pixel based on the pixel values and similarity values of said first subset of candidate pixels.
According to one embodiment, selecting the first subset of the candidate pixels comprises selecting a plurality of the candidate pixels having the highest similarity values.
According to another embodiment, selecting the first subset of the candidate pixels comprises comparing the similarity value of each candidate pixel with a threshold value, and selecting each candidate pixel based on said comparison.
According to a further embodiment, the method further comprises modifying the pixel value of a second pixel of the up-scaled image by: selecting, based on the position of said second pixel in said up-scaled image, a plurality of further candidate pixels in said input image and/or in one or more further input images; generating a similarity value for each further candidate pixel by evaluating the similarity between a group of surrounding pixels of said second pixel and a group of surrounding pixels of each of said further candidate pixels; and generating the modified pixel value of said second pixel based on the pixel and similarity values of all of said further candidate pixels.
According to a further embodiment, the method further comprises modifying the pixel value of a second pixel of the up-scaled image by: selecting, based on the position of said second pixel in said up-scaled image, a plurality of further candidate pixels in said input image and/or in one or more further input images; generating a similarity value for each further candidate pixel by evaluating the similarity between a group of surrounding pixels of said second pixel and a group of surrounding pixels of each of said further candidate pixels; selecting a second subset of said further candidate pixels, said second subset containing more candidate pixels than said first subset; and generating the modified pixel value of said second pixel based on the pixel and similarity values of all of said second subset of candidate pixels.
According to a further embodiment, the method further comprises: determining uniform and non-uniform zones in the up-scaled image, wherein the first pixel is determined to fall within a non-uniform zone, and the second pixel is determined to fall within a uniform zone; and modifying the pixel value of a third pixel based on candidate pixels selected based on whether it falls within a uniform or non-uniform zone.
According to a further embodiment, determining the uniform and non-uniform zones comprises determining a uniformity value (h k ) for at least one block of pixels of said image based on the following equation:
h k =|det( A k )−α·[trace( A k )] 2 |
where A k is the covariance matrix of the block of pixels, det(A k ) is the determinant of the matrix A k , trace(A k ) is the trace of matrix A k , and α is a constant.
According to a further embodiment, the modified pixel value of said first pixel is generated by calculating a weighted mean of the pixel values of the candidate pixels by weighting the pixel values of the candidate pixels of said subset based on the similarity values summing the weighted pixel values.
According to a further embodiment, the modified pixel value of said first pixel is generated based on the following formula:
x
i
=
∑
y
j
∈
Ω
(
i
)
w
ij
y
j
∑
y
j
∈
Ω
(
i
)
w
ij
where wi j is the similarity value of the candidate pixel y j , and x i * is said modified pixel value.
According to a further embodiment, the modified pixel value of the first pixel is generated by determining a weighted median of the pixel values of the candidate pixels based on a cumulative sum of the similarity values of candidate pixels having pixel values above and/or below said weighted median.
According to a further embodiment, the modified pixel value of said first pixel is generated based on the following formula:
∑
y
j
≤
x
i
*
w
ij
=
A
·
∑
y
j
≥
x
i
*
w
ij
where A is a constant, wi j is the similarity value of the candidate pixel y j , and xi* is said modified pixel value.
According to a further embodiment, the method further comprises down-scaling said up-scaled image in order to generate the surrounding pixels of said first pixel.
According a further embodiment, the similarity values are determined based on the following calculation:
W
ij
=
exp
(
-
d
E
2
(
Px
i
,
Py
j
)
2
σ
w
2
)
where σ w is a constant, d E 2 is the Euclidean distance squared, Px i is the group of surrounding pixels of said first pixel and Py i is the group of surrounding pixels of each of said candidate pixels.
According to a further aspect, there is provided a device for generating a super-resolution image comprising a processing device configured to: up-scale an input image; and modify the pixel value of a first pixel of the up-scaled image by: generating a similarity value for each of a plurality of candidate pixels in said input image and/or in one or more further input images chosen based on the position of said first pixel in said up-scaled image, the similarity value being generated by evaluating the similarity of a group of surrounding pixels of each of said candidate pixels with a group of surrounding pixels of said first pixel; selecting a subset of said candidate pixels based on said similarity values; and generating the modified pixel value of said first pixel based on the pixel values and similarity values of said subset of candidate pixels.
According to yet a further aspect, there is provided a computer-readable medium storing a computer program that, when executed by a processing device, causes the above method to be implemented.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other purposes, features, aspects and advantages of the invention will become apparent from the following detailed description of embodiments, given by way of illustration and not limitation with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram schematically representing a super-resolution image reconstruction method according to an example embodiment;
FIG. 2 is a flow diagram illustrating steps in a method of generating a super-resolution image according to an example embodiment;
FIG. 3 illustrates a portion of an up-scaled image and of a low resolution image according to an example embodiment;
FIG. 4 illustrates an example of a search window used in a method of super-resolution image reconstruction according to an example embodiment;
FIG. 5 is a flow diagram illustrating a step in the method of FIG. 2 in more detail according to an example embodiment;
FIG. 6 is a graph illustrating an example of the selection of a median pixel value according to an example embodiment;
FIG. 7 is a flow diagram illustrating steps in a method of generating a super-resolution image according to a further example embodiment;
FIG. 8 is a graph illustrating an example of results obtained by the methods described in the present disclosure according to an example embodiment; and
FIG. 9 schematically illustrates an electronic device for implementing the methods described herein.
DETAILED DESCRIPTION
FIG. 1 schematically illustrates an example of the principal steps in a method for performing super-resolution image reconstruction. As illustrated, one or more low resolution images 102 are provided to a fusion module 104 . The term “low-resolution” as used herein is not limited to any specific resolution, but merely designates an image that has a lower resolution than the super-resolution image to be generated. Furthermore, the term “image” is used herein to designate a set of pixel values corresponding to a 2D array, but in alternative embodiments, an “image” could include other types of signals, such as those captured by an electronic retina.
While a super-resolution image is often generated based on at least two low-resolution input images, in some cases it could be generated from a single low-resolution image. In particular, there are many situations in which different areas of a same low-resolution image may be used to increase the overall image resolution, for example in the case of images containing patterns that repeat multiple times throughout the image.
The fusion module 104 applies a fusion method to the low-resolution image or images, in order to extract pixel information that is used to modify pixels in an up-scaled image.
After fusion has been completed, the super-resolution image is provided to a deblurring module 106 , which applies a deblurring algorithm in order to sharpen the image, and generates the final super-resolution image ISR. In particular, the fusion method often leads to an attenuation of higher frequencies in the image, which can be compensated by the deblurring module.
The following description will focus on the fusion method implemented by module 104 . Debinning algorithms are well known to those skilled in the art, and will not be described in detail herein.
FIG. 2 is a flow diagram illustrating steps in a method of generating a super-resolution image according to an example embodiment, and in particular the steps for performing the fusion operation 104 of FIG. 1 . In particular, the technique involves modifying the pixel values of an up-scaled image to generate a super-resolution image.
The steps of the method of FIG. 2 will be described with reference also to FIG. 3 , which illustrates a portion of an up-scaled image 302 , and a portion of a low-resolution image 308 .
In a first step S 1 of FIG. 2 , one or more input images are received. For example, the one or more input images correspond to the single low-resolution image or sequence of low-resolution images 102 of FIG. 1 . In the case of a sequence of low-resolution images, each of the images for example has the same resolution.
In the next step S 2 , one of the low-resolution images is up-scaled to provide an up-scaled image. If there is a single low-resolution input image, then this image is up-scaled. Alternatively, if there is a sequence of low-resolution images corresponding to frames of a video sequence, an image at or close to the mid-point of the image sequence is for example selected to be up-scaled, such that the up-scaled image is one that is relatively similar to each of the other input images.
An example of a portion of such an up-scaled image 302 is illustrated on the left in FIG. 3 . The pixels 304 of the up-scaled image 302 , which are shown as squares filled with striped shading, represent those originating directly from a low-resolution image. The intermediate pixels 305 , which are shown as empty or dotted squares in FIG. 3 , for example have pixel values generated by an interpolation algorithm applied during the up-scaling operation. For example, the Lanczos interpolation algorithm could be used, or an alternative interpolation algorithm as will be known by those skilled in the art. In the example of FIG. 3 , the up-scaled image has three times as many pixels in each of the horizontal and vertical directions as the original image. However, many other up-scaling ratios could be used.
Referring again to FIG. 2 , in the next step S 3 , a variable i is initiated, for example at zero.
In a subsequent step S 4 , for the pixel xi of the up-scaled image, a similarity value is computed with N candidate pixels selected from the input image or images. The candidate pixels are for example determined based on the position of the pixel x i in the up-scaled image. The number N of candidate pixels can be chosen based on various factors, such as the number of input images, the time interval between the capture time of the images, the resolution of the input images, etc.
The similarity between the pixel xi and each candidate pixel is evaluated based on a pixel patch P x of pixels extracted from the up-scaled image 302 by a down-sampling operation. For example, the resolution of the pixel patch P x is equal to that of the low-resolution image from which the up-scaled image was generated. In the example of FIG. 3 , for a pixel x a of the up-scaled image 302 , a block 306 of pixels is down-sampled to generate a patch Px a corresponding to a three-by-three block of pixels, having the pixel x a as its central pixel. In this example, the patch Px a comprises all pixels taken directly from the low-resolution image used to generate the up-scaled image 302 .
The patch P x is compared to a patch corresponding to each of the candidate pixels. In the example of FIG. 3 , a candidate pixel y a is taken from a low resolution image 308 and has a same pixel position as the pixel x a in the input low-resolution image. A patch Py a is extracted corresponding to a block of three-by-three pixels having pixel y a as its central pixel. The patch Py a is compared to the patch Px a to determine their similarities, for example by calculating their Euclidean distance as described in more detail below.
Similarly, the patch Px a is compared to other patches corresponding to other candidate pixels in the low-resolution image 308 and/or in other low-resolution images. FIG. 3 shows an example of a further patch Py b , associated with a candidate pixel y b one pixel above and to the left of the pixel y a in the low-resolution image 308 .
In some embodiments, candidate pixels are also taken from the low resolution image that was used to generate the up-scaled image 302 . For the pixels xi of the up-sealed image that correspond to pixels of this low resolution image, such as the pixel x a , the candidate patch will correspond exactly to the reference patch, leading to a perfect similarity. This will not be the case however for the interpolated pixels of the up-scaled image, such as the pixel x b .
Similarity values are determined for the other pixels xi of the up-scaled image in a similar fashion to pixel x a . For example, in the case of a pixel x b one pixel above and to the left of pixel x a in the up-scaled image 302 , the patch Px b for example corresponds to the nine pixels shown with dots in FIG. 3 , each of which contains an interpolated value.
In one example, for a pixel xi to be modified in the up-scaled image, the candidate pixels are selected to be those within a search window a certain distance from the pixel y j located at a location corresponding to that of the pixel xi, as will now be described with reference to FIG. 4 .
FIG. 4 illustrates an example of the generation of the patches from the low-resolution image 308 of FIG. 3 . As illustrated, in this example a patch Py c has a radius of R p from the central pixel y c , and assuming that the patch is square, the patch thus has the dimensions of (2R p +1) by (2R p +1). All of the patches for example have the same patch radius, which is for example chosen to be between 1 and 10 pixels. The number of patches compared to the reference patch is determined by the size of the search window S from which the patches are extracted. The search window S in the low resolution image 308 for example corresponds to candidate pixels falling within a radius R s from the central pixel. In the example of FIG. 4 , an example of a candidate pixel y d falling in the bottom left corner of the search window is illustrated with a corresponding patch Py d . Thus, a square search window for example has dimensions (2R s +1) by (2R s +1), and thus would generate a total of (2R s +1) 2 of patches. The search window radius is for example between 1 and 10 pixels. In some embodiments, the search window radius can be selected based on the maximum movement between the image used to generate the up-scaled image 302 and each of the other images. A similar or the same search window is for example used for each low resolution input image.
An example of the steps performed in step S 4 of FIG. 2 will now be described in more detail with reference to FIG. 5 .
FIG. 5 is a flow diagram illustrating the step S 4 of FIG. 2 in more detail according to an example embodiment in which the similarity value is calculated using the Euclidean distance.
Initially, in a sub-step S 4 A, a block of pixels surrounding the pixel xi in the up-scaled image is down-sampled to generate the reference patch Px i .
In a subsequent sub-step S 4 B, the similarity value between the reference patch and a patch Py j surrounding each candidate pixel is calculated, based on the Euclidean distance d E . For example, the similarity value is determined by the following calculation:
W
ij
=
exp
(
-
d
E
2
(
Px
i
,
Py
j
)
2
σ
w
2
)
where σ w is a constant that controls the weights and hence determines the contributions of neighbouring pixels, and “d E 2 ( )” is the Euclidean distance squared, which is for example calculated as:
d
E
2
(
P
x
i
,
P
y
j
)
=
1
N
patch
∑
k
∈
patch
(
P
x
i
(
k
)
-
P
y
j
(
k
)
)
2
where N patch is the number of pixels forming each patch.
In alternative embodiments, other algorithms could be used to calculate the similarity between the patches.
As one example, the following table I below provides a list of candidate pixels and associated similarity values.
TABLE I
Candidate Pixel
Pixel Value
Similarity Value
y 1
199
0.56
y 2
244
0.52
y 3
212
0.61
Y 4
165
0.66
Y 5
207
0.85
Y 6
177
0.69
Y 7
199
0.89
y 8
250
0.57
y 9
166
0.49
For example, in this table, the candidate pixels y 1 to y 9 are the pixels forming a three-by-three pixel block, the pixel values are for example represented by 8 bits, and thus each have a value falling in the range 0 to 255, and the similarity values are for example on a scale between 0 and 1, values close to 0 indicating very little similarity, and values close to 1 indicating very high similarity.
Referring again to FIG. 2 , after the step S 4 , the next step is S 5 , in which a subset of the candidate pixels is selected. For example, for this, a threshold value is used to eliminate certain candidates based on the similarity values. For example, a threshold value of 0.65 would eliminate all of the candidate pixels in Table I except for pixels y 4 to y 7 . The same threshold value is for example used for all pixels. Alternatively, the candidate values may be ranked based on their similarity values, and only a number of the highest ranking candidates is selected. For example, between 90 and 10 percent of candidate values may be selected to form the subset of candidate pixels. An advantage of selecting a percentage of candidate pixels is that the selection is automatically adapted to the distribution of similarity values.
In a next step S 6 , a new pixel value is generated for each pixel xi based on the pixel values and candidate values of the subset of candidate pixels.
For example, taking the example of candidate pixels of table I above, and assuming that a threshold of 0.65 is used to select the subset of candidate pixels, the subset of candidate pixels for example comprises those of table II below, which have been ranked based on the pixel value for each candidate pixel.
TABLE II
Candidate
Similarity
Weighted Pixel
Pixel
Pixel Value
Value
Value
Y 5
207
0.85
176.0
Y 7
199
0.89
177.1
Y 6
177
0.69
122.1
Y 4
165
0.66
108.9
The weighted pixel value is for example determined for each candidate pixel of the subset by multiplying each pixel value by its corresponding similarity value. The new pixel value xi is then for example calculated as a weighted mean of the pixel values, for example based on the following calculation:
x
i
=
∑
y
j
∈
Ω
(
i
)
w
ij
y
j
∑
y
j
∈
Ω
(
i
)
w
ij
where y j are the candidate pixels of the subset Ω(i), and Wi j is the similarity value for each candidate pixel of the subset. Taking the values provided as an example in Table II above, the sum of weighted pixel values is thus 584.1, and the sum of similarity values is thus 3.09, and the modified pixel value can be calculated as being equal to 189. Thus, whereas the mean of the four candidate pixel values is equal to 187, after more heavily weighting the most similar candidates, a more accurate pixel value is achieved.
In an alternative embodiment, rather than taking a weighted mean of the pixel values of the subset of candidate values, the modified pixel value could be calculated as a weighted median pixel value xi* among the subset of candidate values. In particular, the weighted median pixel value xi* is for example chosen to satisfy the following relation:
∑
y
j
≤
x
i
*
w
ij
=
A
·
∑
y
j
≥
x
i
*
w
ij
where A is a constant and wi j is the similarity value of the candidate pixel y j .
In some embodiments, the constant A is equal to 1. In other words, the weighted median value xi* corresponds to the pixel value of the candidate pixel for which the cumulative sum of the similarity values for candidate pixels having a pixel value lower than the weighted median value xi* equals the cumulative sum of the similarity values for candidates pixels having a pixel value higher that the weighted median value xi*.
Alternatively, the constant A could be equal to a value other than 1, for example such that the cumulative sum of the similarities below the value xi* is between 40 and 60 percent of the total sum of similarities. Thus A is for example equal to between 0.667 and 1.5.
More often than not, there will be a single weighted median candidate pixel. Indeed, calculating the cumulative sum of the similarity values from the lowest candidate pixel value towards the highest, it will generally be that the limit determined by the constant A will be exceeded when the similarity value of an nth candidate pixel is added to the cumulative sum. Indeed, if the cumulative sum is instead calculated starting with the highest candidate pixel value and going towards the lowest, the threshold value will be reached when the similarity value of the same nth candidate pixel is added to the cumulative sum. This nth candidate pixel thus for example provides the weighted median value.
As an example, assuming that the constant A is equal to 1, the threshold cumulative similarity value is equal to 50 percent of the total sum of similarity values. Taking the example of Table II above, the threshold cumulative similarity value is thus 3.09/2=1.545. The median pixel value is thus that of pixel Y 7 , equal to 199 in this example.
In some cases however, after adding the similarity value of the nth candidate pixel, the cumulative score may equal exactly the limit value determined by the constant A. In this case, the weighted median value is for example calculated as the mean of the nth and (n+1)th candidate pixel values.
For example, taking the example of Table II above in the case that the constant A is equal to 0.776, the limit for the cumulative sum of the similarity values starting from the lowest candidate value will be equal to (A/A+1)×3.09=1.35. Because this limit will be reached exactly by the sum of the similarity values of pixels y 4 and y 6 in table II, the weighted median value is for example chosen to be the mean of values y 6 and y 7 , i.e. (177+199)/2=188.
Referring again to FIG. 2 , in a subsequent step S 7 , it is determined whether the variable i is equal to M, for example there being a total of M+1 pixels in the up-scaled image. If not, the next step is S 8 , in which the variable i is incremented, and then the method returns to step S 4 . Alternatively, once the final pixel x M of the image has been processed, the step after S 7 is step S 9 , in which the fusion method ends and deblurring is for example performed on the generated image, as described above with reference to FIG. 1 .
FIG. 6 is a graph illustrating the similarity values Wi j plotted against the pixel values y j . It should be noted that for a given pixel value, there may be more than one candidate pixel represented by points on the curve. As represented in this figure, in the case that the constant A is equal to 1, the median pixel value corresponds to the value for which the area under the curve on either side if this value is equal, i.e. equal to 50 percent of the total area under the curve. An example of the weighted mean value y jmean is also illustrated in FIG. 6 , which in this example is higher than the median value.
FIG. 7 is a flow diagram illustrating steps in an alternative method of generating a super-resolution image to that of FIG. 2 .
The initial steps S 1 and S 2 of receiving one or more input images and up-scaling an input image are the same as the corresponding steps of FIG. 2 , and will not be described again in detail.
In a subsequent step S 3 of FIG. 7 , uniformity values are calculated for the low-resolution input image used to generate the up-scaled image. For this, the input image is for example divided into blocks of pixels, and the absolute Harris value is for example calculated for each block. The application of the Harris value for corner and edge detection is for example described in more detail in the technical publication entitled “A combined corner and edge detector”, C. Harrys and M. Stephens, proceeding of 4th Alvey Vision Conference, pages 147-151.
In one example, initially a Gaussian low-pass filter, for example of size five-by-five pixels, is applied to the low-resolution image. Then, horizontal derivatives IH and vertical derivatives IV are for example calculated in the filtered image for every pixel value.
Then, for each block k of the low-resolution image, where k is for example an eight-by-eight block of pixels, a covariance matrix is for example generated as follows:
A
k
=
[
〈
I
H
2
〉
k
〈
I
H
I
V
〉
k
〈
I
H
I
V
〉
k
〈
I
k
2
〉
k
]
where is the mean value for the block k.
The absolute Harris value h k is then for example calculated for each block k based on this covariance matrix using the following equation:
h k =|det( A k )−α·[trace( A k )] 2 |
where det(A k ) is the determinant of the matrix A k , trace(A k ) is the trace of matrix A k , and α is a constant. Based on the absolute Harris value calculated for each block k, a binary uniformity value is for example calculated for each block by comparing the absolute Harris value to a threshold value. For example, the uniformity values are calculated by applying the following rule:
U
(
p
k
)
=
{
0
if
h
k
≥
γ
·
max
{
h
k
}
1
otherwise
where P k are the pixels of block k, γ is a constant, and γ·max{h k } is the threshold value, where max{h k } is the highest Harris value for all of the blocks in the image.
Referring again to the flow diagram of FIG. 7 , in a subsequent step S 4 , the up-scaled image generated in step S 2 is segmented into uniform and non-uniform zones based on the uniformity values generated in step S 3 . For example, for each block k of the low-resolution input image, it is determined that a corresponding block of pixels of the up-scaled image is a non-uniform zone if the uniformity value is equal to 0, or a uniform zone if the uniformity value is equal to 1.
In a subsequent step S 5 , a variable i is for example initiated to 0.
Then, in a subsequent step S 6 , it is determined whether or not the pixel xi of the up-scaled image is in a non-uniform zone. If not, the next step is S 7 , in which similarity values are computed in a similar fashion as described above with reference to step S 4 of FIG. 2 .
After step S 7 , the next step is step S 8 , in which a modified value of pixel xi is generated based on pixel value and similarity values of all of the N candidate pixels. In particular, the techniques for generating this modified pixel value, which could be based on a weighted mean or weighted median value, are for example the same as those described above with reference to step S 5 of FIG. 2 and to Tables I and II, except that all of the candidate pixels are considered, rather than only those of a selected subset.
Alternatively, if in step S 6 the pixel xi is determined to be non-uniform, the next step is S 9 , in which again the similarity values are computed for all N candidate pixels.
However, the step after S 9 is step S 10 , in which a subset of the candidate pixels is selected in a similar fashion as described above in relation to step S 5 of FIG. 2 .
After step S 10 , the next step is S 11 , which is similar to S 6 of FIG. 2 described above, in which a new value of pixel xi is generated based on the selected subset of candidate pixel values.
After steps S 8 and S 11 , the next step is S 12 , in which it is determined whether variable i is equal to M, for example there being a total of M+1 pixels in the up-scaled image. If not, the next step is S 13 , in which the variable i is incremented, and the method returns to S 6 . Alternatively, when i is equal to M, the method for example ends at step S 14 , and deblurring is for example performed on the generated image, as described above with reference to FIG. 1 .
In an alternative implementation, rather than generating a new pixel value based on all candidate pixels, in step S 8 of FIG. 7 , the modified pixel value could be calculated based on a bigger subset of candidate pixels than the one selected in step S 10 . For example, the subset of candidate pixels selected for pixels in the non-uniform zones could be selected based on a first threshold value or a first percentage of candidates, and the subset of candidate pixels selected for pixels in the uniform zones could be selected based on a second threshold value lower than the first threshold value, or a second percentage of candidates higher than the first percentage.
Thus, the flow diagram of FIG. 7 illustrates an example in which one of two pixel modification methods is used based on whether or not each pixel corresponds to a uniform or non-uniform zone. In some embodiments, border zones are additionally defined at the
of FIG. 6 , and xi2(p) is the modified boundary between the uniform and non-uniform zones. The pixels in such border zones are for example processed based on a mix of the two pixel modification methods.
For example, for the pixels in the border zones, the following rule is applied:
x i =(1− U ( p ))· x i1 ( p )+ U ( p )· x i2 ( p )
where xi1(p) is the modified pixel value generated by the method corresponding to steps S 9 to S 11 pixel value generated by the method corresponding to steps S 7 and S 8 of FIG. 6 . U(p) is the uniformity value for the pixel in question, and in the border zones, this value is for example equal to 0.5, such that the weighting applied to the two pixel generation methods is equal. Alternatively, a more gradual transition from the uniform to non-uniform zone could be achieved by progressively decreasing U(p) from 1 to 0 across the uniform to non-uniform boundary.
FIG. 8 is a graph illustrating an example of the results that have been achieved by applying the super-resolution image generation techniques described herein. In particular, this graph plots the logarithmic spectrum against the normalized frequency, which is a radial spatial frequency, i.e. at each spatial frequency the spectrum is obtained from the spectra summed over all orientations. In other words, a 2D spectrum of the image is calculated, with spectrum center (DC) being the average value. Then, the ordinates of the radial spectrum at abscissa R are computed as the sum of the 2D spectrum ordinates for each point that lies at an equal distance R from the spectrum center.
A solid line in FIG. 8 represents an original image. In other words, for the purpose of obtaining the graph of FIG. 8 , an original high resolution image was analyzed to provide the solid line curve of FIG. 8 , and then down-sampled to generate low resolution input images. In particular, in the examples of FIG. 8 , noise of standard deviation 10 was added to an image measuring 512 by 512 pixels. The noisy image was then shifted and down-sampled by a factor of 3 in each dimension to generate each of nine low resolution images.
An important indicator of the performance of a super-resolution image construction technique is the extent to which the spatial spectrum of the resulting image matches that of the original/ideal image.
A dashed line in FIG. 8 represents the result obtained from applying what will be referred to as the “non-local mean” (NLM) method of generating the super-resolution image, which corresponds to the technique described above with respect to FIG. 2 , except that the modified pixel value is calculated based on the weighted mean of all candidate pixels, rather than only on a selected subset of candidates. As illustrated, the resulting spatial frequency spectrum in the image is relatively far from that of the original image.
A dotted line in FIG. 8 represents the result obtained from applying what will be referred to as the “constrained non-local mean” (C-NLM) method, which corresponds to the method described in relation to FIG. 7 , based on a weighted mean of all of the candidate pixels in uniform zones, and of a selected subset of candidate pixels in non-uniform zones. The result is much improved with respect to the NLM method.
A dashed-dotted line in FIG. 8 represents the result obtained from using the weighted median candidate pixel described with reference to FIG. 6 , in combination with the constrained non-local mean method. It will be observed that the result is particularly close to that of the original image.
FIG. 9 schematically illustrates, in block diagram form, a device 900 suitable for implementing the methods as described herein.
The device 900 comprises a processing device 902 , which for example comprises one or more processors capable of executing instructions stored in an instruction memory 904 coupled to the processing device 902 . The execution of these instructions causes the methods as described herein, for example the method represented by the flow diagrams of FIGS. 2, 5 and 7 , to be implemented.
The processing device 902 is for example further coupled to a memory device 906 storing the input images to be processed as well as the final super-resolution image, and any intermediate images generated during the methods. One or more input/output modules 908 , such as input/output ports, a keyboard and/or mouse, touch screen etc., are also for example coupled to the processing device 902 . Furthermore, in some embodiments, a camera 910 is coupled to the processing device for capturing low resolution input images to be used to reconstruct the super resolution image. The camera 910 could comprise an image sensor array, such as a CMOS image sensor, or another type of sensor array, such as those used in electronic retina. Furthermore, a display 912 is for example provided for displaying the various images.
Thus the embodiments described herein provide a method and device for generating a super-resolution image having an improved image quality and reduced complexity with respect to prior solutions. In particular, by choosing candidate pixels based on the location of the pixel to be modified, and then filtering these candidate pixels to select a subset to be used in generating the modified pixel value, an over-smoothing of the image is avoided, and the pixel calculation is simplified.
Furthermore, by selecting the modified pixel value as a weighted median candidate pixel based on the similarity values, a further improvement in the image quality may be achieved.
Furthermore, by modifying pixels present in non-uniform zones of the image based on a subset of the candidate pixels, and those present in uniform zones of the image based on all candidate pixels, the image quality is further improved.
Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art.
For example, while examples have been described in which the pixel value of each pixel in the up-scaled image is modified to generate the super-resolution image, it will be apparent to those skilled in the art that in some cases some zones of the image may be excluded from pixel modification altogether.
Furthermore, while the example embodiments detail the generation of a super-resolution image based on more than one low-resolution input image, it will be apparent to those skilled in the art how the described techniques can be applied to the case of a single low-resolution input image. For example, in the case of a single image, the candidate pixels are chosen to be all those of the input image. Alternatively, the size of the search window is determined based on the image characteristics.
|
The invention relates to a method for generating super-resolution images using a processing device, the method includes: oversampling an input image to generate an oversampled image; modifying the pixel value of a first pixel of the oversampled image by: generating a similarity value for each one of a plurality of candidate pixels in the input image and/or in one or more other input images, candidate pixels being selected based on the position of the first pixel in the oversampled image, similarity value being generated by evaluating the similarity of a group of pixels adjacent to each of the candidate pixels to a group of pixels adjacent to the first pixel; selecting a first subset of candidate pixels on the basis of similarity values, and generating the modified pixel value of the first pixel based on the pixel values and on the similarity values of the first subset of candidate pixels.
| 6
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to managing shared resources and more particularly to consolidating allocated resources across multiple computers to minimize computer resources, and especially memory, consumed by provisioned resources.
2. Background Description
Acquiring and managing Information Technology (IT) is a major budgetary concern for any modern organization. Moreover, local IT hardware is seldom used at full capacity. To reduce IT infrastructure costs and waste, instead of acquiring physical hardware, organizations are increasingly consolidating workload on virtual machines (VMs) hosted on fewer servers. A remote server computer provides each VM as a virtual server with virtual resources, e.g., processing power, memory and disk space. Typically, each VM configuration is selected from a number of virtual resource templates (VRTs or templates). Each VM has allocated capacity (e.g. disk space, processing resources and memory) and is configured (software stack and licenses) for its intended purpose and expected needs. A key problem to managing these VMs is determining how to optimize resource capacity and configuration to maximize VM density without impairing performance.
Typically, a service provider may allocate/place physical resources for each VM based, primarily, on provider system optimization, on workload predictions and on results from continuously monitoring VM resource usage. Under-allocation (providing each VM with only a portion of the entire request) may utilize all resources, while impairing the users' Quality-of-Service (QoS). Over-allocation (providing each VM with the entire request and maintaining some slack) may insure acceptable user QoS, but wastes resources and energy, and reduces available capacity for subsequent requesting users. Ideally, allocation is balanced with adequate IT resources allocated without waste, while also maintaining the user's QoS.
Where a host computer memory was found to limit VM capacity, service providers have tried to increase memory capacity, short of adding more memory, which may require a complete system architecture change in some circumstances. So, for example, providers have used content-based page sharing (CBPS) techniques, such as Kernel Samepage Merging (KSM), to consolidate host memory for identical contents across multiple VMs, to increase the host's VM density and utilization. However, while this has improved capacity on individual hosts, the improvement is only incremental.
Thus, there is a need for locating VMs on host computers for efficiently consolidating resources across virtualized environments; and more particularly, there is a need for migrating VMs between hosts for improved resource allocation efficiency, improved energy conservation and security, while avoiding increasing capital expenditures, network latency, and resource management requirements.
SUMMARY OF THE INVENTION
A feature of the invention is consolidation of resources provisioned for VMs over multiple host systems;
Another feature of the invention is improved VM density among host systems in a cloud environment;
Yet another feature of the invention is optimal utilization of cloud resources from consolidation of resources provisioned for VMs, cloistering existing and new VMs in cloud hosts to maximize utilization.
The present invention relates to a shared resource system, a method of managing resources on the system and computer program products therefor. A resource consolidation unit causes identification of identical memory segments on host computers. The resource consolidation unit may be in one or more host computers. Each identical memory segment is associated with multiple instances of resources provisioned on at least two host computers. The resource consolidation unit causes provisioned resources to be migrated for at least one instance from one of the two hosts to another. On the other host computer the migrated resources share respective identical memory segments with resources already provisioned on the other host.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, aspects and advantages will be better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
FIG. 1 depicts a cloud computing node according to an embodiment of the present invention;
FIG. 2 depicts a cloud computing environment according to an embodiment of the present invention;
FIG. 3 depicts abstraction model layers according to an embodiment of the present invention;
FIG. 4 shows an example of a a resource provisioning and management for consolidated resource allocation, e.g., in the management layer, according to a preferred embodiment of the present invention;
FIG. 5 shows an example of an example of privacy aware selection in more detail, essentially, in two phases, an initialization phase followed by an analysis phase;
FIGS. 6A-B show an example of application of the initialization phase to a pair of hypervisor hosts connected on network, and provisioned with VMs;
FIG. 6C shows an example of application of agnostic or distributed KSM selection to the cloud arrangement of FIG. 6A .
DESCRIPTION OF PREFERRED EMBODIMENTS
It is understood in advance that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed and as further indicated hereinbelow.
Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g. networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models.
Characteristics are as follows:
On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service's provider.
Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).
Resource pooling: the provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter).
Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.
Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service. Moreover, the present invention provides for client self-monitoring for adjusting individual resource allocation and configuration on-the-fly for optimized resource allocation in real time and with operating costs and energy use minimized.
Service Models are as follows:
Software as a Service (SaaS): the capability provided to the consumer is to use the provider's applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based e-mail). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
Platform as a Service (PaaS): the capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including networks, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.
Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources, sometimes referred to as a hypervisor, where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).
Deployment Models are as follows:
Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises.
Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises.
Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.
Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds).
A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure comprising a network of interconnected nodes.
Referring now to FIG. 1 , a schematic of an example of a cloud computing node is shown. Cloud computing node 10 is only one example of a suitable cloud computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, cloud computing node 10 is capable of being implemented and/or performing any of the functionality set forth hereinabove.
In cloud computing node 10 there is a computer system/server 12 , which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.
Computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
As shown in FIG. 1 , computer system/server 12 in cloud computing node 10 is shown in the form of a general-purpose computing device. The components of computer system/server 12 may include, but are not limited to, one or more processors or processing units 16 , a system memory 28 , and a bus 18 that couples various system components including system memory 28 to processor 16 .
Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus.
Computer system/server 12 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 12 , and it includes both volatile and non-volatile media, removable and non-removable media.
System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32 . Computer system/server 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 34 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.
Program/utility 40 , having a set (at least one) of program modules 42 , may be stored in memory 28 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 42 generally carry out the functions and/or methodologies of embodiments of the invention as described herein.
Computer system/server 12 may also communicate with one or more external devices 14 such as a keyboard, a pointing device, a display 24 , etc.; one or more devices that enable a user to interact with computer system/server 12 ; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 12 to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces 22 . Still yet, computer system/server 12 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 20 . As depicted, network adapter 20 communicates with the other components of computer system/server 12 via bus 18 . It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 12 . Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
Referring now to FIG. 2 , illustrative cloud computing environment 50 is depicted. As shown, cloud computing environment 50 comprises one or more cloud computing nodes 10 with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone 54 A, desktop computer 54 B, laptop computer 54 C, and/or automobile computer system 54 N may communicate. Nodes 10 may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described hereinabove, or a combination thereof. This allows cloud computing environment 50 to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices 54 A-N shown in FIG. 2 are intended to be illustrative only and that computing nodes 10 and cloud computing environment 50 can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser).
Referring now to FIG. 3 , a set of functional abstraction layers provided by cloud computing environment 50 ( FIG. 2 ) is shown. It should be understood in advance that the components, layers, and functions shown in FIG. 3 are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided:
Hardware and software layer 60 includes hardware and software components. Examples of hardware components include mainframes, in one example IBM® zSeries® systems; RISC (Reduced Instruction Set Computer) architecture based servers, in one example IBM pSeries® systems; IBM xSeries® systems; IBM BladeCenter® systems; storage devices; networks and networking components. Examples of software components include network application server software, in one example IBM WebSphere® application server software; and database software, in one example IBM DB2® database software. (IBM, zSeries, pSeries, xSeries, BladeCenter, WebSphere, and DB2 are trademarks of International Business Machines Corporation registered in many jurisdictions worldwide).
Virtualization layer 62 provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers; virtual storage; virtual networks, including virtual private networks; virtual applications and operating systems 64 ; and virtual clients.
In one example, management layer 66 may provide the functions described below. Resource provisioning 68 provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing 70 provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may comprise application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. User portal provides access to the cloud computing environment for consumers and system administrators. Service level management 72 provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment 74 provide pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA.
Workloads layer 76 provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation; software development and lifecycle management; virtual classroom education delivery; data analytics processing; and transaction processing.
FIG. 4 shows an example of resource provisioning and management 100 for consolidated resource allocation, e.g., in management layer 66 , according to a preferred embodiment of the present invention with reference to FIGS. 1-3 . Preferred resource provisioning and management 100 may reside in one or more network nodes 10 , in resource provisioning 68 , Metering and Pricing 70 , service level management 72 , SLA planning and fulfillment 74 , or separately as a resource consolidation unit within the management layer 66 . Preferred resource provisioning and management 100 analyzes virtual machine (VM) requests and provisioned VMs to identify instances of storage commonality, such that the identified VMs require identical memory data segments/pages; and, where appropriate places/migrates those identified VMs to reduce the total physical memory requirements to consolidate memory allocation for those VMs.
Resource provisioning and management 100 may select memory for consolidation using any or all of brute force selection 102 , Operating System (OS) and process aware selection 104 , privacy aware selection 106 and distributed Kernel Samepage Merging (KSM) selection 110 , individually or sequentially. Preferably, resource provisioning and management 100 consolidates VMs across a cloud to optimize physical memory use, placing VMs to minimize physical memory use through content-based page sharing across the cloud nodes 10 . Consolidating VMs 100 in a distributed environment, such as a cloud environment, with a common memory representation to a single physical node, reduces overall the total physical memory requirements by virtually replicating memory spaces occupied by identical contents, which increases virtual memory capacity without changing physical capacity.
During brute force selection 102 , cloud hosts 10 compare memory footprints of each provisioned VM across all the physical hosts 10 to identify common memory sections, e.g., sections or pages with common data and/or programs, that are used by all the processes on multiple VMs. Typically, this cloud-wide matching is computationally intensive, especially for large collections of systems.
OS and process aware selection 104 places VMs based on estimated memory requirements, extracted from information on operating systems and processes present in each VM. VM memory contents are estimated based on the particular OS, e.g., version and services, and listed running processes. By exchanging OS details and process lists for each VM node, VMs are placed to maximize the predicted number of shared pages, i.e., to minimize the number of repetitious instances of identical individual pages.
FIG. 5 shows an example of privacy aware selection 106 , essentially, in two phases, an initialization phase 1060 to create a shared dictionary 120 , followed by an analysis phase 122 comparing new images against existing dictionary images. Preferably, the hosts 10 re-initialize 106 periodically, at specified intervals, based on frequency of VM creation/destruction or based on load.
Initialization begins with each host ( 10 in FIGS. 1 and 2 ) identifying 1062 the number of memory pages or segments on each VM that are shared with VMs both on that host and on other hosts. Recording 1064 the results generates the dictionary 120 . Then, the hosts 10 rank 1066 VMs according to shared pages. Preferably, the hosts 10 rank 1066 VMs based on the level of commonality with other VMs on that same host 10 . So, for example, lowest ranked VMs may have the least shared memory with other VMs on the same host.
Each host 10 iteratively selects 1068 VMs with the least shared memory, and copies 1070 the selected VMs to another, target host 10 . Preferably each host 10 copies the VM(s) with the least local commonality (or pre-computed hashes of unshared memory space) with other local VMs to a target host 10 . The target host 10 analyzes 1072 the commonality of the copied or migrated VM with local VMs, and shares 1074 the results. When all VMs, or a predetermined maximum number of VMs, 1076 have been selected 1068 , copied 1070 and analyzed 1072 , the shared dictionary 120 is complete. The hosts 10 examine the results 1078 to determine a migration plan that optimizes utilization and the hosts 10 migrate selected images 1080 to whichever host 10 is predicted to share the most pages. Thereafter, the hosts 10 use the dictionary to analyze 122 each new VM against known VMs to assist in deciding how to optimally migrate the new VMs.
FIGS. 6A-B show an example of application of the initialization phase to a pair of hypervisor hosts 130 , 132 connected on network 134 , and provisioned with VMs 136 , 138 , 140 , 142 , 144 , with reference to FIG. 5 . During initialization, the hosts 130 , 132 each rank 1066 VMs 136 , 138 , 140 , 142 , 144 , according to the degree of commonality in memory pages, shown in tables 146 , 148 . In this example, VM 3 140 shares little with VM 4 142 and VM 5 144 , which share common memory contents, e.g., memory with identical OS and/or applications. Thus, potentially, migrating VM 3 140 to the other host 130 may improve consolidation.
So, after host 130 identifies 1062 common content 150 in VM 1 136 and VM 2 138 ; and, host 132 identifies 1062 common content 152 in VM 4 142 and VMS 144 ; and the hosts 130 , 132 rank 1066 the results. Host 132 selects 1068 and copies 1070 VM 3 140 to target host 130 . The target host 130 compares 1072 the copy 154 with provisioned memory, including common content 150 memory, to determine whether the copied VM 3 150 shares any commonality with local VM 1 136 and VM 2 138 to identify segments 156 with common content. Likewise, subsequently copying, first VM 2 132 and then, VM 2 to host 132 can identify areas to further consolidate based on any other identified commonality. This comparison prevents migration or copying of VMs that does not lead to an optimal placement or improve the existing placement and is, therefore, undesirable and/or unnecessary.
FIG. 6C shows an example of application of agnostic or distributed KSM selection 110 to the cloud arrangement of FIG. 6A with similar results in this example and with like features labeled identically. Distributed KSM selection 110 is similar to KSM, which is used to consolidate resources for a single host. However where KSM focuses on a single host, distributed KSM selection 110 maintains a distributed hash table (DHT) 160 across distributed cloud hosts 130 , 132 . The DHT 160 chronicles physical machine history for hosts 130 , 132 with one or more VMs 136 , 138 , 140 , 142 , 144 running.
Preferably, the DHT 160 includes a history of recorded hashed values that indicate page stability. For example, the DHT 160 may include a value field that stores page characteristics across VMs 136 , 138 , 140 , 142 , 144 and physical nodes 130 , 132 . Further, the DHT 160 also may include additional metadata on the pages, e.g., size, frequency of access, VM and physical node. Optionally, the DHT 160 may be multi-layer, with one layer for VMs 136 , 138 , 140 , 142 , 144 and another layer for physical nodes 130 , 132 . In this optional multi-layer example, only the physical node layer is updated for every occurrence of a merge/migrate operation. By comparing hashed value history stability, the DHT 160 identifies pages as relatively stable or unstable.
A kernel-level memory ordering technique may be used to address/minimize memory effect fragmentation across identified pages. Thus, combining distributed KSM with kernel-level memory ordering prevents memory faults from occurring from address mismatches to facilitate maintaining block integrity for memory fragmented across multiple pages, even after migration in a scalable and controlled manner.
Advantageously, the present invention selectively migrates virtual machines (VMs) from one server to another to consolidate server resources in virtualized environments. This consolidation improves efficient allocation of existing resources, energy conservation, and security, and reduces capital expenditures, network latency, and management requirements. In particular, application of the present invention optimally places VMs in a distributed environment to maximize hardware resource utilization, by optimizing content-based page sharing (CBPS) effectiveness over a distributed computational environment.
While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. It is intended that all such variations and modifications fall within the scope of the appended claims. Examples and drawings are, accordingly, to be regarded as illustrative rather than restrictive.
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A shared resource system, a method of managing resources on the system and computer program products therefor. A resource consolidation unit causes identification of identical memory segments on host computers. The resource consolidation unit may be in one or more host computers. Each identical memory segment is associated with multiple instances of resources provisioned on at least two host computers. The resource consolidation unit causes provisioned resources to be migrated for at least one instance from one of the two hosts to another. On the other host computer the migrated resources share respective identical memory segments with resources already provisioned on the other host.
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[0001] This application claims the priority of Korean Patent Application No. 10-2013-0026516 filed on Mar. 13, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a linear vibrator able to be mounted in small electronic devices, and more particularly, to implementation of a small and light horizontal linear vibrator.
[0004] 2. Description of the Related Art
[0005] In general, one of the fundamental functions of communications devices is the call notification function. Examples thereof may include a sound generation function, such as melody or bell and a vibration function, in which vibrations are transferred to devices.
[0006] Among these functions, the vibration function has mainly been used to prevent a melody or a bell provided through a speaker of a device from inconveniencing others.
[0007] In order to implement the vibration function, generally, vibratory force, generated by driving a small vibration motor, is transferred to a case to allow devices to be vibrated.
[0008] In recent times, as demand for small and multifunctional mobile phone has increased, a touch screen type display device, or the like, has been frequently adopted. However, there is a need to increasingly improve vibration motors to have a function of generating vibrations when the display device is touched, and the like.
[0009] Vibration motors used in existing mobile phones employ a method of generating a torque to rotate a rotating part of an unbalance mass so as to obtain mechanical vibrations. In this case, the torque is mainly generated by a structure in which a current commutated through a contact between a brush and a commutator is supplied to a rotor coil.
[0010] However, a brush-type structure using the commutator causes mechanical friction and generates electrical sparks, while the brush passes through a gap between segments of the commutator at the time of rotating the motor and therefore wears the brush and the commutator, thereby shortening the lifespan of the motor.
[0011] Further, rotational inertia may be present in the brush-type structure when voltage is applied to the motor, thus requiring a relatively long period of time to reach a targeted vibration amount, and therefore, it may be difficult to implement an amount of vibrations appropriate for personal digital assistants (PDAs), and the like, to which the touch screen is applied.
[0012] Therefore, in order to improve lifespan and response characteristics of the display device, a linear vibrator generating vibrations through a scheme other than a rotational scheme has been used.
[0013] Such a linear vibrator uses a spring mounted therein and a mass body coupled to the spring, having a determined resonance frequency and excited by electromagnetic force, to thereby generate vibrations.
[0014] However, since the linear vibrator may be vibrated vertically and only generates vibrations in the case in which the linear vibrator moves, securing a vertical displacement of the mass body mounted therein, the linear vibrator may have a restriction in terms of a thickness.
[0015] Further, since the thickness of the linear vibrator increases with the increase in the amount of vibrations generated thereby, PDAs require a large space to allow the linear vibrator to be mounted therein, such that it is difficult to miniaturize the linear vibrator.
[0016] Meanwhile, as the related art, there are provided Patent Documents 1 and 2. Both of Patent Documents 1 and 2 disclose a linear vibrator. However, Patent Document 1 does not have a configuration allowing for a stable reciprocating motion to be induced in a vibration part, such that it is difficult to obtain a constant vibrational frequency. On the other hand, according to Patent Document 2, a constant vibrational frequency may be obtained by a shaft guiding a reciprocating motion of the vibration part. However, according to Patent Document 2, since the shaft and the vibration part may not be easily assembled and the shaft may be easily deformed due to external impacts, the miniaturization and lightness of the linear vibrator may not be easily implemented and the linear vibrator may be inappropriate for portable electronic devices to which external impacts are frequently applied.
RELATED ART DOCUMENT
[0000]
(Patent Document 1) KR10-1152417 B1
(Patent Document 2) JP2012-016153 A
SUMMARY OF THE INVENTION
[0019] An aspect of the present invention provides a horizontal linear vibrator which can be easily miniaturized, is reduced in weight and can withstand external impacts.
[0020] According to an aspect of the present invention, there is provided a horizontal linear vibrator, including: a housing;
[0021] a mass member movably mounted within the housing in a length direction thereof; a coil member mounted in the housing; a magnet member mounted in the mass member and interacting with the coil member to generate a magnetic field so as to enable movement of the mass member; an elastic member mounted in the housing and applying force in the same direction as or an opposite direction to a moving direction of the mass member; and a bearing member disposed between the mass member and the housing to enable a sliding motion of the mass member relative to the housing.
[0022] The elastic member may be a coil spring.
[0023] The elastic member may include: a first spring connecting one end of the housing to one end of the mass member; and a second spring connecting the other end of the housing to the other end of the mass member.
[0024] The first spring and the second spring may have different spring constants.
[0025] The housing may have a cylindrical shape having a circular cross-section, and the mass member may have a cylindrical shape having a circular cross-section.
[0026] The magnet member may be disposed to be deflected in one direction from a center of a magnetic field of the coil member to provide a deflected magnetic field to the coil member in a state in which the mass member stops.
[0027] According to an aspect of the present invention, there is provided a horizontal linear vibrator, including: a housing; a mass member movably mounted within the housing in a length direction thereof; a magnet member mounted in the housing; a coil member mounted in the mass member and interacting with the magnet member to generate a magnetic field so as to enable movement of the mass member; an elastic member mounted in the housing and applying force in the same direction as or an opposite direction to a moving direction of the mass member; and a bearing member disposed between the mass member and the housing to enable a sliding motion of the mass member relative to the housing.
[0028] The elastic member may be a coil spring.
[0029] The elastic member may include: a first spring connecting one end of the housing to one end of the mass member; and a second spring connecting the other end of the housing to the other end of the mass member.
[0030] The first spring and the second spring may have different spring constants.
[0031] The housing may have a cylindrical shape having a circular cross-section and the mass member may have a cylindrical shape having a circular cross-section.
[0032] The magnet member may be disposed to be deflected in one direction from a center of a magnetic field of the coil member to provide a deflected magnetic field to the coil member in a state in which the mass member stops.
[0033] According to an aspect of the present invention, there is provided a horizontal linear vibrator, including: a housing provided with a groove extending lengthily in a length direction; amass member movably mounted within the housing in a length direction thereof and provided with a protrusion inserted into the groove; a coil member mounted in the housing; a magnet member mounted in the mass member and interacting with the coil member to generate a magnetic field so as to enable movement of the mass member; and an elastic member mounted in the housing and applying force in the same direction as or an opposite direction to a moving direction of the mass member.
[0034] The elastic member may be a coil spring.
[0035] The elastic member may include: a first spring connecting one end of the housing to one end of the mass member; and a second spring connecting the other end of the housing to the other end of the mass member.
[0036] The first spring and the second spring may have different spring constants.
[0037] The housing may have a cylindrical shape having a circular cross-section and the mass member may have a cylindrical shape having a circular cross-section.
[0038] The magnet member may be disposed to be deflected in one direction from a center of a magnetic field of the coil member to provide a deflected magnetic field to the coil member in a state in which the mass member stops.
[0039] According to an aspect of the present invention, there is provided a horizontal linear vibrator, including: a housing having a receiving space extending in a length direction; amass member mounted in the receiving space and movable along the length direction; a coil member mounted in the housing; a magnet member mounted in the mass member and interacting with the coil member to generate a magnetic field so as to enable movement of the mass member; and an elastic member mounted in the housing and applying force in the same direction as or an opposite direction to a moving direction of the mass member, wherein the receiving space has an asymmetrical cross-section or an oval or polygonal cross-section and the mass member has a cross-sectional shape coinciding with a section of the receiving space.
[0040] The elastic member may be a coil spring.
[0041] The elastic member may include: a first spring connecting one end of the housing to one end of the mass member; and a second spring connecting the other end of the housing to the other end of the mass member.
[0042] The first spring and the second spring may have different spring constants.
[0043] The magnet member may be disposed to be deflected in one direction from a center of a magnetic field of the coil member to provide a deflected magnetic field to the coil member in a state in which the mass member stops.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0045] FIG. 1 is a cross-sectional view of a horizontal linear vibrator according to a first embodiment of the present invention;
[0046] FIG. 2 is a cross-sectional view taken along line A-A of the horizontal linear vibrator illustrated in FIG. 1 ;
[0047] FIG. 3 is a cross-sectional view illustrating another form of the horizontal linear vibrator illustrated in FIG. 1 ;
[0048] FIG. 4 is a cross-sectional view of a horizontal linear vibrator according to a second embodiment of the present invention;
[0049] FIG. 5 is a cross-sectional view of a horizontal linear vibrator according to a third embodiment of the present invention;
[0050] FIG. 6 is a cross-sectional view taken along line B-B of the horizontal linear vibrator illustrated in FIG. 5 ;
[0051] FIGS. 7 and 8 are cross-sectional views of another form of the horizontal linear vibrator taken along line B-B illustrated in FIG. 5 ;
[0052] FIG. 9 is a cross-sectional view of a horizontal linear vibrator according to a fourth embodiment of the present invention;
[0053] FIG. 10 is a cross-sectional view taken along line C-C of the horizontal linear vibrator illustrated in FIG. 9 ; and
[0054] FIGS. 11 and 12 are cross-sectional views of another form of the horizontal linear vibrator taken along line C-C illustrated in FIG. 9 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0055] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein.
[0056] Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0057] FIG. 1 is a cross-sectional view of a horizontal linear vibrator according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view taken along line A-A of the horizontal linear vibrator illustrated in FIG. 1 ; FIG. 3 is a cross-sectional view illustrating another form of the horizontal linear vibrator illustrated in FIG. 1 ; FIG. 4 is a cross-sectional view of a horizontal linear vibrator according to a second embodiment of the present invention; FIG. 5 is a cross-sectional view of a horizontal linear vibrator according to a third embodiment of the present invention; FIG. 6 is a cross-sectional view taken along line B-B of the horizontal linear vibrator illustrated in FIG. 5 ; FIGS. 7 and 8 are cross-sectional views of another form of the horizontal linear vibrator taken along line B-B illustrated in FIG. 5 ; FIG. 9 is a cross-sectional view of a horizontal linear vibrator according to a fourth embodiment of the present invention; FIG. 10 is a cross-sectional view taken along line C-C of the horizontal linear vibrator illustrated in FIG. 9 ; and FIGS. 11 and 12 are cross-sectional views of another form of the horizontal linear vibrator taken along line C-C illustrated in FIG. 9 .
[0058] The horizontal linear vibrator according to a first embodiment of the present invention will be described with reference FIGS. 1 through 3 .
[0059] A horizontal linear vibrator 100 according to the embodiment of the present invention may include a housing 110 , a mass member 120 , a magnet member 130 , and a coil member 140 . In addition, the horizontal linear vibrator 100 may further include an elastic member 150 and a bearing member 160 .
[0060] The housing 110 has a receiving space 112 and may be formed to lengthily extend in one direction. For example, the housing 110 may have a hollow cylindrical shape (see FIG. 2 ). However, the shape of the housing 110 is not limited to the cylindrical shape. In other words, the housing 110 may have a polygonal shape or other shapes, as necessary.
[0061] The housing 110 may be formed of a material having sufficient rigidity to protect members disposed in the receiving space 112 from external impact. For example, the housing 110 may be formed of a metal or a plastic material. However, the housing 110 is not only formed of the above-mentioned materials, but may be formed of other materials, as needed.
[0062] The housing 110 may be formed of a plurality of members. In other words, the housing 110 may be formed by coupling two members which are symmetrical, relative to each other. By this configuration, the plurality of members may easily be mounted in the receiving space 112 of the housing 110 and the mounted members may easily be replaced and exchanged with other members.
[0063] The mass member 120 may be mounted in the receiving space 112 of the housing 110 . In other words, the mass member 120 has a size smaller than that of the housing 110 , and therefore may be completely received in the receiving space 112 . For reference, according to the embodiment of the present invention, the mass member 120 has a cylindrical shape which substantially coincides with the receiving space 112 of the housing 110 . However, the shape of the mass member 120 is not limited to a cylinder, but may be changed variously, as needed.
[0064] The mass member 120 may move in the receiving space 112 . In other words, the mass member 120 may move in a reciprocal manner in a length direction of the housing 110 . To this end, a length L1 of the mass member 120 may be shorter than a length of the housing 110 or a length L2 of the receiving space 112 . In this case, a length deviation L2-L1 between the length L2 of the receiving space 112 and the length L1 of the mass member 120 may be determined depending on a type of a natural vibrational frequency of the horizontal linear vibrator 100 . For example, when the natural vibrational frequency having relatively large amplitude is required, the length deviation L2-L1 may be large and when the natural vibrational frequency having relatively small amplitude is required, the length deviation L2-L1 may be small.
[0065] The mass member 120 may have a mass required to induce the vibrations of the horizontal linear vibrator 100 . In other words, the mass of the mass member 120 may be changed depending on the natural vibrational frequency of the horizontal linear vibrator 100 . For example, when the natural vibrational frequency in a high frequency band is required, the mass of the mass member 120 may be decreased, and when the natural vibrational frequency in a low frequency band is required, the mass of the mass member 120 may be increased.
[0066] The mass member 120 may be formed of a metal or a rubber material. The metal may be used in increasing a size of amass with a small size and the rubber material may be used in relieving a breakage phenomenon due to impact between the housing 110 and the mass member 120 .
[0067] The magnet member 130 may be mounted in the mass member 120 . In other words, the magnet member 130 may be mounted on a circumference of the mass member 120 (see FIG. 2 ). To this end, the circumference of the mass member 120 may be provided with a groove 122 in which the magnet member 130 is mounted. However, the circumference of the mass member 120 is not necessarily provided with the groove 122 . For example, the magnet member 130 may be attached to the circumference of the mass member 120 by an adhesive.
[0068] Both ends (horizontal direction based on FIG. 1 ) of the magnet member 130 may have different polarities. For example, one end of the magnet member 130 may be a first polarity (N pole) and the other end thereof may be a second polarity (S pole). The magnet member 130 , so disposed, may form a magnetic force, along with the coil member 140 to move the mass member 120 in a reciprocal manner in a length direction (horizontal direction based on FIG. 1 ) of the housing 110 .
[0069] As illustrated in FIG. 1 , the magnet member 130 may be formed to be wider than the coil member 140 . The magnet member 130 , so formed, may continuously face the coil member 140 during the reciprocating motion of the mass member 120 to form the magnetic force.
[0070] Meanwhile, as illustrated in FIG. 3 , the magnet member 130 may be disposed to be deflected in one direction with respect to the coil member 140 in a state in which the mass member 120 stops. In other words, a center line C1-C1 of the magnet member 130 may be disposed to be deflected with a center line C2-C2 of the coil member 140 at a predetermined distance. The structure, so disposed, generates a magnetic field deflected in one direction between the magnet member 130 and the coil member 140 , which may be applied to the case of starting the mass member 120 in the stopped state.
[0071] The coil member 140 may be mounted in the housing 110 . In other words, the coil member 140 may be mounted on an inner circumferential surface of the housing 110 and may be disposed at a position facing the magnet member 130 in the stop state of the mass member 120 (see FIGS. 1 and 2 ).
[0072] The coil member 140 may be connected to an external power supply. In other words, the coil member 140 may have a current applied thereto from the external power supply to generate a predetermined magnetic field.
[0073] The so configured coil member 140 may alternately generate a magnetic field which coincides with or does not coincide with the magnetic field of the magnet member 130 depending on a supply direction of current, thereby reciprocally moving the mass member 120 .
[0074] The elastic member 150 may be mounted in the receiving space 112 of the housing 110 and may provide a predetermined elastic force in a one-axis direction (horizontal direction based on FIG. 1 ). To this end, the elastic member 150 may have a spring shape. In other words, the elastic member 150 may be a coil spring.
[0075] The elastic member 150 may be disposed between one end of the housing 110 and one end of the mass member 120 and between the other end of the housing 110 and the other end of the mass member 120 . The elastic member 150 , so disposed, may provide elastic force in a direction opposite to a moving direction of the mass member 120 . For example, when the mass member 120 moves in a first direction (a left direction, based on FIG. 1 ), the elastic member 150 may apply the elastic force to the mass member 120 in the second direction (a right direction, based on FIG. 1 ), and when the mass member 120 moves in a second direction, the elastic member 150 may apply the elastic force to the mass member 120 in the first direction.
[0076] Further, the elastic member 150 may prevent the mass member 120 from colliding with the housing 110 . In other words, the elastic member 150 may prevent both ends of the mass member 120 from colliding with left and right ends of the housing 110 due to a sudden motion of the mass member 120 .
[0077] Meanwhile, the elastic members 150 disposed at both ends of the mass member 120 may have different elastic moduli as illustrated in FIG. 3 . In other words, a first coil spring 152 disposed at one side of the mass member 120 may have a first spring constant and a second coil spring 154 disposed at the other side thereof may have a second spring constant. As such, when the coil springs 152 and 154 having different spring constants are disposed at both ends of the mass member 120 , deflecting the mass member 120 in one direction in the stop state of the mass member 120 may obtain the same as or a similar effect to deflecting the magnet member 130 .
[0078] The bearing member 160 may be disposed between the housing 110 and the mass member 120 and may be mounted in the housing 110 or the mass member 120 . In other words, the bearing member 160 may be disposed between the inner circumferential surface of the housing 110 and an outer circumferential surface of the mass member 120 . The bearing member 160 , so disposed, relieves contact and friction between the inner circumferential surface of the housing 110 and the outer circumferential surface of the mass member 120 , thereby allowing for reciprocation of the mass member 120 to be smooth.
[0079] According to the horizontal linear vibrator 100 configured as described above, the moving position of the mass member 120 may be stably maintained by the elastic member 150 and the bearing member 160 to stably secure straightness of the mass member 120 , thereby obtaining a constant and reliable vibrational frequency. Further, the horizontal linear vibrator 100 according to the embodiment of the present invention may prevent or relieve the collision phenomenon between the mass member 120 and the housing 110 due to the elastic member 150 and the bearing member 160 , thereby improving durability against external impact.
[0080] Next, a horizontal linear vibrator according to another embodiment of the present invention will be described. For reference, in describing the following embodiments, components that are the same as those of the above-mentioned embodiment of the present invention will be denoted by the same reference numerals as the foregoing embodiments and a detailed description thereof will be omitted.
[0081] Hereinafter, a horizontal linear vibrator according to a second embodiment of the present invention will be described with reference to FIG. 4 .
[0082] The horizontal linear vibrator 100 according to the embodiment of the present invention may be differentiated from the first embodiment in terms of the positions of the magnet member 130 and the coil member 140 . In other words, according to the embodiment of the present invention, the magnet member 130 may be mounted on the inner circumferential surface of the housing 110 and the coil member 140 may be mounted on the outer circumferential surface of the mass member 120 .
[0083] The so configured horizontal linear vibrator 100 has a structure in which the coil member 140 is wound around the mass member 120 separable from the housing 110 , such that the coil member 140 may be mounted relatively easily.
[0084] Next, a horizontal linear vibrator according to a third embodiment of the present invention will be described with reference FIGS. 5 through 8 .
[0085] The horizontal linear vibrator 100 according to the embodiment of the present invention may be differentiated from the foregoing embodiments in terms of the shapes of the housing 110 and the mass member 120 . In other words, according to the embodiment of the present invention, the housing 110 may be provided with the groove 114 and the mass member 120 may be provided with a protrusion 124 .
[0086] The groove 114 may be formed lengthily in the length direction of the housing 110 . In other words, the groove 114 may be formed lengthily in the reciprocating motion direction (horizontal direction based on FIG. 5 ) of the mass member 120 .
[0087] The protrusion 124 may be formed in the mass member 120 . In other words, the protrusions 124 may be formed lengthily in the reciprocating motion direction of the mass member 120 . Alternatively, the plurality of protrusions 124 may be formed along the reciprocating motion direction of the mass member 120 at a predetermined distance. The protrusion 124 may be inserted into the groove 114 of the housing 110 . In other words, the protrusion 124 has a size which substantially coincides with the groove 114 and may move along the groove 114 in the significantly reduced contact friction state. That is, the protrusion 124 and the groove 114 are precisely machined with a significantly reduced tolerance, and therefore may slidably contact each other.
[0088] According to the horizontal linear vibrator 100 configured as described above, the straightness of the mass member 120 may be secured by the protrusion 124 inserted into the groove 114 . Therefore, in the present embodiment, the bearing member 160 may be omitted, such that the manufacturing costs of the horizontal linear vibrator 100 may be saved and the manufacturing process thereof may be simplified.
[0089] Meanwhile, as illustrated in FIGS. 7 and 8 , the plurality of grooves 114 and the plurality of protrusions 124 may be formed in the circumference of the housing 110 and the mass member 120 at a predetermined distance.
[0090] Next, a horizontal linear vibrator according to a fourth embodiment of the present invention will be described with reference FIGS. 9 through 12 .
[0091] The horizontal linear vibrator 100 according to the embodiment of the present invention may be differentiated from the foregoing embodiments in terms of the cross-sectional shapes of the housing 110 and the mass member 120 .
[0092] In the present embodiment, the housing 110 may have a vertical or horizontal asymmetrical cross-sectional shape, a rectangular or squared cross-sectional shape, or a polygonal or oval cross-sectional shape. In other words, as illustrated in FIG. 10 , the housing 110 may have a cross-sectional shape in which a portion of a circle is flat. Alternatively, as illustrated in FIG. 11 , the housing 110 may have a rectangular cross-sectional shape. Alternatively, as illustrated in FIG. 12 , the housing 110 may have an oval cross-sectional shape. That is, in the present embodiment, the housing 110 may have a cross-sectional shape having directivity.
[0093] The mass member 120 may have a cross-sectional shape corresponding to the housing 110 . That is, the mass member 120 illustrated in FIG. 10 may have the cross-sectional shape which coincides with a shape in which the housing 110 is reduced at a predetermined ratio, the mass member 120 illustrated in FIG. 11 may have a rectangular or squared cross-sectional shape, and the mass member 120 illustrated in FIG. 12 may have an oval cross-sectional shape.
[0094] The cross-sectional shapes of the housing 110 and the mass member 120 having the above-mentioned shape have directivity, such that the mass member 120 may be deflected in a specific direction within the housing 110 . That is, the structure serves to restrict the motion of the mass member 120 in the section, thereby improving the straightness of the mass member 120 .
[0095] As set forth above, according to the embodiments of the present invention, the high-frequency vibrations may be generated by forming the mass member to have an appropriate size.
[0096] Further, according to the embodiments of the present invention, the manufacturing costs of the horizontal linear vibrator may be saved by significantly reducing the number of components of the horizontal linear vibrator.
[0097] In addition, according to the embodiments of the present invention, since the internal structure of the horizontal linear vibrator is robust, an influence on the performance of the horizontal linear vibrator due to the external impact may be significantly reduced.
[0098] While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
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There is provided a horizontal linear vibrator including a housing, a mass member movably mounted within the housing in a length direction thereof, a coil member mounted in the housing, a magnet member mounted in the mass member and interacting with the coil member to generate a magnetic field so as to enable movement of the mass member, an elastic member mounted in the housing and applying force in the same direction as or an opposite direction to a moving direction of the mass member, and a bearing member disposed between the mass member and the housing to enable a sliding motion of the mass member relative to the housing.
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