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BACKGROUND OF THE INVENTION
The present invention relates to a process for the separation of melts, according to the nozzle drawing process, in which flows of melt which, under the effect of gravity and additional pressure forces, flow out of melt outflow openings which are arranged at the lower end of a melting pot containing the melt, are separated, and optionally drawn out on passing through drawing nozzles, under the effect of gases which flow at a high velocity in a substantially parallel direction to the flows of melt, and are cooled below the temperature of solidification. A process of this type was suggested, as early as 1922, for the production of mineral wool in DE-PS No. 429,554.
A separation apparatus has now been described in EP Offenlegungsschrift No. 38,989, in which the flow of melt is split into a large number of individual fibers under the effect of as powerful a pressure gradient as is possible in the inlet of the drawing nozzle.
SUMMARY OF THE INVENTION
It has now been found that the pressure gradient may be produced by providing obstacles to the flow in the inlet of the drawing nozzle.
An object of the present invention is to provide a process for the separation of melts, according to the nozzle drawing process, which is characterised in that obstacles to the flow are provided at the inlet opening of the drawing nozzle substantially transversely to the direction of a flow of gas which is entering the drawing nozzle.
Mechanical obstacles to the flow may be provided as obstacles to the flow. The flow which is flowing into the drawing nozzle is preferably disturbed by blowing a fluid in a substantially transverse direction to the flow which is entering the nozzle, which would be formed if it was not disturbed. The fluid which is blown in contributes to increasing the pressure gradient in the nozzle inlet, on the one hand, in that it provides additional mass which has to be advanced, and on the other hand, in that if fluid is blown in in the form of fine streams, it acts as an obstacle to the flow of ambient air which is flowing in and thus in the sense of a contraction of the cross section of the inlet directly at the inlet of the nozzle. Consequently the fluid is preferably blown in in the form of fine streams--henceforth referred to as cross streams--the cross streams, until they mix with the ambient air which is flowing into the nozzle, having a range in the stream direction which almost corresponds to the distance between the nozzle inlet and the melt outflow opening of the melting pot. The cross streams should preferably extend at least to the bisector plane of the drawing nozzle.
The fluid may, in the simplest case, be a gas, such as ambient air, water vapour (steam) or an inert gas such as nitrogen. The separation of the melt may be further influenced by producing the cross streams from a gas which reacts with the ambient gas with the release of heat. Hydrogen or hydrocarbons which burn with the oxygen in the ambient air may, for example, be used as gas for the cross-streams. This is particularly advantageous when melts, which have a high viscosity, such as glass melts, are to be separated, and in particular if they are to be drawn out to produce fibers. Evaporating liquids, such as water, may also be used as fluid for producing the cross-streams. This is particularly appropriate if a rapid cooling of the melt which is to be separated is required, as in the separation of metal melts.
The quantity of fluid which is blown in as cross streams should be from 2 to 40%, by weight, of the total quantity of gas entering the drawing nozzle. The quantity of gas which is blown in as cross streams should preferably be from 5 to 20%, by weight, of the gas entering the drawing nozzle. If a liquid is used as fluid, the liquid should be preferably completely evaporated in the inlet of the drawing nozzle. The use of a mixture of a gas and a liquid may be particularly advantageous.
The direction of the cross streams upon meeting the inlet flow may be by from 50° against the inlet flow to 25° towards the inlet flow measured with respect to the perpendicular on the axis resp. the bisector plane, of the drawing nozzle. The inlet flow should preferably be directed at a position from perpendicular to the axis of the nozzle to 30° against the direction of the inlet flow.
The velocity of the cross streams, the direction thereof and the quantity of fluid which is blown in as cross streams and the pressure gradient in the drawing nozzle inlet (as would be produced in the absence of cross streams) are all closely connected. Good results are preferably achieved in supersonic drawing nozzles, if the cross stream velocity is also within the supersonic range, such as from 1 to 3 times the sound velocity. In this instance, the gas which is blown in as cross streams amounts more particularly to from 8 to 16%, by weight, of the total quantity of gas entering the drawing nozzle.
In addition to advantageously influencing the drawing-out process in view of increasing the pressure gradient in the inlet of the nozzle, the cross streams also contribute to substantially improving the economicalness of the process. The melt outflow openings of the melting pot may be moved closer to the upper surface of the drawing nozzle, so that on account of the more powerful suction effect of the inlet flow, a greater quantity of melt flows out of the melting pot through each nipple. The melt outflow openings may, moreover, be arranged closer to each other, since the cross streams also exert a separating effect on the individual fibers of melt, so that adjacent flows of melt do not flow together. If the arrangement is favorable, it is possible to do without nipples on the lower surface of the melting pot. On account of the separating effect of the cross streams, it is possible to let the melt flow out through simple bores on a substantially level lower surface of the melting pot, without this causing the melt to overflow the lower edge of the melting pot as is a known phenomenon.
The process, according to the present invention, effects an intensive separation of the fibre of melt in the inlet of the drawing nozzle. In particular when separating mineral fibers into fibers, this produces finer fibers which have a smaller proportion of beads, shot, thick pieces of fiber and fibers which are stuck together. The fiber diameter distribution of the fibers which are produced, according to the present invention (mineral or glass wool), has a particularly narrow range of fluctuation.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is explained in detail with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic sectional view showing the relative arrangement of drawing nozzle, cross streams and melt pot,
FIG. 2 is an enlarged view as shown in FIG. 1.
FIG. 3 is a perspective view of a drawing nozzle and melt pot as in FIG. 2.
FIGS. 4, 5, 6 and 7 are schematic sectional views of details of the drawing nozzle inlet showing different embodiments for cross stream nozzles.
FIGS. 8, 9, 10, 11 and 12 are schematic horizontal projections of the relative arrangements of melt stream cross stream and drawing nozzle inlet.
FIG. 13 is a schematic sectional view of the embodiment of FIG. 12 along arrows 13--13 of FIG. 12.
FIGS. 14 and 15 are schematic views onto the top of the drawing nozzle showing mechanical flow obstacles.
FIG. 16 is a schematic vertical cross section of the drawing nozzles of FIGS. 14 and 15.
FIG. 17 is a schematic cross sectional view of the drawing nozzle inlet showing isobars of the inlet flow without cross streams.
FIG. 18 is a view corresponding to FIG. 17, showing isobars of the inlet flow if disturbed by cross streams.
FIG. 19 is a view perpendicular to the view of FIG. 18 along arrows 19--19 of FIG. 18.
DETAILED DESCRIPTION OF THE INVENTION
The numbers which are given in the Figures describe, in each case, the following structural or functional elements:
1: Melting pot
2: Mineral melt
3: Melt outflow opening of the melting pot (nipples)
4: Stream of melt
5: Inlet of the drawing nozzle
6: Drawing-out part of the drawing nozzle
7: Propulsion jet nozzle
8: Propellant gas chamber
9: Propellant gas supply pipe
10: Diffuser
11: Inlet flow
12: Cross stream
13: Gas pipe for cross streams
14: Cross stream nozzle.
By way of example, an apparatus for the production of mineral fibers, according to the nozzle drawing process, is shown in FIG. 1. A melting pot 1 contains the mineral melt 2. Melt outflow openings 3, which are arranged in series in a straight line, are positioned at the bottom of the melting pot. Streams of melt 4 issue from the melt outflow openings 3. The streams of melt 4 enter the slit-shaped drawing nozzle which is shown below this, perpendicular to the plane of the drawing. The drawing nozzle consists of a nozzle inlet 5, a drawing-out part 6 and a diffuser 10 which is arranged below the drawing out part 6. The drawing nozzle contains, moreover, propulsion jet nozzles 7, which issue from a propellant gas chamber 8. Compressed gas of from 3 to 12 atmospheres is supplied to the propellant gas chamber 8 via a propellant gas pipe which is not shown. The compressed gas is released through the propulsion jet nozzles 7. The propulsion jets which are produced by the propulsion jet nozzles 7 cause a low pressure in the drawing nozzle, so that ambient air from the area above the drawing nozzle is drawn by suction into the drawing nozzle with the formation of the inlet flow 11.
Under the effect of the pressure gradient in the flow entering the drawing nozzle, the fiber of melt 4 is split into a plurality of individual fibers in the area of the nozzle inlet 5, fibers which are drawn even further out in the drawing-out part of the nozzle. The effect of the inlet flow on the fiber of melt becomes more intense, the greater the pressure gradient along the inlet flow.
According to the present invention, additional bores 14 are now provided from the propellant gas chamber 8, bores which point upwards in a diagonal direction towards the axis of the drawing nozzle. Cross streams 12 issue through the bores 14, cross streams which flow in a substantially transverse direction to the inlet flow, which would form in the absence of the cross streams. In the arrangement which is shown, the bores 14 are, in each case, arranged on both sides of the nozzle inlet 5, in each case between two flows of melt 4.
In a specific arrangement, according to FIG. 1, in which the distance of the melt outflow opening 3 from the drawing nozzle inlet 5 is from 5 to 6 mm, disruptive streams of gas, which have an adequate range, are produced if the nozzles, from which the streams of disruptive gas 14 issue, have a diameter of 0.2 mm and if the pressure in the propellant gas chamber is 85 bars.
FIG. 2 shows an apparatus similar to the one shown in FIG. 1 on a slightly enlarged scale. In this instance, the melting pot contains a double row of nipples 3, 3' which are staggered with respect to each other on its bottom. In each case the cross stream 12 is blown into the inlet stream only on one side from the side of the drawing nozzle which is opposite the flow of melt 4 or 4'.
FIG. 3 depicts an arrangement consisting of a drawing nozzle and a melting pot which is shown in perspective. A double row of melt outflow nipples 3 and 3' may be observed at the bottom of the melting pot 1. According to the present invention, the drawing nozzle contains bores for the cross streams 14, which issue from the propellant gas chamber 8, in the drawing nozzle inlet 5.
FIGS. 4, 5, 6 and 7 show different possibilities for the design of the cross stream nozzles. FIG. 4 shows first of all, an enlarged view of, in each case, the right-hand half of the nozzle inlet 5, as was shown in FIGS. 2 and 3. Cross stream nozzle 14 and propulsion jet nozzle 7 are supplied from the common propellant gas chamber 8 under compressed gas, the cross stream 12 being designed as shown by the arrow. Unlike in FIGS. 2 and 3, this cross stream nozzle 14 is designed as a Laval nozzle which has an expanding section. The embodiment, according to FIG. 5, has a divided supply pipe 13 for the cross streams 12. This enables the pressure in the cross stream gas supply pipe 13 to be regulated independently of the pressure of propulsion jet gas in the propellant gas chamber 8.
FIG. 6 shows an embodiment of the cross stream gas supply pipe 13, which enables the direction of the cross stream 12 to be varied. In this instance, the cross stream gas supply pipe 13 consists of a pipe 15, having cross stream nozzles 14, which fits into the contour of the inlet of the drawing nozzle. The pipe 15 may be rotated around its axis, so that the direction of the cross stream 12 may be varied corresponding to the arrow 16 which is shown.
The embodiment in FIG. 7 shows a detail similar to the one shown in FIGS. 4, 5 and 6, it being possible, in this instance, to adjust the cross stream nozzle 14 in the outlet direction of the cross stream 12. The bores are positioned on the top of the drawing nozzle, and small pipes 17 may be inserted into these bores. The small pipes may be displaced along their longitudinal axis corresponding to arrow 18 which is shown. In this way mechanical obstacles to the flow 17 may be combined with cross streams. The movability of the small pipe 17 is unnecessary during constant operation. Of course, the small pipe 17 may also be supplied from the propellant gas supply pipe 8 if separate regulation of the cross stream gas pressure and movability of the small pipe 17 are not required. The embodiments according to FIGS. 5, 6 and 7 are particularly suitable if the cross stream fluid is distinct from the propellant gas. If water is used as cross stream fluid, the cooling effect of the water is particularly advantageous for the life-span of the drawing nozzle.
FIGS. 8 to 13 show preferred relative arrangements of melting pot outflow openings 3 and cross streams 12. FIGS. 8 to 12 show, in each case, a top view of the nozzle inlet 5, the melt outflow openings projecting into the nozzle inlet. FIG. 8 shows a double row of melt outflow openings 3 and 3'. Cross streams 12 flow, in each case, from one side of the nozzle inlet towards the melt outflow openings on the opposite side.
A similar arrangement is shown in FIG. 9, each cross stream 12 which was shown in FIG. 8 being substituted by two cross streams 12 flowing towards each other at an angle. The cross-section contracting effect on the nozzle inlet 5 and on the pressure gradient is increased further by the cross streams as a result of this.
FIG. 10 shows, as opposed to the slit-shaped drawing nozzle according to FIG. 8 and FIG. 9, a circular symmetrical drawing nozzle. An arrangement of this type is provided if FIG. 2 is taken as a section through a rotationally symmetrical arrangement. The cross streams flow, in each case, between two melt outflow openings 3.
FIG. 11 shows an arrangement consisting of three rows of melt outflow openings 3, the cross streams 11 flowing, in each case, towards the flows of melt in the middle row.
In FIG. 12, the cross streams 11 shown in FIG. 11 are, in each case, substituted by two cross streams 11 which point towards each other, similar to those in FIG. 9.
In cross stream arrangements according to FIGS. 9 and 12, in each case cross streams 12' and 12" which point in pairs towards each other in the plane which is perpendicular to the center plane of the drawing nozzle, may be at different angles towards the center plane of the drawing nozzle, so that they do not meet each other. This is shown in FIG. 13. FIG. 13 shows a section from FIG. 9 or FIG. 12.
FIGS. 14, 15 and 16 show arrangements of mechanical obstacles to the flow 20. FIG. 14 and FIG. 15 show top views of drawing nozzle inlet 5. 19 denotes the upper edge of the drawing nozzle, and 12 denotes the melt outflow openings which project into the plane of the drawing. The obstacle to the flow 20 is a strip of metal which runs in a transverse direction across the slit-shaped nozzle inlet 5. The strip of metal 20 is preferably soldered only on one side of the drawing nozzle (soldering point 21), so that the drawing nozzle may be opened for example when it is started up or when it is to be cleaned.
FIG. 16 shows a vertical section through the drawing nozzle according to FIG. 14 and illustrates the arrangement of the obstacle to the flow 20.
FIGS. 17, 18 and 19 show measurements of the pressure gradient in the nozzle inlet of the slit-shaped drawing nozzle. Since it is very difficult to take measurements of the pressure in the slit nozzles which are actually used for separating a substance into fibres, the width of the slit of which is about from 4 to 8 mm, a model of a drawings nozzle of this type was constructed which was enlarged 6 times. In the model, the width of the slit of the drawing nozzle was 24 mm and the radius of curvature R of the inlet contour of the drawing nozzle was 6 mm. An adequate low pressure was produced below the drawing nozzle, so that a pressure of 0.53 bars was produced at the narrowest point of the nozzle. This corresponds to the pressure which is produced at this point in a supersonic drawing nozzle which is true to scale. Thereafter measurements of the isobars in the inlet flow were taken using a manumetric capsule.
In the absence of cross streams, an isobar profile as shown in FIG. 17 would be produced. Measurements were subsequently taken on a corresponding arrangement with cross streams. The arrangement and the results of the measurements are given in FIG. 18. The cross streams 12 issue at an angle of 10° with respect to the direction perpendicular to the axis of symmetry of the drawing nozzle. A pressure of 6 bars was applied to the cross stream supply pipes 13. The diameter of the cross stream nozzles 14 was 3 mm.
FIG. 19 shows a longitudinal section along line A--A through the isobar profile according to FIG. 18. The black line 19 which is drawn across the page in FIG. 13 denotes the upper edge of the drawing nozzle according to 19 in FIG. 12.
The Figures clearly show the influence of the cross streams on the pressure gradient in the nozzle inlet. The actual conditions would be even more pronounced if the hot flow of melt had an additional influence on the pressure profile.
It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and shanges may be made without departing from the spirit and scope of the present invention.
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A process for finely dividing melts according to the nozzle drawing process is described wherein the pressure gradient of the gas flowing into the inlet opening of the drawing nozzle is increased by the provision of obstacles to that flow of gas. The obstacles may be streams or jets of gas directed a traverse of the flow of gas.
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PRIORITY
[0001] This application claims the benefit under 35 U.S.C. Section 119(e) of prior U.S. Provisional Patent Application No. 60/218,023, filed Jul. 12, 2000, the disclosure of which is incorporated herein by this reference.
TECHNICAL FIELD
[0002] This invention relates to ridge type roof vents, and more particularly to a novel ridge type roof vent designed for placement on the ridge of a tile roof, including heavy or light tiles, whether slate, clay, or of similar looking material, to allow ventilation of the space below the tile roof.
BACKGROUND
[0003] Although a variety of designs exist for roof vents, historically, “ridge type” roof vents have not been widely used for tile roofs. This is rather easy to understand, since although such a design would reduce the number of roof penetrations necessary to achieve adequate ventilation, the cumbersome and weighty nature of roof tiles has not been generally conducive to incorporation of a ridge type vent system in the roof design. And, although a few designs have been proposed or actually used, in so far as is known to us, prior art ridge vent designs have not adequately addressed the problem of preventing ingress of wind blown water, as might occur during a thunderstorm or hurricane, for example. Thus, it would be desirable to provide a new ridge vent design that is resistant to entry of wind blown water, especially if such a design were provided in a structurally strong, low profile, artistically pleasing ridge top roof vent system suitable for tile roofs or the like.
SUMMARY
[0004] We have invented a novel ridge type roof vent for incorporation in tile or tile type roof applications. The ridge vent design may be easily adapted for various tile roofs, ranking from flat tile to high profile (undulating design) tile roof structures. The ridge vent design is simple and strong enough to support the necessary tile and weather loads (wind, water, snow, ice, etc.), even though relatively lightweight. The roof vent designs are relatively inexpensive and easy to manufacture, and otherwise superior to heretofore known roof vent designs for tile roofs. Importantly, my ridge type roof vent for tile roofs provides exemplary protection against entry of wind driven water, as well as unwanted debris, insects, or vermin, while allowing a preselected ventilation volume per running foot of installed roof vent.
[0005] The new ridge vent design utilizes (a) a pair of opposing sub-flashing portions, each having therein a longitudinally running, preferably substantially vertically oriented vent apertures that allow passage of air therethrough, and (b) a top cap portion, having therein longitudinally running vent apertures spaced a preselected distance from the center longitudinal axis thereof.
[0006] Each of the sub-flashing portions spans a gap in the roofing deck adjacent the longitudinally running ridge support. Preferably, a top batten is longitudinally attached above the sub-flashing to affix the sub-flashing to the roof deck. Tiles are mounted above the top batten, in conventional fashion, sloping down the roof.
[0007] An elongated top cap portion is then affixed above the ridge beam. The top cap portion supports the ridge cap tiles. Also, when a low profile or S-type tile design is utilized, an appropriate weather block is affixed between the top of the undulating tile and the lower side of the top cap portion. In a flat tile design, the underside of the top cap is directly sealed to the top of the adjacent flat tiles.
OBJECTS, ADVANTAGES, AND FEATURES OF THE INVENTION
[0008] An important and primary object of the present invention resides in the provision of a novel, ridge type vent that is easy to manufacture and install on tile type roofs. Other important objects, advantages, and novel features include a ridge vent which:
[0009] can be manufactured in a simple, straightforward manner;
[0010] in conjunction with the preceding object, have the advantage that they can be configured by installation personnel to quickly and efficiently utilize the method disclosed herein to provide a ridge vent in a tile roof;
[0011] provides a ridge type vent that is fully protective from windblown debris, large insects, and vermin; and
[0012] that are structurally designed to provide sturdy support for heavy tiles;
[0013] that provide appropriate variations in the design for use in either flat tile roofs or in undulating type tile roofs.
[0014] Other aspects of various embodiments will become apparent to those skilled in the art from the foregoing and from the detailed description that follows and the appended claims, evaluated in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0015] In order to enable the reader to attain a more complete appreciation of the invention, and of the novel features and the advantages thereof, attention is directed to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0016] [0016]FIG. 1 is a perspective view of an exemplary ridge vent system installed in a flat type tile roof, showing the use of the sub-flashing to span a gap in the roof deck, and a ventilated top cap flashing that supports a tile cap.
[0017] [0017]FIG. 2 is an exploded perspective view of the ridge vent system shown in FIG. 1, now showing the various parts and pieces that make up the system, including (a) a roof decking having therein voids defined by sidewall portions to allow upward flow of ventilation air through the roof deck, (b) first and second sub-flashing portions, one for each side of the roof, (c) first and second battens for securing the first and second sub-flashing portions, respectively, (d) a ridge beam that extends longitudinally across the ridge of a roof, (e) a top cap flashing portion that is mounted above the ridge beam, and over which a top cap or ridge-cap row of tiles is mounted.
[0018] [0018]FIG. 3 is a perspective view of a portion of the vent apertures in flashing, provided to more clearly show construction details of vent apertures.
[0019] [0019]FIG. 4 is an exploded perspective of the roof first shown in FIG. 1, now showing construction details, including the installation of first and second sub flashing portions, and a top flashing portion which is covered by a top cap row of roofing tiles.
[0020] [0020]FIG. 5 is a cross-sectional view of the roof vent system first illustrated in FIG. 1 above taken across line 5 - 5 of FIG. 1, now showing the ridge cap tiles at a longitudinal location where the lateral edges extend down to the flashing.
[0021] [0021]FIG. 6 shows a side view of a finished roof with ridge vent, installed utilizing the ridge vent system disclosed herein, and, in particular, illustrates the generally triangular space below the outer edge of slanted ridge-cap tiles which allows ventilation air to escape outward.
[0022] [0022]FIG. 7 is an exploded perspective view of the ridge vent system installed in a low profile S-type roofing, further illustrating the version which is useful in “S-tile” or “undulating” type tile roof construction, here showing the use of subflashing on both sides of the ridge beam, and a top beam mounted above the ridge beam to support ridge-cap tiles.
[0023] [0023]FIG. 8 is a vertical cross-section of a ridge top roof vent installed on a roof having low profile type roofing types as just illustrated in FIG. 7.
[0024] [0024]FIG. 9 is an exploded perspective of view of a ridge vent system adapted for use in S-tile roofing.
[0025] [0025]FIG. 10 is a vertical cross-section of a ridge top roof vent installed on a roof having an S-tile roof as just illustrated I FIG. 9 above.
[0026] [0026]FIG. 11 is a top plan view of a section of subflashing, shown flat during manufacture of the subflashing, before the subflashing is formed and shaped for installation.
[0027] [0027]FIG. 12 is a close up view of a portion of FIG. 11, taken to more clearly show construction details of vent apertures.
[0028] [0028]FIG. 13 is yet a closer view of a portion of the sub-flashing shown in FIG. 12, provided to more clearly show construction details of one exemplary type of vent apertures.
[0029] [0029]FIG. 14 is a top plan view of a section of top cap flashing for a flat type tile roof, shown flat during manufacture of the top cap flashing, before the top cap flashing is shaped for installation.
[0030] [0030]FIG. 15 is a close-up view of a portion of FIG. 14, taken to more clearly show construction details of the top cap flashing.
[0031] [0031]FIG. 16 is yet a closer view of a portion of the top cap shown in FIG. 7, provided to more clearly show construction details of the top cap flashing.
[0032] [0032]FIG. 17 is a top plan view of a section of sub-flashing, shown flat during manufacture of the sub-flashing for an undulating tile roof, before the subflashing is formed and shaped for installation.
[0033] [0033]FIG. 18 is a close up view of a portion of FIG. 17, taken to more clearly show construction details of vent apertures.
[0034] [0034]FIG. 19 is yet a closer view of a portion of the sub-flashing shown in FIG. 18, provided to more clearly show construction details of one exemplary type of vent apertures.
[0035] [0035]FIG. 20 is a top plan view of a section of top cap flashing for use on an undulating type tile roof, shown flat during manufacture of the top cap flashing, before the top cap flashing is shaped for installation.
[0036] [0036]FIG. 21 is a close-up view of a portion of FIG. 20, taken to more clearly show construction details of the top cap flashing.
[0037] [0037]FIG. 22 is yet a closer view of a portion of the top cap shown in FIG. 21, provided to more clearly show construction details of the top cap flashing.
[0038] The foregoing figures, being merely exemplary, contain various elements that may be present or omitted from actual implementations depending upon the circumstances. An attempt has been made to draw the figures in a way that illustrates at least those elements that are significant for an understanding of the various embodiments and aspects of the invention. However, various other elements of the ridge vent system and accompanying roofing system are also shown and briefly described to enable the reader to understand how various optional features may be utilized in order to provide an efficient, ridge vent.
DETAILED DESCRIPTION
[0039] Attention is directed to FIGS. 1 and 5, where respectively a perspective view and a cross-sectional view are shown of a ridge vent system installed in a flat tile type roof system 28 . Roof rafters 30 and 32 have ridge ends 34 and 36 ending at a center beam 38 . Above the center beam 38 is mounted a longitudinally running ridge beam 40 which extends across the roof system. First 42 and second 44 roof decking is affixed above the upper sides 46 and 48 of the respective rafters 30 and 32 . Either through roof deck 42 , or preferably above the upper end 49 of first roof deck 42 and up to the first side 50 of ridge beam 40 , a first air gap G 1 is provided. First air gap G 1 is provided to allow air to flow upward or downward in the direction of reference arrows 60 and 62 , respectively. Between the upper end 64 of second roof deck 44 and the second side 66 of ridge beam 40 , a second air gap G 2 is provided to allow air to flow upward or downward in the direction of reference arrows 70 and 72 , respectively.
[0040] A first longitudinally extending sub-flashing 80 having a plurality of ventilation apertures A 1 therein is provided to span gap G 1 . A second longitudinally extending sub-flashing 84 having a plurality of apertures A 2 therein is provided to span gap G 2 . A first top batten 90 is provided to affix first subflashing 80 to the first roof deck 42 . A second top batten 92 is provided to affix the second sub-flashing 82 to the second roof deck 44 . Each of first and second top battens 90 and 92 may be secured to first and second roof decks 42 and 44 , respectively, by nails or other suitable fasteners N as indicated in FIG. 2. First water proof roof felting 96 is provided above first roof deck 42 , below flat tiles generally noted with reference numeral 100 , but in this case, more specifically shown as 100 1 and 100 2 . A second water proof roof felting 102 is provided above second roof deck 44 , below flat tiles 100 3 and 100 4 .
[0041] A top cap flashing 120 is mounted over the top 122 of ridge beam 40 . The top cap flashing 120 is longitudinally extending to support a plurality of ridge cap tiles 130 , or as more specifically identified, cap tiles in a series from 130 1 , 130 2 , to 130 Z , where Z is a positive integer. In the embodiment shown in this FIG. 1, the top cap flashing 120 has a downwardly directed U-shaped center section 132 and a pair of opposing first and second outward wing portions 134 and 136 , each of which may be bounded at the outer tip T thereof by a an upwardly directed flange portion F. Preferably, a sealant layer S is provided between the lower side 138 and 140 of wing portions 134 and 136 , respectively, and the adjacent tiles 100 1 and 100 3 , respectively.
[0042] In FIG. 1, a view of an exemplary ridge vent flashing is in place on a roof, showing the position of (a) the sub-flashing 80 and 84 , and (b) the top cap flashing 120 , and including flat tile roofing 100 and the longitudinally oriented ridge cap tiles 130 . Also, the various figures provide general views of certain embodiments, without limitation as to details of exact size, for convenience of stocking distributors and for contractor installation, one set of exemplary dimensions for my ridge vent system as applied to flat type tile roofs can be provided, as detailed in FIGS. 11, 12, and 13 . For example, sub-flashing 80 and 84 can be provided in convenient widths, often of about 6.5 inch width, when measured flat, before forming into an “S” shape for installation, and in standard lengths of 48 inches. Also, I have found it convenient to provide apertures A 1 and A 2 spaced at about 0.25 inch centers vertically (Y dimension) and at about 0.20 inch centers longitudinally (X dimension) as also noted in FIG. 3. Also, for strength of sub-flashing 80 and 84 , 1 have found it useful to provide apertures A 1 and A 2 in rectangular strips of about 10.8 inches long, and slightly over one inch wide, with about 1.2 inch strips of solid metal provided longitudinally between rectangular strips of apertures, and with the first aperture spaced about 1.1 inches from the edge E (see FIG. 12 for this detail). However, these are merely exemplary embodiments and the actual dimensions and sizes may be varied to suit individual needs, without varying from the more general teachings hereof.
[0043] Turning now to the top cap 120 , FIG. 14 shows a top plan view of a 48 inch long section of top cap flashing 120 for a flat type tile roof, shown flat during manufacture of the top cap flashing in a 14.25 inch width, before the top cap flashing 120 is shaped for installation in the roofing system. Apertures A 3 and A 4 are provided in generally rectangular strips of about 10.8 inches long, longitudinally spaced apart by solid strengthening portions 150 of about 1.2 inches long, longitudinally (see FIGS. 15 and 16 for this detail). Also, it has been found it convenient to provide apertures A 3 and A 4 spaced at about 0.25 inch centers vertically and at about 0.20 inch centers longitudinally (see FIG. 15 for this detail). Drain holes 152 are provided, about 0.1875 inches in diameter and spaced inward from tip T about 0.75 inches and spaced longitudinally apart about 2 inches or so (see FIG. 14 for these details).
[0044] Returning now to FIGS. 2 and 4, a series of steps in an exemplary method for installing a ridge vent system for flat type tile roofs is shown. A first step in a method of installation of a ridge vent in a flat tile roof system is shown in FIG. 2, wherein the roof decks 42 and 44 are is cut back to provide an air flow space, optionally, but not necessarily U-shaped, defined by edge wall portions 154 , and providing space between roof decks 42 or 44 and the center beam 38 . Next, a second step involves covering the roof decking 44 with felt 102 prior to tile installation. Next, a third step in a method of installation of the ridge vent in a flat tile roof system, involves installing (a) the sub-flashing 84 is installed, and (b) securing the sub-flashing by use of a top batten 92 which is nailed over the subflashing 84 , to hold the sub-flashing 84 in place over deck 44 . It is easily understood that the first sub-flashing 80 and first batten 90 are similarly installed, either before or after installation of the second sub-flashing and the second batten. Now, a fourth step in a method of installation of a ridge vent in a flat tile roof, includes centering the top cap 120 and fastening it to the ridge beam 40 . the top cap flashing 120 is preferably fastened to the ridge beam 40 using a #6 or better galvanized roofing nails N spaced 12 inch on center. Further, as best seen in FIG. 5, a bead of caulking S is used to seal between the bottom 156 of first wing 134 and tile 100 1 , and between the bottom 158 of second wing 136 and tile 100 3 .
[0045] In FIG. 4, a fifth step in a method of installation of a ridge vent in a flat type tile roof is shown, wherein the “ridge cap” tiles 130 are centered over the top cap flashing 120 , and sealed together per the tile manufacturer's specifications.
[0046] To understand the functionality, it should be recognized that air escapes outward (or inward, as the case may be) between the ridge tiles 130 and the top cap flashing 120 . More specifically, between adjacent ridge tiles 130 , a slight triangular shaped gap is created between bottom edges 160 and 162 . and the upper surface 164 o the top cap flashing 120 therebelow. In FIGS. 1 and 6, the gap is indicated by the area between bottom edges 160 and 162 and the broken line of position 170 therebelow. In other words, from the line of position indicated in broken lines, to the bottom edges 160 and 164 of the ridge tiles 130 directly thereabove, a gap exists through which an adequate amount of ventilation air can escape, as indicated by arrows V in FIG. 1 and FIG. 6. Of course, as shown in FIG. 1, a first laid ridge tile 1 30 , may be provided flat against top cap flashing 120 , or, alternately, a suitable height block may be provided to allow ventilation to occur.
[0047] Attention is now directed to FIGS. 7 through 10, where the installation of an exemplary ridge vent in two types of S-tile or “undulating” tile roof is shown. First, in FIGS. 7 and 8, the installation of tile in a low profile type undulating roof is shown. Roof rafters 230 and 232 have ridge ends 234 and 236 ending at a center beam 238 . Above the center beam 238 is mounted a longitudinally running ridge beam 240 which extends across the roof system. First 242 and second 244 roof decking is affixed above the upper sides 246 and 248 of the respective rafters 230 and 232 . Between the upper end 250 of first roof deck 242 and first side 254 of the ridge beam 240 , an air gap G 3 is provided to allow air to flow upward or downward in the direction of reference arrow 260 . Between the upper end 264 of second roof deck 244 and the second side 266 of ridge beam 240 , an air gap G 4 is provided to allow air to flow upward or downward in the direction of reference arrow 270 .
[0048] A first longitudinally extending sub-flashing 280 , preferably but not necessarily in a general S-shape, and having a plurality of ventilation apertures A 5 therein is provided to span gap G 3 . A second longitudinally extending subflashing 280 , preferably but not necessarily in a general S-shape, and having a plurality of apertures A 6 therein is provided to span gap G 4 . A first top batten 290 is provided to affix first sub-flashing 280 to the first roof deck 242 . A second top batten 292 is provided to affix the second sub-flashing 282 to the second roof deck 244 . Each of first and second top battens 290 and 292 may be secured to first and second roof decks 242 and 244 , respectively, by nails or other suitable fasteners N (not shown). Also, a water proof roof felting 296 is provided above first roof deck 242 . A similar waterproof roof felting 202 is provided above decking 244 . Low profile type roof tiles 200 are shown affixed on the roof.
[0049] A top cap flashing 220 is mounted over the top 222 of ridge beam 230 . The top cap flashing 220 is longitudinally extending to support a plurality of ridge cap tiles 290 , as clearly shown in FIGS. 7 and 8. In the embodiment shown in FIGS. 7 and 8, the top cap flashing 220 has a relatively flat, outwardly spreading center section 232 with a slight downward U-shape, and a pair of opposing first and second outward wing portions 234 and 236 , each of which may be bounded at the outer tip T thereof by a an upwardly directed flange portion F. Placement of overlapping ridge cap tiles 290 , and resultant generally triangular air gap below the outer edges 292 and 294 thereof, is generally as just described above with respect to the flat tile type of ridge cap.
[0050] In FIGS. 17 through 22, I have provided a set of exemplary detailed dimensions for one embodiment of a ridge vent system as applied to undulating tile type roofs. For example, sub-flashing 280 and 284 can be provided in about a 8.5 inch width, when measured flat, before forming into an “S” shape for installation, and in standard lengths of 48 inches (see FIG. 17 for this detail). Also, it is convenient to provide apertures A 6 and A 7 spaced at about 0.25 inch centers laterally and at about 0.20 inch centers longitudinally (see FIG. 19 for this detail). Also, for strength of sub-flashing 280 and 284 , it is useful, but not necessary, to provide apertures A 6 and A 7 in rectangular strips of about 10.8 inches long, and slightly over one inch wide, with about 1.2 inch strips of solid metal provided longitudinally between rectangular strips of apertures, and with the first aperture spaced about 1.1 inches from the edge E (see FIG. 18 for this detail).
[0051] Attention is now directed to FIG. 20, where the top cap 220 is shown. In this figure, a top plan view of a 48 inch long section of top cap flashing 220 for an S-tile type roof is provided, shown flat during manufacture of the top cap flashing in a 15.5 inch width, before the top cap flashing 220 is shaped into generally recognized W-shape for installation in a roofing system. Apertures A 7 and A 8 are provided in generally rectangular strips of about 10.8 inches long, longitudinally spaced apart by solid strengthening portions 250 of about 1.2 inches long (see FIGS. 21 and 22 for this detail). Also, I have found it convenient to provide apertures A 7 and A 8 spaced at about 0.25 inch centers laterally and at about 0.20 inch centers longitudinally (see FIG. 22 for this detail). Drain holes 252 are provided, about 0.1875 inches in diameter and spaced inward from tip T about 0.75 inches and spaced longitudinally apart about 2 inches or so (see FIG. 20 for these details).
[0052] A method of installing a ridge vent system for an S-tile (undulating) type tile roof system can be easily understood in view of the previously provided method for installing an exemplary roof vent system for a flat tile roof. A first step in a method of installation of an exemplary ridge vent in an S-tile roof system is shown, wherein the roof deck 244 is cut back from the center beam 238 and the ridge beam 240 in the roof, to provide an aperture defined by edge wall 299 . A second step in a method of installation of a ridge vent in an S-type tile roof system is to cover roof decking 244 with a conventional roofing felt 296 prior to installation of the tiles 200 . Next, a third step in a method of installation of a ridge vent in an S-tile roof system, involves (a) installing the sub-flashing 284 , and (b) installing a top batten 292 by nailing it over the sub-flashing 284 , to hold the subflashing 284 in place. Although the second sub-flashing and second batten installation procedure is discussed, it is easily understood that the first subflashing 280 and first batten 290 are similarly installed, either before or after installation of the second sub-flashing and the second batten. Now, a fourth step in a method of installation of a ridge vent in an S-tile roof, involves centering the top cap 220 and fastening it to the ridge beam 240 ; this is preferably accomplished using a #6 or better galvanized roofing nails N spaced 12 inch on center. Finally, a fifth step in an exemplary method of installation of a ridge vent in a tile roof system is to install the “ridge cap” tiles 290 , centered over the top cap 220 flashing, and sealing the ridge cap tiles per the tile manufacturer's specifications.
[0053] In FIGS. 9 and 10, yet another embodiment of a ridge vent for tile roofs is illustrated, wherein the top cap flashing 320 includes a slight downwardly U-shaped center section 322 . This top cap flashing section 320 is provided with apertures A 9 and A 10 each of which are defined by edge portions, preferably as illustrated in FIG. 3 with respect to apertures A 1 . Wing portions 334 and 336 are similar to portion 234 and 236 previously described. Otherwise, the parts are structurally and functionally the same as previously identified with respect to the discussion of FIGS. 7 and 8, and thus the parts are identified accordingly.
[0054] In the various sub-flashing and top cap flashing designs, apertures are provided for passage of air therethrough. It is also a desirable function of such apertures, whether A 1 , A 2 , A 3 , A 4 , A 4 , A 6 , A 7 , or A 8 to resist the passage of water therethrough. Consequently, note that an exemplary design applicable to any of the just mentioned apertures is set forth in FIG. 3. Rather than the provision of a mere punched hole, in one embodiment it has been found desirable to provide the apertures in an outwardly directed “volcano” or “cheese grater” shape, wherein water that is wind blown from the outside does not funnel toward passage through the aperture. In contrast, water would have to hit the aperture opening itself, since sloping sidewalls 400 provide for a narrow throat 402 that ends at the interior periphery (circumference 404 as shown in FIG. 3) of the preferably annular face portion 406 . Thus, the “volcano” shaped vent apertures protrude, in the outward direction (against ingress of water) for a preselected height H, as shown in FIG. 3, which height H may vary depending upon the desired ventilation and water intrusion results to be achieved.
[0055] Although the various embodiments of an exemplary ridge vent design have been described herein in detail, it is important to note that such ridge vents have been tested according to the Metro Dade County Florida Number PA100(A)-95 Test Procedure for Wind and Wind Driven Rain Resistance, and the designs described herein passed such testing. In particular, the test results indicated that there was no lift of movement of any tile or ridge vent components during the test. Also, the amount of water which entered through the vent opening during the test was well below the regulatory limits. In one test, 830,720 ml of water was delivered to an 8 foot by 6 foot test roofing area during 50 minutes of testing. In that test, the maximum amount of water infiltration allowable, per the test procedure, was 0.05% of the water delivered to the test area. Given the delivered quantity of water, a maximum of 415 ml was the regulatory limit established for the test. However, the novel ridge vent system disclosed and claimed herein was able to limit water passage to a total of only 194 ml; in other words only 0.023% of the water which was applied to the roof deck tested actually passed through the ridge vent system.
[0056] In another test, where the ridge vent system was tested on a High Profile Spanish “S” Tile type roof, a total of 830,720 ml of water was delivered to an 8 foot by 6 foot test area during 50 minutes of testing. Again, the maximum amount of water infiltration per the test procedure was 0.05% of the water delivered to the test area, or, given the delivered quantity of water, a maximum of 415 ml of leakage was permissible during the test. However, the test, as conducted by outside engineering experts, determined that only 1 ml of water (0.0001%) of the water applied to the test deck entered the vent-opening throughout the test. It is interesting that a portion of the two tests involved simulated rainfall of 8.8 inches per hour during wind velocity tests of 35 mph, 70 mph, 90 mph, and 110 mph. Moreover, during the tests, there was no lift or movement of tile or vent components. These results were totally unexpected by the test facility. Thus, the performance of the ridge vent design set forth herein represents an important advance in the state of the art of ridge vents for tile roofs.
[0057] It is to be appreciated that the novel ridge vent system provided by way of the present invention is a significant improvement in the state of the art of ridge type roof vents for tile roofs. The vent is lightweight, being normally manufactured of lightweight metal or other structurally strong material, and is capable of being easily packaged and shipped.
[0058] Importantly, the ridge vent for tile roofs allows installation of a ridge vent system even in locales where it has heretofore been impossible to do so and comply with building code requirements, since the ridge vent system is fully capable of passing the most stringent regulatory tests for wind and wind driven rain resistance.
[0059] Although only a few exemplary embodiments and aspects of this invention have been described in detail, various details are sufficiently set forth in the drawing and in the specification provided herein to enable one of ordinary skill in the art to make and use such exemplary embodiments and aspects, which need not be further described by additional writing in this detailed description. Importantly, the designs described and claimed herein may be modified from those embodiments provided without materially departing from the novel teachings and advantages provided by this invention, and may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the embodiments presented herein are to be considered in all respects as illustrative and not restrictive. As such, this disclosure is intended to cover the structures described herein and not only structural equivalents thereof, but also equivalent structures. 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. Thus having described some embodiments of the invention, though not exhaustive of all possible equivalents, what is desired to be secured by letters patent is claimed below. Therefore, the scope of the invention, as set forth in the appended claims, and as indicated by the drawing and by the foregoing description, is intended to include variations from the embodiments provided which are nevertheless described by the broad interpretation and range properly afforded to the plain meaning of the claims set forth below.
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A ridge vent for tile roofs. The vent includes first and second sub-flashing portions for spanning air gaps provided between the upper reaches of a roof deck and below a centrally located ridge beam. A plurality of ventilation apertures are provided in each of the sub-flashing portions. A top cap flashing is provided for attachment above the ridge beam. Included in the top cap flashing are a plurality of ventilation apertures defined by edge wall portions. A tile roof is provided, of the flat, low profile undulating, or of the S-tile (undulating) type. Tiles are provided in rows up to the edge of the sub-flashing. The gap between the top of the tiles and the bottom of the top cap flashing is preferably provided with a weathertight seal. Ridge cap tiles are provided in conventional stacked fashion running along above the top cap flashing. As a result, a generally triangular ventilation gap is provided along and below the lateral edges of the ridge cap tile, which allows air to enter and leave the attic space below the tile roof, while providing high resistance to wind blown water.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/764,111 filed Jun. 15, 2007 entitled Embolization Device Constructed From Expansile Polymer, which claims the benefit of U.S. Provisional Patent Application No. 60/814,309 filed on Jun. 15, 2006 entitled HESII: Embolization Device Constructed From Expansile Polymer, both of which are hereby incorporated herein in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to devices for the occlusion of body cavities, such as the embolization of vascular aneurysms and the like, and methods for making and using such devices.
BACKGROUND OF THE INVENTION
[0003] The occlusion of body cavities, blood vessels, and other lumina by embolization is desired in a number of clinical situations. For example, the occlusion of fallopian tubes for the purposes of sterilization, and the occlusive repair of cardiac defects, such as a patent foramen ovale, patent ductus arteriosis, and left atrial appendage, and atrial septal defects. The function of an occlusion device in such situations is to substantially block or inhibit the flow of bodily fluids into or through the cavity, lumen, vessel, space, or defect for the therapeutic benefit of the patient.
[0004] The embolization of blood vessels is also desired in a number of clinical situations. For example, vascular embolization has been used to control vascular bleeding, to occlude the blood supply to tumors, and to occlude vascular aneurysms, particularly intracranial aneurysms. In recent years, vascular embolization for the treatment of aneurysms has received much attention. Several different treatment modalities have been shown in the prior art. One approach that has shown promise is the use of thrombogenic microcoils. These microcoils may be made of biocompatible metal alloy(s) (typically a radio-opaque material such as platinum or tungsten) or a suitable polymer. Examples of microcoils are disclosed in the following patents: U.S. Pat. No. 4,994,069—Ritchart et al.; U.S. Pat. No. 5,133,731—Butler et al.; U.S. Pat. No. 5,226,911—Chee et al.; U.S. Pat. No. 5,312,415—Palermo; U.S. Pat. No. 5,382,259—Phelps et al.; U.S. Pat. No. 5,382,260—Dormandy, Jr. et al.; U.S. Pat. No. 5,476,472—Dormandy, Jr. et al.; U.S. Pat. No. 5,578,074—Mirigian; U.S. Pat. No. 5,582,619—Ken; U.S. Pat. No. 5,624,461—Mariant; U.S. Pat. No. 5,645,558—Horton; U.S. Pat. No. 5,658,308—Snyder; and U.S. Pat. No. 5,718,711—Berenstein et al; all of which are hereby incorporated by reference.
[0005] A specific type of microcoil that has achieved a measure of success is the Guglielmi Detachable Coil (“GDC”), described in U.S. Pat. No. 5,122,136—Guglielmi et al. The GDC employs a platinum wire coil fixed to a stainless steel delivery wire by a solder connection. After the coil is placed inside an aneurysm, an electrical current is applied to the delivery wire, which electrolytically disintegrates the solder junction, thereby detaching the coil from the delivery wire. The application of current also creates a positive electrical charge on the coil, which attracts negatively-charged blood cells, platelets, and fibrinogen, thereby increasing the thrombogenicity of the coil. Several coils of different diameters and lengths can be packed into an aneurysm until the aneurysm is completely filled. The coils thus create and hold a thrombus within the aneurysm, inhibiting its displacement and its fragmentation.
[0006] A more recent development in the field of microcoil vaso-occlusive devices is exemplified in U.S. Pat. No. 6,299,619 to Greene, Jr. et al., U.S. Pat. No. 6,602,261 to Greene, Jr. et al., and co-pending U.S. patent application Ser. No. 10/631,981 to Martinez; all assigned to the assignee of the subject invention and incorporated herein by reference. These patents disclose vaso-occlusive devices comprising a microcoil with one or more expansile elements disposed on the outer surface of the coil. The expansile elements may be formed of any of a number of expansile polymeric hydrogels, or alternatively, environmentally-sensitive polymers that expand in response to a change in an environmental parameter (e.g., temperature or pH) when exposed to a physiological environment, such as the blood stream.
[0007] This invention is a novel vaso-occlusive device, a novel expansile element, and a combination thereof.
SUMMARY OF THE INVENTION
[0008] The present invention is directed to novel vaso-occlusive devices comprising a carrier member, novel expansile elements, and a combination thereof. Generally, the expansile element comprises an expansile polymer. The carrier member may be used to assist the delivery of the expansile element by providing a structure that, in some embodiments, allows coupling to a delivery mechanism and, in some embodiments, enhances the radiopacity of the device.
[0009] In one embodiment, the expansile polymer is an environmentally sensitive polymeric hydrogel, such as that described in U.S. Pat. No. 6,878,384, issued Apr. 12, 2005 to Cruise et al., hereby incorporated by reference. In another embodiment, the expansile polymer is a novel hydrogel comprised of sodium acrylate and a poly(ethylene glycol) derivative. In another embodiment, the expansile polymer is a hydrogel comprising a Pluronics® derivative.
[0010] In one embodiment, the expansile polymer is a novel hydrogel that has ionizable functional groups and is made from macromers. The hydrogel may be environmentally-responsive and have an unexpanded bending resistance of from about 0.1 milligrams to about 85 milligrams. The macromers may be non-ionic and/or ethylenically unsaturated.
[0011] In another embodiment, the macromers may have a molecular weight of about 400 to about 35,000, more preferably about 5,000 to about 15,000, even more preferably about 8,500 to about 12,000. In another embodiment, the hydrogel may be made of polyethers, polyurethanes, derivatives thereof, or combinations thereof. In another embodiment, the ionizable functional groups may comprise basic groups (e.g., amines, derivatives thereof, or combinations thereof) or acidic groups (e.g., carboxylic acids, derivatives thereof, or combinations thereof). If the ionizable functional groups comprise basic groups, the basic groups may be deprotonated at pHs greater than the pKa or protonated at pHs less than the pKa of the basic groups. If the ionizable functional groups comprise acidic groups, the acidic groups may be protonated at pHs less than the pKa or de-protonated at pHs greater than the pKa of the acidic groups.
[0012] In another embodiment, the macromers may comprise vinyl, acrylate, acrylamide, or methacrylate derivatives of poly(ethylene glycol), or combinations thereof. In another embodiment, the macromer may comprise poly(ethylene glycol) di-acrylamide. In another embodiment, the hydrogel is substantially free, more preferably free of unbound acrylamide.
[0013] In another embodiment, the macromers may be cross-linked with a compound that contains at least two ethylenically unsaturated moities. Examples of ethylenically unsaturated compounds include N, N′-methylenebisacrylamide, derivatives thereof, or combinations thereof. In another embodiment, the hydrogel may be prepared using a polymerization initiator. Examples of suitable polymerization initiators comprise N,N,N′,N′-tetramethylethylenediamine, ammonium persulfate, azobisisobutyronitrile, benzoyl peroxides, derivatives thereof, or combinations thereof. The polymerization initiator may be soluble in aqueous or organic solvents. For example, azobisisobutyronitrile is not water soluble; however, water soluble derivatives of azobisisobutyronitrile, such as 2,2′-azobis(2-methylproprionamidine) dihydrochloride, are available. In another embodiment, the hydrogel may be substantially non-resorbable, non-degradable or both, at physiological conditions.
[0014] In another embodiment, the invention comprises a method for preparing an environmentally-responsive hydrogel for implantation in an animal. The method includes combining at least one, preferably non-ionic, macromer with at least one ethylenically unsaturated moiety, at least one macromer or monomer having at least one ionizable functional group and at least one ethylenically unsaturated moiety, at least one polymerization initiator, and at least one solvent to form a hydrogel. The solvent may include aqueous or organic solvents, or combinations thereof. In another embodiment, the solvent is water. Next, the hydrogel may be treated to prepare an environmentally-responsive hydrogel, preferably one that is responsive at physiological conditions. The ionizable functional group(s) may be an acidic group (e.g., a carboxylic acid, a derivative thereof, or combinations thereof) or a basic group (e.g., an amine, derivatives thereof, or combinations thereof). If the ionizable functional group comprises an acidic group, the treating step may comprise incubating the hydrogel in an acidic environment to protonate the acidic groups. If the ionizable functional group comprises a basic group, the treating step may comprise incubating the hydrogel in a basic environment to de-protonate the basic groups. In certain embodiments, it is preferable that the acidic groups are capable of being de-protonated or, conversely, the basic groups are capable of being protonated, after implantation in an animal.
[0015] In another embodiment, the ethylenically unsaturated macromer may have a vinyl, acrylate, methacrylate, or acrylamide group; including derivatives thereof or combinations thereof. In another embodiment, the ethylenically unsaturated macromer is based upon poly(ethylene glycol), derivatives thereof, or combinations thereof. In another embodiment, the ethylenically unsaturated macromer is poly(ethylene glycol) di-acrylamide, poly(ethylene glycol) di-acrylate, poly(ethylene glycol) di-methacrylate, derivatives thereof, or combinations thereof. In another embodiment, the ethylenically unsaturated macromer is poly(ethylene glycol) di-acrylamide. The ethylenically unsaturated macromer may be used at a concentration of about 5% to about 40% by weight, more preferably about 20% to about 30% by weight. The solvent may be used at a concentration of about 20% to about 80% by weight.
[0016] In another embodiment, the combining step also includes adding at least one cross-linking agent comprising an ethylenically unsaturated compound. In certain embodiments of the present invention, a cross-linker may not be necessary. In other words, the hydrogel may be prepared using a macromer with a plurality of ethylenically unsaturated moieties. In another embodiment, the polymerization initiator may be a reduction-oxidation polymerization initiator. In another embodiment, the polymerization initiator may be N,N,N′,N′-tetramethylethylenediamine, ammonium persulfate, azobisisobutyronitrile, benzoyl peroxides, 2,2′-azobis(2-methylproprionamidine) dihydrochloride, derivatives thereof, or combinations thereof. In another embodiment, the combining step further includes adding a porosigen.
[0017] In another embodiment, the ethylenically unsaturated macromer includes poly(ethylene glycol) di-acrylamide, the macromer or monomer or polymer with at least one ionizable group and at least one ethylenically unsaturated group includes sodium acrylate, the polymerization initiator includes ammonium persulfate and N,N,N,′,N′ tetramethylethylenediamine, and the solvent includes water.
[0018] In another embodiment, the ethylenically unsaturated macromer has a molecular weight of about 400 to about 35,000 grams/mole, more preferably about 2,000 to about 25,000 grams/mole, even more preferably about 5,000 to about 15,000 grams/mole, even more preferably about 8,000 to about 12,500 grams/mole, and even more preferably about 8,500 to about 12,000 grams/mole. In another embodiment, the environmentally-responsive hydrogel is substantially non-resorbable, or non-degradable or both at physiological conditions. In certain embodiments, the environmentally-responsive hydrogel may be substantially free or completely free of unbound acrylamide.
[0019] In one embodiment, the carrier member comprises a coil or microcoil made from metal, plastic, or similar materials. In another embodiment, the carrier member comprises a braid or knit made from metal, plastic, or similar materials. In another embodiment, the carrier member comprises a plastic or metal tube with multiple cuts or grooves cut into the tube.
[0020] In one embodiment, the expansile element is arranged generally co-axially within the carrier member. In another embodiment, a stretch resistant member is arranged parallel to the expansile element. In another embodiment, the stretch resistant member is wrapped, tied, or twisted around the expansile element. In another embodiment, the stretch resistant member is positioned within the expansile element.
[0021] In one embodiment, the device comprising the expansile element and carrier member are detachably coupled to a delivery system. In another embodiment, the device is configured for delivery by pushing or injecting through a conduit into a body.
[0022] In one embodiment, the expansile element is environmentally sensitive and exhibits delayed expansion when exposed to bodily fluids. In another embodiment, the expansile element expands quickly upon contact with a bodily fluid. In another embodiment, the expansile element comprises a porous or reticulated structure that may form a surface or scaffold for cellular growth.
[0023] In one embodiment, the expansile element expands to a dimension that is larger than the diameter of the carrier member in order to provide enhanced filling of the lesion. In another embodiment, the expansile element expands to a dimension equal to or smaller than the diameter of the carrier member to provide a scaffold for cellular growth, release of therapeutic agents such as pharmaceuticals, proteins, genes, biologic compounds such as fibrin, or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective view showing one embodiment of the present invention prior to expansion of the expansile element;
[0025] FIG. 2 is a perspective view showing a device similar to FIG. 1 in an expanded state;
[0026] FIG. 3 is a perspective view of an alternative embodiment of the present invention;
[0027] FIG. 4 is a perspective view of an alternative embodiment wherein the carrier member comprises a fenestrated tube, braid or knit;
[0028] FIG. 5 is a perspective view of an alternative embodiment incorporating a stretch resistant member running approximately parallel to the expansile element;
[0029] FIG. 6 is a perspective view of an alternative embodiment incorporating a stretch resistant member approximately intertwined with the expansile element;
[0030] FIG. 7 is a perspective view of an alternative embodiment wherein the expansile element has formed a loop or fold outside the carrier member.
[0031] FIG. 8 is a perspective view of an alternative embodiment showing a device similar to those shown in FIG. 1 and FIG. 2 wherein the expansile element is not expanded to a diameter larger than the carrier member.
DESCRIPTION OF THE INVENTION
[0032] As used herein, the term “macromer” refers to a large molecule containing at least one active polymerization site or binding site. Macromers have a larger molecular weight than monomers. For example, an acrylamide monomer has a molecular weight of about 71.08 grams/mole whereas a poly(ethylene glycol) di-acrylamide macromer may have a molecular weight of about 400 grams/mole or greater. Preferred macromers are non-ionic, i.e. they are uncharged at all pHs.
[0033] As used herein, the term “environmentally responsive” refers to a material (e.g., a hydrogel) that is sensitive to changes in environment including but not limited to pH, temperature, and pressure. Many of the expansile materials suitable for use in the present invention are environmentally responsive at physiological conditions.
[0034] As used herein, the term “non-resorbable” refers to a material (e.g., a hydrogel) that cannot be readily and/or substantially degraded and/or absorbed by bodily tissues.
[0035] As used herein, the term “unexpanded” refers to the state at which a hydrogel is substantially not hydrated and, therefore, not expanded.
[0036] As used herein, the term “ethylenically unsaturated” refers to a chemical entity (e.g., a macromer, monomer or polymer) containing at least one carbon-carbon double bond.
[0037] As used herein, the term “bending resistance” refers to the resistance exhibited by a sample (e.g., an unexpanded hydrogel) as it steadily and evenly is moved across a resistance-providing arm or vane. The maximum displacement of the resistance-providing arm or vane is measured at the point the sample bends and releases the resistance-providing arm or vane. That maximum displacement is converted to bending “resistance” or “stiffness” using conversions appropriate to the machine, its calibration, and the amount of resistance (e.g., weight), if any, associated with the resistance-providing arm or vane. Herein, the units of measure for bending resistance will be milligrams (mg) and essentially is the amount of force required to bend the sample.
[0038] Referring to FIG. 1-8 , the invention is a device comprising an expansile element 1 and a carrier member 2 . The expansile element 1 may be made from a variety of suitable biocompatible polymers. In one embodiment, the expansile element 1 is made of a bioabsorbable or biodegradable polymer, such as those described in U.S. Pat. Nos. 7,070,607 and 6,684,884, the disclosures of which are incorporated herein by reference. In another embodiment, the expansile element 1 is made of a soft conformal material, and more preferably of an expansile material such as a hydrogel.
[0039] In one embodiment, the material forming the expansile element 1 is an environmentally responsive hydrogel, such as that described in U.S. Pat. No. 6,878,384, the disclosure of which is incorporated herein by reference. Specifically, the hydrogels described in U.S. Pat. No. 6,878,384 are of a type that undergoes controlled volumetric expansion in response to changes in such environmental parameters as pH or temperature. These hydrogels are prepared by forming a liquid mixture that contains (a) at least one monomer and/or polymer, at least a portion of which is sensitive to changes in an environmental parameter; (b) a cross-linking agent; and (c) a polymerization initiator. If desired, a porosigen (e.g., NaCl, ice crystals, or sucrose) may be added to the mixture, and then removed from the resultant solid hydrogel to provide a hydrogel with sufficient porosity to permit cellular ingrowth. The controlled rate of expansion is provided through the incorporation of ethylenically unsaturated monomers with ionizable functional groups (e.g., amines, carboxylic acids). For example, if acrylic acid is incorporated into the crosslinked network, the hydrogel is incubated in a low pH solution to protonate the carboxylic acid groups. After the excess low pH solution is rinsed away and the hydrogel dried, the hydrogel can be introduced through a microcatheter filled with saline at physiological pH or with blood. The hydrogel cannot expand until the carboxylic acid groups deprotonate. Conversely, if an amine-containing monomer is incorporated into the crosslinked network, the hydrogel is incubated in a high pH solution to deprotonate amines. After the excess high pH solution is rinsed away and the hydrogel dried, the hydrogel can be introduced through a microcatheter filled with saline at physiological pH or with blood. The hydrogel cannot expand until the amine groups protonate.
[0040] In another embodiment, the material forming the expansile element 1 is may be an environmentally responsive hydrogel, similar to those described in U.S. Pat. No. 6,878,384; however, an ethylenically unsaturated, and preferably non-ionic, macromer replaces or augments at least one monomer or polymer. The Applicants surprisingly have discovered that hydrogels prepared in accordance with this embodiment can be softer and/or more flexible in their unexpanded state than those prepared in accordance with U.S. Pat. No. 6,878,384. Indeed, hydrogels prepared in accordance with this embodiment may have an unexpanded bending resistance of from about 0.1 mg to about 85 mg, about 0.1 mg to about 50 mg, about 0.1 mg to about 25 mg, about 0.5 mg to about 10 mg, or about 0.5 mg to about 5 mg. The Applicants also have discovered that ethylenically unsaturated and non-ionic macromers (e.g., poly(ethylene glycol) and derivatives thereof) may be used not only to prepare a softer unexpanded hydrogel; but, in combination with monomers or polymers containing ionizable groups, one that also may be treated to be made environmentally responsive. The surprising increase in unexpanded flexibility enables the hydrogels to be, for example, more easily deployed in an animal or deployed with reduced or no damage to bodily tissues, conduits, cavities, etceteras.
[0041] The hydrogels prepared from non-ionic macromers in combination with monomers or polymers with ionizable functional groups still are capable of undergoing controlled volumetric expansion in response to changes in environmental parameters. These hydrogels may be prepared by combining in the presence of a solvent: (a) at least one, preferably non-ionic, macromer with a plurality of ethylenically unsaturated moieties; (b) a macromer or polymer or monomer having at least one ionizable functional group and at least one ethylenically unsaturated moiety; and (c) a polymerization initiator. It is worthwhile to note that with this type of hydrogel, a cross-linking agent may not be necessary for cross-linking since, in certain embodiments, the components selected may be sufficient to form the hydrogel. As hereinbefore described, a porosigen may be added to the mixture and then removed from the resultant hydrogel to provide a hydrogel with sufficient porosity to permit cellular ingrowth.
[0042] The non-ionic macromer-containing hydrogels' controlled rate of expansion may be provided through the incorporation of at least one macromer or polymer or monomer having at least one ionizable functional group (e.g., amine, carboxylic acid). As discussed above, if the functional group is an acid, the hydrogel is incubated in a low pH solution to protonate the group. After the excess low pH solution is rinsed away and the hydrogel dried, the hydrogel can be introduced through a microcatheter, preferably filled with saline. The hydrogel cannot expand until the acid group(s) deprotonates. Conversely, if the functional group is an amine, the hydrogel is incubated in a high pH solution to deprotonate the group. After the excess high pH solution is rinsed away and the hydrogel dried, the hydrogel can be introduced through a microcatheter, preferably filled with saline. The hydrogel cannot expand until the amine(s) protonates.
[0043] More specifically, in one embodiment, the hydrogel is prepared by combining at least one non-ionic macromer having at least one unsaturated moiety, at least one macromer or monomer or polymer having at least one ionizable functional group and at least one ethylenically unsaturated moiety, at least one polymerization initiator, and a solvent. Optionally, an ethylenically unsaturated crosslinking agent and/or a porosigen also may be incorporated. Preferred concentrations of the non-ionic macromers in the solvent range from about 5% to about 40% (w/w), more preferably about 20% to about 30% (w/w). A preferred non-ionic macromer is poly(ethylene glycol), its derivatives, and combinations thereof. Derivatives include, but are not limited to, poly(ethylene glycol) di-acrylamide, poly(ethylene glycol) di-acrylate, and poly(ethylene glycol) dimethacrylate. Poly(ethylene glycol) di-acrylamide is a preferred derivative of poly(ethylene glycol) and has a molecular weight ranging from about 8,500 to about 12,000. The macromer may have less than 20 polymerization sites, more preferably less than 10 polymerization sites, more preferably about five or less polymerization sites, and more preferably from about two to about four polymerization sites. Poly(ethylene glycol) di-acrylamide has two polymerization sites.
[0044] Preferred macromers or polymers or monomers having at least one ionizable functional group include, but are not limited to compounds having carboxylic acid or amino moieties or, derivatives thereof, or combinations thereof. Sodium acrylate is a preferred ionizable functional group-containing compound and has a molecular weight of 94.04 g/mole. Preferred concentrations of the ionizable macromers or polymers or monomers in the solvent range from about 5% to about 40% (w/w), more preferably about 20% to about 30% (w/w). At least a portion, preferably about 10%-50%, and more preferably about 10%-30%, of the ionizable macromers or polymers or monomers selected should be pH sensitive. It is preferred that no free acrylamide is used in the macromer-containing hydrogels of the present invention.
[0045] When used, the crosslinking agent may be any multifunctional ethylenically unsaturated compound, preferably N, N′-methylenebisacrylamide. If biodegradation of the hydrogel material is desired, a biodegradable crosslinking agent may be selected. The concentrations of the crosslinking agent in the solvent should be less than about 1% w/w, and preferably less than about 0.1% (w/w).
[0046] As described above, if a solvent is added, it may be selected based on the solubilities of the macromer(s) or monomer(s) or polymer(s), crosslinking agent, and/or porosigen used. If a liquid macromer or monomer or polymer solution is used, a solvent may not be necessary. A preferred solvent is water, but a variety of aqueous and organic solvents may be used. Preferred concentrations of the solvent range from about 20% to about 80% (w/w), more preferably about 50% to about 80% (w/w).
[0047] Crosslink density may be manipulated through changes in the macromer or monomer or polymer concentration, macromer molecular weight, solvent concentration and, when used, crosslinking agent concentration. As described above, the hydrogel may be crosslinked via reduction-oxidation, radiation, and/or heat. A preferred type of polymerization initiator is one that acts via reduction-oxidation. Suitable polymerization initiators include, but are not limited to, N,N,N′,N′-tetramethylethylenediamine, ammonium persulfate, azobisisobutyronitrile, benzoyl peroxides, 2,2′-azobis(2-methylpropionamidine) dihydrochloride, derivatives thereof, or combinations thereof. A combination of ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine is a preferred polymerization initiator for use in the macromer containing embodiments of the invention.
[0048] After polymerization is complete, the hydrogels of the present invention may be washed with water, alcohol or other suitable washing solution(s) to remove any porosigen(s), any unreacted, residual macromer(s), monomer(s), and polymer(s) and any unincorporated oligomers. Preferably this is accomplished by initially washing the hydrogel in distilled water.
[0049] The hydrogels of the present invention may be made environmentally-responsive by protonating or deprotonating the ionizable functional groups present on the hydrogel network, as discussed above. Once the hydrogel has been prepared and, if needed, washed, the hydrogel may be treated to make the hydrogel environmentally-responsive. For hydrogel networks where the ionizable functional groups are carboxylic acid groups, the hydrogel is incubated in a low pH solution. The free protons in the solution protonate the carboxylic acid groups on the hydrogel network. The duration and temperature of the incubation and the pH of the solution influence the amount of control on the expansion rate. In general, the duration and temperature of the incubation are directly proportional to the amount of expansion control, while the incubation solution pH is inversely proportional thereto.
[0050] It has been determined that incubation solution water content also affects expansion control. In this regard, higher water content enables greater hydrogel expansion and is thought to increase the number of protonation-accessible carboxylic acid groups. An optimization of water content and pH is required for maximum control on expansion rate. Expansion control, among other things, has an effect on device positioning/repositioning time. Typically, a positioning/repositioning time of about 0.1 to about 30 minutes is preferred for hydrogel devices in accordance with the present invention.
[0051] After incubation, the excess treating solution is washed away and the hydrogel material is dried. A hydrogel treated with the low pH solution has been observed to dry down to a smaller dimension than an untreated hydrogel. This effect is desirable since devices containing these hydrogels may be delivered through a microcatheter.
[0052] For hydrogel networks where the ionizable functional groups are amine groups, the hydrogel is incubated in a high pH solution. Unlike carboxylic acid functional groups, deprotonation occurs on the amine groups of the hydrogel network at high pH. Aside from incubation solution pH, the incubation is carried out similarly to that of the carboxylic acid containing hydrogels. In other words, the duration and temperature of the incubation and the pH of the solution are directly proportional to the amount of expansion control. After incubation is concluded, the excess treating solution is washed away and the hydrogel material is dried.
[0053] In a preferred embodiment, the expansile element 1 is an expansile hydrogel comprised of (a) at least one, preferably non-ionic, ethylenically unsaturated macromer or monomer or polymer having at least two crosslinkable groups; (b) at least one monomer and/or polymer which has at least one crosslinkable groups, and at least one moiety that is sensitive to changes in an environmental parameter; and (c) a polymerization initiator. In some embodiments, the monomers and polymers may be water soluble, while in other embodiments they may be non-water soluble. Suitable polymers for components (a) and (b) include poly(ethylene glycol), poly(ethylyene oxide), poly(vinyl alcohol), poly(propylene oxide), poly(propylene glycol), poly(ethylene oxide)-co-poly(propylene oxide), poly(vinyl pyrrolidinone), poly(amino acids), dextrans, poly(ethyloxazoline), polysaccharides, proteins, glycosaminoglycans, and carbohydrates, and derivatives thereof. The preferred polymer is poly(ethylene glycol) (PEG), especially for component (a). Alternatively, polymers that biodegrade partly or completely may be utilized.
[0054] One embodiment comprises combining in the presence of a solvent (a) about 5% to about 40% of a non-ionic, ethylenically unsaturated macromer or monomer or polymer; (b) about 5% to about 40% of an ethylenically unsaturated monomer or polymer with at least one ionizable functional group; and, (c) a polymerization initiator. Suitable ionizable, ethylenically unsaturated monomers include acrylic acid and methacrylic acid, as well as derivatives thereof. One suitable monomer having at least one ionizable functional group is sodium acrylate. Suitable macromers with two ethylenically unsaturated moities include poly(ethylene glycol) di-acrylate and poly(ethylene glycol) di-acrylamide, and poly(ethylene glycol) di-acrylamide, which have molecular weights ranging between 400 and 30,000 grams/mole. The use of macromers with a plurality of ethylenically unsaturated groups permits the elimination of the crosslinker, as the crosslinker functions are performed by the multi-functional polymer. In one embodiment, the hydrogel comprises, about 5% to about 40% sodium acrylate, about 5% to about 40% poly(ethylene glycol) di-acrylamide, and the remaining amount water.
[0055] A sodium acrylate/poly(ethylene glycol) di-acrylamide hydrogel is used to enhance the mechanical properties of the previously-described environmentally responsive hydrogel. Since a sodium acrylate/poly(ethylene glycol) di-acrylamide hydrogel is softer than a sodium acrylate/acrylamide hydrogel (e.g., the one utilized in Hydrogel Embolic System (HES) made by MicroVention, Aliso Viejo, Calif.), devices incorporating it may be more flexible. Due to the relative stiffness of the HES, MicroVention recommends pre-softening the device by soaking in warm fluid or steaming the implant. In addition, devices made from acrylamide are relatively straight before pre-softening because the stiffness of the acrylamide-based hydrogel prevents the carrier member (for the HES, a microcoil) from assuming its secondary configuration. Devices made from a sodium acrylate/poly(ethylene glycol) di-acrylamide hydrogel may not require pre-softening techniques such as soaking in warm fluid such as saline or blood or exposure to steam in order to form into a secondary configuration heat-set into the carrier member 2 or a similar carrier member. Thus, in embodiments comprising, for example, sodium acrylate and poly(ethylene glycol) di-acrylamide, a substantially continuous length of hydrogel disposed either within the lumen 3 of the carrier member 2 as shown in, for example, FIG. 1 or on a carrier element such as those shown in the Martinez '981 application or Greene '261, will form into the secondary configuration pre-formed into the carrier member without pre-treatment (e.g. exposure to steam, fluid, or blood). This makes the device easier to use because it allows elimination of the pre-treatment step and the device may be safer when deployed into the patient because a softer device is less likely to cause damage to the lesion.
Example
[0056] 3 g of acrylamide, 1.7 g of acrylic acid, 9 mg of bisacrylamide, 50 mg of N,N,N′,N′-tetramethylethylenediamine, 15 mg of ammonium persulfate, and 15.9 g water were combined and polymerized in a 0.020 inch tube. The tubularized polymer was removed from the tubing to prepare Hydrogel 1 in accordance with U.S. Pat. No. 6,878,384.
[0057] 4.6 g of poly(ethylene glycol) diacrylamide, 3.3 g of sodium acrylate, 100 mg of N,N,N′,N′-tetramethylethylenediamine, 25 mg of ammonium persulfate, and 15.9 g water were combined and polymerized in a 0.020 inch tube. The tubularized polymer was removed from the tubing to prepare Hydrogel 2, in accordance with a macromer-containing hydrogel embodiment of the present invention.
[0058] A hydrogel identical to Hydrogel 2 was prepared; however, it additionally was acid treated in accordance with the present invention to prepare Hydrogel 2-Acid.
[0059] A large platinum microcoil has a 0.014 inch outer diameter and a 0.0025 inch filar. A small platinum microcoil has a 0.010 inch outer diameter and a 0.002 inch filar.
[0060] The bending resistance of the unexpanded hydrogel samples and the bending resistance of the microcoils were obtained using a Gurley 4171 ET tubular sample stiffness tester with a 5-gram counterweight attached to its measuring vane. The sample length was 1 inch. The average measured resistance and standard deviation of five replicates each are summarized in the following table.
[0000]
MEASURED RESISTANCE,
SAMPLE
milligrams
Hydrogel 1
88 ± 13
Hydrogel 2
23 ± 1
Hydrogel 2-Acid
1 ± 0
Large Platinum Coil
5 ± 1
Small Platinum Coil
2 ± 1
[0061] The results show the large difference in relative stiffness between the first generation Hydrogel 1 (HES), the second generation macromer-containing Hydrogel 2, the second generation macromer-containing Hydrogel 2 that has been acid treated, and the microcoils. Hydrogel 1 is nearly 20 times stiffer than a large platinum microcoil whereas Hydrogel 2 is less than 5 times stiffer than a large platinum microcoil. The acid-treated Hydrogel 2 is less stiff than a large platinum microcoil and about as stiff as a small platinum microcoil. A skilled artisan will appreciate that much more flexible unexpanded macromer-containing hydrogels are provided by the methods and materials disclosed in the present invention. When used in a medical device, these hydrogels may result in a more flexible medical device as well.
[0062] In another embodiment, monomers are used to impart moieties to the expansile element 1 that are suitable for coupling bioactive compounds, for example anti-inflammatory agents such as corticosteroids (e.g. prednisone and dexamethasone); or vasodilators such as nitrous oxide or hydralazine; or anti-thrombotic agents such as aspirin and heparin; or other therapeutic compounds, proteins such as mussel adhesive proteins (MAPs), amino acids such as 3-(3,4-dihydroxyphenyl)-L-alanine (DOPA), genes, or cellular material; see U.S. Pat. No. 5,658,308, WO 99/65401 , Polymer Preprints 2001, 42(2), 147 Synthesis and Characterization of Self - Assembling Block Copolymers Containing Adhesive Moieties by Kui Hwang et. al., and WO 00/27445; the disclosures of which are hereby incorporated by reference. Examples of moieties for incorporation into hydrogel materials include, but are not limited to, hydroxyl groups, amines, and carboxylic acids.
[0063] In another embodiment, the expansile element 1 may be rendered radiopaque by incorporation of monomers and/or polymers containing, for example, iodine, or the incorporation of radiopaque metals such as tantalum and platinum.
[0064] In some embodiments, the carrier member 2 is a flexible, elongate structure. Suitable configurations for the carrier member 2 include helical coils, braids, and slotted or spiral-cut tubes. The carrier member 2 may be made of any suitable biocompatible metal or polymer such as platinum, tungsten, PET, PEEK, Teflon, Nitinol, Nylon, steel, and the like. The carrier member may be formed into a secondary configuration such as helix, box, sphere, flat rings, J-shape, S-shape or other complex shape known in the art. Examples of appropriate shapes are disclosed in Horton U.S. Pat. No. 5,766,219; Schaefer application. Ser. No. 10/043,947; and Wallace U.S. Pat. No. 6,860,893; all hereby incorporated by reference.
[0065] As previously described, some embodiments of the instant invention may comprise polymers that are sufficiently soft and flexible that a substantially continuous length of the expansile element 1 will form into a secondary configuration similar to the configuration originally set into the carrier member 2 without pre-softening the device or exposing it to blood, fluid, or steam.
[0066] In some embodiments, the carrier member 2 incorporates at least one gap 7 that is dimensioned to allow the expansile element 1 to expand through the gap (one embodiment of this configuration is shown in FIGS. 1-2 ). In other embodiments, the carrier member 2 incorporates at least one gap 7 that allows the expansile element 1 to be exposed to bodily fluids, but the expansile element 1 does not necessarily expand through the gap (one embodiment of this configuration is shown in FIG. 8 ). In other embodiments, no substantial gap is incorporated into the carrier member 2 . Rather, fluid is allowed to infiltrate through the ends of the device or is injected through a lumen within the delivery system and the expansile element 1 expands and forces its way through the carrier member 2 .
[0067] In one embodiment shown in FIG. 1 , the expansile element 1 comprises an acrylamide or poly(ethylene glycol)-based expansile hydrogel. The carrier member 2 comprises a coil. At least one gap 7 is formed in the carrier member 2 . The expansile element 1 is disposed within the lumen 3 defined by the carrier member 2 in a generally coaxial configuration. A tip 4 is formed at the distal end of the device 11 by, for example, a laser, solder, adhesive, or melting the hydrogel material itself. The expansile element 1 may run continuously from the proximal end to the distal end, or it may run for a portion of the device then terminate before reaching the distal or proximal end, or both.
[0068] As an example, in one embodiment the device is dimensioned to treat a cerebral aneurysm. Those skilled in the art will appreciate that the dimensions used in this example could be re-scaled to treat larger or smaller lesions. In this embodiment, the expansile element 1 is about 0.001″−0.030″ before expansion and about 0.002″−0.25″ after expansion. The expansile element is, for example, approximately 5%-30% sodium acrylate, 10%-30% poly(ethylene glycol) di-acrylamide with a molecular weight ranging between 400 and 30,000 grams/mole, and the remainder water. Those skilled in the art will appreciate that the ratio of expansion could be controlled by changing the relative amounts of sodium acrylate, PEG di-acrylamide, and water. The carrier member 2 in this embodiment is a microcoil in the range of about 0.005″-0.035″ in diameter. In an alternate embodiment, the microcoil diameter has a range of 0.008′-0.016′. The microcoil may have a filar in the range of 0.0005″-0.01″. In an alternate embodiment, the filar range is 0.00075″-0.004″. The implant 11 comprises at least one gap 7 ranging from 0.5 filars (0.00025″) long to 20 filars (0.2″) long. In an alternate embodiment, the gap range is between approximately 0.00025″ to 0.005″. In one preferred embodiment, the microcoil has a diameter of 0.012″ and a 0.002″ filar, with a gap 7 of 0.0013″. A coupler 13 is placed near the proximal end to allow the implant 11 to be detachably coupled to a delivery system or pushed or injected through a catheter. Examples of delivery systems are found in co-pending application Ser. No. 11/212,830 to Fitz, U.S. Pat. No. 6,425,893 to Guglielmi, U.S. Pat. No. 4,994,069 to Ritchart, U.S. Pat. No. 6,063,100 to Diaz, and U.S. Pat. No. 5,690,666 to Berenstein; the disclosures of which are hereby incorporated by reference.
[0069] In this embodiment, the implant 11 is constructed by formulating and mixing the hydrogel material as previously described in order to form the expansile element 1 . The carrier member 2 is wound around a helical or complex form, and then heat-set by techniques known in the art to form a secondary diameter ranging from 0.5 mm to 30 mm and a length ranging from 5 mm to 100 cm. After processing, washing, and optional acid treatment, the expansile element 1 is threaded through the lumen 3 of the carrier member 2 . The distal end of the expansile element 1 is then tied, for example by forming a knot, to the distal end of the carrier member 2 . Adhesive, such as UV curable adhesive or epoxy, may be used to further enhance the bond between the expansile element 1 and the carrier member 2 and to form the distal tip 4 . Alternatively, the tip may be formed by, for example, a laser weld or solder ball.
[0070] In some embodiments, depending on the size of the gap 7 and the ratio of expansion, loops or folds 12 may form as shown in FIG. 7 as the expansile element 1 expands. Although the loop or fold 12 may not affect the functionality of the device, in some embodiments it is desirable to prevent the loop or fold 12 from forming. This can be done by stretching the expansile element 1 either before placing it within the carrier member 2 or after the distal end of the expansile element 1 is secured to the carrier member 2 . For example, once the distal end of the expansile element 1 is secured to the carrier member 2 , the expansile element 1 is stretched to a final length between 101% to 1000% of its initial length (e.g. if the initial length is 1″, the expansile element is stretched to 1.01″-10.0″) or to a length sufficient to prevent loops from forming in the expansile element 1 after expansion. For example, in the previously described cerebral aneurysm treatment embodiment, the expansile element 1 is stretched to a final length, which is approximately 125%-600% of the initial length. In an alternate embodiment, the expansile element 1 is stretched to a final length, which is approximately 125%-300% of the initial length. In one preferred embodiment the expansile element is stretched to a final length that is approximately 267% of its initial length. After stretching, the expansile element 1 may be trimmed to match the length of the carrier member 2 and then bonded near the proximal end of the carrier member 2 by, for example, tying a knot, adhesive bonding, or other techniques known in the art.
[0071] Once the implant 11 has been constructed, it is attached to a delivery system previously described by methods known in the art. The device may also be exposed to, for example, e-beam or gamma radiation to cross-link the expansile element 1 and to control its expansion. This is described in U.S. Pat. No. 6,537,569 which is assigned to the assignee of this application and hereby incorporated by reference.
[0072] Previously, the secondary dimensions of prior devices (e.g. HES) are generally sized to a dimension 1-2 mm smaller than the dimension (i.e. volume) of the treatment site due to the relative stiffness of these devices. The increased flexibility and overall design of the implant 11 of the instant invention allows the secondary shape of the implant 11 to be sized to a dimension approximately the same size as the treatment site, or even somewhat larger. This sizing further minimizes the risk of the implant moving in or slipping out of the treatment site.
[0073] Prior implant devices, such as the HES device, currently provide the user with about 5 minutes of repositioning time. However, the implant 11 of the present invention increases the length of repositioning time. In some embodiments, the repositioning time during a procedure can be increased to about 30 minutes. In this respect, the user is provided with a longer repositioning time to better achieve a desired implant configuration
[0074] FIG. 2 shows an implant 11 similar to that shown in FIG. 1 after the expansile element 1 has expanded through the gap 7 to a dimension larger than the carrier member 2 .
[0075] FIG. 3 shows an implant 11 wherein multiple expansile elements 1 run somewhat parallel to each other through the carrier member 2 . In one embodiment, this configuration is constructed by looping a single expansile element 1 around the tip 4 of the implant 11 and tying both ends of the expansile element 1 to the proximal end of the carrier member 2 . In another embodiment, multiple strands of the expansile element 1 may be bonded along the length of the carrier member 2 . The construction of these embodiments may also comprise stretching the expansile element 1 as previously described and/or forming gaps in the carrier member 2 .
[0076] FIG. 4 shows an embodiment wherein the implant 11 comprises a non-coil carrier member 2 . In one embodiment, the carrier member 2 is formed by cutting a tube or sheet of plastic such as polyimide, nylon, polyester, polyglycolic acid, polylactic acid, PEEK, Teflon, carbon fiber or pyrolytic carbon, silicone, or other polymers known in the art with, for example; a cutting blade, laser, or water jet in order to form slots, holes, or other fenestrations through which the expansile element 1 may be in contact with bodily fluids. The plastic in this embodiment may also comprise a radiopaque agent such as tungsten powder, iodine, or barium sulfate. In another embodiment, the carrier member 2 is formed by cutting a tube or sheet of metal such as platinum, steel, tungsten, Nitinol, tantalum, titanium, chromium-cobalt alloy, or the like with, for example; acid etching, laser, water jet, or other techniques known in the art. In another embodiment, the carrier member 2 is formed by braiding, knitting, or wrapping metallic or plastic fibers in order to form fenestrations.
[0077] FIG. 5 shows an implant 11 comprising a carrier member 2 , an expansile element 1 , and a stretch resistant member 10 . The stretch resistant member 10 is used to prevent the carrier member 2 from stretching or unwinding during delivery and repositioning. The stretch resistant member 10 may be made from a variety of metallic or plastic fibers such as steel, Nitinol, PET, PEEK, Nylon, Teflon, polyethylene, polyolefin, polyolefin elastomer, polypropylene, polylactic acid, polyglycolic acid, and various other suture materials known in the art. Construction of the implant 11 may be by attaching the ends of the stretch resistant member 10 to the ends of the carrier member 2 as described by U.S. Pat. No. 6,013,084 to Ken and U.S. Pat. No. 5,217,484 to Marks both hereby incorporated by reference. Alternatively, the distal end of the stretch resistant member 10 may be attached near the distal end of the carrier member 2 and the proximal end to the stretch resistant member 10 attached to the delivery system as described in co-pending application. Ser. No. 11/212,830 to Fitz.
[0078] FIG. 6 is an alternative embodiment comprising a stretch resistant member 10 wrapped around, tied to, or intertwined with the expansile element 1 . This may occur over the length of the expansile element 1 , or the wrapping or tying may be in only one area to facilitate bonding the expansile element 1 to the carrier element 2 by using the stretch resistant member 10 as a bonding element.
[0079] FIG. 7 shows a loop or fold 12 of the expansile element 1 protruding outside the carrier element 2 . In some embodiments, it may be desirable to avoid this condition by, for example, stretching the expansile element 1 as previously described. This would be done, for example, in embodiments configured for delivery through a small microcatheter to prevent the implant 11 from becoming stuck in the microcatheter during delivery. In other embodiments, slack may be added to the expansile element 1 so that the loop or fold will be pre-formed into the implant 11 . This would be done in embodiments where, for example, a large amount of volumetric filling were necessary because the loops or folds would tend to increase the total length of the expansile element 1 .
[0080] FIG. 8 shows an embodiment wherein the expansile element 1 is configured to expand to a dimension larger than its initial dimension, but smaller than the outer dimension of the carrier member 2 . This may be done by adjusting the ratio of, for example, PEG di-acrylamide to sodium acrylate in embodiments wherein the expansile element 1 comprises a hydrogel. Alternatively, a relatively high dose of radiation could be used to cross-link the expansile element 1 , thus limiting its expansion. Embodiments such as shown in FIG. 8 are desirable when low volumetric filling is necessary and it is desirable to have a substrate for tissue growth and proliferation that the expansile element 1 provides. In an embodiment used to treat cerebral aneurysms, this configuration would be used as a final or “finishing” coil, or in devices dimensioned to treat small (under 10 mm diameter) aneurysms, or as a first “framing” or 3-D coil placed. In one embodiment, the expansile element 1 comprises a hydrogel incorporating a porosigen as previously described to provide a reticulated matrix to encourage cell growth and healing. Incorporating, for example, growth hormones or proteins in the expansile element 1 as previously described may further enhance the ability of the implant 11 to elicit a biological response.
[0081] In one embodiment of the invention a vaso-occlusive device comprises an expansile polymer element having an outer surface, a carrier member that covers at least a portion of the outer surface of the expansile polymer element, and wherein no carrier is disposed within the outer surface of the expansile element.
[0082] In another embodiment, a vaso-occlusive device comprises a coil having a lumen and a hydrogel polymer having an outer surface wherein the hydrogel polymer is disposed within the lumen of the coil and wherein the hydrogel polymer does not contain a coil within the outer surface of the hydrogel polymer.
[0083] In another embodiment, a vaso-occlusive device comprises a carrier member formed into a secondary configuration and an expansile element, wherein the expansile element is made from a polymer formulated to have sufficient softness that the expansile element will substantially take the shape of the secondary configuration formed into the carrier member without pre-treatment.
[0084] In another embodiment, a vaso-occlusive device comprises a carrier member formed into a secondary configuration and a substantially continuous length of hydrogel, wherein the device will substantially take the shape of the secondary configuration formed into the carrier member without pre-treatment.
[0085] In another embodiment, a vaso-occlusive device comprises a microcoil having an inner lumen and an expansile element disposed within the inner lumen. In this embodiment the expansile element comprises a hydrogel selected from the group consisting of acrylamide, poly(ethylene glycol), Pluronic, and poly(propylene oxide).
[0086] In another embodiment, a vaso-occlusive device comprises a coil and a hydrogel polymer disposed at least partially within the coil wherein the hydrogel has an initial length and wherein the hydrogel polymer has been stretched to a second length that is longer than the initial length.
[0087] In another embodiment, a vaso-occlusive device comprises an expansile element and a carrier member defining an inner lumen, wherein the expansile element is disposed within the inner lumen of the carrier member and wherein the expansile element has been stretched to a length sufficient to prevent a loop of the expansile element from protruding through the carrier member.
[0088] The invention disclosed herein also includes a method of manufacturing a medical device. The method comprises providing a carrier member having an inner lumen and an expansile element, inserting the expansile element into the inner lumen of the carrier member, and stretching the expansile element.
[0089] In another embodiment, a vaso-occlusive device comprises an expansile element encapsulated by a carrier element, wherein said expansile element is comprised substantially entirely and substantially uniformly of material having an expansile property.
[0090] In another embodiment, a vaso-occlusive device comprises a carrier element and an expansile element wherein the carrier element has a secondary shape that is different from its primary shape and wherein the expansile element is sufficiently flexible in a normal untreated state to conform with the secondary shape of the carrier.
[0091] In another embodiment, a vaso-occlusive device includes a carrier and an expansile element wherein the expansile element is fixed to the carrier in a manner such that the expansile element is in a stretched state along the carrier.
[0092] In another embodiment, a vaso-occlusive device includes a carrier having a plurality of gaps along the carrier and an expansile element positioned along an inside envelope of the carrier and wherein the expansion of the expansile element is controlled such that the expansile element expands into the gaps but not beyond the external envelope of the carrier.
[0093] In another embodiment, a vaso-occlusive device includes a carrier member and an expansile element wherein the expansile element is comprised of multiple strands extending along the carrier.
[0094] In another embodiment, a vaso-occlusive device includes a carrier and an expansile member wherein the carrier is a non-coiled cylindrically shaped structure and wherein said expansile member is disposed inside said carrier.
[0095] In another embodiment, a vaso-occlusive device includes a carrier and an expansile member and a stretch resistant member; said expansile member and said stretch resistant member being disposed in an internal region of the carrier and wherein the stretch resistant member is in tension on said carrier.
[0096] The invention disclosed herein also includes a method of treating a lesion within a body. The method comprises providing a vaso-occlusive device comprising a carrier member and an expansile element wherein the carrier member is formed into a secondary configuration that is approximately the same diameter as the lesion and inserting the vaso-occlusive device into the lesion.
[0097] Although preferred embodiments of the invention have been described in this specification and the accompanying drawings, it will be appreciated that a number of variations and modifications may suggest themselves to those skilled in the pertinent arts. Thus, the scope of the present invention is not limited to the specific embodiments and examples described herein, but should be deemed to encompass alternative embodiments and equivalents.
[0098] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, 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 present invention. 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 at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0099] The terms “a,” “an,” “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0100] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
[0101] Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
[0102] Furthermore, numerous references have been made to patents and printed publications throughout this specification. Each of the above-cited references and printed publications are individually incorporated herein by reference in their entirety.
[0103] In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.
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Devices for the occlusion of body cavities, such as the embolization of vascular aneurysms and the like, and methods for making and using such devices. The devices may be comprised of novel expansile materials, novel infrastructure design, or both. The devices provided are very flexible and enable deployment with reduced or no damage to bodily tissues, conduits, cavities, etceteras.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 13/144,439 filed Jul. 13, 2011 which is a U.S. national stage of International Application No. PCT/US2010/021572 filed Jan. 21, 2010 which claims the benefit of U.S. Provisional Ser. No. 61/145,985 filed Jan. 21, 2009. The entire disclosure of each of the above-noted applications is incorporated herein by reference.
FIELD
The present disclosure relates to a driveline for a motor vehicle having a system for disconnecting a hypoid ring gear from rotating at driveline speed. In particular, a power take-off unit includes a coupling for ceasing the transfer of torque from a power source to a rear driveline while another disconnect selectively interrupts the flow of power from a vehicle wheel to a hypoid ring gear of the rear driveline. A torque coupling selectively connects a portion of rear driveline with an input to the hypoid ring gear.
BACKGROUND
Typical power take-off units transfer power from a transaxle in receipt of torque from a vehicle power source. The power take-off unit transfers power to a propeller shaft through a gear arrangement that typically includes a hypoid cross-axis gearset. Other gear arrangements such as parallel axis gears may be provided within the power take-off unit to provide additional torque reduction.
Power take-off units have traditionally been connected to the transaxle output differential. Accordingly, at least some of the components of the power take-off unit rotate at the transaxle differential output speed. Power losses occur through the hypoid gear churning through a lubricating fluid. Efficiency losses due to bearing preload and gear mesh conditions are also incurred while the components of the power take-off unit are rotated.
Similar energy losses occur when other driveline components are rotated. For example, many rear driven axles include hypoid gearsets having a ring gear at least partially immersed in a lubricating fluid. In at least some full-time all-wheel drive configurations, the rear drive axle hypoid gearset continuously rotates during all modes of operation and transmits a certain level of torque. In other applications, the rear axle hypoid gearset still rotates but with out the transmission of torque whenever the vehicle is moving. Regardless of the particular configuration, churning losses convert energy that could have been transferred to the wheels into heat energy that is not beneficially captured by the vehicle. As such, an opportunity may exist to provide a more energy efficient vehicle driveline.
SUMMARY
A vehicle drive train for transferring torque to first and second sets of wheels includes a first driveline adapted to transfer torque to the first set of wheels and a synchronizing clutch. A second driveline is adapted to transfer torque to the second set of wheels and includes a power disconnection device and a friction clutch. A hypoid gearset is positioned within the second driveline in a power path between the synchronizing clutch and the power disconnection device. The friction clutch and the power disconnection device are positioned on opposite sides of the hypoid gearset. The hypoid gearset is selectively disconnected from being driven by the first driveline, the second driveline or the wheels when the synchronizing clutch and the power disconnection device are operated in disconnected, non-torque transferring, modes.
Furthermore, a vehicle drive train for transferring torque from a power source to first and second sets of wheels includes a first driveline adapted to transfer torque from the power source to the first set of wheels and includes a power take-off unit. The first driveline includes a differential, a first hypoid gearset and a synchronizer positioned between the differential and the first hypoid gearset to selectively transfer or cease the transfer of torque from the power source to the first hypoid gearset. A second driveline is in receipt of torque from the first hypoid gearset and transfers torque to the second set of wheels. The second driveline includes a power disconnection device selectively interrupting the transfer of torque from the second set of wheels to the first hypoid gearset. The second driveline also includes a friction clutch for transferring torque between the first hypoid gearset and a second hypoid gearset associated with the second driveline.
Furthermore, a method for transferring torque from a power source to a first pair and a second pair of wheels in a vehicle drive train is disclosed. The method includes transferring torque from the power source to the first pair of wheels through a first transmission device. A synchronizing clutch, within the first power transmission device, is actuated to transfer torque to a driveline interconnecting the first pair and second pair of wheels. A friction clutch is subsequently actuated to transfer torque from the driveline to a rear drive axle to initiate rotation of a gearset within the rear drive axle. The method further includes actuating a disconnect to drivingly interconnect a shaft coupled to one wheel of the second pair of wheels and a rotatable member of the rear drive axle once speed synchronization between the components coupled by the disconnect is achieved.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples 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 illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
FIG. 1 is a schematic of an exemplary vehicle equipped with a vehicle drive train of the present disclosure;
FIG. 2 is an enlarged schematic depicting a portion of the drive train shown in FIG. 1 ;
FIG. 3 is an enlarged schematic depicting another portion of the drive train shown in FIG. 1 ;
FIG. 3A is an enlarged schematic depicting an alternate portion of the drive train shown in FIG. 1 ;
FIG. 4 is a schematic of another exemplary vehicle equipped with another alternate drive train; and
FIG. 5 is an enlarged schematic depicting a portion of the drive train depicted in FIG. 4 .
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
In general, the present disclosure relates to a coupling and hypoid disconnect system for a driveline of a motor vehicle. A power take-off unit may be equipped with a synchronizer to disconnect the power source from a portion of the driveline and to reconnect through synchronization of the driveline. A dog or roller-type clutch may be provided to disconnect a portion of the driveline from one or more of the vehicle wheels. Additionally, a friction coupling may be positioned in series within the driveline to provide speed synchronization between front and rear driveline components when a power reconnection is desired. The hypoid gearing of the vehicle driveline may be separated from the driving source of power to reduce churning losses and other mechanical inefficiencies.
With particular reference to FIGS. 1-3 of the drawings, a drive train 10 of a four-wheel drive vehicle is shown. Drive train 10 includes a front driveline 12 and a rear driveline 14 both drivable from a source of power, such as an engine 16 through a transmission 18 which may be of either the manual or automatic type. In the particular embodiment shown, drive train 10 is a four-wheel system incorporating a power transmission device 20 for transmitting drive torque from engine 16 and transmission 18 to front driveline 12 and rear driveline 14 . Power transmission device 20 is shown as a power take-off unit.
Front driveline 12 is shown to include a pair of front wheels 24 individually driven by a first front axle shaft 26 and a second front axle shaft 28 , as well as a differential assembly 32 . Power take-off unit 20 includes a reduction speed gearset 30 , a synchronizer clutch 34 , an output gearset 35 and a right-angled drive assembly 36 .
Rear driveline 14 includes a propeller shaft 38 connected at a first end to right-angled drive assembly 36 and at an opposite end to one side of a friction coupling 39 . The opposite side of friction coupling 39 is connected to a rear axle assembly 40 . Rear driveline 14 also includes a pair of rear wheels 42 individually driven by a first rear axle shaft 44 and a second rear axle shaft 46 . Rear axle assembly 40 also includes a hypoid ring and pinion gearset 48 driving a differential assembly 50 . A disconnect 52 selectively drivingly disconnects second rear axle shaft 46 from ring and pinion gearset 48 and differential assembly 50 .
Reduction speed gearset 30 of power take-off unit 20 includes a drive gear 56 fixed for rotation with an output shaft of transmission 18 . A driven gear 58 is in constant meshed engagement with drive gear 56 and is also fixed for rotation with a carrier 60 of differential assembly 32 . Differential assembly 32 includes a first side gear 62 fixed for rotation with first front axle shaft 26 and a second side gear 64 fixed for rotation with second front axle shaft 28 . Each of first and second side gears 62 , 64 are in meshed engagement with pinion gears 66 , 68 which are rotatably supported by carrier 60 .
Power take-off unit 20 also includes an input shaft 76 supported for rotation within a housing. Input shaft 76 is fixed for rotation with carrier 60 of center differential assembly 32 . A drive gear 78 is supported for rotation on second front axle shaft 28 . A driven gear 80 is in meshed engagement with drive gear 78 and fixed for rotation with a ring gear 82 of right-angled drive assembly 36 . Driven gear 80 and ring gear 82 are fixed for rotation with a countershaft 84 . Synchronizer clutch 34 selectively drivingly interconnects input shaft 76 and drive gear 78 . Synchronizer clutch 34 includes a hub 86 fixed for rotation with input shaft 76 . An axially moveable sleeve 88 is in splined engagement with hub 86 . A second hub 90 is fixed for rotation with drive gear 78 and includes an external spline 92 . Synchronizer clutch 34 also includes a blocker ring 94 positioned between hub 86 and second hub 90 . Blocker ring 94 functions to assure that the rotational speed of input shaft 76 is substantially the same as drive gear 78 prior to allowing a driving connection between hub 86 and second hub 90 via sleeve 88 . It should be appreciated that an alternate synchronizer (not shown) may not require a blocker ring to function properly.
A synchronizer clutch actuation mechanism 96 includes a shift fork 98 slidingly positioned with a groove 100 formed in sleeve 88 . An actuator 102 is operable to move fork 98 and sleeve 88 from a first position where sleeve 88 is disengaged from spline 92 and a second position where sleeve 88 concurrently drivingly engages hub 86 and second hub 90 .
Right-angled drive assembly 36 includes ring gear 82 and a pinion gear 108 in meshed engagement with ring gear 82 . Pinion gear 108 may be integrally formed with a pinion shaft 110 . Pinion shaft 110 is fixed for rotation with propeller shaft 38 via a flange 112 . Synchronizer clutch 34 may be placed in an activated mode where torque is transferred between input shaft 76 and drive gear 78 . Synchronizer clutch 34 is also operable in a deactivated mode where no torque is transferred to rear driveline 14 . Power from engine 16 is not transferred to right-angled drive assembly 36 when synchronizer clutch 34 is in the deactivated mode.
Friction coupling 39 is depicted as a friction clutch fixed to a rear axle assembly 113 . Rear axle assembly 113 includes differential assembly 50 , rear axle shaft 44 , rear axle shaft 46 and disconnect 52 . Differential assembly 50 includes a carrier housing 114 fixed for rotation with a ring gear 115 of ring and pinion gearset 48 . Differential assembly 50 also includes first and second side gears 116 , 117 fixed for rotation with first and second rear axle shafts 44 , 46 , respectively. A pair of pinion gears 118 are positioned within carrier housing 114 and placed in constant meshed engagement with side gears 116 , 117 . Friction coupling 39 includes a drum 120 fixed for rotation with propeller shaft 38 . A hub 122 is fixed for rotation with a pinion shaft 124 . A pinion gear 126 of pinion gearset 48 may be integrally formed with pinion shaft 124 . Outer clutch plates 128 are splined for rotation with drum 120 . A plurality of inner clutch plates 130 are splined for rotation with hub 122 and interleaved with outer clutch plates 128 . An actuator 134 is operable to apply a clutch actuation force to clutch plates 128 , 130 and transfer torque through friction coupling 39 . In one example, an axially moveable piston may be in receipt of pressurized fluid to provide the actuation force. Alternatively, an electric motor may cooperate with a force multiplication mechanism. In yet another embodiment described below in greater detail, the friction clutch may be actuated based on wheel slip or a difference in rotational speed across the friction clutch.
Disconnect 52 is depicted in FIGS. 1 and 3 as a dog clutch. Disconnect 52 includes a first hub 140 fixed for rotation with a shaft 142 drivingly engaged with side gear 117 of differential assembly 50 . An external spline 146 is formed on first hub 140 . An axially translatable sleeve 148 is in splined engagement with first hub 140 . A second hub 150 is fixed for rotation with rear axle shaft 46 . A spline 152 is formed on an outer periphery of second hub 150 .
A dog clutch actuation system 156 includes a fork 158 slidably positioned within a groove 160 formed in sleeve 148 . An actuator 162 is operable to translate fork 158 and sleeve 148 between a first position where sleeve 148 is engaged only with first hub 140 and a second position where sleeve 148 simultaneously engages splines 146 and 152 to drivingly interconnect shaft 142 with rear axle shaft 46 .
FIG. 3A depicts an alternate rear driveline 14 A and rear axle assembly 40 A. Rear axle assembly 40 A is substantially similar to rear axle assembly 40 , previously described. Accordingly, like elements will retain their previously introduced reference numerals. Rear axle assembly 40 A includes another disconnect identified as disconnect 52 A. The elements of disconnect 52 A are identified in similar fashion to the components of disconnect 52 except that the suffix “A” has been added. Disconnect 52 A may selectively drivingly connect and disconnect rear axle shaft 44 with an axle shaft portion 142 A that is fixed for rotation with side gear 116 . During operation, ring and pinion gearset 48 and differential assembly 50 may be entirely disconnected from rear axle shaft 44 and rear axle shaft 46 . Accordingly, even the internal components of differential assembly 50 will not be rotated due to input from rear wheels 42 . To return to the all wheel drive mode of operation, actuator 162 A is controlled at substantially the same time as actuator 162 to reconnect shaft 142 A and rear axle shaft 44 in the same manner as shaft 142 is coupled to rear axle shaft 46 .
FIGS. 4 and 5 depict an alternate drive train 10 ′. Drive train 10 ′ is substantially similar to drive train 10 . As such, like elements will be identified with the previously introduced reference numerals including a prime suffix. Drive train 10 ′ includes a power take-off unit 20 ′ that differs from power take-off unit 20 by being a single axis power transmission device that does not include countershaft 84 , previously described. On the contrary, power take-off unit 20 ′ includes a concentric shaft 166 having ring gear 82 ′ fixed thereto. Ring gear 82 ′ is in meshed engagement with pinion gear 108 ′ to drive propeller shaft 38 ′.
FIGS. 4 and 5 also show that disconnect 52 may be alternatively formed as a roller clutch identified as reference numeral 52 ′. The driveline depicted in FIGS. 1 and 4 may include either a dog clutch, a roller clutch or one of a number of other power transmission devices operable to selectively transfer torque and cease the transfer of torque between rotary shafts. In the example depicted, roller clutch 52 ′ includes an inner member 170 fixed for rotation with rear axle shaft 46 ′ and an outer member 172 fixed for rotation with shaft 142 ′. Inner member 170 includes a surface 174 having a plurality of curved recesses. Each recess is in receipt of a roller 176 . A split ring 178 is positioned between rollers 176 and outer member 172 . Split ring 178 also includes a plurality of curved recesses facing the recesses of inner member 170 and in receipt of rollers 176 . A control arm 180 cooperates with split ring 178 to restrict or permit relative rotation between inner member 170 and split ring 178 . When relative rotation is permitted, rollers 176 are forced radially outwardly to radially outwardly expand split ring 178 into engagement with outer member 172 to transfer torque across roller clutch 52 ′. When relative rotation between inner member 170 and split ring 178 is restricted, rollers 176 are not displaced, the rollers are not wedged between split ring 178 and inner member 170 and torque is not transferred across disconnect 52 ′. An actuator 182 may move control arm 180 to operate disconnect 52 ′.
During vehicle operation, it may be advantageous to reduce the churning losses associated with driving ring and pinion gearset 48 as well as right-angled drive assembly 36 . With reference to FIG. 1 , a controller 190 is in communication with a variety of vehicle sensors 192 providing data indicative of parameters such as vehicle speed, four-wheel drive mode, wheel slip, vehicle acceleration and the like. One sensor 192 may be positioned at a location proximate ring and pinion gearset 48 to provide a signal indicating the rotational speed of a ring and pinion gearset component. At the appropriate time, controller 190 may output a signal to control actuator 96 and place synchronizer clutch 34 in the deactuated mode where torque is not transferred from engine 16 to rear driveline 14 . Controller 190 may also signal actuator 162 , associated with disconnect 52 , to place fork 158 in a position to cease torque transfer across disconnect 52 such that the energy associated with one of rotating rear wheels 42 will not be transferred to ring and pinion gearset 48 or differential assembly 50 . Accordingly, the hypoid gearsets 36 , 48 will not be driven by differential assembly 32 . Furthermore, because side gear 116 is not restricted from rotation, input torque provided by rear axle shaft 44 will only cause the internal gears within differential assembly 50 to rotate. Ring and pinion gearset 48 is not driven. It should be appreciated that friction coupling 39 may be operated in either of an open mode or a torque transferring mode when synchronizer clutch 34 and disconnect 52 do not transfer torque because rear driveline 14 is not rotating at this time.
When controller 190 determines that a four wheel drive mode of operation is to commence, controller 190 signals actuator 102 to slide sleeve 88 toward hub 90 . During this operation, speed synchronization between input shaft 76 and drive gear 78 occurs. Once the speeds are matched, sleeve 88 drivingly interconnects hub 86 and second hub 90 . At this time, right-angled drive assembly 36 is also driven by engine 16 . Once the front driveline components and the right-angled drive components are up to speed, controller 190 provides a signal to actuator 134 to begin speed synchronization of ring and pinion gearset 48 as well as differential assembly 50 . This sequence of operations will cause the speed of shaft 142 to match the speed of rear axle shaft 46 . At this time, controller 190 provides a signal to actuator 162 to place disconnect 52 in a torque transferring mode by axially translating sleeve 148 . At the end of this sequence, drive train 10 is operable in an all wheel drive mode. It should be appreciated that the procedure previously described may be performed while the vehicle is moving.
It is contemplated that friction coupling 39 may be alternatively configured as a passive device having an actuation system operable in response to a speed differential between propeller shaft 38 and pinion shaft 124 . In particular, FIG. 4 depicts friction coupling 39 ′ including a pump 202 driven by propeller shaft 38 when a speed differential exists between propeller shaft 38 ′ and pinion shaft 124 . Pressurized fluid from pump 202 is provided to a piston 204 for applying a compressive force to inner clutch plates 130 ′ and outer clutch plates 128 ′. In this arrangement, control of synchronizer clutch 34 ′ also provides control of friction coupling 39 ′ because rotation of propeller shaft 38 ′ relative to pinion shaft 124 ′ will cause pressurized fluid to cause torque transfer across friction coupling 39 ′ thereby quickly achieving speed synchronization of the front driveline and rear driveline components. Furthermore, the inclusion of friction coupling 39 or 39 ′ allows synchronizer clutch 34 or 34 ′ to be relatively minimally sized because only some of the components of power transmission device 20 and propeller shaft 38 are speed synchronized through actuation of synchronizer clutch 34 . The relatively large rotating masses within rear axle assembly 40 are accelerated through actuation of friction coupling 39 .
While a number of vehicle drivelines have been previously described, it should be appreciated that the particular configurations discussed are merely exemplary. As such, it is contemplated that other combinations of the components shown in the Figures may be arranged with one another to construct a drive train not explicitly shown but within the scope of the present disclosure.
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A vehicle drive train for transferring torque to first and second sets of wheels includes a first driveline adapted to transfer torque to the first set of wheels and a synchronizing clutch. A second driveline is adapted to transfer torque to the second set of wheels and includes a power disconnection device and a friction clutch. A hypoid gearset is positioned within the second driveline in a power path between the synchronizing clutch and the power disconnection device. The friction clutch and the power disconnection device are positioned on opposite sides of the hypoid gearset. The hypoid gearset is selectively disconnected from being driven by the first driveline, the second driveline or the wheels when the synchronizing clutch and the power disconnection device are operated in disconnected, non-torque transferring, modes.
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FIELD OF THE INVENTION
This invention relates to a process for forming a coating and an organic coating.
The invention is particularly concerned with at least two different coatings on metallic surfaces and preferably on aluminum, copper, iron, magnesium, zinc or of an alloy containing aluminum, copper, iron, magnesium and/or zinc.
BACKGROUND OF THE INVENTION
The term “conversion coating” is a well known term of the art and refers to the replacement of native oxide on the surface of a metallic material by the controlled chemical formation of a film on the metallic surface by reaction with chemical elements of the metallic surface so that at least some of the cations dissolved from the metallic material are deposited in the conversion coating. Other coatings are formed on the surface of the metallic material without or without significant deposition of constituents dissolved by chemical reactions with the metallic material.
In the search for alternative, less toxic coatings than chromium containing coatings, research has been conducted on non-conversion coatings and on conversion coatings based e.g. on zirconium and/or titanium as well as fluoride containing aqueous solutions instead of chromium bearing solutions.
However, there is considerable room for improvement in the adhesion and corrosion protection properties of prior titanium/zirconium-fluoride based coatings. The need for improvement is particularly true for coatings on certain metal alloys, such as 1000, 2000, 3000, 5000 and 6000 series aluminum alloys, which coatings can have variable adherence or no adherence.
Over the years there have been numerous attempts for the replacement of chromating chemicals by ones less hazardous to the health and the environment. Their major disadvantage is that they either form coatings with poor paint adhesion properties or there are working concentrations required showing a risk of blue discoloration which does not disturb performance but makes the process undesirable in the eyes of the users. Zirconium and titanium based coating processes have found some applications in certain market niches, but they have failed in the past 25 years to replace chromating as a pretreatment prior to painting especially of aluminum, magnesium, zinc or their alloys.
Accordingly, it is an object of the present invention to provide a surface treatment process for the surface of a metallic material which overcomes, or at least alleviates, one or more of the disadvantages or deficiencies of the prior art. It is also an object of the present invention to provide an aqueous, titanium/zirconium-fluoride containing coating solution for use especially together with a further organic coating or paint. Specifically, it was an object of this invention to propose such a process to suit industrial requirements of short time formation of the coating and of near-ambient operating temperature.
It has been discovered that the combination treatment of a titanium/zirconium-fluoride treatment with an application of self assembling molecules can greatly promote corrosion resistance and paint adhesion of the coating.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a process of treating metallic surfaces showing at least two separate steps for applying two different coatings one after the other, whereby the metallic surfaces are contacted at a temperature in the range of from 10 to 100° C. first with an aqueous solution A and later on with an aqueous solution B or vice versa characterized in that the solution A contains an effective amount of zirconium, hafnium, titanium, silicon and/or boron as well as of fluoride in the form of ions and/or complex ions able to pickle the metallic surface and to generate a coating on the pickled metallic surface and that the solution B contains an effective amount of one or more compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X*, where Y is an organic group with 2 to 50 carbon atoms, where X as well as Z is a group—each same or different—of OH—, SH—, NH 2 —, NHR′—, CN—, CH═CH 2 —, OCN—, CONHOH— (=hydroxamic), COOR′ (=alkyl ester), acrylamide-, epoxide-, CH 2 ═CR″—COO—, COOH—, HSO 3 —, HSO 4 —, (OH) 2 PO—, (OH) 2 PO 2 —, (OH)(OR′)PO—, (OH)(OR′)PO 2 —, SiH 3 —, Si(OH) 3 —, where R′ is an alkyl group with 1 to 4 carbon atoms, where R″ is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms, and where the groups X and Z are each bound to the group Y in their terminal position, where Y* is an organic group with 1 to 30 carbon atoms, where X* as well as Z* is a group—each same or different—of OH—, SH—, NH 2 —, NHR′—, CN—, CH═CH 2 —, OCN—, CONHOH— (=hydroxamic), COOR′ (=alkyl ester), acrylamide-, epoxide-, CH 2 ═CR″—COO—, COOH—, HSO 3 —, HSO 4 —, (OH) 2 PO—, (OH) 2 PO 2 —, (OH)(OR′)PO—, (OH)(OR′)PO 2 —, SiH 3 —, Si(OH) 3 —, >N—CH 2 —PO(OH) 2 —, —N—[CH 2 —PO(OH) 2] 2 -where R′ is an alkyl group with 1 to 4 carbon atoms, where R″ is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process according to the invention may be characterized in that the metallic surfaces consist essentially e.g. of aluminum, copper, iron, magnesium, zinc or of an alloy containing aluminum, copper, iron, magnesium and/or zinc. p In the following it is not distinguished between the metallic surfaces and the already coated metallic surfaces, especially, if both possibilities may be possible at the same time, e.g. with reaction products and deposited compounds of the solution A not to make the text too complicate as the expert in the art knows what is meant. Furtheron, it is not distinguished by this term, if there is a very thin “natural” oxide and/or hydroxide layer. This oxide and/or hydroxide layer is typically extremely thin, mostly of few nm thickness. The solution A according to the invention may react chemically with the metallic surface by depositing cations in the coating being dissolved from the metallic material, but must not. Therefore, the coating is not generally called a conversion coating, although this may be in some cases a conversion coating.
Further on, it is preferred to have in the solution A concerning the fluoride content of the solution a high or very high percentage of complex fluoride and no or a low percentage of fluoride ions. In the case that in the same solution A titanium and zirconium would be present, it is preferred that the content of titanium is higher than the content of zirconium. On the other hand, it may be often preferred to have a content mainly or only of zirconium referring to chemical elements selected from the group of titanium, zirconium, hafnium, silicon and boron. Normally, no further additive is necessary for the use of solution A; in the case that a further additive is necessary, then surfactants, acids, or alkaline materials may be added. The coating formed by contacting the metallic surface may be a conversion or may be a non-conversion coating, depending on the type of metallic surface and on the contacting conditions. This coating is favorably located directly on the very thin oxide/hydroxide layer formed on the metallic surface or even directly on the metallic surface and contains often titanium, zirconium, hafnium, silicon and/or boron as well as hexafluoride and/or oxide/hydroxide. In the process according to the invention, the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* used in the solution B may preferably show a group Y with 3 to 30 carbon atoms, more preferred with 4 to 20 carbon atoms, much more preferred with 4 to 16 carbon atoms, especially preferred with 9 to 14 carbon atoms as well as a group Y* with 2 to 24 carbon atoms, more preferred with 3 to 20 carbon atoms, much more preferred with 4 to 16 carbon atoms, especially preferred with 9 to 14 carbon atoms. It is preferred that the groups X* and Z* of the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* are each bound to the group Y* in their terminal positions. In preferred embodiments, the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* are able to form self assembling molecules which may form a layer, especially a thin layer or even a monolayer, of these self assembling molecules (SAM) on the metallic surfaces.
These compounds may show a group Y or Y* that is a linear unbranched group. Alternatively, these groups Y or Y* may be a linear group branched with at least one functional group, preferably branched with at least one alkyl group and/or one aromatic group. The functional groups may stand aside from the linear group.
The most effective constituent of the solution B may be a compound XYZ, X*Y*Z* and/or X*Y*Z*Y*X* with a group Y or Y* that has an even number of carbon atoms. Besides this most effective constituent which may have self assembling molecules there may be any surfactant in the solution B to improve the rate of deposition of self assembling molecules. Often compounds are used according to the process of the invention which may be able to form self assembling molecules and which may organize themselves parallel one to the other and in about perpendicular to the metallic surfaces with the hydrophobic regions of the molecules located at the metallic surfaces and with the hydrophilic regions of the molecules extending into the liquid away from the metallic surfaces. Nevertheless, there is no necessity that these compounds organize their molecules in such a way to generate coatings. There is the target to form a uniform coating quality as far as possible and an at least randomly distribution of islands of molecules of the solution B, but not the necessity of totally covering the metallic surfaces. Often even a very short exposure of the solution B to a metallic surface may lead to a random distribution of at least one of the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X*, nevertheless, sometimes a longer contacting time may be preferable for a high surface quality.
For the process according to the invention it is preferred that at least one compound of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* is present in the aqueous solution as salt and/or acid.
The more effective constituents of the solution B may be compounds XYZ, X*Y*Z* and/or X*Y*Z*Y*X* with an unbranched straight-chain alkyl group with 3 to 30 carbon atoms as Y or Y*. Preferably, this group Y or Y* has 4 to 20 carbon atoms, more preferred 4 to 18 carbon atoms, much more preferred 5 to 14 carbon atoms and most preferred 10 to 14 carbon atoms.
In specific embodiments, the compound XYZ, X*Y*Z* and/or X*Y*Z*Y*X* may have as Y or Y* an unbranched straight-chain group consisting of 1 to 4 aromatic C 6 H 4 nuclei connected in the para-position, or a group consisting of 1 or 2 unbranched, straight-chain alkyl residues each with 1 to 12 carbon atoms or 1 to 4 aromatic C 6 H 4 nuclei connected in the para-position.
The most effective constituent of the solution B may be a compound XYZ, X*Y*Z* and/or X*Y*Z*Y*X* with a group Y or Y* that is an unbranched, straight-chain alkyl group with 6 to 14 carbon atoms or a p-CH 2 —C 6 H 4 —CH 2 -group or a p,p′-C 6 H 4 —C 6 H 4 -group.
The most effective constituent of the solution B may be a compound XYZ, X*Y*Z* and/or X*Y*Z*Y*X* with a group (OH) 2 PO 2 — or (OH)(OR′)PO 2 — as X or X*. The most effective constituent of the solution B may be a compound XYZ, X*Y*Z* and/or X*Y*Z*Y*X* with a group (OH) 2 PO 2 —, (OH)(OR′)PO 2 —, OH—, SH—, NHR′—, CH═CH 2 or CH 2 ═CR″—COO— as Z or Z*.
In preferred embodiments, the aqueous solution may contain at least one compound of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* selected from the group of:
1-phosphonic acid-12-mercaptododecane,
1-phosphonic acid-12-(N-ethylamino)dodecane,
1 -phosphonic acid-12-dodecene,
p-xylylene diphosphonic acid,
1,10-decanediphosphonic acid,
1,12-dodecanediphosphonic acid,
1,14-tetradecanediphosphonic acid,
1-phosphoric acid-12-hydroxydodecane,
1-phosphoric acid-12-(N-ethylamino)dodecane,
1-phosphoric acid-12-dodecene,
1 -phosphoric acid-12-mercaptododecane,
1,10-decanediphosphoric acid,
1,12-dodecanediphosphoric acid,
1,14-tetradecanediphosphoric acid,
p,p′-biphenyldiphosphoric acid,
1-phosphoric acid-12-acryloyldodecane,
1,8-octanediphosphonic acid,
1,6-hexanediphosphonic acid,
1,4-butanediphosphonic acid,
1,8-octanediphosphoric acid,
1,6-hexanediphosphoric acid,
1,4-butanediphosphoric acid,
aminetrimethyleneposphonic acid,
ethylenediaminetetramethylenephosphonic acid,
hexamethylenediaminetetramethylenephosphonic acid,
diethylenetriaminepentamethylenephosphonic acid and
2-phosphonobutane-1,2,4-tricarboxylic acid.
In the process according to the invention the time of contacting the metallic surfaces with the solution. A may be in the range of from 0.001 seconds to 10 minutes. Applications in the coil industry may need contacting times in the range of from 0.001 seconds to 30 seconds, whereas other applications may often necessitate contacting times in the range of from 1 minute to 3 minutes. For the contacting of wheels, a time range of from 10 seconds to 5 minutes are preferred and of from 30 seconds to 2 minutes are more preferred. For the coil coating process, a contacting time range of from 0.002 to 20 seconds is preferred, of from 0.01 to 8 seconds is more preferred. For the contacting of singular metallic parts, a time range of from 10 seconds to 10 minutes is often preferred and of from 20 seconds to 6 minutes is more preferred. If the contacting time is very short, the percentage of the metallic surface being covered with at least one of the compounds of the type XYZ, X*Y*Z* and X*Y*Z*Y*X* may be relatively low and/or the molecules of these compounds may be not or only partially assembled. The longer the contacting time, the higher may be the percentage of metallic surface covered with at least one of these compounds. The longer the contacting time, the higher may be the percentage of molecules that are arranged perpendicular to the metallic surface as a reason of the self assembling effect. Although compounds of the type XYZ, X*Y*Z* and X*Y*Z*Y*X* with Y or Y* having 10 to 14 carbon atoms gave excellent results of corrosion inhibition and paint adhesion, it has been found that even in the cases that these compounds should not form a continuous coating on the metallic surface, but only a smaller or higher percentage of coating islands distributed on the metallic surface and/or that these compounds did not or only partially arrange perpendicular to the metallic surface, the such prepared coatings were astonishingly good concerning paint adhesion and corrosion inhibition.
The aqueous solution A may have a pH value in the range of from 1 to 5, preferably in the range of from of 2 to 4 and more preferred in the range of from 2.5 to 3.5 if the concentration of fluoride anions is in the range of from 10 to 1000 mg/L, but the pH value is preferably in the range of from 1 to 3 if the concentration of fluoride anions is in the range of from 6,000 to 18,000 mg/L. At a lower pH value than 1, a suitable coating according to the invention will be generated, but normally significantly higher pH values will be used. At a pH value higher than 5, an instability of the solution A may occur in some cases; but if this instability does not occur due to the specific conditions, an acceptable coating will be created. The pH value may be adjusted within the regular coating process to values of e.g. 4.0 or 4.2 minimum, preferably by adding a fluoride containing compound, which may be in a water soluble form, to cut the pH value down to e.g. 4.2. The buffering of the solution A may be made favorably by any addition, e.g. of sodium fluoride or ammonium bifluoride.
The solution A may preferably be applied to the metallic surface at a temperature of up to 30° C. to avoid in every case blue discoloration of the coating. The solution B may preferably be applied to the metallic surface at a temperature of up to 60° C. The process according to the invention may be characterized in that in the solution A the concentration of the titanium is in the range of from 0.0001 to 0.1% by weight if titanium is added, the concentration of the zirconium is in the range of from 0.0001 to 0.1% by weight if zirconium is added, the concentration of the hafnium is in the range of from 0.0001 to 0.1% by weight as hafnium added intentionally, whereby only one selected from the group of titanium, zirconium, hafnium, silicon and boron has to be present. Instead of or together with at least one of the chemical elements of the group of titanium, zirconium and hafnium, silicon and/or boron may be used. The total amount of all the five chemical elements present in the solution may be in the range of from 0.0001 to 0.2% by weight. Preferably, the concentration of titanium, zirconium, hafnium, silicon and/or boron each may be in the range of from 0.0008 to 0.05% by weight, more preferred in the range of from 0.001 to 0.02% by weight. A mixture of at least two of them may be favorable to generate a combination effect with improved results, especially of the combination of titanium with zirconium. Furtheron, it is more preferred that the range of the concentration when used for spraying is of from 0.002 to 0.08% by weight of titanium, zirconium, hafnium, silicon and/or boron each, much more preferred of from 0.005 to 0.025% by weight. The solution A may contain ZrOCl 2 which may be very advantageous.
The concentration of the total fluoride may be in the range of from 0.001 to 0.2% by weight calculated as fluoride. The concentration of the total fluoride in the solution A may be preferably in the range of from 0.005 to 0.15% by weight, more preferred in the range of from 0.01 to 2% by weight, much more preferred of from 0.008 to 0.09% by weight. The moiety of complex fluoride anions at the total of the fluoride may be in the range of from 50 to 95%. If there is less titanium, zirconium, hafnium, silicon and/or boron in the solution A, then there will be less fluoride necessary; an excess of fluoride with regard to the content of titanium, zirconium, hafnium, silicon and/or boron enhances the pickling effect and may help to control the thickness of the generated coating. If there is a too high content of titanium, zirconium, hafnium, silicon and/or boron in the solution A in relation to the total fluoride content, then there will be a thicker coating which may disturb in some cases when a paint will be later applied upon as such a too thick coating may lead to filiform corrosion and a worse paint adhesion; furtheron, there may occur only a very weak pickling effect.
The aqueous solution A shows primarily a pickling effect, but even some deoxidation effect. Then a reaction to generating a coating may occur, which may for example contain hydroxides, oxides and other compounds of aluminum and/or other metallic elements that are constituents of the metallic material together with titanium, zirconium, hafnium, silicon and/or boron.
The coating containing titanium, zirconium, hafnium, silicon and/or boron may show a thickness in the range of from 0.1 to 100 nm. Its coating weight may be in the range of from 1 to 100 mg/m 2 .
The coating containing one or more compounds of the type XYZ, X*Y*Z* arid/or X*Y*Z*Y*X* may show a thickness which is measured in the range of from 0.1 to 100 nm, often in the range of from 1 to 20 nm. Its coating weight may be often in the range of from 1 to 20 mg/m 2 , but it may be even higher than 20 mg/m 2 or sometimes even in the range of about 80 or 120 mg/cm 2 as for cans and other containers. If the concentration of the solution B is significantly enlarged, the thickness of the generated coating often may remain in the same thickness range as applied with a much more diluted solution B.
The concentration of the solution B may vary in the range of from 0.00001 to about 50%, whereby the upper concentration limit is greatly dependent on the water solubility limit of the used compounds and the specific conditions. If compounds are used with relative short chain length of Y resp. Y* then the water solubility may be much enhanced. If the chain length of Y resp. Y* is in the range of from 10 to 14 carbon atoms, then the water solubility is reduced significantly and there may be a solubility limit of about 1%. This effect is proportional to the chain length and hydrophobicity of the hydrocarbon chain: The longer the hydrocarbon chain, the higher the hydrophobicity properties. Furtheron, the higher the concentration of these compounds in solution B, the greater may be the possibility to generate foam which is undesirable. For example, the dodecanediphosphonic acid may be dissolved in water without further aids in the range of from 100 to 300 mg/L, whereas it can be dissolved in hot water in an amount of up to 600 mg/L. For the amount of dodecanediphosphonic acid dissolved it may be an influencing factor, if the compound added is of low or of high purity. The amount of dissolved dodecanediphosphonic acid can be greatly enhanced by adding organic solvents. Such a proportion of an organic solvent may aid for quicker drying and may help to generate a higher concentration of the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* in the solution B than without such organic solvent. Without any organic solvent, there are often only up to 400 mg/L of compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* in solution B, whereas with an organic solvent, its concentration can be enhanced up to a much higher extent.
It may be favorable, not to use any organic solvent. When an organic solvent is used, it may replace 0.01 to 50% of the water. This solvent may be an alcohol with 1 to 4 carbon atoms, acetone, dioxane and/or tetrahydrofurane.
It is preferred that the solution B contains essentially no further cations added intentionally. Furtheron, it is preferred that solution B contains essentially no nitrites, no nitrates and no peroxocompounds.
The water quality used for the preparation of solution B may be a water quality like natural water of very low hardness or like de-ionized water. The water quality shows preferably an electrical conductivity of less than 20 μS/cm, but in some cases values of less than 200 μS/cm may be sufficient.
Such a solution B containing only pure water and dodecanediphosphonic acid may show a pH value in the range of from 2.5 to 3.5. For the pretreatment of cans and other containers, a pH value in the range of from 0.5 to 2.5 may be preferred. Such a solution may show an electrical conductivity in the range of from 200 to 350 μS/cm, if the pure water used had an electrical conductivity of less than 20 μS/cm. The bath of the solution B may preferably be controlled with a photometer for the phosphorus and phosphate content or via measurement of the electrical conductivity. If the last mentioned method is used for controlling, the range of electrical conductivity may be held for dodecanediphosphonic acid in pure water in the range between 250 and 300 μS/cm. The solution B can be controlled and maintained very easily in a well workable state.
The pH values of the solution B may vary in the range of from 1 to 10, preferably in the range of from 1.5 to 5.5, more preferred for some of the applied compounds in the range of from 1.8 to 4, whereas for others having alkaline additives the preferred range may be of from 7 to 14, preferably in the range of from 8 to 12, more preferred in the range of from 9 to 11. Most of the phosphorus containing compounds of the solution B may be used with such low pH values as mentioned above first, but some may be used with a higher pH value. As further additives to solution B may be used e.g. any alcohol, any silane, any amine, any phosphate, any phosphonate, any surfactant, any organic acid or any mixture of these. These additives may be used as defoamers, stabilizers, wetting agents, corrosion inhibitors and/or hydrophobic agents.
The metallic surfaces may be contacted with the solution A and/or separately with the solution B by dipping, immersing, roll-coating, squeegeeing or spraying, each application type independent from the other for the solution A resp. B. For coil coating, all kinds of application may be used with the exception of dipping; for other applications all types of application may be used. If in the process of spraying the aqueous solution B considerable amounts of foam should occur, then an adjustment of the spray nozzle concerning the flood effect may be necessary. If spraying is used, it is favorable to minimize the formation of foams, e.g. by selection of an angle of about 45°; then there will be normally no addition of a defoamer necessary.
The time of contacting the metallic surfaces with the aqueous solution B may be selected from the range of I second to 10 minutes, preferably of 5 seconds to 5 minutes. Therefore, it may be used for coil coating applications having a need of contacting times in the range of from 1 to 30 seconds as well as for other applications where there may be contacting times in the range of from 1 minute to 3 minutes. The process according to the invention may be further varied by applying several coatings to generate a multilayer of organic and inorganic layers by applying e.g. solution B, then solution A, then solution B, then solution A and finally solution B again. The multilayer may have at least 3, preferably 5, favorably up to 12 of these layers. Such multilayers are preferably generated with a zirconium rich solution A. It has been detected that there is an interesting chemical interaction between phosphonic acid functional groups and zirconium which may react again with phosphonic acid functional groups and then with zirconium again, e.g. as zirconyl chloride.
The process according to the invention may be started by subjecting the metallic surfaces to cleaning and/or degreasing before applying the first of the aqueous solutions A resp. B to the metallic surfaces. The cleaning and/or degreasing may be done with the help of conventional alkaline cleaners or solvent cleaners or acidic cleaners or cleaner mixtures. This cleaning and/or degreasing is only necessary if the solution B is the first applied aqueous pretreatment/treatment solution, as the solution A is often as acidic that a cleaning and/or degreasing before applying the solution A is favorable, but not necessary. In both cases, it is preferable to use after cleaning and/or degreasing a deoxidation step which may be carried out by contacting the metallic surfaces with an acidic solution typically with a pH value of up to 3 and which may contain any fluoride. On the other hand, the metallic surface may be cleaned and pickled or only pre-annealed before contacting it with one of the solutions A or B.
If the solution A is the first of the two applied solutions A and B, then there may be a cleaning, rinsing, pickling and one or two times rinsing before applying solution A as may be useful for the pretreatment of wheels. If the solution B is the first of the two applied solutions A and B, then there may be a cleaning and one or two times rinsing before applying solution B as may be useful for the pretreatment of wheels or a cleaning, rinsing, pickling and one or two times rinsing before applying the solution B as may be useful for the pretreatment/treatment of cans or other containers. Preferably, in between any of the process steps and the next following process step of contacting with a reactive liquid there is at least one rinsing with water. In most of the steps, especially after cleaning and/or degreasing, tap water may be used for rinsing, but after the deoxidation as well as after contacting with the solutions A resp. B, de-ionized water is preferred. After the coating with the solution B, there is no necessity to rinse the metallic surfaces, as the unreacted material will not impair paint or other materials adhesion being applied to the coated surfaces later on. The coated metallic surfaces may be dried and/or the excess liquid may be blown away after having been coated with. the solution B. The solution B may therefore be applied in a no rinse method. There should be a rinsing in between contacting the metallic surfaces with the solution A and contacting them with the solution B. This is preferred to avoid drag in of the solution A into the solution B as there may be the risk of reaction of both solutions one with the other, causing precipitation and reducing the concentration of active compounds. In the case that first the solution B is applied and afterwards the solution A, it is preferable to have a rinsing in between because of the same reason, but it is not necessary because of the very small concentration of the effective ingredients of the dragged in liquid into the bath of the solution A. Alternatively, the excess liquid of the solution B could be dried or blown away instead of a rinsing. On the other hand, the drying of excess liquid of the solution A instead of a rinsing may be disadvantageous as there may be a decomposition or damage of the possibly later on applied paint or any other similar layer because of a possible reaction of the residue and the subsequently applied layer.
The metallic surfaces coated with the reaction products and deposited compounds of the solution A resp. B may then be coated with a lacquer, a paint, an adhesive, an after rinse, a sealing, a rubber and/or an organic material, especially with a polymeric material. The rubber layer may be useful for a metal to rubber bonding.
It is preferable that first the solution A is applied and then afterwards the solution B. But it may be favorable, too, first to apply the solution B and then the solution A. In this case, the coating as applied with the solution B may be partially or even only to a very small amount dissolved by applying the solution A. Furtheron, if the afterwards applied coating of the solution A should be thicker, the favorable effect of self assembling molecules will decrease or will be hindered and the advantages of this coating in contact with the later thereon applied layer of a paint or any other polymer containing coating will be reduced. If the coating applied with the solution A should be thin, this favorable effect may be partially or even essentially maintained. If the solution A should show a low or very low concentration, the coating applied by this solution will be quite thin. The combination process according to the invention combines the benefits of two treatments together: The solution A provides coatings which provide excellent corrosion protection by inorganic passivation of the surface. The solution B provides organic coatings, sometimes as monolayers, which create a hydrophobic barrier and also promote excellent paint adhesion. The use of both pretreatments result therefore in complementary protection of the metallic surface. Furtheron, the organic molecules of the compounds of the type XYZ, X*Y*Z* and/or X*Y*Z*Y*X* are reactive especially to zirconium.
The applied coatings are very suitable for applying a lacquer, a paint, an adhesive, an after rinse, a sealing, a rubber and/or an organic material, especially a polymeric material because of excellent adhesive strength, homogeneity of the surface and good reactivity to the functional groups of these further on applied coatings.
The metallic surfaces going to be coated according to the process of the invention may be such of castings, extruded parts, forgings, frames, housings, profiles, sheet stock, small parts, stampings, strips, wheels, wires, parts for aircraft industry, for apparatuses, for automobile industry, for beverage and other containers like cans, for construction or for mechanical engineering.
EXAMPLES
The following examples illustrate, in detail, embodiments of the invention. The following examples shall help to clarify the invention, but they are not intended to restrict its scope:
Substrates
1. Panels of aluminum alloy 6061, an alloy which is generally used in a certain percentage for sheets and for which corrosion testing results may be compared with results on an aluminum alloy A356 as used for castings like wheels.
2. Further on, testing was conducted on wheels resp. wheel sections of aluminum alloy A356. Two types of wheel sections were also used: “as-cast” which have a rough finish and generally more oxides on the surface and “machine-finished” which have been further processed by milling to obtain a bright surface.
3. Panels of 3003 aluminum alloys.
Process
The sheets as well as sections of wheels were coated using a standard process sequence for pre-treatment and after-treatment; the process is shown in Table I. The cleaning is done by spray application of an aqueous, non-etching, silicate-free alkaline cleaner, Oakite® Aluminum Cleaner NSS of Chemetall Oakite Inc.; the pH value of the bath solution was 9.0 after make up. As a deoxidizer for these alloys which contain small amounts of copper (<0.4%) and relatively low amounts of silicon (<7.5%), a hydrofluoric/sulfuric acid mixture, Oakite® 27-AA-15 of Chemetall Oakite Inc. was used at a total concentration of 0.4 mol/I of free acid. The coating stages were either performed by spraying or immersing to generate two sets of data—with the exception of the chromating solution which was only applied by immersing.
(Oakite® is a registered trademark of Chemetall Oakite Inc., Berkeley Heights, N.J., U.S.)
TABLE I
Process Sequence
Concen-
Chemicals,
tration
Tempera-
Time
Step
Process
Equipment
[g/L]
ture [° C.]
[sec]
1
Alkaline
Aluminum Oakite ®
30 to 50
55
120
Cleaning
Cleaner NSS
2
Rinsing
Tap water
ambient
30
3
Deoxidizing
Oakite ® 1/ -27-AA-
50
ambient
90
15
4
Rinsing
Tap water
ambient
30
5
Rinsing
De-ionized water
ambient
10
6
Coating with
See specific examples
solution A
7
Rinsing
De-ionized water
ambient
30
8
Coating with
See specific examples
solution B
9
Rinsing
De-ionized water
ambient
30
10
Drying
Oven
50
300
In the comparative examples 1 to 3, which employ only one coating solution, the process as shown in Table I was only partially used, but as far as possible. In example 4, the complete process was used as shown in Table I. Solutions referred to in the examples are further described in a subsequent section.
Example 1
Chromating
A chrome conversion coating was applied by immersion in Solution 1—which is a solution of type A—for 90 seconds at 35° C. After rinsing, the panel was dried before the presence of the chrome conversion coating was confirmed by x-ray fluorescence spectroscopy.
Example 2
Application of Solution A without the Subsequent Application of Solution B
A titanium/zirconium coating was applied by either immersion or spray application of Solution 2—which is a solution of type A—for 90 seconds at ambient temperature. After rinsing, the panel was dried before the presence of the coating was confirmed by checking the appearance of the part for a faint iridescent luster, indicative of homogenous formation of the coating.
Example 3
Application of Solution B without Prior Application of Solution A
A phosphonic acid coating was applied by either immersion or spray application of Solution 3—which is a solution of type B—for 90 seconds at ambient temperature. After rinsing, the panel was dried and the presence of the coating was confirmed by contact angle measurement.
Example 4
According to the Invention: Application of Solution A Prior to Solution B
After formation of the first coating by either spray or immersion application of Solution 2—which is a solution of type A—for 90 seconds at ambient temperature, the coated substrates were rinsed without drying. (Additional substrates were prepared and dried after rinsing in order to visually confirm the presence and homogeneity of the coating. In this way, it was possible to verify the formation of the first coating without interrupting the process.) Then Solution 3—which is a solution of type B—was applied to the already coated substrates for 30 seconds at ambient temperature. Individual substrates were exposed to both Solutions 2 and 3 in the same manner (either by immersion or by spray). The appearance of the twice coated substrates did not change after application of the second coating. The quality of the second coating was evaluated by contact angle measurements and further tested after painting by adhesion testing of the painted substrates.
Solutions
Solution 1 for the Comparative Example 1: Chromating
The coating solution 1—which is a solution of type A—was prepared by dissolving 30 g/L of Oakite® 27-GD-5 (a concentrated product for the formation of chromium conversion coatings) in de-ionized water, and potassium hydroxide was added until the level of the pH value of 3.0 was reached. This corresponds to a chromic acid concentration of 1.1 g/L.
Solution 2 for the Comparative Example 2: Application of Solution A without the subsequent application of Solution B
The coating solution 2—which is a solution of type A—was prepared by dissolving hexafluorozirconic acid and hexafluorotitanic acid in de-ionized water until reaching a zirconium concentration of 0.016% by weight, a titanium concentration of 0.043% by weight and a fluoride concentration of 0.12% by weight. In solution, the fluoride was largely present as complexed hexafluoride. The pH value of the solution was adjusted to 3.0 with ammonium hydroxide.
Solution 3 for the Comparative Example 3: Use of Solution B without prior application of Solution A
The coating solution 3—which is a solution of type B—was prepared by dissolving 0.33 g of dodecanediphosphonic acid per liter of de-ionized water which resulted in a pH value of 3.6.
Preparation of Solution 2 and of Solution 3 for use in the dual-stage process in Example 4 according to the invention: Application of Solution A prior to Solution B
The coating solution 2—which is a solution of type A—was prepared by dissolving hexafluorozirconic acid and hexafluorotitanic acid in de-ionized water until reaching a zirconium concentration of 0.016% by weight, a titanium concentration of 0.043% by weight and a fluoride concentration of 0.12% by weight. In solution, the fluoride was largely present as complexed hexafluoride. The pH value of the solution was adjusted to 3.0 with ammonium hydroxide.
The coating solution 3—which is a solution of type B—was prepared by dissolving 0.33 g of dodecanediphosphonic acid per liter of de-ionized water which resulted in a pH value of 3.6.
Preparation of Solution 2, Solution 3, Solution 4, and Solution 5 for the use in a dual-stage process in Comparative Example 7: Application of Alternative Solution. A's prior to Application of Solution B
The coating solution 2—which is a solution of type A—was prepared by dissolving hexafluorozirconic acid and hexafluorotitanic acid in de-ionized water until reaching a zirconium concentration of 0.016% by weight, a titanium concentration of 0.043% by weight and a fluoride concentration of 0.12% by weight. In solution, the fluoride was largely present as complexed hexafluoride. The pH value of the solution was adjusted to 3.0 with ammonium hydroxide.
The coating solution 3—which is a solution of type B—was prepared by dissolving 0.33 g of dodecanediphosphonic acid per liter of de-ionized water which resulted in a pH value of 3.6.
The coating solution 4—which is a solution of type A—was prepared by dissolving hexafluorozirconic acid and sulfuric acid in de-ionized water until reaching a zirconium concentration of 0.015% by weight, a sulfate concentration of 0.048%, and a fluoride concentration of 0.019% by weight. In solution, the fluoride was largely present as complexed hexafluoride. The pH value of the solution was adjusted to 3.0 with ammonium hydroxide.
The coating solution 5—which is a solution of type A—was prepared by dissolving hexafluorozirconic acid and an acrylic resin in de-ionized water until reaching a zirconium concentration of 0.015% by weight, a polymer concentration of 0.2% by weight, and a fluoride concentration of 0.04% by weight. In solution, the fluoride was largely present as complexed hexafluoride. The pH value of the solution was adjusted to 3.0 with ammonium hydroxide.
Preparation of Solution 3 and of Solution 6 for the use in the dual stage process in Example 10 and 11 according to the invention as well as for the comparison Example 12 and also in a multilayer process in Example 13 according to the invention:
The coating solution 3—which is a solution of type B—was prepared by dissolving 0.33 g of dodecanediphosphonic acid per liter of de-ionized water which resulted in a pH value of 3.6.
The coating solution 6—which is a solution of type A—was prepared by dissolving 1.00 g of zirconyl chloride (ZrOCl 2 ) per liter of de-ionized water. This solution had a pH value of 3.0.
Results
The coatings were judged for iridescent appearance, for complete coverage, and for uniformity. The coating weight was analyzed for the TiZr content by X-ray fluorescence analysis using samples for calibration of the same alloys with a known Ti and Zr content on the surface.
All sections were powder painted with 3.0 to 3.5 mil of Ferro VP-188 clearcoat polyester powder paint. 24 hours after painting, parts were scribed in the face and window region of the section and installed into a CASS chamber for 240 hour exposure to Copper-Accelerated Acetic Acid-Salt Spray Testing according to CASS DIN 50021. The performance was determined by total creepage, a measure of paint debonding and corrosion development, reported in Table II in millimeters.
TABLE II
Results of CASS testing in millimeters.
Example
1 (comp.)
2 (comp.)
3 (comp.)
4 (invention)
by immersion
3.00
3.20
3.16
2.83
by spray
—
3.39
3.75
3.04
The performance data of Table II indicate that there is a combination effect of both treatments according to the invention. The CASS test as used is a standardized test procedure especially for the corrosion inhibition of wheels and is very significant for the quality of the results. The results for immersed substrates as well as the results for sprayed substrate show significantly better data for the process according to the invention, when there was a first coating with a solution of type A and then a second coating with a solution of type B. All these data were gained with considerable diligence. Therefore, the process 4 according to the invention as far as applied by immersion should be significantly better than the typical chromating process as normally used.
Furtheron, all aluminum alloy sheet panels were tested with the Impact Test, ECCA T5 with 20 inch-pounds; the results were okay for the use of solutions 2 and 3 together. All aluminum alloy sheet panels were tested with Accelerated Outdoor Exposure Test with Common Salt in accordance to VDA test sheet 621-414; the results were below 1 mm for all examples according to the invention.
All aluminum alloy sheet panels were tested with Filiform Corrosion Test over 3000 hours in accordance to DIN EN 3665; the results were maximum lengths below 1 mm for all examples according to the invention. For the comparison examples 2 and 3, the results varied in the range of from 1 to 2 mm.
All aluminum alloy sheet panels as well as wheel sections were tested with Cross Hatch Test in accordance to DIN EN ISO 2409; the results were Gt=0 lengths for all examples according to the invention. For the comparison example 2, the results varied at about Gt=1.
Typically, sections of wheels as well as parts made of aluminum alloys show after more than 1000 h CASS values<1 mm and after more than 1000 h Salt Spray Test values< 1 mm.
Further Experiments for Optimization and Comparison
Example 5
Variation of the pH Value of the Solution of the Type A
Additional panels of AA 6061 were prepared using the process according to the invention as described above in example 4. For these substrates, the pH of Solution 2—which initially contained 0.016% by weight of zirconium, 0.043% by weight of titanium, and a fluoride concentration 0.12% by weight—was adjusted by the addition of small quantities of ammonium hydroxide. The composition of Solution 3 was not modified for this set of panels. After application of both solutions and painting as previously described, the panels were scribed and exposed to CASS solution for 240 hours in accordance with CASS DIN 50021. The total creepage which developed is reported in Table III.
TABLE III
Results of CASS testing of pH series of panels
pH value
1.5
2.0
2.9
5.5
creepage [mm]
1.75
1.00
1.00
1.75
Table III indicates that there is an optimum of corrosion inhibition if a pH value in a range about 2.0 and 2.9 is used.
Example 6
Variation of the Concentration of the Solution A
In a similar series of tests as in example 5, the concentration of Solution 2 was varied while the pH value was maintained in the range of 3.0 to 3.5 with specific additions of ammonium hydroxide. The concentration of Solution 2 which is indicated in Table IV will be reflected in a proportional dilution of the content of zirconium, titanium, and fluoride in comparison to the neat solution. The composition of Solution 3 was not modified for this set of tests. Machine-finished wheel sections were prepared using the process described in Example 4, and painted and scribed as described previously. After 240 hour exposure to CASS in accordance to CASS DIN 50021, the wheel sections were evaluated and total creepage (mm) is reported in Table IV.
TABLE IV
Results of CASS testing of Solution 2 concentration series.
concentration [%]
7.1
14.3
28.6
71.4
100.0
creepage [mm]
1.5
2.0
2.0
2.0
2.5
Table IV indicates that very low concentrations of Solution 2 may be preferable.
Example 7
Comparison with Comparable Coatings
A series of wheel sections were treated with a variety of solutions which contain at least zirconium and fluoride in common. Solution 2 was diluted with de-ionized water such that it contained 0.012% by weight titanium, 0.004% by weight zirconium and 0.034% by weight fluoride, Solution 4 contained 0.015% by weight zirconium and 0.019% by weight fluoride with additional sulfate, and Solution 5 contained 0.015% by weight zirconium and 0.04% by weight fluoride with additional polymer in solution. Sections were processed according to the invention as described above in Example 4 using Solution 3 as Solution B. After painting with the same paint as described previously and scribing, CASS performance was evaluated by measuring creepage (in mm) after 240 hour exposure of the parts to Copper-accelerated Acetic Acid-Salt Spray testing according to CASS DIN 50021.
TABLE V
Results of CASS testing of Solution A Variation Series
Solution
2
4
5
Concentration* [%]
0.016
0.015
0.015
creepage [mm]
1.5
2.0
1.5
*of the sum of titanium and zirconium
The data of Table V seem to describe that alternate compositions of the solution used as Solution A in the process as described in Example 4 may be appropriate as long as the solution meets the compositional requirements as described previously.
Example 8
Variation of the Concentration of the Solution B
A series of panels of 6061 AA were treated as described in Example 4 with a sample of Solution 2 which had been diluted with deionized water such that it contained. 0.0061% of titanium, 0.0022% of zirconium and 0.017% of fluoride. For Solution B, a sample of Solution 3 was modified with a series of dilutions with deionized water such that the resulting total concentration of phosphonic acids in solution was decreased from 1 mM to 0.001 mM. Although the majority of phosphonic acids present were 1,12-dodecanediphosphonic acid, impurities and isomers may also have been present. Parts were painted with the same paint as described previously, scribed, and exposed to CASS for a 240 hour exposure in accordance with CASS DIN 50021. Panels were than evaluated for corrosion performance by measuring creepage (in mm).
TABLE VI
Results of CASS testing of Solution B Concentration Series
Concentration [mM]*
1
0.5
0.1
0.05
0.01
0.005
0.001
pH value
3.6
4.0
4.6
4.9
5.5
5.7
5.9
creepage [mm]
2.5
2.5
2.5
2.0
2.5
2.5
2.5
*total of the phosphonic compounds
The data of Table VI vary only slightly, but seem to indicate a minimum at about 0.05 mM of diphosphonic compounds in Solution B.
Example 9
Variation of the Type of Phosphonic Compounds and their Concentration
Wheel sections were treated using the process as described in Example 4 with a sample of solution 2 which had been diluted with deionized water such that it contained 0.0061% by weight titanium, 0.0022% by weight zirconium, and 0.017% of fluoride. Then one of a series of solutions were applied which either contained 1 mM dodecanephosphonic acid, or either 0.01%, 0.1%, or 1.0% aminotri(methylene phosphonic acid), or either 0.01%, 0.1%, or 1.0% 2-phosphonobutane-1,2,4-tricarboxylic acid. After painting with the same paint as described previously and scribing, CASS performance was evaluated by measuring creepage (in mm) after 240 hour exposure according to CASS DIN 50021. For comparison, wheel sections were also prepared by chromating as in Comparative Example 1, painted and tested. Additional sections were also prepared by cleaning and deoxidizing but with no further processing other than a deionized water rinse prior to painting and testing.
TABLE VII
Results of CASS testing of Solution B Variation Series
DI Rinse
Amino tri
only
1,12-dodecane
(methylene
Final
(Compara-
Chromate
diphosphonic
phosphonic
Processing
tive)
(Comparative)
acid
acid)
Conc. [%]*
0
0.0011
0.03
0.01
pH value
6.9
3.0
3.6
4.0
Creep [mm]
4.0
3.0
2.0
2.0
Amino
Amino
2-phos-
2-phos-
2-phos-
tri(methyl-
tri(methyl-
phonobu-
phonobu-
phonobu-
ene
ene
tane-1,2,4-
tane-1,2,4-
tane-1,2,4-
Final
phosphon-
phosphon-
tricarbo-
tricarbo-
tricarbo-
Processing
ic acid)
ic acid)
xylic acid
xylic acid
xylic acid
Conc. [%]*
0.1
1.0
0.01
0.1
1.0
pH value
3.3
2.4
4.0
3.4
2.8
Creep [mm]
2.0
4.0
1.5
1.5
2.5
*weight percentage of phosphonic acids or chromium
The data of Table VII show that all of the phosphonic solutions result in better corrosion resistance than the comparative chromium application. The use of 2-phosphonobutane-1,2,4-tricarboxylic acid gave the best results of all tests.
All test results gave significantly better results when coatings with solution A and with solution B were applied than with solution B alone.
Examples 10 to 12
Variation of the Order of the Solutions A and B as Well as Omission of Solution A
For the examples 10 to 12, the cleaning and deoxidation sequence of Table I was used. The cleaning was done by spray application of an aqueous, non-etching, silicate-free alkaline cleaner, Qakite® Aluminum Cleaner NSS of Chemetall Oakite Inc.; the pH value of the bath solution was 9.0 after make up. As a deoxidizer for these alloys which contain small amounts of copper (<0.4%) and relatively low amounts of silicon (<7.5%), a hydrofluoric/sulfuric acid mixture, Oakite® 27-AA-15 of Chemetall Oakite Inc. was used at a total concentration of 0.4 mol/l of free acid. In examples 10 to 12, all processing was performed by immersion.
For example 10 according to the invention, first Solution 6 was applied as Solution A to panels of aluminum alloy 3003 for 90 seconds at ambient temperature. Following a DI rinse, Solution 3 was applied as Solution B. For example 11 according to the invention, first Solution 3 was applied as Solution B and afterwards Solution 6 was applied as solution A. For comparison example 12, only Solution 3 was applied to panels as Solution B with no subsequent exposure to any Solution A. All prepared substrates were painted after a DI rinse and drying as described previously, scribed and installed for 168 hr exposure to CASS. The following maximum creepage was recorded:
TABLE VIII
Results of CASS testing of Sequence Variation Trials.
example
10 (invention)
11 (invention)
12 (comp.)
CASS [mm]
2.0
2.0
5.0
The results indicate that the order of the solutions A and B may be exchanged, but that the use of a solution B alone may be significantly worse than the combination treatment of the solutions A and B.
Multilayer Experiments
Example 13
Variation of the Number of Layers of the Multilayer
A molybdate reagent solution which turns blue upon contact with aluminum was applied to panels of 6061 aluminum alloy treated with monolayers (P resp. P-Z) and bilayers (P-Z-P resp. P-Z-P-Z). Panels had been alternately treated at ambient temperature with phosphonates by immersion in Solution 3 and zirconium ions by immersion in Solution 6 separated by DI rinses. Generally, the solution will turn blue instantly on untreated panels. Here, the monolayers turned blue after 15 minutes and the bilayers after 20 minutes of contact with the molybdate reagent solution. This experiment indicates that the permittivity of the coating formed by a multilayer treatment is less than that of formed by a monolayer treatment. As total exposure time to coating solutions was kept constant for all prepared substrates, the reduced permittivity is attributed to multilayer formation, not just densification of a monolayer structure on the surface. This reduced permittivity has implications for the transport of water, ions, and other corrosive agents to the surface which is reflected in corrosion test data presented below.
Humidity testing of unpainted panels in accordance with ASTM standard D1735 was performed demonstrating the anti-corrosive benefit of multilayer applications of phosphonic acid and zirconium salt solutions. Panels of 6061 aluminum alloy were prepared by application of phosphonate by immersion in Solution 3 or by application of zirconium by immersion in Solution 6 separated by DI rinsing for 30 seconds. In the following, the numbers in the center column describe the contacting time in minutes for each immersion, the numbers in the right column show the relative performance quality with “1” for the best outcome:
TABLE IX
Relative Humidity Trial Performance of Monolayers and Bilayers
Coating
Sequence
Relative Performance
Monolayer
5 minutes
6
Monolayer
2 minutes
5
Bilayer
2-2-2 minutes
4
Bilayer
2-5-5 minutes
3
Bilayer
2-2-5 minutes
2
Bilayer
5-5-5 minutes
1
Panels of aluminum alloy 6061 were also prepared to perform CASS testing per CASS DIN 50011 and GM Filiform testing per GM standard 9682P. Panels were immersed at ambient temperature either for 3 minutes in Solution 3 to produce a monolayer or for a sequence of 1 minute in Solution 3 followed by 1 minute in Solution 6 followed by 1 minute in Solution 3 (separated by 30 second DI rinses) to produce a bilayer. Panels were painted as described before, scribed, and installed into testing. For the CASS testing, the total average creepage after 168 or 336 hours exposure is reported in millimeters; however, for the filiform testing the maximum filament length which developed after 4 week exposure is reported below in Table X:
TABLE X
CASS and F liform Test Performance of Monolayers and Bilayers
Sequence
168 h CASS
336 h CASS
Fillform
Monolayer
3 minutes
1.50
3.00
0.75
Bilayer
1-1-1 minutes
0.92
1.00
0.25
These tests show that a bilayer, formed of two layers of phosphonic acid linked by transition metal ions, offer better corrosion protection than a monolayer developed for comparable exposure times.
|
Sequentially applying two different coatings, in two steps, to metallic surfaces. Metallic surfaces are contacted at temperatures from 10-100° C. with aqueous solution A and then with aqueous solution B, or vice versa, wherein
solution A contains an effective amount of zirconium, hafnium, titanium, silicon and/or boron, and of fluoride as ions and/or complex ions able to pickle metallic surfaces and generate a coating on the pickled metallic surface and that solution B contains an effective amount of one or more of XYZ, X*Y*Z* and/or X*Y*Z*Y*X* where Y is an organic group with 2-50 carbons,
where X as well as Z is a group—each same or different—of OH—, SH—, NH 2 —, NHR—, CN—, CH═CH 2 —, OCN—, CONHOH—, COOR′, acrylamide-, epoxide-, CH 2 ═CR″—COO—, COOH—, HSO 3 —, HSO 4 —, (OH) 2 PO—, (OH) 2 PO 2 —, (OH)(OR′)PO—, (OH)(OR′)PO 2 —, SiH 3 —, Si(OH) 3 —,
where R′ is an alkyl group with 1-4 carbons,
where R″ is hydrogen or an alkyl group with 1-4 carbons,
and where X and Z are each bound to the Y in their terminal position,
where Y* is an organic group with 1-30 carbons,
where X* as well as Z* is a group—each same or different—of OH—, SH—, NH 2 —, NHR′—, CN—, CH═CH 2 —, OCN—, CONHOH—, COOR′, acrylamide-, epoxide-, CH 2 ═CR″—COO—, COOH—, HSO 3 —, HSO 4 —, (OH) 2 PO—, (OH) 2 PO 2 —, (OH)(OR′)PO—, (OH)(OR′)PO 2 —, SiH 3 —, Si(OH) 3 —,N—CH 2 —PO(OH) 2 —, —N—[CH 2 —PO(OH) 2 ] 2 — where R′ is an alkyl group with 1-4 carbons, where R″is hydrogen or an alkyl group with 1-4 carbons.
| 2
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a color display device comprising a cathode ray tube, means for generating at least one electron beam, a display screen, and a deflection unit for generating deflection fields for deflecting electron beam(s) across the display screen, and magnetic field-generating means at or near a display screen-facing end of the deflection unit to reduce raster distortions.
[0002] U.S. Pat. No. 4,746,837 discloses a color display device having a deflection unit, in which a number of pole shoes are arranged around the deflection unit and at the side of the deflection unit facing the display screen. A pincushion-shaped distortion of the deflection field is formed between the pole shoes. Said pincushion distortion provides for a raster correction.
[0003] Although the known devices and similar devices in which magnetic correction fields are provided substantially reduce raster errors especially in the corners of the display screen, remaining raster errors are still noticeable, especially at 0.5 N and 0.5 S of the display screen.
SUMMARY OF THE INVENTION
[0004] It is an object of the invention to provide a display device having a deflection unit in which improved raster corrections are obtainable.
[0005] To this end, in accordance with an aspect of the invention, the display device according to the invention is characterized in that the magnetic field-generating means comprise correction coils and means for supplying said correction coils, in operation, with a correction current, the ratio between the correction current and the vertical deflection current being a function of the vertical deflection and being less for full vertical deflection than for half vertical deflection.
[0006] The invention is based on the recognition that, when a correction field, for which the strength is proportional to the strength of the vertical deflection field, is generated independently of the vertical direction (as is the case in the prior art because the poles divert the flux of the vertical deflection coils and thus the strength of the correction field is directly proportional to the vertical deflection field), it is possible to correct for raster distortions at the top and bottom (North and South) of the display screen, but raster corrections at positions between the bottom and top of the display screen and the East-West axis of the display screen are less than optimally performed. In the display device and deflection unit in accordance with the invention, the ratio of the current through the correction coils and the current through the vertical deflection coils is less for full vertical deflection than for half vertical deflection.
[0007] This enables the correction coils to better influence the inner pincushion errors (i.e. around 0.5 North and South vertical deflection) as well as the geometry along the edges. An improved raster correction is thereby obtainable.
[0008] Preferably, said ratio of the currents at half the vertical deflection is between 1.5 and 2.5 times larger than that at full vertical deflection.
[0009] Preferably, the delay time between the current through the correction coils and the current through the vertical deflection coils after fly-back is less than 400 μsec, preferably less than 300 μsec. A larger delay time introduces raster distortions in North or South.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and further aspects of the invention will be explained in greater detail by way of example and with reference to the accompanying drawings, in which
[0011] [0011]FIG. 1 is a display device
[0012] [0012]FIG. 2 is a sectional view of a deflection unit comprising compensation coils.
[0013] [0013]FIG. 3 shows schematically a circuit for a display device in accordance with the invention
[0014] [0014]FIG. 4 illustrates the current through the compensation coils in relation to the current through the vertical deflection coils.
[0015] [0015]FIGS. 5A and 5B illustrate the raster correction with and without use of raster correction coils.
[0016] The Figures are not drawn to scale. In general, like reference numerals refer to like parts.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] A color display device 1 (FIG. 1) includes an evacuated envelope 2 comprising a display window 3 , a cone portion 4 and a neck 5 . Said neck 5 accomodates an electron gun 6 for generating three electron beams 7 , 8 and 9 . A display screen 10 is present on the innerside of the display window. Said display screen 10 comprises a phosphor pattern of phosphor elements luminescing in red, green and blue. On their way to the display screen, the electron beams 7 , 8 and 9 are deflected across the display screen 10 by means of a deflection unit 11 and pass through a shadow mask 12 which is arranged in front of the display window 3 and comprises a thin plate having apertures 13 . The shadow mask is suspended in the display window by means of suspension means 14 . The three electron beams converge and pass through the apertures of the shadow mask at a small angle with respect to each other and, consequently, each electron beam impinges on phosphor elements of only one color. In FIG. 1 the axis (z-axis) of the envelope is also indicated.
[0018] [0018]FIG. 2 is a sectional view of a deflection unit in accordance with the invention. Said deflection unit comprises two deflection coil systems 21 and 22 for deflecting the electron beams in two mutually perpendicular directions. Coil system 21 comprises coils for the vertical deflection (deflection with relatively low frequency) of the electron beams. In this example, the deflection unit further comprises a yoke 23 . Said yoke is made of a soft-magnetic material. Compensation coils 24 are arranged around the display device, in this example on the deflection unit 11 . In this example, compensation coils 24 are fitted into a holder 25 . Means 27 are provided to supply coils 24 , in operation, with a current of the same frequency as the vertical deflection current though coils 21 .
[0019] [0019]FIG. 3 illustrates schematically a circuit for a display device in accordance with the invention. The frame current generator 31 supplies a current I 21 through the vertical deflection coils 21 which, in this example, are placed in parallel with a resistor 26 . The correction coils 24 are coupled to the deflection coils, but two Zener diodes Z 1 and Z 2 and, in this example, a resistor 27 are placed parallel across the correction coils. These Zener diodes are chosen to be such that the current I 24 through the correction coils 24 is topped at a maximum current value.
[0020] [0020]FIG. 4 shows schematically the currents I 21 and I 24 as a function of time. Initially, I 21 and I 24 are equal. Above a certain threshold value I max for I 21 , the current I 24 is held at a fixed value I max . The ratio between the two currents thus starts at 1 up to a certain deflection, whereafter it is reduced.
[0021] [0021]FIGS. 5A and 5B show schematically raster errors without application of raster correction coils 24 (FIG. 5A) and with correction of error coils (FIG. 5B), but with a constant ratio between the vertical deflection current and the current through the correction coils (i.e. I 21 /I 24 is a constant value). FIG. 5A shows considerable raster errors. Raster errors up to 3 mm at full deflection may occur, which are clearly visible. As can be seen in FIG. 5B, the raster errors can be reduced to negligible values at full deflection (North and South) but some raster errors are left at 0.5 N and 0.5 S (typically of the order of 0.5 to 1 mm which is still visible). By sending more current through the correction coils 24 (or by using more turns), the raster errors at 0.5 N and 0.5 S can be reduced, however, at the expense of introducing raster errors at full deflection, because over-correction would occur.
[0022] The inventors have realized that the raster errors can be better corrected by reducing the ratio between the currents I 24 and I 21 , i.e. such that, relative to the deflection current, the current through the correction coils 24 at full vertical deflection is less than that at half vertical deflection. Making use of the invention, with a ratio at full deflection which is less than a ratio at half deflection in this example, the raster errors can be reduced to such an extent that they are no longer visible on this scale.
[0023] The vertical deflection current exhibits a sudden change from full deflection in one direction to full deflection in the opposite direction. This change is called the ‘fly-back’. In FIG. 4, the fly-back is shown by the steep step 42 . There will be a time delay depending on the circuit used and indicated in FIG. 4 by Δt between the currents I 21 and I 24 directly following fly-back. Current I 21 shows a value directly before fly-back and reaches a maximum value after fly-back. The difference between them is ΔI as indicated in FIG. 4. The delay time Δt is calculated as the time between the start of the fly-back and the point at which roughly 90% of this difference is reached. This delay time is preferably less than 400 microseconds, preferably even less than 300 microseconds. Larger values for the time delay result in currents I 24 directly after fly-back (i.e. at full North deflection) which are less than wanted. The time delay time depends on the RC time of the circuit chosen (inclusive of the correction coils) and can be theoretically calculated and/or experimentally determined.
[0024] It will be clear that many more variations, within the scope of the invention, are possible to those skilled in the art.
|
A color display device comprising a cathode ray tube and a deflection unit is described. The display device includes compensation coils for correcting a raster distortion in the raster displayed on the screen and means for providing correction currents through the correction coils. The ratio between the correction current I 24 and the vertical deflection current I 21 is higher at half vertical deflection than at full vertical deflection.
| 7
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FIELD OF THE INVENTION
[0001] The present invention provides a process for the preparation of pazopanib of Formula la or salts, and intermediates thereof.
BACKGROUND OF THE INVENTION
[0002] Pazopanib is a tyrosine kinase inhibitor of Formula Ia.
[0000]
[0003] Pazopanib is marketed as the hydrochloride salt, with the chemical name 5-[[4-[(2,3-dimethyl-2H-indazol-6-yl)methylamino]-2-pyrimidinyl]amino]-2-methylbenzenesulfonamide monohydrochloride, having the structure as depicted in Formula I:
[0000]
[0004] U.S. Pat. No. 7,105,530 provides a process for the preparation of a hydrochloride salt of a compound of Formula II
[0000]
[0000] involving the reduction of 2,3-dimethyl-6-nitro-2H-indazole with tin (II) chloride in concentrated hydrochloric acid in the presence of 2-methoxyethyl ether at 0° C. It also describes the preparation of a compound of Formula III
[0000]
[0000] involving the reaction of a hydrochloride salt of compound of Formula II with 2,4-dichloropyrimidine in the presence of a base and solvent mixture of tetrahydrofuran/ethanol followed by stirring for 4 hours at 85° C.
[0005] PCT Publication No. WO 2007/064752 provides a process for the preparation of a compound of Formula II comprising reducing 2,3-dimethyl-6-nitro-2H-indazole with 10% Palladium-carbon (50% wet) in the presence of methanol, followed by the addition of ammonium formate at a rate that ensures the reaction temperature is maintained at or between 25° C. and 30° C. It also discloses the preparation of a compound of Formula III comprising heating the compound of Formula II with sodium bicarbonate in presence of tetrahydrofuran and ethanol at or between 75° C. and 80° C. followed by cooling to 20° C. to 25° C.
[0006] The present invention provides a process for the preparation of a compound of Formula II which offers recycling of the Raney nickel catalyst used in the process, and an easy filtration work-up procedure. Further, the present invention offers selective reduction under mild conditions that is economical to use at an industrial scale.
[0007] The present invention also provides a process for the preparation of compound of Formula III which avoids the use of two or more solvents, and additionally, also circumvents heating and cooling procedures during the reaction. The aforesaid advantages yield a compound of Formula III with a lesser amount of N-(4-chloropyrimidin-2-yl)-2,3-dimethyl-2H-indazol-6-amine (CPDMI) impurity.
[0008] The compounds of Formula II and Formula III prepared by the present invention yield a compound of Formula Ia or its salts in comparable yield and suitable purity required for medicinal preparations.
SUMMARY OF THE INVENTION
[0009] A first aspect of the present invention provides a process for the preparation of pazopanib of Formula Ia or its salts
[0000]
[0000] comprising:
i) treating 2,3-dimethyl-6-nitro-2H-indazole with Raney nickel to obtain a compound of Formula II;
[0000]
ii) treating the compound of Formula II at a temperature of about 45° C. or below with 2,4-dichloropyrimidine to obtain a compound of Formula III;
[0000]
iii) converting the compound of Formula III to pazopanib of Formula Ia or its salts; and
iv) isolating pazopanib of Formula Ia or its salts.
[0014] A second aspect of the present invention provides a process for the preparation of pazopanib of Formula Ia or its salts
[0000]
[0000] comprising:
i) treating 2,3-dimethyl-6-nitro-2H-indazole with Raney nickel to obtain a compound of Formula II;
[0000]
ii) treating the compound of Formula II with 2,4-dichloropyrimidine to obtain a compound of Formula III;
[0000]
iii) converting the compound of Formula III to pazopanib of Formula Ia or its salts; and
iv) isolating pazopanib of Formula Ia or its salts
wherein the compound of Formula II is not isolated from the reaction mixture.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Various embodiments and variants of the present invention are described hereinafter.
[0020] The term “about”, as used herein, refers to ±5% variation in the values mentioned herein.
[0021] The 2,3-dimethyl-6-nitro-2H-indazole may be prepared by processes known in the prior art, for example, the process known in PCT Publication No. WO 2007/064752, or may be prepared by the process provided herein.
[0022] The Raney nickel used in the reaction is in the form of a fine grained solid. Step i) is carried out in the presence of an organic solvent and hydrogen gas. The organic solvent may be an alcoholic solvent. Examples of the alcoholic solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, or mixtures thereof. The compound of Formula II may be isolated from the reaction mixture or may be carried as such on to step ii) without isolation. The compound of Formula II may be isolated from reaction mixture by any method known in the art. The catalyst Raney nickel is recovered back and recycled.
[0023] The compound of Formula II may be further treated with suitable solvents, or mixtures thereof The treatment of compound of Formula II with solvents may include preparing a suspension, stirring, or slurrying. Examples of the solvents to be used include halogenated solvents, aliphatic hydrocarbon solvents, or mixtures thereof Examples of halogenated solvents include dichloromethane, dichloroethane, chloroform, and carbon tetrachloride. Examples of aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, and n-octane.
[0024] Step ii) is carried out in the presence of an organic solvent and a base. Examples of organic solvents include alcoholic solvents like methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, or mixtures thereof The base may be selected from organic or inorganic bases. The organic base is selected from the group comprising N,N-diisopropylethylamine, triethylamine, tri-isopropylamine, N,N-2-trimethyl-2-propanamine, N-methylmorpholine, 4-dimethylaminopyridine, 2,6-di-tert-butyl-4-dimethylaminopyridine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene, or mixtures thereof. The inorganic base is selected from the group comprising sodium carbonate, potassium carbonate, sodium hydride, sodium bicarbonate, potassium bicarbonate, or mixtures thereof.
[0025] Step ii) is carried out at a temperature of about 45° C. or below, for example, at about 25° C. to 30° C. The temperature of about 45° C. or below is critical for controlling the formation of N-(4-chloropyrimidin-2-yl)-2,3-dimethyl-2H-indazol-6-amine impurity (4-CPDMI as disclosed in PCT Publication No. WO 2011/069053) during step ii).
[0000]
[0026] The compound of Formula III is subjected to sequential treatment with water and an organic solvent. The treatment of the compound of Formula III with water and an organic solvent may include preparing a suspension, stirring, or slurrying. The organic solvent is selected from the group comprising ethyl acetate, n-propyl acetate, butyl acetate, or mixtures thereof The compound of Formula III may be isolated from the reaction mixture or may be carried as such on to step iii) without isolation. The compound of Formula III may be isolated from the reaction mixture by any method known in the art.
[0027] Step iii) may be carried out as per the embodiments described hereinafter, or by any other method known in the art.
[0028] The isolation of pazopanib or its salts is carried out by any method known in the art.
[0029] The salt of pazopanib is the hydrochloride salt of Formula I.
[0030] The compound of Formula I prepared by the process of the present invention may be further converted to pazopanib hydrochloride thereof by any method known to a person skilled in the art.
[0031] In the following section, preferred embodiments are described by way of examples to illustrate the process. However, these are not intended in any way to limit the scope of the invention. Several variants of these examples would be evident to persons ordinarily skilled in the art.
EXAMPLES
[0032] Step 1: Synthesis of 2,3-dimcthyl-6-nitro-2H-indazole
Example 1:
[0033] Trimethyloxonium tetrafluoroborate (125.2 g, 0.85 mol) was added to a stirred suspension of 3-methyl-6-nitro-indazole (100 g, 0.56 mol) in ethyl acetate (2000 mL) over a period of 4 hours in four equal lots at 1 hour time intervals. The reaction mixture was stirred at 25° C. to 30° C. for 16 hours. The solvent was recovered under reduced pressure. A saturated sodium bicarbonate solution (3240 mL) was added to the mixture slowly, and the reaction mixture was extracted with 4:1 mixture of dichloromethane isopropyl alcohol (1080 mL×5). The solvent was recovered under reduced pressure. Methyl tert-butyl ether (800 mL) was added to the residue, and the reaction mixture was stirred for 30 minutes at 45° C. to 50° C. The reaction mixture was cooled to 25° C. to 30° C. and was stirred at this temperature for 30 minutes. The solid was filtered, washed with methyl tert-butyl ether (100 mL×2), and dried in an air oven at 50° C. for 12 hours to afford 2,3-dimethyl-6-nitro-2H-indazole as a yellow solid.
[0034] Yield: 82.4% w/w
[0000] Step 2: Synthesis of 2,3-dimethyl-2H-indazol-6-amine
Example 2a
[0035] Raney nickel (12.50 g) was added to a suspension of 2,3-dimethyl-6-nitro-2H-indazole (50 g, 0.26 mol) in methanol (500 mL). The reaction mixture was stirred in an autoclave under hydrogen pressure of 3.5 kg/cm 2 -4.0 kg/cm 2 at 25° C. to 30° C. for 5 hours. Further, the reaction mixture was filtered through a hyflo bed, and the catalyst was washed with methanol (100 mL×2). The filtrates were combined, and the solvent was recovered completely. n-Heptane (250 mL) and dichloromethane (50 mL) were added to the residue, and the reaction mixture was stirred for 1 hour at 25° C. to 30° C. The solid was collected by filtration, washed with n-heptane (50 mL×2), and dried under vacuum at 40° C. to 45° C. to afford 2,3-dimethyl-2H-indazol-6-amine as a light brown solid.
Yield: 95% w/w
Example 2b
[0036] Raney nickel (21.25 g) was added to a suspension of 2,3-dimethyl-6-nitro-2H-indazole (85 g, 0.45 mol) in methanol (850 mL). The reaction mixture was stirred in an autoclave under hydrogen pressure of 3.5 kg/cm 2 -4.0 kg/cm 2 at 25° C. to 30° C. for 5 hours.
[0037] Further, the reaction mixture was filtered through a hyflo bed, and the catalyst was washed with methanol (85 mL×3). The filtrates were combined, and the solvent was recovered up to the volume of 850 mL. The 2,3-dimethyl-2H-indazol-6-amine in methanol was used as such in the next step.
[0000] Step 3: Synthesis of N-(2-chloropyrimidin-4-yl)-2,3-dimethyl-2H-indazol-6-amine
Example 3
[0038] Sodium bicarbonate (112 g, 1.34 mol) was added to a stirred solution of 2,3-dimethyl-2H-indazol-6-amine (as obtained from step 2; Examples 2a and 2b) in methanol 2,4-Dichloropyrimidine (99.35 g, 0.67 mol) was added to the reaction mixture followed by stirring of the reaction mixture for 24 hours at 25° C. to 30° C. De-ionized water (850 mL) was added to the reaction mixture followed by stirring of the reaction mixture at 25° C. to 30° C. for 1 hour. The solid was filtered. The wet solid was washed with de-ionized water (170 mL×2) to obtain a wet material. De-ionized water (850 mL) was added to the wet material to obtain a slurry, and the slurry was stirred at 25° C. to 30° C. for 30 minutes. The solid was filtered, then washed with de-ionized water (170 mL×2). The wet material obtained was treated with ethyl acetate (340 mL) to obtain a slurry. The slurry was stirred at 35° C. to 40° C. for 30 minutes and then cooled to 0° C. to 5° C. The slurry was further stirred at 0° C. to 5° C. for 30 minutes. The solid was collected by filtration, then washed with cold ethyl acetate (170 mL×2). The solid was dried in an air oven at 50° C. for 16 hours to afford N-(2-chloropyrimidin-4-yl)-2,3-dimethyl-2H-indazol-6-amine as an off-white solid.
Yield: 86.7% w/w
Step 4: Synthesis of Pazopanib Hydrochloride
Example 4a: Synthesis of N-(2-Chloropyrimidin-4-yl)-N,2,3-trimethyl-2H-indazol-6-amine
[0039] Cesium carbonate (238 g, 0.73 mol) and iodomethane (57 g, 0.40 mol) were added to a stirred suspension of N-(2-chloropyrimidin-4-yl)-2,3-dimethyl-2H-indazol-6-amine (100g, 0.37 mol) in N,N-dimethylformamide (300 mL) at 25° C. to 30° C. The reaction mixture was further stirred at 25° C. to 30° C. for 6 hours followed by cooling of the reaction mixture to 0° C. to 5° C. De-ionized water (300 mL) was added drop-wise to the reaction mixture, then the reaction mixture was stirred at 5° C. to 10° C. for 30 minutes. The solid was collected by filtration, and washed with de-ionized water (100 mL×2). The wet material so obtained was dried in an air oven at 50° C. for 12 hours to obtain the title compound.
Yield: 90.4% w/w
Example 4b: Synthesis of Pazopanib Hydrochloride
[0040] To a suspension of N-(2-chloropyrimidin-4-yl)-N-2,3-trimethyl-2H-indazol-6-amine (90 g, 0.312 mol) and 5-amino-2-methyl benzene sulfonamide (64.07 g, 0.344 mol) in isopropyl alcohol (900 mL) was added 4M hydrochloric acid solution in isopropyl alcohol (1.56 mL, 6.25 mol). The reaction mixture was heated to reflux temperature for 10 hours to 12 hours. The reaction mixture was cooled to 25° C. The reaction mixture was further stirred at 25° C. to 30° C. for 30 minutes, then the solid was filtered. The wet solid was washed with isopropyl alcohol (180 mL×2), and then dried under vacuum at 45° C. to 50° C. for 12 hours to afford the hydrochloride salt of 5-({4-[(2,3-dimethyl-21-I-indazol-6-yl)(methyl) amino] pyrimidin-2-yl} amino-Z-methylbenzene sulfonamide as a light brown solid.
[0000] Yield: 97% w/w
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The present invention provides a process for the preparation of pazopanib of Formula Ia or salts, and intermediates thereof.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims benefit of priority to U.S. provisional patent application 60/982,424, filed Oct. 25, 2007, which is hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention pertains generally to gas shocks or air bags, more particularly to conveniently pressurized gas shocks or air bags, and still more particularly to devices for readily changing the pressure in pressurized devices.
[0006] 2. Description of Related Art
[0007] Gas filled shock absorbers, and air bags, are used to vary the riding conditions of a vehicle under large changes in loading conditions. Typically, changing the pressures in these devices is not easy, as one must find nitrogen or another gas source, and apply this pressurized source to the device in a controlled manner so as to not rupture the device. In high performance off-road conditions, this need is exacerbated, since gas filling facilities are scarce or nonexistent.
[0008] Furthermore, in bicycling, flat tires are frequently encountered when using pneumatic tubes. Such frequent flats give rise to bulky pumps for reinflating patched flat tires. These pumps are another source of weight that would most desirably be reduced.
BRIEF SUMMARY OF THE INVENTION
[0009] An aspect of the invention is a hand held apparatus for pressurizing gas shocks or air bags, comprising: an object to be pressurized; and a means for pressurizing the object. The object to be pressurized may comprise a gas shock, an air bag, or other component requiring accurate fill pressures, such as tires or other pneumatic leveling devices. Additionally, brake lines may be pressurized to assist in brake bleeding procedures.
[0010] Without limitation, the object may be substantially pressurized with a gas selected from a group of gasses consisting essentially of: helium, argon, nitrogen, argon, carbon dioxide, dry air, a refrigerant, and one or more of the preceding. Nothing in this application precludes pressurization by other, more expensive gasses such as Xenon or Helium, or flammable gasses, such as hydrogen or methane.
[0011] Typically, the attachment to the object to be pressurized is hose terminated with a Schrader or Presta valve, although it is not limited to these types of valves.
[0012] The means for pressurizing the object may comprise a hand held unit comprising: an attachment to the object to be pressurized at a pressure outlet; and an attachment to a highly pressurized gas source.
[0013] The hand held unit may comprise: a. a vent valve that fluidly and displaceably connects a pressurized plenum to an ambient atmosphere, the pressurized plenum fluidly connected to the pressure outlet; b. a vent actuator that displaces the vent valve, thereby causing actuation of the vent valve with a consequent flow of gas from the pressurized plenum to the atmosphere; c. a high pressure inlet section, comprising: i. a high pressure valve fluidly and displaceably connected between the highly pressurized gas source and the pressurized plenum, whereby a flow of high pressure gas from the highly pressurized gas source to the pressurized plenum is allowed during actuation of the high pressure valve; ii. a high pressure valve actuator that displaces the high pressure valve, thereby causing displacement and actuation of the high pressure valve.
[0014] The hand held apparatus above may further comprise a pressure gage capable of indicating the pressure of the object to be pressurized in fluid connection with the pressurized plenum. In this manner, the means for pressurizing the object may comprise a pressure gage capable of indicating the pressure of the object to be pressurized.
[0015] The hand held apparatus for pressurizing the object above may have as the means for pressurizing the object comprising: a. means for inflating the object to be pressurized; and b. means for deflating the object to be pressurized.
[0016] In another aspect of the invention, a method for hand held pressurizing of gas shocks or air bags may comprise: a. providing a hand held unit; b. attaching a high pressure gas source to the hand held unit; c. attaching the hand held unit to an object to be pressurize; d. activating a high pressure valve allowing a flow of a high pressure flow of gas from the high pressure gas source to a pressurized plenum in fluid connection with the object to be pressurized; and e. activating a vent valve allowing a flow of gas from the pressurized plenum to ambient atmosphere, thereby allowing the object to be deflated.
[0017] The method for hand held pressurizing of gas shocks or air bags above may further comprise monitoring the pressure of the object to be pressurized.
[0018] The monitoring the fill pressure step above may comprise using a pressure gage fluidly connected to the object to be pressurized.
[0019] A device may be capable of performing the steps of the method for hand held pressurizing of gas shocks or air bags above.
[0020] In yet another aspect of this invention, a hand held apparatus for pressurizing gas shocks or air bags may comprise: a. a high pressure inlet section, comprising: i. a high pressure valve that connects a highly pressurized gas source to a pressurized plenum, whereby a flow of high pressure gas from the highly pressurized gas source to the pressurized plenum is allowed; ii a high pressure valve actuator that can activate the high pressure valve; b. the pressurized plenum, comprising: i. a vent valve that connects the pressurized plenum to an ambient atmosphere, whereby a flow of gas from the pressurized plenum to the atmosphere is allowed; ii. a vent valve actuator that can activate the vent valve, thereby causing actuation of the vent valve.
[0021] In still another aspect of the invention, a hand held apparatus for inflating or deflating an object may be constructed, the hand held apparatus comprising: a. a high pressure port that fluidly connects a highly pressurized gas source to a pressurized plenum with a high pressure valve; b. a vent port that fluidly connects a vent valve to the pressurized plenum, the vent valve venting gas from the pressurized plenum to an external atmosphere; c. a gage port that fluidly connects to the pressurized plenum, wherein a gage attached to the gage port indicates the pressure of the pressurized plenum; d. a pressure output port fluidly connects to the pressurized plenum, wherein a change in pressure of the pressurized plenum reflects a change in pressure of an object to be inflated or deflated.
[0022] The ports of the hand held apparatus above may comprise a manifold.
[0023] The manifold may be comprised of a composition selected from a group of materials consisting essentially of: aluminum; fiberglass; a thermoplastic; and a thermoset plastic. The thermoplastic and thermoset plastics may both be foamed plastics when a foaming agent is added. Although aluminum is a likely choice of metals to use, other metals, such as copper, tin, steels, or titanium may be used, the only limitation being difficulties in fabrication and material cost. For ease of machining, low cost, and low weight, it is difficult to prefer any of the other alternative metals over aluminum.
[0024] The foamed plastics above may comprise a fiber filling with a weight percentage (Wt %) of fiber selected from the group of weight percentages consisting of: ≧1 Wt %, ≧2 Wt %, ≧5 Wt %, ≧10 Wt %, ≧15 Wt %, ≧20 Wt %, ≧30 Wt %, ≧40 Wt %, and ≧50 Wt %.
[0025] The fiber filling may be glass, carbon, or other relatively inexpensive fiber compatible with the plastic chemistries above.
[0026] Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0027] The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
[0028] FIG. 1 is a cross sectional view of a hand held apparatus for pressurizing gas shocks or other pneumatic devices.
[0029] FIG. 2 is a blown up section of the high pressure valve section of the hand held unit previously discussed in FIG. 1 .
[0030] FIG. 3 is a cross-sectional view of the hand held unit body.
[0031] FIG. 4A is a bottom left perspective view of a machine hand held unit body without the pressure source or gage attached.
[0032] FIG. 4B is a top right perspective view of a machine hand held unit body without the pressure source or gage attached.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 4B . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.
[0034] Pneumatic devices that provide lift and shock absorbing capacity are widely used world-wide. Frequently, these devices are filled with nitrogen gas, as this is substantially non-reactive relative to the materials (usually some sort of rubber) exposed to the gas. Dry air may be used, but it suffers from increase reactivity, hence oxidation. Simple compressed air suffers from the moisture that is ubiquitous in the atmosphere. Where non-dry air is used, reactivity may be increased over that of dry air, and the moisture may change state from gas to liquid or even solid, greatly changing the pressure of a confined sample of the air. For these reasons, and relatively low cost, nitrogen is a preferred filler for pressurized pneumatic devices such as gas shock absorbers (otherwise known as gas shocks) and “air bags” used for load levelling.
[0035] Refer now to FIG. 1 , which is a cross-sectional view of a hand held gaged gas filling apparatus 100 . Here, we find a hand held unit 102 , which is attached to a monitoring gage 104 on one end, and a highly pressurized gas source 106 at the other end. A cartridge puncture device 108 is mounted within the hand held unit 102 , which pierces the highly pressurized gas source 106 .
[0036] Highly pressurized gas source 106 is shown as a bottle, and in reality it is a thin walled pressure vessel confining a pressurized gas. The gas may be CO 2 , N 2 , O 2 , Ar, Xe, dry air, other dry gas, or any mixture of the preceding. Most likely, and most economically for filing pressurized components, the gas is N 2 or CO 2 gas.
[0037] A high pressure valve 110 , which is actuated by a high pressure actuator 112 , controls the release of the highly pressurized gas source 106 into a slanted portion 114 of a pressurized plenum. The pressurized plenum provides a source of pressurized gas controlled by vent actuator 118 by way of low-pressure vent valve 116 . The vent actuator 118 in turn controls the release of gas from the pressurized plenum into ambient atmosphere.
[0038] A longitudinal portion 120 of the pressurized plenum is in fluid connection with the slanted portion 114 of the pressurized plenum. The pressurized plenum (comprised of slanted portion 114 and longitudinal portion 120 ) fluidly communicates with pressure gage 104 and to pressure outlet 122 . Pressure outlet 122 is in turn connected to an object to be pressurized (not shown) through a pressure hose or other pressure containing tube. Thus, the pressure gage 104 indicates the pressure in the object to be pressurized. Ideally, the pressure gage 104 is fluid filled, and has a rather small orifice for pressure reading, so as to minimize fluctuations of the pressure gage 104 needle indicator, and thereby protect the needle from damage.
[0039] In operation, high pressure actuator 112 is depressed, allowing a flow of gas from the highly pressurized gas source 106 into the slanted portion 114 of the pressurized plenum. Gas released into the pressurized plenum equalizes with the pressure inside an object connected with the pressure outlet 122 . Then the high pressure actuator 112 is released when the vicinity of a correct inflation pressure is indicated by the pressure gage 104 .
[0040] Due to the relative complexity of the high pressure actuator 112 , a blowup 200 of the actuator is further described in FIG. 2 below.
[0041] Should the pressure indicated by the pressure gage 104 be too high, then the vent actuator 118 is depressed, allowing a flow of gas through a small diameter vent 126 from the slanted portion 114 of the pressurized plenum and from the object to be pressurized by the pressure outlet 122 . By controlling the flow exiting the vent 126 to ambient atmosphere, the pressure in the object may be carefully and precisely achieved.
[0042] In fabrication, high pressure valve 110 has a preferred rating of 2000 psi, and vent valve 116 has a preferred pressure rating of 500 psi. A relief valve 124 is threaded into the hand held unit 102 to provide pressure relief of plenum 114 for conditions exceeding 400 psi. The relief valve serves to also protect the pressure gage 104 from over pressure conditions that might otherwise be achieved through incorrect operation of the device, or blocking of the pressure outlet 122 to the object to be inflated. The highly pressurized bottle 106 is recessed 132 into the hand held unit 102 to minimize inadvertent disconnection. Further, the pressure gage 104 is attached to the hand held unit 102 through a threaded engagement.
[0043] Seal 128 may be used to separate the high pressure region behind the cartridge puncture device 108 from the slanted 114 and longitudinal 120 portions of the pressurized plenum. This seal 128 may be used when the hand held unit 102 is machined from a solid to minimize machining operations and consequent fabrication costs.
[0044] Highly pressurized gas source 106 may be nitrogen supplied from a replaceable 95 cm 3 cartridge style bottle that is approved for shipment via common carrier through the United States Department of Transportation (US DOT). A standard cartridge seal 130 is used to seal the high pressure gas source 106 to the hand held body 102 .
[0045] Refer now to FIG. 2 , which is a blown up section 200 of the high pressure valve 110 region of the hand held unit 102 previously discussed in FIG. 1 . Here, the high pressure actuator 112 translates an actuator shaft 202 where the high pressure actuator 112 is retained by detent 204 and has conical spring return 206 acting to return it from depression.
[0046] Interior circular clip 208 retains a pressure seal 210 which seals pressure in the slanted portion 114 of the pressurized plenum via large O-ring 212 to the hand held unit 102 , and to the actuator shaft 202 via small O-ring 214 . Both of these O-rings 212 and 214 are greased with silicone grease to minimize gas leakage from the slanted portion 114 of the pressurized plenum to ambient atmosphere outside the hand held unit 102 . Although not shown here, the vent actuator 118 actuates the low-pressure valve 116 in a similar fashion, but without an analog to the pressure seal 210 to the pressurized plenum being necessary.
[0047] Actuator shaft 202 is a ground and polished pin, with a highly smooth surface finish, allowing a low leak and reliable high pressure seal with small O-ring 214 .
[0048] Refer now to FIG. 3 , which is a cross-sectional view of the hand held unit 102 . Here, the Top, Bottom, Left and Right sides are indicated for ease of comparison in subsequent FIGS. 4A and 4B . For clarity's sake, all hardware contained within and attached to hand held unit 102 has been removed. This cross-section is useful for understanding the unitary design of the hand held unit 102 . Here, a block of metal, or high strength plastic, may be formed into the hand held unit 102 . By high strength plastic, glass filled polycarbonate would be a likely candidate. If machined from a metal, aluminum would be a likely hand held unit 102 material.
[0049] In operation, the palm of the hand presses against the Right side, and the fingers operated the high pressure and vent actuators previously described on the left side. To make the hand held unit 102 more ergonomically comfortable, the Right side is larger to better conform to the palm of the hand.
[0050] Refer now to FIG. 4A , which is a bottom left perspective view of a hand held unit 102 with just the actuators and no other hardware attached.
[0051] For rapid filling of an object to be pressurized, the high pressure actuator 112 is continuously depressed, so long as the monitoring pressure gage 104 (previously shown in FIG. 1 ) does not indicate an over-pressure condition on the object to be pressurized. Should the hose attached to the object to be pressurized be constricted, then the relief valve 124 operates to vent the pressurized plenum (previously shown in FIG. 3 ). In this manner, the relief valve 124 protects the pressure gage 104 (previously shown in FIG. 1 ).
[0052] In this view, the recess 132 for the highly pressurized bottle 106 (previously shown in FIG. 1 ) is visible on the bottom side of the hand held unit 102 . Also visible are the high pressure actuator 112 and the vent actuator 118 on the left side.
[0053] Refer now to FIG. 4B , which is a top right perspective view of the hand held unit 102 . In this view, we see the threaded region 134 where the pressure gage 104 (previously shown in FIG. 1 ) is installed. Also, vent 126 is seen. Since vent 126 is on the top of the hand held unit 102 , it is easily heard when in the process of venting pressure. Pressure outlet 122 is shown here as a traditional high pressure disconnect, but it may be any other pressure fitting.
[0054] Refer now to FIGS. 1-4B , it may be seen that the hand held gaged gas filling apparatus 100 may easily fit in the palm of a person's hand, and may be readily used for pressurizing and depressurizing objects connect to it through the pressure outlet 122 . Although here a highly pressurized gas source 106 is principally described, a more traditional pressure quick connect may be used as the filling gas source, allowing fill gas up to very high pressures to be used.
[0055] A common issue in the inflation and deflation of tires, shocks, and other pneumatic objects is that upon filling, the pressure is overshot, and must be reduced. However, in the process of reducing the pressure, the pressure is not easily measured without further pressure loss through reconnection of a pressure gage. Here, if pressure is overshot, the vent actuator is depressed, allowing a very controlled deflation of the object, with constant monitoring of the object inflation pressure.
[0056] Although the hand held gaged gas filling apparatus 100 is small enough to be easily hand held, it may be permanently or semi-permanently attached to allow for quick inflation and deflation of items such as pneumatic shock absorbers.
[0057] Although the description above contains many details, 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. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”
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An apparatus for hand held inflating or deflating gas shocks or air bags is disclosed that is substantially hand held. A body comprises a high pressure valve, a lower pressure vent valve, and a pressurized plenum between the two valves. A high pressure gas source is connected tot the high pressure valve on one side. An object to be pressurized is connected to the other side to the lower pressure pressurized plenum. A gage is optionally available to monitor the pressure of the object to be pressurized. This device, which may fit into traditionally glove compartments and tool boxes, allows for quick and accurate pressurization of gas filled devices with pressure tunable characteristics. Although described here with a standalone highly pressurized gas source, a standard pressure disconnect can allow the device to be used with conventional tire inflation and deflation with an external pump supplying the high pressure source.
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FIELD OF THE INVENTION
This invention relates to a case and particularly to a case provided for holding a toiletry kit.
BACKGROUND OF THE INVENTION
It is common, especially on commercial airline flights, to provide complimentary toiletry or amenity kits (at times referred to as ‘convenience kit’) for use by travelers. Such kits may be used also by campers, hikers, etc.
These kits typically include small, single-use items which may be useful during travel, such as socks, hand cream, tooth brush and tooth paste, ear-plugs, etc. In general, each kit is contained within a small pouch or sack.
It is known that the lavatories of an aircraft do not retain their cleanliness throughout the duration of a flight, in particular long flights, and thus entering a lavatory barefooted or wearing socks may be an unpleasant experience. Thus, wearing shoes or slippers is desired.
By necessity, these kits, especially on airlines, are small, and thus the number and nature of the items which may be included therein is limited.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided an article having a primary use associated with an open position thereof, and a secondary use associated with a closed position thereof, the primary use being that of a piece of clothing, the secondary use being that of a storage container, the article comprising a pouch having a closable opening, the pouch constituting, in the open position of the article, a functional portion of the piece of clothing, and, in a the closed position of the article, a storage pocket.
The piece of clothing may be a slipper, wherein the pouch functions, in the open position of the article, as a vamp thereof.
The pouch may comprise at least one back wall extending beyond the opening, the back wall constituting, in the open position of the article, a sole of the slipper, and, in a the closed position of the article, a closing flap of the storage container.
The article, in its closed position, is configured to receive at least another same article. Said same article is typically stored within the article also at its closed position. For example, the article may be made of flexible material such as fabric.
The article may comprise a securing arrangement. A first part of the securing arrangement is located on the back wall at an end which is farthest from the pouch, and a second part of the securing arrangement is located on the pouch. The first and second parts of the securing arrangement cooperate together for retaining the article in its closed position. The securing arrangement may be one of a hook and pile arrangement, such as sold under the name Velcro®, snaps, buttons and buttonholes, and hooks and eyelets.
A lower surface of the back wall, which constitutes the sole of the slipper when the article is in the open position, may comprise treads, or the sole portion may be made of, or coated with a liquid permeable material.
The article may comprise toiletry items stored within the pouch. The toiletry items may comprise at least one of a pair of socks, toothpaste, a toothbrush, a collapsible toothbrush, a face-wipe, a shaving kit, mouthwash, hand cream, a facemask, a comb, earplugs, etc.
When the toiletry items includes a pair of socks, the article and the socks may comprise cooperating parts of a fastening arrangements correspondingly located such that when a user is wearing the socks and the article as a slipper, the cooperating parts of the fastening arrangements are aligned. The first part of the securing arrangement may constitute one of the parts of the fastening arrangement of the article. The fastening arrangement may be one of a hook and pile arrangement, such as sold under the name Velcro®, snaps, buttons and buttonholes, and hooks and eyelets.
According to another aspect of the present invention, there is provided a kit comprising an article as described above, and at least one toiletry item stored within the pouch. The kit may comprise two of the articles, for example, a first of the articles stored, in its closed position, within a second of the articles, for example, in its pouch. The at least one toiletry item may be stored within the pouch of the first of the articles.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in practice, an embodiment will now be described, by way of a non-limiting example only, with reference to the accompanying drawings, in which:
FIG. 1A is a perspective view of an article according to the present invention in an open position;
FIG. 1B is a perspective view of the article illustrated in FIG. 1A in a closed position;
FIG. 2 illustrates a pair of socks according to an embodiment of the present invention;
FIG. 3A illustrates a kit according to the present invention;
FIG. 3B is a cross-sectional view of the kit illustrated in FIG. 3A , taken along line III-III;
FIG. 4A is a perspective view of the article according to another embodiment, comprising an attachment arrangement;
FIG. 4B is a perspective view of the article illustrated in FIG. 4A , with another of the articles partially received within the attachment arrangement; and
FIG. 4C is a perspective view of the articles illustrated in FIG. 4B , both in their respective closed position, and fully attached via the attachment arrangement.
DETAILED DESCRIPTION OF EMBODIMENTS
FIGS. 1A and 1B illustrate an article, generally indicated at 10 , which is readily transformable between an open position, as illustrated in FIG. 1A , and a closed position, as illustrated in FIG. 1B .
The article comprises a pouch portion 12 having an opening designated at 20 . The pouch 12 is formed by a top wall 14 , a back wall 16 , and a side wall 18 therebetween. The opening 20 is defined by edges of the top and side walls 14 and 18 , respectively.
The pouch 12 is sized and shaped for receiving various toiletry/convenience articles such as a pair of socks, toothpaste, a toothbrush, a collapsible toothbrush, a face-wipe, a shaving kit, mouthwash, hand cream, a facemask, a comb, earplugs, etc. (not illustrated in the FIGS. 1A and 1B ).
In the open position as illustrated in FIG. 1A , the article 10 functions as a slipper, once the convenience articles have been removed from the pouch portion 12 . Thus, the pouch 12 constitutes the vamp thereof, and the back wall 16 constitutes the sole thereof. In the closed position ( FIG. 1B ) the article 10 functions as a storage pouch/container for holding the toiletry items, wherein the back wall 16 constitutes a cover thereof.
The top and side walls 14 and 18 are made of fabric which is flexible yet has sufficient stiffness to maintain the pouch 12 such that the opening 20 remains open when no external force acts thereupon. In addition, an interior liner may be provided. The liner is preferably of a material which offers comfort to a user when the article 10 is being worn as a slipper.
The back wall 16 may comprise an interior shell (not seen), which gives the article its shape in its open and closed positions, and is flexible enough to be easily bent between the two positions. The shell may be made of, e.g., a polyethylene or viscoelastic sheet, or a stiff woven material. The liner is covered with a fabric which is similar or aesthetically complementary to that used to make the top and side walls 14 and 18 . Treads 22 (seen in FIG. 1B ), for example made from a viscoelastic material, may be provided on the underside of the back wall 18 in order to provide traction to a user when used as a slipper. Alternatively, the bottom face of the back wall 16 may be made of or coated with a liquid impermeable material, or the shell (not seen) may be made of such a material.
According to another embodiment, the article 10 is made of an inexpensive material, such that the article is disposable, such as SMS, or a staple non-woven made with cellulose. The article 10 may then be provided for a single use.
On the upper side of the back wall 16 , on the end farthest from the pouch 12 , is a first part 24 a of a securing arrangement (seen in FIG. 1A ). A second part 24 b of the securing arrangement is located on top wall 14 of the pouch 12 , on the outer side thereof. Thus, the article 10 can be retained in its closed position. The securing arrangement may be a hook and pile arrangement, such as that sold under the name Velcro®, snaps, buttons and buttonholes, or hooks and eyelets.
According to another embodiment, at least one of the articles 10 may be provided with an attachment arrangement adapted to attach two articles to each other. For example, as illustrated in FIG. 4A , a strap 32 may be provided on the underside of the back wall 18 . The strap 32 is loose enough to receive therein the back wall 18 of a second one of the articles 10 , as illustrated in FIG. 4B . As illustrated in FIG. 4C , the second of the articles is pulled such that it may be closed around the strap 32 , thus attaching the two articles 10 . Thus, twice the storage capacity may be realized.
According to modifications of this embodiment, the attachment arrangement may be, e.g., a hook and pile arrangement (such as Velcro™), snaps, buttons and buttonholes, hooks and eyelets, etc. When appropriate, each of the articles 10 may comprise corresponding portions of the attachment arrangement.
The article may be provided with toiletry items within the pouch, such as a pair of socks, toothpaste, a toothbrush, a collapsible toothbrush, a face-wipe, a shaving kit, mouthwash, hand cream, a facemask, a comb, and/or earplugs.
As seen in FIG. 2 , in the event that socks 25 are provided, the heel portion thereof may be provided with a first part 26 of a fastening arrangement, a second part of the fastening arrangement may be located on the article 10 , such that when a user is wearing the socks and the two of the articles as slippers, on each foot, the two parts of the fastening arrangements are aligned, so that the articles are retained on the feet of the user. The first part 26 of the fastening arrangement may be located and designed so as to cooperate with the first part 24 a of the securing arrangement, which would constitute the second part of the fastening arrangement vis-à-vis the socks 25 . Alternatively, a distinct second part of the fastening arrangement may be located on the article 10 . Furthermore, the location of the parts of the fastening arrangement may be located elsewhere of the sock 25 and the article 26 , respectively.
As seen in FIGS. 3A and 3B , the article 10 as described above may be provided as part of a kit, generally indicated at 30 , which comprises two of such articles in the closed position. The pouch 12 of a first of the articles 10 a comprises toiletry items, indicated at 28 , such as described above. The first of the articles 10 a , in its closed position, is then placed inside the pouch 12 of the second of the articles 10 b , which is closed. Accordingly, the side wall 18 of at least the second of the articles 10 b should be sizes so that the pouch 12 thereof can accommodate the first of the articles 10 a in the closed position, with the toiletry items contained therein. A toiletry kit may thus be provided, wherein the storage container for the toiletry items, comprising the first and second of the articles 10 a , 10 b , may be opened to form a pair of slippers.
Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations and modifications can be made without departing from the scope of the invention mutatis mutandis.
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An article having a primary use associated with an open position thereof, and a secondary use associated with a closed position thereof. The primary use is that of a piece of clothing, and the secondary use is that of a storage container. The article comprises a pouch portion ( 12 ) having an opening ( 20 ), the pouch constituting, in the open position of the article, a functional portion of said piece of clothing, and, in a the closed position of the article, a storage pocket.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for modifying non-leaf entries in an OSI (Open System Interconnection) directory of a tree structure, and more particularly to a directory service system using an OSI directory in which entries can be added, modified or removed to or from a directory information tree (DIT).
2. Description of the Related Art
Generally, in order to make it possible to communicate with a destination terminal without knowing a physical arrangement of a network, in an OSI directory, address information and attribute information of the destination terminal are provided on the basis of a logical name thereof, to be informed to a source terminal.
A system for implementing such a directory service as mentioned above usually comprises a directory user agent (DUA), a directory service agent (DSA) and a directory information base (DIB). Entities to be managed by the OSI directory are called objects which are stored as entries in the DIB. A structure in which these entries are arranged in a tree form, based on correlation of the entries with each other, is called a directory information tree (DIT). The highest entry of this DIT is called a root which is connected with lower entries. Of these lower entries, entries which are not connected with further lower entries are called leaf entries, and entries which are not the leaf entries are called non-leaf entries.
The commands which can be used in the above system including the DUA and DSA, include LIST, READ, ADD, MODIFY RDN, and so on. These commands, however, operate only for leaf entries so that the system has a drawback that non-leaf entries cannot be modified through the commands. For example, in a case where a certain section is shifted into another section or a name of the section is changed, because of the change in organization without changing constituent elements of the section, the inherent name of the section as a non-leaf entry must be modified. In this case, the prior art, however, cannot modify the inherent name by a single operation or command.
Prior art related to the OSI directory is described in "OSI--The Directory (ISO9594)" proposed as a Draft International Standard (DIS), and a conventional technique related to a system based on this DIS is disclosed in "Implementation of DIRECTORY (DSA)", JOHOSHORI GAKKAI 38-th 5H-1/2/3. However, this technique is mainly related to the directory (DSA).
Prior art for improving operationality for a directory user is disclosed in, for example, "Proposal of Function for Supporting Directory User", JOHOSHORI GAKKAI 35-th 5U-1. This prior art, however, relates to a search for directories and does not take into consideration improvement of service for users such as addition, modification, etc., of entries for a DIT.
SUMMARY OF THE INVENTION
An object of the present invention is to solve problems of the above prior art in a directory service system and to provide an OSI directory service system which can execute a request for modifying a non-leaf entry in a directory tree structure through one operation.
In accordance with the present invention, in order to attain the above object, when the directory service system receives the request with old and new inherent names for modifying an inherent name of the non-leaf entry, the standard commands are issued to the DSA and the DUA so as to perform a standard operation for the DIB and the inherent name of the non-leaf entry is modified. More specifically, the LIST commands are issued to obtain the DIT structure information of a designated entry having an old inherent name and all its lower entries, the READ commands are issued to obtain all attribute information of the designated entry and all the lower entries, the REMOVE Entry commands are issued to remove the designated entry and all the entries from the DIT structure, and the ADD Entry commands are issued to add the designated entry having the new inherent name and all the lower entries to the DIT structure, thus completing the modification of the inherent name of the designated non-leaf entry.
The directory service system according to the present invention comprises sufficient memory to store information of each of the non-leaf entries. When the directory service system receives the old and new inherent name of the designated non-leaf entry from a directory user, the old inherent name of the designated non-leaf entry is modified to the new inherent name on the basis of standard service (operations by the commands of LIST, READ, REMOVE Entry and ADD Entry) provided by the OSI directory, all entries lower than the designated entry are added to the DIT structure as the lower entries of the non-leaf entry with the new inherent name, and completion of the DIT structure modification process is informed to the user.
In this way, the directory user has only to issue one command to modify the inherent name of a designated non-leaf entry and shift all the lower entries of the designated non-leaf entry to the lower side of the non-leaf entry with the new name.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing arrangement of a directory service system according to a first embodiment of the present invention;
FIG. 2 is a flowchart for explaining an operation of the first embodiment;
FIG. 3 is a view for explaining modification of a DIT structure;
FIGS. 4, 5 and 6 are views for explaining a LIST operation a READ operation and an ADD operation which are standard operations, respectively;
FIG. 7 is a view for explaining data stored in an information area of a work area in a memory;
FIG. 8 is a flowchart for explaining an operation of a second embodiment of the present invention; and
FIG. 9 is a view for explaining modification of the DIT structure in the second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, referring to the accompanying drawings, explanation will be given for a directory service system for an OSI directory structure according to the present invention.
FIG. 1 is a block diagram showing an arrangement of a first embodiment of the directory service system according to the present invention. FIG. 2 is a flowchart for explaining an operation of the first embodiment. FIG. 3 is a view for explaining modification of a Directory Information Tree (DIT) structure.
In FIG. 1, an interface unit 2 is a characteristic portion of the present invention. A display unit 4 displays output data from the interface unit 2. When commands are input from an input device 6 such as a keyboard to interface unit 2, the interface unit 2 outputs a train of commands. A Directory User Agent (DUA) 8 is a standard user interface for utilizing a OSI directory service. The command train from the interface unit 2 is sent to the DUA 8. A Directory Information Base (DIB) stores directory information in the form of a tree structure. A Directory Service Agent (DSA) 12 receives a command from the DUA 8 through a communication network 10 to execute for the DIB 14 an operation determined in accordance with the command, and returns the executing result to the interface unit 2 through the network 10 and DUA 8. The display unit 4 displays the result sent from the interface unit 2.
Interface unit 2 includes a decoding section 22, a structure changing section 24 and a memory 26. The section 22 decodes a command input from the keyboard 6. When the input command is one of predetermined commands, i.e., the standard commands for the OSI directory, the section 22 outputs the input commands to the DUA 8. When the input command is not one of the predetermined commands, the section 22 activates the structure changing section 24 to execute a structure changing processing. The memory 26 stores data and programs necessary for the structure changing processing. Specifically, the memory 26 stores, in addition to a main program 26-1 for controlling the DIT structure changing processing through one command, a LIST and READ program 26-2, a MODIFY RDN program 26-3, a REMOVE program 26-4, an ADD program 26-5 and a MODIFY program 26-6. Memory 26 further comprises an information area 26-7 for storing information read out from the DIB 14 and information input from the keyboard 6, and a work area 26-8 used for the structure changing processing.
Explanation will be made of the standard directory service operations through DUA 8 and DSA 12.
FIGS. 4, 5 and 6 are views for explaining the LIST operation, the READ operation and the ADD operation which are the standard service operations. As seen from these figures, the directory includes entry names and the tree structure information indicative of correlation among entries and the directory is stored in the DIB 14. Several operations for commands issued from a directory user are executed using the DIB 14.
(1) LIST operation
In this LIST operation, all names of entries directly lower than a designated entry are returned to DUA 8. When it is desired to know names of lower entries of an entry B, as shown in FIG. 4, a LIST command (entry name =B) is issued from the DUA 8 to the DSA 12. The LIST command is supplied to the DSA 12 through the DUA 8. In response to this LIST command, the DSA 12 searches the DIB 14 to thereby know that names of entries directly lower than the entry B are B1, B2 and B3. These entry names are responded to the DUA 8. Likewise, when the LIST command is issued to the DSA 12 through the DUA 8 for each of the entries B1, B2 and B3, entry names X and Y are responded for the entry B1 and an entry name Z is responded for the entry B2. However, since the lead entry B3 has no directly lower entry, "No entry" is responded for the LIST command. By executing the LIST operation until all the leaf entries are responded, the directory user can know a structure portion of the directory information tree (DIT) structure.
(2) READ operation
In this operation, information of a designated entry such as an attribute type, an attribute value, and the like is read out. The directory user issues a READ command to the DSA 12 through the DUA 8. In response to this command, information possessed by the designated entry can be known. The entire or part of the information can be obtained in accordance with a parameter of the command. As seen from FIG. 5, the information of each entry is composed of a relative distinguished name for distinguishing the designated entry from other entries and its attribute data which includes an attribute type and attribute values.
(3) ADD Entry operation
In this operation, an entry is added at a lower portion than a designated leaf entry in the tree structure. The directory user sets the name of an entry to be added and also its attribute information (which is occasionally not included) in a parameter to issue an ADD entry command to the DSA 12 through the DUA 8. In the example of FIG. 6, an entry name B.B4 and its attribute information are set in the parameter. The entry name B.B4 means an entry B4 which is lower than the entry B and has the relative distinguished name B4. In response to the ADD Entry command, the DSA 12 searches the DIB 14 to check whether or not the entry B.B4 is already present in the DIT structure stored in the DIB 14. If the entry B.B4 is not present there, this entry is added at a designated position of the DIT structure. If the entry B.B4 is already present, a response of error is sent to the DUA 8.
In addition to the above standard service commands, operations for a REMOVE Entry command for removing a designated entry, a MODIFY command for modifying attribute information, a MODIFY RDN command for modifying the inherent name of a designated entry, and the like can be provided. It should be noted that the REMOVE command and the MODIFY RDN command of these commands can be issued only for leaf entries.
Referring to FIG. 2, an operation of the first embodiment of the present invention will be explained in connection with processing for modifying the inherent name of a non-leaf entry.
Now it is assumed that a directory user intends to modify the inherent name of an object entry of a DIT structure stored in the DIB 14. In this case, generally, the user does not know whether the object entry is a non-leaf entry or a leaf entry. Hence, first, the user issues a standard command for modifying the name of the object entry, MODIFY RDN to the decoding section 22 from the keyboard 6. The decoding section 22, when the issued command is one of predetermined standard commands, outputs that command to the DUA 8. In response to this command, the DUA 8 requests, through network 10, the DSA 12 to execute the command.
The DSA 12 examines the storage contents of the DIB 14 to check if the entry designated by the command is a leaf entry or not. If the designated entry is a leaf entry, its name will be modified. If the designated entry is a non-leaf entry, on the basis of the response from the DSA 12, the DUA 8 transfers, to the display unit 4 through the interface unit 2, a response that the name of the designated entry, which is a non-leaf entry, cannot be modified.
If, regardless of this response, the directory user still desires to modify the name of the designated non-leaf entry, the user issues to the decoding section 22 a name modification command with an old inherent name and a new inherent name as a parameter. The decoding section 22 decodes this command to activate the structure changing section 24. In accordance with main program 26-1 and programs 26-2 to 26-6 for issuing predetermined directory standard commands, the section 24 executes the structure changing processing, e.g. the name modification processing in this embodiment. In this case, the information area 26-7 in the memory 26 is used to temporarily store information of the designated entry and of its lower entries. The DUA 8 receives commands from the section 24 and requests the DSA 12 to execute these commands.
The structure changing section 24 receives a command for modifying the name of a designated non-leaf entry and performs operations in accordance with the flowchart of FIG. 2 to modify the name of the designated non-leaf entry. The flowchart will be explained below.
In step 122, the decoding section 22 receives, from a directory user, a name modification command with as a parameter a current inherent name as an old inherent name and a new inherent name. The old inherent name of the object entry is "Japan--A corporation--B division--a department--second section". The "second section" is a relative distinguished name of the object entry. The new inherent name has the same form with the relative distinguished name of "third section".
In step 124 the section 24 is activated in accordance with the program 26-1. In order to acquire all the entries for which modification should be made, the section 24 executes the program 26-2. As a result, a LIST command is repeatedly issued to the DUA 8 to obtain all the entries directly lower than a designated non-leaf entry, the entries directly lower than each of the lower entries thus obtained, and so on. Thus, the DIT structure information of the designated entry and all its lower entries can be obtained.
In step 126, the DIT structure information is stored in the information area 26-7 of the memory 26 as shown in FIG. 7, but attribute information is not stored yet.
In step 128, READ commands are issued to the DUA 8 on the basis of the program 26-2 to obtain the attribute information. Then, a data link as shown in FIG. 7 is created in the work area 26-8 in accordance with the structure information stored in the information area 26-7. Each data in the data link includes a pointer and a flag. Each flag is set to "1" when the data link is created and it is reset to "0" whenever the READ command for the entry is issued. Respective READ commands are executed to obtain the attribute information of the designated entry and its all lower entries.
In step 130, the attribute information thus obtained is stored in the information area 26-7 of the memory 26 as shown in FIG. 7.
In step 132, after all the flags are set again, the REMOVE Entry commands are sequentially issued to the DUA 8 in accordance with a data link reverse to the data link as described above on the basis of the program 26-5. In response to each REMOVE Entry command received through the network 10, the DSA 12 sequentially removes the designated entry, "second section", and all its lower entries, "Tanaka, Yamada and Aoki", from the DIT structure in the DIB 14.
In step 134, after all the flags are set again in accordance with the decoded command, the ADD Entry commands are sequentially issued to the DUA 8 in accordance with the data link, the DIT structure information and the attribute information of each entry on the basis of the program 26-5. Then, an entry with the new inherent name containing a relative distinguished name "third section" is added. Further, the entries lower than the object entry with the old inherent name are added at a lower portion than the added entry with new inherent names. In this way, the entry with the new inherent name and all its lower entries are added to the DIT structure.
In step 136, the structure changing process is ended, and completion thereof is informed to the directory user through the display unit 4.
According to this embodiment of the present invention, in order to modify the name of a non-leaf entry, only one command has been executed to change the object entry and all the lower entries with the old inherent names into those with the new inherent names.
The manner of modifying the entry name as described above is shown in FIG. 3 in terms of the DIT structures before and after execution of the modification. The example of FIG. 3 shows that the entry with the name of "A corporation--B division--a department--second section" is shifted to the position of the entry with the name of "A corporation--C division--c department--third section", and the lower entries in the former directory tree structure such as Tanaka, Yamada and Aoki who are members of the section are also shifted to corresponding positions in the latter directory tree structure.
Incidentally, although in this embodiment, the standard service commands for modifying an inherent name of a non-leaf entry were used in the order of LIST, READ, REMOVE Entry and ADD Entry, it is apparent that the order of REMOVE Entry and ADD Entry may be reversed.
Further, the removal of a non-leaf entry can be attained through the LIST operations and the REMOVE Entry operations, and the addition of a non-leaf entry can be attained through the LIST operations, the READ operations and the ADD Entry operation.
Now referring to the flowchart of FIG. 8 and FIG. 1, a second embodiment of the present invention will be explained only in its differences from the first embodiment.
In step 122, a message input from the keyboard 6 is received by the decoding section 22.
In step 142, the decoding section 22 decides if the received message is one of predetermined standard operation commands.
If the answer in step 142 is `Yes`, in step 146, the message is passed to the DSA 12 through the DUA 8 and the network 10. If the answer in step 142 is `No`, in step 144, the decoding section 22 decides if the received message is one of specially defined commands or an error message for the command sent to the DSA 12 in the step 122.
If the answer in step 144 is `Yes`, the operations of step 124 et seq. are executed as in the same manner as in the first embodiment. FIG. 9 shows the DIT structures before and after execution of the modification.
As described above, in accordance with the present invention, a command for changing the directory structure only has to be issued once to shift a non-leaf entry and all its lower entries to other positions with new inherent names.
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A method for changing an OSI (Open Systems Interconnection) directory information including a plurality of entries of a tree structure includes the steps of decoding a change command for changing a portion of the directory information including a non-leaf entry and at least one lower entry associated with the non-leaf entry, sequentially issuing, in response to the decoded change command, OSI directory commands for the non-leaf entry and the at least one lower entry, the issued OSI directory commands being determined based on the decoded change command, and executing the issued OSI directory commands to change the tree structure of the directory information.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method of specifying a location on a surface. The invention also relates to an article having a surface on which the location is or can be specified.
BACKGROUND OF THE INVENTION
[0002] A problem in specifying a location on a surface is that various types of coordinates are often used, and the coordinates often are inherently complex and/or relatively inaccurate and/or provide no obvious clue by which to envisage the position of the location.
[0003] It is an object of the present invention to provide a method of specifying a location on a surface which at least partly avoids or mitigates one or more of the foregoing and other problems and drawbacks.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention there is provided a method of specifying a location on the surface of a map or an overlay for a map, comprising dividing the said surface into a plurality of regions which are each identifiable by a respective single digit, wherein the plurality of regions is selected from either (i) six regions or (ii) nine regions, and allocating a respective one of the numbers (i) 1 to 6 , or (ii) 1 to 9 , to each region whereby each number identifies a respective region including at least part of the location, and dividing each region into a plurality of areas which are each indicated or identified by a respective single digit character
[0005] In one aspect, the invention provides a method of specifying a location on a surface, the method being in accordance with claim 1 of the claims which follow this description, and optionally in accordance with one or more of the feature(s) of one or more of the other claims.
[0006] In another aspect, the invention provides an article comprising a surface in accordance with the independent claim to an article which follows this description, and optionally in accordance with one or more of the feature(s) of one or more of the other claims.
BRIEF DESCRIPTION OF THE FIGURES
[0007] [0007]FIG. 1 shows a page from a map or atlas or a transparent overlay for use with one or more pages from a map or atlas, in accordance with the invention;
[0008] [0008]FIG. 2 shows some features of another embodiment in accordance with the invention;
[0009] [0009]FIG. 3 shows some features of another embodiment in accordance with the invention;
[0010] [0010]FIG. 4 shows a part of the embodiment of any one of FIGS. 1, 2 or 3 wherein a region is divided into a plurality of areas, in accordance with the invention;
[0011] [0011]FIG. 5 shows another embodiment of FIG. 4;
[0012] [0012]FIG. 6 shows another embodiment of FIG. 4 or FIG. 5;
[0013] [0013]FIG. 7 shows another embodiment of FIGS. 4, 5 or 6 ;
[0014] [0014]FIG. 8 shows one embodiment of an ikon or sign for use with any embodiment of the invention using a 3×3 array of rectangles. The ikon or sign is also shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In one embodiment of the invention, described by way of non-limitative example, a map (e.g., of a town) is provided on one or more sheets, which may be pages in a book or atlas. There may be an index of features (e.g., streets and/or other landmarks) shown on the map. The or each page of the map may be divided into rectangular spaces, which could be squares in one type of embodiment. Each rectangle may be indicated or denoted by a single respective digit. In one type of embodiment employing six rectangles, which could be in an array of 2 by 3 rectangles or 3 by 2 rectangles, the respective digits may be the numbers 1 , 2 , 3 , 4 , 5 and 6 . In another type of embodiment employing nine rectangles, suitably in an array of three rectangles by three rectangles, the respective digits may be the numbers 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and 9 . The nine rectangles may be arranged and numbered like the numbered keys on a conventional keypad of a telephone.
[0016] An ikon or sign (preferably small relative to the page or an overlay for a page) may be shown on the page(s) of the map or atlas (or overlay) as a guide or reminder to the user of the arrangement of rectangles. If the “keys” on the ikon or sign are numbered in the manner intended for the rectangles of the map or overlay, it may not be necessary to show the numbering of the rectangles on the map or overlay itself (since the numbering would be apparent to the user from the ikon or sign) thereby reducing still further clutter on the map or atlas and improving its clarity.
[0017] The digits may be applied (e.g., printed) on the page(s) of the map,or they may be applied on a transparent overlay which may also have the rectangular markings (e.g., squares). If the rectangular markings are on an overlay, there may be no need to provide them (or all of them) on the page(s) of the map. The index of features shown on the map may refer only to the number of the rectangle in which a particular feature appears on the page of the map. Thus, a particular feature can be found on a map by referring to the single digit in the index which identifies the rectangle of the map or overlay in which the feature is located. If the map is a multi-page map, the index would additionally refer to the page of the map on which the feature is shown. An advantage, from the user's viewpoint, is that the map is relatively less cluttered than maps of previous types in which the location of a feature is given in the index for the or each page by more than one digit, usually a combination of letters and numbers (e.g., the so-called “battleship” array).
[0018] As a result of the simple mode of indicating locations on a map in accordance with the invention, the user can find the location of a feature on a map or atlas more quickly and with more precision than previously. The convenience of use is enhanced by the reduced clutter on the map or atlas.
[0019] In another embodiment for which the location of features on the map can be found with more precision, each rectangle (e.g., square) of the map or overlay is divided into sub-divisions, each of which is or may be denoted or identified by a single digit.
[0020] There may be any convenient number of sub-divisions. In one embodiment, there may be nine sub-divisions, and they may be arranged in a three by three array. They may be identified by respective numbers 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 . The nine sub-divisions may be arranged and numbered like the numbered keys on a conventional keypad of a telephone. In another embodiment, there may be six sub-divisions. They may be in a two by three array or a three by two array, and identified by respective numbers 1 , 2 , 3 , 4 , 5 and 6 . In yet another embodiment, there may be four sub-divisions in a two by two array, each of which may be identified by a respective one of the numbers 1 , 2 , 3 , 4 . The four sub-divisions may be demarcated by two mutually perpendicular lines forming a cross. The use of subdivisions as just described enables the user to identify the location of a feature on a page of a map with great precision from a simple index of features without cluttering the map or overlay with numbers and letters. Moreover, the user is not burdened with more than three digits for the or each page of the map or overlay.
[0021] For even greater precision, the sub-divisions may each be further divided into smaller areas on the map or overlay. There may be any convenient number of smaller areas. For example, there may be nine or six or four smaller areas for each sub-division, and they may each be indicated by a respective number. If there are (e.g.) nine smaller areas, they may be arranged in a three by three array, and each numbered by a respective digit from 1 to 9 . Similarly, if there are six smaller areas, which could be in a two by three array or three by two array, the smaller areas may be indicated by a respective single number in the range 1 to 6 . If there are four smaller areas, which would preferably be in a two by two array, the smaller areas may each be indicated by a respective one of the numbers 1 , 2 , 3 , 4 . The smaller areas may be demarcated by two lines which are mutually perpendicular in the form of a cross. Thus, by way of non-limitative illustration, for the 29th page of a street atlas of a town, a feature indicated in an index by the reference 29 5-5-5- would obviously be in the central rectangle of a 3×3 array of rectangles on page 29, and would also be in the center of that central rectangle if the latter were subdivided into a 3×3 array of sub-rectangles. The final “5” would indicate the center of the central subrectangle if the latter were further divided into 3×3 smaller rectangular areas. Indeed, the user would rapidly learn where, on the page(s) of a map, various combinations of locational indicia would indicate. For example, the reference 15 1-1-1 in the map index would indicate page 15, top left-hand corner. An experienced user would probably be able to find the location of a feature on a map without the need to refer to any actual or notional lines and/or other markings (e.g., colors and/or hues) demarcating the smallest areas.
[0022] The invention is now described by way of non-limitative examples and with reference to the accompanying diagrammatic figures.
[0023] Referring first to FIG. 1, there is shown a page from a map or atlas, or alternatively, a single sheet transparent overlay for use with a map or atlas. The page or overlay is divided into nine rectangular regions in a three by three array. The rectangular regions are each numbered with a respective number 1 to 9 . It can be appreciated that the location of a feature on the page can be identified by referring to the single digit number indicating the rectangle around the feature. Thus, the number 7 refers to features in the bottom left rectangle of the page or overlay.
[0024] [0024]FIG. 2 is similar to FIG. 1 except that the page or overlay is divided into six rectangular regions in a two by three array. The rectangular regions are numbered 1 to 6 . In FIG. 2, as shown, number 4 indicates the rectangle at the center-right of the page or overlay.
[0025] [0025]FIG. 3 is similar to FIG. 2 in that the page or overlay is divided into six rectangular regions. However, the six regions are in a three by two array, and in this embodiment, the single digit “4” indicates the rectangular region at the bottom left of the page or overlay.
[0026] [0026]FIG. 4 shows, to a larger scale, one rectangular area of the page(s) or overlay(s) of any of FIGS. 1, 2 or 3 . The rectangular region is subdivided into nine rectangular areas in a three by three array. Each rectangular area is identified by a respective single digit numbered from 1 to 9 . Thus, area 3 , as depicted in FIG. 4, indicates the top right rectangular area within its larger rectangular region. Thus if the rectangular region were rectangle 2 in FIG. 2, the rectangular area 3 would be at the top right corner of the map or overlay, without significant or substantial clutter on the map or overlay. Similarly, FIGS. 5, 6 and 7 show other arrays for rectangular areas which could be used in the embodiments of FIGS. 1, 2 and 3 .
[0027] [0027]FIG. 8 shows one type of small ikon or sign that may be provided on (e.g.) FIG. 1 to indicate the numbers allocated to the respective numbered rectangular regions 1 to 9 . The ikon has the layout of a standard telephone keypad. It maybe used to obviate the need to provide numbers in or on the rectangular regions whereby the map appears less cluttered, and its clarity is correspondingly enhanced. The type of ikon or sign employed would correspond with the type of array on the page(s) of the map or overlay.
[0028] In another type of embodiment (not shown), the rectangular areas of FIGS. 4, 5 and 6 can be further divided into zones in the same way as is shown for the subdivisions into areas of the “large” rectangular regions of FIGS. 1, 2 and 3 . This further sub-division into zones provides great precision of identification of locations on the page of the map or overlay without necessarily cluttering the page or overlay. In many instances, an experienced user would find it adequate to have the single digit references for each zone resulting from the further division of the rectangular areas quoted in an index of features without the need to show the lines and/or other means (e.g., colors and/or hues) demarcating the zones or their respective numbers. The user would quickly appreciate that (for example) in a map using, e.g., nine by nine arrays of rectangular regions, areas and zones, the index reference 13 5-9-1 would indicate page 13, region 5 (the central rectangle 5 ), bottom right area (“sub-rectangle 9 ”), top left zone (of the sub-rectangular area 9 ), giving greater precision when only the rectangular regions and rectangular areas are indicated on the page(s) or overlay, or even when only the regions are demarcated or indicated.
[0029] The invention may also comprise an index listing features indicated on the map or atlas together with a map reference indicating the rectangular regions, areas, zones (and even finer divisions such as sub-zones, etc). If the map or atlas is a multi-page work, the index may also comprise a page reference for each feature.
[0030] The rectangular regions and/or overlays and/or zones may be separately depicted on two overlays, rather than on a single overlay, and/or in part on the map or atlas. For example, the rectangular regions of FIGS. 1, 2 and/or 3 could be shown on the page(s) of a map or atlas. The finer sub-divisions (e.g., as shown and/or described with reference to FIGS. 4, 5, 6 and 7 ) could be on one or more overlays.
[0031] Reference is now made again to FIG. 1 wherein it will be observed that (by way of non-limitative illustration) the rectangular regions 1 to 9 are each divided into nine rectangular areas in a 3×3 array. The nine areas are each numbered respectively 1 to 9 (i.e., in an arrangement like that used on a conventional telephone keypad). By way of a non-limiting illustration, area 5 of the nine areas is shown sub-divided into nine rectangular zones. The nine zones are in a 3×3 array, and each zone is numbered respectively 1 to 9 (i.e., as in a conventional telephone keypad array). The location of the point “X” shown in FIG. 1 would be indicated in an index by the references 5-3-1. The user would quickly become accustomed to the telephone keypad layout, and would easily be able to identify the location of a point on a map (or overlay) from the numbers allocated in the index to the region and the area (and the zone, if further accuracy were required). In addition to the ease of use, it is worthwhile considering that accuracy or precision is a feature of the system of the invention.
[0032] Often, ease of use of maps, atlases, etc. is compromised for the sake of accuracy, but in the case of the present invention, the two (i.e., ease of use and accuracy) are available together. By way of example referring to FIG. 1, in terms of accuracy, each rectangular region represents one ninth of the area of the page or overlay. Each rectangular area represents {fraction (1/81)} of the area of the map or overlay, and probably provides a degree of locational precision which would be adequate for most purposes (and more accurate than most traditional “battleship” type map indexing systems used in, e.g., street atlases). Each rectangular zone represents {fraction (1/729)} of the area of a map page or of an overlay, virtually pinpointing the location of a feature sought by the user, yet employing only three indexing digits (e.g., 5-3-1 for “X” in FIG. 1). Such accuracy with attendant facility and convenience for the map's user has not previously been available for maps, atlases and overlays therefor.
[0033] A small keypad ikon 20 is shown in FIG. 1 to indicate to the user the type of array and numbering system used for the array, obviating the necessity to number at least the regions 1 to 9 , thereby reducing clutter on the page(s) of the map and/or overlay. The user will, after a short period of experience, become so accustomed to the array and its numbering system that no numbering might be required or needed on any of the rectangles, whereby the clarity of the map (or overlay) would or could be further enhanced.
[0034] In a further embodiment (not shown), the lines demarcating the large rectangles may be abbreviated or truncated to short lines or projections at or on the margin or edge of the map and/or overlay and/or in (and/or on) a frame around the map or overlay. The experienced user would be able to find locations by mentally projecting or extending the abbreviated lines from the margin and/or edge so as to form the rectangles that they would in fact define if they were provided in full.
[0035] Where sets of parallel lines are employed to define the various regions, areas and zones, the lines may be of different types for the regions, areas and zones. For example, the lines for the regions may be relatively bold, and those for the areas and zones may each be relatively finer. Alternatively, or in addition, the regions, areas and zones may be defined by different colors and/or shadings. Thus, in one embodiment, the division(s) of the page(s) of a map or atlas may be provided at least in part by checkerboard-type shading(s) and/or coloring(s) either alone and/or supplemented in part by lines (e.g., parallel lines), as described above, or as stated above, not demarcated at all or in full.
[0036] Where one or more overlays are employed, the map or atlas may have indicia to ensure that the overlay(s) is or are accurately aligned or positioned on the or each page.
[0037] Features of the invention as disclosed, defined or claimed herein which are shown and/or disclosed in connection with one embodiment may be used in combination(s) with other feature(s) shown and/or described while remaining within the scope of the invention.
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A method of specifying a location on a surface. The invention also relates to an article having a surface on which the location is or can be specified.
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BACKGROUND
[0001] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
[0002] Blowout preventers (BOPs) are used extensively throughout the oil and gas industry. Typical blowout preventers are used as a large specialized valve or similar mechanical device that seal, control, and monitor oil and gas wells. The two categories of blowout preventers that are most prevalent are ram blowout preventers and annular blowout preventers. Blowout preventer stacks frequently utilize both types, typically with at least one annular blowout preventer stacked above several ram blowout preventers. The ram units in ram blowout preventers allow for both the shearing of the drill pipe and the sealing of the blowout preventer. A blowout preventer stack may be secured to a wellhead and may provide a safe means for sealing the well in the event of a system failure.
[0003] In a typical ram blowout preventer, a ram bonnet assembly may be bolted to the main body using a number of high tensile bolts or studs. These bolts are required to hold the bonnet in position to enable the sealing arrangements to work effectively. During normal operation, the blowout preventers may be subject to pressures up to 20,000 psi, or even higher. To be able to operate against and to contain fluids at such pressures, blowout preventers are becoming larger and stronger. Blowout preventer stacks, including related devices, 30 feet or more in height are increasingly common. Further, ram-type blowout preventers may require interchangeable parts to be used with pipe having different sizes and strengths. Such requirements, if not impractical, may require the presence of personnel at locations that can be hazardous, and may be limited due to particular size or equipment restrictions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] For a detailed description of embodiments of the subject disclosure, reference will now be made to the accompanying drawings in which:
[0005] FIG. 1 shows a sectional view of a blowout preventer;
[0006] FIG. 2 shows a wire cutting apparatus for use within a blowout preventer in accordance with one or more embodiments of the present disclosure;
[0007] FIG. 3 shows a side cross-sectional view of a wire cutting apparatus in a retracted position in a blowout preventer in accordance with one or more embodiments of the present disclosure;
[0008] FIG. 4 shows an above schematic view of a wire cutting apparatus in a retracted position in a blowout preventer in accordance with one or more embodiments of the present disclosure;
[0009] FIG. 5 shows a side cross-sectional view of a wire cutting apparatus in an extended position in a blowout preventer in accordance with one or more embodiments of the present disclosure;
[0010] FIG. 6 shows an above schematic view of a wire cutting apparatus in an extended position in a blowout preventer in accordance with one or more embodiments of the present disclosure;
[0011] FIG. 7 shows an above schematic view of a wire cutting apparatus in a push-type configuration to cut a tubular member in accordance with one or more embodiments of the present disclosure; and
[0012] FIG. 8 shows an above schematic view of a wire cutting apparatus in a pull-type configuration to cut a tubular member in accordance with one or more embodiments of the present disclosure.
DETAILED DESCRIPTION
[0013] The following discussion is directed to various embodiments of the invention. The drawing figures are not necessarily to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be an illustration of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
[0014] Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but are the same structure or function.
[0015] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. In addition, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. The use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components.
[0016] Referring now to FIG. 1 , a sectional view of a blowout preventer 10 is shown. The blowout preventer 10 includes a housing 12 , such as a hollow body, with a bore 14 that enables passage of fluid or a tubular member through the blowout preventer 10 . The housing 12 further includes one or more cavities 16 , such as cavities 16 opposed from each other with respect to the bore 14 , with a ram 18 movably positioned within each cavity 16 . The blowout preventer 10 may be coupled to other equipment that facilitates natural resource production. For instance, production equipment or other components may be attached to the top of the blowout preventer 10 using a connection 20 (which may be facilitated in the form of fasteners), and the blowout preventer 10 may be attached to a wellhead or spool using the flange 22 and additional fasteners.
[0017] One or more bonnet assemblies 24 are secured to the housing 12 and include various components that facilitate control of the rams 18 positioned in the blowout preventer 10 . The bonnet assemblies 24 are coupled to the housing 12 by using one or more fasteners 26 to secure the bonnets 28 of the bonnet assemblies 24 to the housing 12 . The rams 18 are then actuated and moved through the cavities 16 , into and out of the bore 14 , by operating and moving a piston 30 and a rod 32 coupled thereto within a housing 34 of the bonnet assemblies 24 . In operation, a force (e.g., from hydraulic pressure) may be applied to the pistons 30 to drive the rods 32 , which in turn drives the rams 18 coupled thereto into the bore 14 of the blowout preventer 10 . The rams 18 cooperate with one another when driven together to seal the bore 14 and inhibit flow through the blowout preventer 10 . In another embodiment, the rams 18 may be shear rams such that, when driven towards each other, shear a tubular member present within the bore 14 of the housing 12 of the blowout preventer 10 .
[0018] Referring now to FIG. 2 , a wire cutting apparatus 220 for use within a blowout preventer in accordance with one or more embodiments of the present disclosure is shown. The wire cutting apparatus 220 may be included in a housing of a blowout preventer to cut and shear a tubular member that is positioned within the bore of the blowout preventer. This may involve moving, extending, and retracting the wire cutting apparatus 220 into and out of the bore of the blowout preventer such that the wire cutting apparatus 220 may cut an object (e.g., tubular member) present within the bore of the blowout preventer. The use of a wire cutting apparatus 220 within a blowout preventer may enable the blowout preventer to operating at lower pressures and forces, thereby reducing the size and equipment requirements.
[0019] The wire cutting apparatus 220 in this embodiment includes a cutting wire 222 that is supported by pulleys 224 . An example of a cutting wire 222 may include a diamond impregnated wire, though other types of cutting wire may be used without departing from the scope of the present disclosure. A motor 226 may then be coupled to the pulleys 224 to drive the cutting wire 222 . The pulleys 224 may include a drive pulley 224 A and one or more support pulleys 224 B. The motor 226 may be operatively coupled to the drive pulley 224 A to drive the drive pulley 224 A and the cutting wire 222 supported by the pulleys 224 .
[0020] The wire cutting apparatus 220 may have a frame 228 with the pulleys 224 supported by the frame 228 . In particular, one or more axles of the pulleys 224 may be connected to the frame 228 such that the pulleys 224 are rotatably coupled to the frame 228 . One or more gears may be used with the wire cutting apparatus 220 , such as to control a speed of the cutting wire 222 , as desired. For example, as shown, a gearbox 230 may be included with the wire cutting apparatus 220 with the gearbox 230 coupled between the motor 226 and the drive pulley 224 A. The gearbox 230 may enable the motor 226 to control the speed at which the drive pulley 224 A rotates, and hence, control the speed at which the cutting wire 222 rotates through the wire cutting apparatus 220 .
[0021] As discussed above, the motor 226 may be used to drive the pulleys 224 and the cutting wire 222 though the cutting wire 222 , the pulleys 224 , and the frame 228 move with respect to the motor 226 (e.g., the cutting wire 222 may extend into and out of a bore of a blowout preventer while the motor 226 remains relatively stationary). The wire cutting apparatus 220 may include one or more components or mechanisms to enable this type of movement between the motor 226 and the cutting wire 222 . In this embodiment, a telescoping assembly 232 may be used to operatively couple the motor 226 to the pulleys 224 , and more specifically the drive pulley 224 A. The telescoping assembly 232 may include an inner shaft 234 and an outer shaft 236 (or more shafts as necessary), with the telescoping assembly 232 extending between the motor 226 and the gearbox 230 . This may enable the motor 226 to be operatively coupled to and drive the drive pulley 224 A through the telescoping assembly 232 and the gearbox 230 as the cutting wire 222 , pulleys 224 , and the frame 228 move with respect to the motor 226 . The present disclosure also contemplates other components, mechanisms, and assemblies included within the scope of the present disclosure that may also be used to enable such movement between the motor and the cutting wire, if necessary.
[0022] The wire cutting apparatus 220 , or a blowout preventer including the wire cutting apparatus 220 , may include a drive assembly 240 to move, extend, and retract the wire cutting apparatus 220 into and out of the bore of the blowout preventer. In FIG. 2 , the drive assembly 240 includes a housing 242 (e.g., such as a bonnet housing of a blowout preventer) with a piston 244 movably positioned within the housing 242 . A rod 246 may then be coupled and extend between the piston 244 and the wire cutting apparatus 220 , or more particularly the frame 228 of the wire cutting apparatus 220 in this embodiment, to enable the piston 244 to move the wire cutting apparatus 220 within a blowout preventer. For example, pressure (e.g., hydraulic pressure) may be selectively introduced on either side of the piston 244 to selectively move the piston 244 , and hence the wire cutting apparatus 220 . The present disclosure also contemplates other types of drive assemblies that may be used to move the wire cutting apparatus 220 within a blowout preventer that are included within the scope of the present disclosure.
[0023] In accordance with one or more embodiments, as the wire cutting apparatus 220 may be included within a blowout preventer, and the blowout preventer may be used subsea, the wire cutting apparatus 220 may include multiple sources to power the wire cutting apparatus 220 . For example, as shown in FIG. 2 , a remotely-operated vehicle (ROV) drive coupling 238 may be included with the wire cutting apparatus 220 . In this embodiment, the ROV drive coupling 238 may be operatively coupled to the motor 226 to enable an ROV to supplement or provide power to the motor 226 . This may enable additional or alternative power sources to drive the cutting wire 222 of the wire cutting apparatus 220 . Accordingly, in one or more embodiments, the wire cutting apparatus 220 may be able to operate independent of a blowout preventer control system, without power from the surface of the blowout preventer control system, and/or electrical power. In one or more such embodiments, the wire cutting apparatus 220 may not include electrical components or electronics.
[0024] Referring now to FIGS. 3-6 , a blowout preventer 300 including a wire cutting apparatus 320 in accordance with one or more embodiments of the present disclosure is shown. FIG. 3 shows a side cross-sectional view of the blowout preventer 300 in a retracted position, and FIG. 4 shows an above view of the blowout preventer 300 in the retracted position. Further, FIG. 5 shows a side cross-sectional view of the blowout preventer 300 in an extended position, and FIG. 6 shows an above view of the blowout preventer 300 in the extended position.
[0025] The blowout preventer 300 includes a housing 302 , in which the housing 302 includes a bore 304 extending through the housing 302 and one or more cavities 306 in the housing 302 that intersect with the bore 304 . The wire cutting apparatus 320 may be movably positioned within the housing 302 , such as within the cavity 306 , of the blowout preventer 300 . The wire cutting apparatus 320 may then move (e.g., extend and retract) into and out of the bore 304 of the housing 302 of the blowout preventer 300 . As such, if an object, such as a tubular member 308 , is included within the bore 304 of the blowout preventer 300 , the wire cutting apparatus 320 may be used to cut or shear the tubular member 308 .
[0026] As discussed above, the wire cutting apparatus 320 includes a wire 322 supported by pulleys 324 with a motor 326 to drive the cutting wire 322 using the pulleys 324 . The wire cutting apparatus 320 may have a frame 328 with the pulleys 324 supported by the frame 328 , and a gearbox 330 may be coupled between the motor 326 and the pulleys 324 to enable the motor 226 to control the speed at which the pulleys 324 (e.g., drive pulley 324 A) rotates, and hence, control the speed at which the cutting wire 322 rotate through the wire cutting apparatus 320 .
[0027] To facilitate the cutting motion of the wire cutting apparatus 320 within the blowout preventer 300 , one or more components, such as a support block 350 , may be included to support the object (e.g., tubular member 308 ) included within the bore 304 of the blowout preventer 300 . The support block 350 is shown as positioned opposite the wire cutting apparatus 320 with respect to the bore 304 of the housing 302 of the blowout preventer 300 . In one or more embodiments, the support block 350 may be movably positioned within the housing 302 , such as within a cavity 306 , of the blowout preventer 300 . The support block 350 may then move (e.g., extend and retract) into and out of the bore 304 of the housing 302 of the blowout preventer 300 . In particular, the support block 350 may extend and retract into and out of the bore 304 along with the wire cutting apparatus 320 .
[0028] As shown, the support block 350 may include in this embodiment a concave-profiled face to facilitate supporting the tubular member 308 by the support block 350 . In this embodiment, the support block 350 is shown as including a “V” profiled type face 352 such that this profile centralizes and/or stabilizes the tubular member 308 against the support block 350 . Further, the support block 350 may include an opening 354 or channel formed therein. This opening 354 may then enable the wire cutting apparatus 320 to be received, at least partially, within and correspond to the support block 350 , as shown particularly in FIG. 5 , to enable the wire cutting apparatus 320 to fully cut across the tubular member 308 .
[0029] As discussed above, the wire cutting apparatus 320 , or the blowout preventer 300 including the wire cutting apparatus 320 , may include a drive assembly 340 to move, extend, and retract the wire cutting apparatus 320 into and out of the bore 304 of the blowout preventer 300 . In this embodiment, the drive assembly 340 includes a housing 342 with a piston 344 movably positioned within the housing 342 , and a rod 346 coupled and extending between the piston 344 and the wire cutting apparatus 320 .
[0030] Similarly, the support block 350 , or the blowout preventer 300 including the support block 350 , may include a drive assembly 360 to move, extend, and retract the support block 350 into and out of the bore 304 of the blowout preventer 300 . In FIGS. 3-6 , the drive assembly 360 includes a housing 362 (e.g., such as a bonnet housing of the blowout preventer 300 ) with a piston 364 movably positioned within the housing 362 . A rod 366 may then be coupled and extend between the piston 364 and the support block 350 to enable the piston 364 to move the support block 350 within the blowout preventer 300 .
[0031] In one embodiment, as the support block 350 may extend and retract into and out of the bore 304 along with the wire cutting apparatus 320 , the drive assembly 360 of the support block 350 and the drive assembly 340 of the wire cutting apparatus 320 may be linked to each other, in operation with each other, and/or on the same drive circuit to similarly control the movements of the support block 350 and the wire cutting apparatus 320 . For example, in the embodiment shown here, the hydraulic pressure used to drive the drive assembly 360 may also be used to drive the drive assembly 340 . Further, the present disclosure also contemplates other types of drive assemblies that may be used to move the support block 350 within a blowout preventer that are included within the scope of the present disclosure.
[0032] In one or more embodiments, a wire cutting apparatus may include a tensioning mechanism, such as to maintain a predetermined tension upon the cutting wire. For example, a tensioning mechanism may involve selectively controlling movement of one or more pulleys with respect to each other to maintain a predetermined tension upon the cutting wire across the pulleys. This may facilitate keeping the cutting wire taut, particularly when cutting an object with the cutting wire.
[0033] Further, in one or more embodiments, the wire cutting apparatus and/or the support block may be movable at or with a predetermined constant force within the blowout preventer. For example, when the wire cutting apparatus 320 and the support block 350 are extending into the bore 304 of the blowout preventer 300 to cut the tubular member 308 , the movement of the wire cutting apparatus 320 and/or the support block 350 may be controlled to apply a predetermined constant force upon the tubular member 308 . This may facilitate the cutting motion of the wire cutting apparatus 320 and prevent potential jamming or stalling of the wire cutting apparatus 320 .
[0034] Furthermore, in one or more embodiments, the wire cutting apparatus and/or the support block may be protected, such as from contents included within the bore of the blowout preventer, when not in use and positioned within the bore of the blowout preventer. For example, a flap may be used to cover and/or seal the opening through which the wire cutting apparatus 320 and/or the support block 350 protrude when extending into the bore 304 of the blowout preventer 300 . The flap may enable the wire cutting apparatus 320 and/or the support block 350 to extend into the bore 304 of the blowout preventer 300 , such as by having the flap rotate out of the way. The flap may then rotate back to protect the openings and prevent content from the bore 304 flowing back into the cavities 306 of the blowout preventer 300 . The flap may be biased to close over the openings and then may move out of the way of the wire cutting apparatus 320 and/or the support block 350 when engaged. Alternatively, the flap may be separately controlled to move as the wire cutting apparatus 320 and/or the support block 350 move into and out of the bore 304 of the blowout preventer 300 .
[0035] In one or more embodiments, the wire cutting apparatus and/or the support block may be used to seal the bore of the blowout preventer. For example, after the tubular member 308 is cut with the wire cutting apparatus 320 , the support block 350 may move and extend across the bore 304 . By extending out and across the bore 304 , the support block 350 may be able to seal the bore 304 , such as to prevent fluid from passing through the bore 304 after the tubular member 308 is cut. This may enable the blowout preventer 300 to not only be capable of shearing the tubular member 308 positioned therein, but also capable of sealing the bore 304 within the blowout preventer 300 after the tubular member 308 has been cut.
[0036] Referring now to FIGS. 7 and 8 , multiple schematic above views of a wire cutting apparatus 720 to cut a tubular member 708 in accordance with one or more embodiments of the present disclosure are shown. In particular, FIG. 7 shows an embodiment of the wire cutting apparatus 720 in a push-type configuration to cut the tubular member 708 , and FIG. 8 shows an embodiment of the wire cutting apparatus 720 in a pull-type configuration to cut the tubular member 708 .
[0037] As with the above, the wire cutting apparatus 720 may include a wire 722 supported by pulleys 724 with a motor 726 to drive the cutting wire 722 using the pulleys 724 . A gearbox 730 may be coupled between the motor 726 and the drive pulley 724 A to control the speed at which the cutting wire 722 rotates through the wire cutting apparatus 720 . Further, a telescoping assembly 732 including an inner shaft 734 and an outer shaft 736 (or more shafts as necessary) may extend between the motor 726 and the gearbox 730 .
[0038] In the above embodiments, and in FIG. 7 , the wire cutting apparatus 720 may be used in the push-type configuration to cut the tubular member 708 , in which the wire cutting apparatus 720 is pushed (e.g., extended) into the bore of the blowout preventer to contact and cut the tubular member 708 . In another embodiment, and in FIG. 8 , the wire cutting apparatus 720 may be used in the pull-type configuration to cut the tubular member 708 , in which the wire cutting apparatus 720 is pulled (e.g., retracted) from or out of the bore of the blowout preventer to contact and cut the tubular member 708 . In such an embodiment, the cutting wire 722 may be positioned within the bore of the blowout preventer to have the tubular member 708 received into a loop formed by the cutting wire 722 . Then, once desired, the wire cutting apparatus 720 may be retracted out of the bore of the blowout preventer to have the cutting wire 722 contact and cut the tubular member 708 . Accordingly, a blowout preventer in accordance with the present disclosure may employ either of these types of configurations without departing from the scope of the present disclosure.
[0039] As mentioned above, a blowout preventer in accordance with the present disclosure may be able to operate at lower pressures and with lower forces, such as due to the use of a wire cutting apparatus. This may reduce the size and equipment requirements necessary for the use of a blowout preventer, in particular in a subsea environment where higher pressures and higher forces are often necessary for the shearing of tubular members.
[0040] Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.
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An apparatus includes a blowout preventer housing comprising a bore extending therethrough and a cavity intersecting the bore and a wire cutting apparatus with a cutting wire. The wire cutting apparatus is movably positionable within the cavity of the blowout preventer housing and is extendable into the bore of the blowout preventer housing.
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FIELD OF THE INVENTION
The present invention is directed to the field of cleaning particulates from contamination sensitive surfaces using an impinging stream of an aerosol containing at least substantially solid argon or nitrogen particles. More particularly, the present invention is directed to cleaning particles and films from sensitive microelectronic surfaces by impinging a stream of an aerosol of solid argon or nitrogen particles against such surfaces to displace the particles and/or film and remove the byproducts by venting.
BACKGROUND OF THE PRIOR ART
Small quantities of contamination are detrimental to the microchip fabrication process. Contamination in the form of particulates, films or molecules causes short circuits, open circuits, silicon crystal stacking faults, and other defects. These defects can cause the finished microelectronic circuit to fail. Such failures are responsible for significant yield reductions in the microelectronics industry. Yield reductions caused by microcontamination substantially increase processing costs.
Microelectronic circuits require many processing steps. Processing is performed under extremely clean conditions. However, the amount of contamination needed to produce fatal defects in microcircuits is extremely small. For example, an individual particle as small as 100 Angstroms in diameter can result in a killer defect in a modern microcircuit. Microcontamination may occur at any time during the many steps needed to complete the circuit. Therefore, periodic cleaning of the wafers used for microelectronic circuits is needed to maintain economical production yields. Also, tight control of purity and cleanliness in the processing gas is required.
Future microcircuits will have smaller feature sizes and greater complexities, and will require more processing steps. Therefore, in order to maintain economical yields, contamination control techniques in the process gas system and processing environment must be significantly improved and an improved wafer cleaning procedure must be developed.
Several methods are presently used to clean surfaces for the electronics industry. Solvent or chemical cleaning is used to remove contaminant films from surfaces. Since solvents are selective in the materials they can dissolve, an appropriate solvent must be chosen to remove the contamination. Chemical solutions can be combined with Megasonic or Ultrasonic cleaners. These devices impart high energy sonic waves to the surface which can remove organic films, ionic impurities and particles as small as 3000 Angstroms. However, solvent or chemical cleaning requires extremely pure and clean agents. High purity and cleanliness is difficult and/or expensive to achieve in liquid agents. In addition, the agent becomes progressively more contaminated as it is used and must be disposed of periodically. Failure to change the agent periodically causes redeposition of contaminants, which reduces the effectiveness of the cleaning process. Disposal of such agents frequently results in environmental damage. Also, such agents require special safety procedures during handling in order to minimize exposure to operators.
Gas jet cleaning and liquid spray cleaning are presently used to clean relatively large particles from silicon wafers. Gas jets, (e.g., filtered nitrogen jets) are ineffective in removing particles smaller than about 50,000 Angstroms. Smaller particles are more difficult to remove. This is because the adhesive force tending to hold the particle to the surface is proportional to the particle diameter while the aerodynamic drag force by the gas tending to remove the particle is proportional to the diameter squared. Therefore, the ratio of these forces tends to favor adhesion as the particle size shrinks. Also, smaller particles are not exposed to strong drag forces in the jet since they can lie within the surface boundary layer where the gas velocity is low. Liquid jets provide stronger shear forces to remove particles but are expensive and/or difficult to obtain at high purity and may leave contaminating residues after drying. Also, a common liquid spray solvent (Freon TF) is environmentally damaging.
Exposure to ozone combined with ultraviolet light can be used to decompose contaminating hydrocarbons from surfaces. However, this technique has not been shown to remove contaminating particles.
A recently developed cleaning technique involves the use of a carbon dioxide aerosol to "sandblast" contaminated surfaces. Pressurized gaseous carbon dioxide is expanded in a nozzle. The expansion drops the carbon dioxide pressure to atmospheric pressure. The resulting Joule-Thompson cooling forms solid carbon dioxide particles which traverse the surface boundary layer and strike the contaminated surface. In some cases the carbon dioxide forms a soft material which can flow over the surface, displacing particles without leaving a residue. The technique requires extremely clean and pure carbon dioxide. Trace molecular contaminants (eg., hydrocarbons) in the feed gas can condense into solid particulates or droplets upon expansion, causing deposition of new contaminants on the surface. Carbon dioxide is difficult and/or expensive to provide in ultrahigh purity, i.e., with less than parts per million levels of trace impurities. Because of this problem, the carbon dioxide cleaning technique has not yet been shown to be effective in ultraclean (eg., silicon wafer) applications.
The technique of utilizing solid carbon dioxide to remove particulates from a surface is set forth in U.S. Pat. No. 4,806,171.
European Published Application 0 332 356 discloses a cleaning technique using carbon dioxide wherein the purity of the carbon dioxide is enhanced by first vaporizing liquid carbon dioxide, filtering the resulting gas and reliquefying the gas for use as a cleaning agent in the form of dry ice snow.
UK Published Application 2 146 926 A describes a carbon dioxide cleaning media comprising formed solid carbon dioxide, an overlayer of water ice and an entraining jet of compressed air. This technique complicates the possible sources of contamination for a cleaning media which is required to provide high purity cleaning without recontaminating the surface being treated with materials carried in the cleaning media.
Equipment for attempting cleaning with carbon dioxide is described in a brochure from Airco Special Gases titled "Spectra-CleanT CO 2 ". The system comprises a submicron filter and conduit attached to a carbon dioxide pressurized gas cylinder with several stages of pressure reduction to provide a directed stream of carbon dioxide snow for cleaning purposes.
An article in Chemical Processing, November 1989, page 54 identifies that a dry ice "Carbon dioxide" system is available for cleaning from Liquid Carbonic identified as a COLD JET* CLEANING SYSTEM.
In an article contained in Semiconductor International, November 1989, page 16 Mitsubishi's LSI Research and Development Laboratory reports the use of water ice to clean semiconductor wafers. See also Abstract No. 377 titled "Ultraclean Ice Scrubber Cleaning with Jetting Fine Ice Particles" by T. Ohmori, T. Fukumoto, an T. Kato.
An article by Stuart A. Hoenig, "Cleaning Surfaces with Dry Ice" appearing in Compressed Air Magazine, August 1986, pages 22 through 24 describes a device for using carbon dioxide snow in mixture with dry nitrogen gas as a cleaning agent for appropriate surface cleaning.
A dry ice technique is also disclosed by Stuart A. Hoenig, et al. in the article "Control of Particulate Contamination by Thermophoresis, Electrostatics and Dry Ice Techniques" appearing in the Ninth ICCCS Proceedings 1988 Institute of Environmental Sciences, page 671 through 678. The article described various techniques for reduction of contamination in semiconductor and electronic materials. The use of a stream of dry ice particles is also critiqued.
Despite the attempts at providing the thoroughness of cleaning necessary for microelectronic fabrications and materials, the prior art systems predicated upon liquid solvents, carbon dioxide or water-based cleaners suffer from the disadvantage that these substances themselves are considered to be impurities in the microchip fabrication process. For example, present purity specifications for bulk nitrogen shipped to electronics manufacturers permits no more than about 10 parts per billion carbon dioxide and no more than about 50 parts per billion water. When carbon dioxide or water are used as cleaning agents, a significant amount of these substances will remain on the surface as adsorbed contaminants. Many wafer processing steps such as annealing and dopant diffusion are performed at high temperatures and are affected by the presence of reactive contaminants. For example, trace amounts of carbon dioxide may decompose during high temperature processing steps and leave deposited carbon on the silicon wafer surface. The carbon will significantly affect the electrical properties of the finished microcircuit.
Carbon dioxide as a cleaning agent is prone to contamination in excess of the requirements of the microelectronic circuit fabricating industry. Carbon dioxide is typically produced by oxidizing natural gas. Considerable levels of impurities remain in the product of this reaction including many unreacted components of the natural gas and byproducts of the reaction. Carbon dioxide may be further purified through adsorption of impurities on molecular sieves, but purity levels better than parts per million are difficult to achieve. Purification through distillation is not practical since typical impurities, such as hydrocarbons, have molecular weights and boiling points near that of carbon dioxide and therefore cannot be separated efficiently. Carbon dioxide can be sold as a gas or liquid, but must be compressed using lubricated pumps. This increases the contamination level of the carbon dioxide. Finally, liquid carbon dioxide is a strong solvent for hydrocarbon lubricants. Therefore it tends to pick these materials up and become more contaminated during transport to the point of use.
The intrinsically higher contamination level of carbon dioxide, especially with regard to hydrocarbons, results in an unacceptable deposit of condensed, oily droplets on the surface of the microelectronic device to be cleaned. The droplets render the carbon dioxide cleaner unacceptable for microelectronic applications. Efforts have attempted to improve the purity level of carbon dioxide feed gas for such cleaning utilities.
It is also known that water ice-based cleaners have been found to cause damage specifically pits to substrates treated during the cleaning process with the particulate water-ice.
U.S. Pat. 5,062,898 discloses the use of gaseous argon to supply the cryogen for the production of solid argon aerosol for cleaning.
The present invention overcomes the drawbacks of the prior art by providing a highly pure and inert particulate aerosol for cleaning substrates and other surfaces to a level of cleanliness required by the microelectronics industry, while avoiding re-contamination by the particles of the cleaning aerosol themselves. This advance in such cleaning as well as other advantages and distinctions will be demonstrated more particularly by the disclosure of the present invention which follows.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a method for removing contaminating particles and/or films from a particle and/or film-containing surface using an impinging stream of an at least substantially solid argon or nitrogen particle-containing aerosol, comprising: expanding a pressurized liquid argon or gaseous and/or liquid nitrogen-containing stream, which is at a temperature at the existing stream pressure prior to expansion so as to form at least substantially solid particles of argon or nitrogen in the stream by the cooling resulting from the expansion to form an at least substantially solid argon or nitrogen particle-containing aerosol, and directing the aerosol at the surface to remove said contaminating particles and/or film.
Preferably, in the case of argon aerosol, the present invention includes a nitrogen carrier gas with the argon-containing stream which nitrogen carrier gas remains in the gaseous state after the expansion so as to form an aerosol of at least substantially solid argon particles in a nitrogen carrier gas.
Preferably, the expansion of the argon or nitrogen-containing stream is conducted into a zone maintained at pressures ranging from high vacuum to greater than atmospheric.
Preferably, the gaseous nitrogen-containing stream is precooled to a temperature near its liquefaction point to condense out condensable impurities in the stream prior to the expansion, and the impurities are separated from the stream. Specifically, the impurities may include water carbon dioxide and hydrocarbons.
Preferably, the pressurized argon or nitrogen-containing stream is at a pressure in the range of approximately 20 to 690 psig, more preferably approximately 20 to 100 psig.
Preferably, an acute angle is formed by the plane of the surface to be cleaned and the direction of the aerosol impinging the surface.
Preferably after removal of the contaminating particles and/or film, the surface is warmed above the liquefaction temperature of argon or nitrogen at the existing pressure. Optimally, the surface is warmed above the liquefaction temperature of water at the existing pressure.
Preferably, the surface may include among others: the inside surface of gas distribution system components such as pipes, valves and conduits, microelectronic processing equipment such as furnaces and plasma chambers, as well as silicon wafers and microelectronic components.
Preferably, in the case of argon aerosol where the argon is mixed with nitrogen, the argon to nitrogen ratio is in the range of approximately 10% to 100% argon with the remainder being nitrogen by volume.
Preferably, the precooling is performed to a temperature in the range of approximately -190° F. to -340° F.
Preferably, the acute angle of impingement of the at least substantially solid argon or nitrogen particle containing stream with the surface to be cleaned is approximately 45°.
Preferably, contaminating particles on the surface are smaller than 10,000 angstroms.
In a preferred embodiment, the present invention is a method for removing contaminating particles and/or films from a particle and/or film-containing surface using an impinging aerosol stream of solid nitrogen particles comprising, precooling gaseous nitrogen to a temperature sufficient to condense out condensable impurities, separating the condensable impurities from the nitrogen, rapidly expanding the nitrogen from a pressure in the range of approximately 20 to 100 psig to a lower pressure condition, at a temperature so as to form solid particles of nitrogen by the cooling resulting from the expansion to produce the aerosol stream, and directing the aerosol stream at the surface to remove the contaminating particles and/or film.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a schematic representation of a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention uses an at least substantially solid argon or nitrogen particle-containing aerosol to "sandblast" contaminated surfaces. Argon and nitrogen are inert substances which are not harmful to silicon wafers or microcircuits. Argon and nitrogen can be produced in ultrahigh purity economically. In the case of argon aerosol, the argon can be used alone or mixed with ultrapure nitrogen in the present invention. In this case, the nitrogen remains in the gaseous phase and serves as a carrier medium to impart high velocities to the argon particles. The addition of nitrogen to the argon aerosol also permits higher expansion ratios which enhances the Joule-Thompson effect and permits increased cooling. The mixture ratio of argon to nitrogen may range from approximately 10% to 100% argon by volume.
The previously purified argon or nitrogen is first filtered free of any remaining contaminating particles and preferably precooled for example in a heat exchanger. The argon or nitrogen may remain in the gaseous phase following the precooling operation. Precooling also permits partial condensation and removal of any remaining trace impurities onto the heat exchanger walls. Precooling may be combined with simultaneous removal of trace impurities using a molecular sieve or catalytic impurities removal device or an impurities getter located upstream of the heat exchanger. Such methods for removing trace molecular impurities from inert gases are well known in the field. The pressure of the precooled cryogen is typically held in the range of 20 psig to 690 psig, preferably 20 psig to 100 psig. The temperature of the precooled cryogen is typically in the range -190° F. to -340° F. for the first pressure range above and -250° F. to -340° F. for the second pressure range above.
The precooled cryogen is then expanded in a nozzle or expansion valve to a lower pressure. The pressure of the expanded cryogen may range from high vacuum to greater than atmospheric pressure. The resulting Joule-Thompson cooling serves to solidify argon or nitrogen particles. For the purpose of this invention, the argon or nitrogen may form liquid particles as well as solid particles and still be efficacious for cleaning. It is preferred to form solid particles, but if at least a substantial portion of the argon or nitrogen particles are solid, the cleaning process is significantly improved over prior techniques. Argon or nitrogen particles may condense through a process of homogeneous nucleation. The resulting cryogenic aerosol is then directed at an inclined angle (typically 45°) toward a contaminated surface to be cleaned. The jet is typically at a vertical distance of approximately 1/16 "to several inches above the contaminated surface. The gas mixture is expanded through a nozzle. The nozzle geometry may vary. The present invention has been shown to be effective for circular nozzles and slit nozzles. Slit nozzles are well suited for broad surfaces such as silicon wafers. Circular nozzles are well suited for more localized cleaning applications. Complete removal of surface contaminants is typically achieved within several seconds of exposure to the aerosol.
The argon cleaning technique has been shown to provide effective cleaning of silicon wafers. Examples of gaseous cleaning jets demonstrate that 0.624 micrometer (6240 Angstrom) particles are not removed using conventional nitrogen gas jet cleaning techniques. However, the same particles are completely removed using the argon aerosol cleaning technique (approximately 100% effectiveness). The argon cleaner has also been shown to be effective in removing 1000 Angstrom-size particles from bare silicon wafers and thick films of bearing grease from glass surfaces. In the context of the present invention, the term particles includes particles at the molecular size level.
Cleaning of contaminated surfaces is accomplished in this invention through a process of colliding argon or nitrogen particles at high velocity against the surface to be cleaned. The argon or nitrogen particles strike contaminating particles, films and molecules located on the surface. The collision imparts sufficient energy to the contamination to release it from the surface. The released contamination becomes entrained in the gas flow and is vented. The gaseous phase of the aerosol impinges against the surface and flows across it, forming a thin boundary layer. The dimensions of the contaminating material (particles, films, etc.) are typically so small that they exist completely within the low velocity boundary layer. Therefore, the gas phase alone cannot remove small contamination because of insufficient shearing force. However, the argon or nitrogen particles have significant inertia and are thus able to cross through the boundary layer to the surface.
The argon or nitrogen particles tend to decelerate as they pass through the boundary layer toward the surface. In order for cleaning to occur, the argon or nitrogen particles must traverse the boundary layer and strike the surface. A simple model assumes that the gas flow creates a boundary layer of thickness "h" having a negligible normal component of velocity. In order to strike the surface, the solidified argon or nitrogen particles must enter the boundary layer with a normal component of velocity equal to at least "h/t". The particle relaxation time "t" is given by:
T=2 a.sup.2 Pp C/9m (1)
where "all is the argon or nitrogen particle radius, "Pp" is the particle density, "m" is the dynamic viscosity of the gas and "C" is the Stokes-Cunningham slip correction factor which is given by:
C=1+1.246 (g/a)+0.42 (g/a) exp[-0.87 (g/a)] (2)
"g" is the mean free path of the gas molecules which is inversely proportional to the gas pressure.
The above analysis demonstrates that the cleaning process is most effective for argon or nitrogen particles having large mass or high initial velocity. The cleaning process is also enhanced at lower pressures due to the increased particle slip and at lower gas viscosities due to the decreased decelerating drag force on the argon or nitrogen particles.
The argon or nitrogen particles are formed during the expansion process. The temperature drop associated with the expansion causes argon or nitrogen to nucleate and condense and/or solidify into at least substantially solid particles. Solid argon or nitrogen particles will form directly from the liquid argon or gaseous and/or liquid nitrogen if the pressure of the expanded mixture is lower than the argon or nitrogen triple point. If the pressure of the mixture is higher than the triple point the argon or nitrogen will first condense into liquid droplets before freezing into solid particles. The triple point of argon is at 9.99 psia, -308.9° F. The triple point of nitrogen is at 1.82 psia, -345.9° F.
The present invention will now be described in greater detail with reference to the drawing. In the drawing, liquid argon or gaseous and/or liquid nitrogen available in highly purified form from cryogenic distillation of air is provided, for example, in a typical industrial gas cylinder 10 prepped for high purity. Alternatively, the argon or nitrogen is supplied from a liquid storage tank or a gas pipeline. The argon or nitrogen is metered through valve 12. In the case of argon aerosol, the argon is mixed with nitrogen 18 also supplied from cryogenic air separation and stored in an industrial gas cylinder prepped for high purity duty. Alternatively, the nitrogen is supplied from a liquid storage tank or a gas pipeline. This nitrogen flows through valve 20. In this case, the argon and nitrogen are mixed in manifold 16 in the range of 100% up to 100% argon in comparison to nitrogen by volume. During periods of shutdown or repair on the downstream system, gas can be vented through valve 24, but in normal operation the argon or nitrogen mixture is passed through a filter 26 which is designed to trap submicron particles and offer additional cleaning of the high purity argon or nitrogen. Other inline cleaning devices may also be used such as adsorbent beds, catalytic purifiers or getters. The pressurized argon or nitrogen-containing stream is next precooled to a temperature near its liquefaction point at its pressurized condition in indirect-heat exchanger 28 in order to condense out remaining condensable impurities and separate such condensed impurities by adherence to the inside surfaces or walls of the passageways 30 of the heat exchanger 28 through which the argon or nitrogen-containing stream passes. The cooling effect for the argon or nitrogen-containing stream is provided, for example, by cryogenic liquid nitrogen supplied in containment 48 and metered through valve 50 which enters the heat exchanger 28 through alternate passageways 32 which have an indirect heat exchange relationship with passageways 30. Rewarmed nitrogen is removed from the heat exchanger in line 52 further warmed in a water bath 54 and passed through valve 56 to vent to atmosphere. Alternatively, precooling can be achieved by other means such as a closed cycle cryogenic cooler or a recuperative heat exchanger using the argon/nitrogen gas vented after cleaning duty, or precooling may not be necessary if the argon and/or nitrogen is already sufficiently cool, such as if it is supplied from a cryogenic liquid source. The precooled argon or nitrogen-containing stream is rapidly expanded from a pressure in the range of approximately 20 to 690 psig, preferably 20 to 100 psig (monitored by pressure gauge 22) and a temperature (monitored by temperature gauge 14) to form at least substantially solid particles of argon or nitrogen in admixture with either argon or nitrogen which results in an at least substantially solid argon or nitrogen particle-containing aerosol. These at least substantially solid argon or nitrogen particles are formed by the cooling resulting from the expansion, taking advantage of the Joule-Thompson effect. This expansion is performed in an expansion nozzle 36 comprising a variably adjustable reduced diameter orifice and a throat which directs the at least substantially solid argon or nitrogen particle-containing aerosol 38 to a contaminated surface 40 to be cleaned in an ultra-clean process chamber 34 which may be under vacuum conditions provided through line 44 and valve 46 connected to appropriate vacuum inducing means such as a vacuum pump, etc. The aim of the nozzle 36 and the resulting stream 38 against the surface to be cleaned 40 is preferably at an acute angle to the plane of the surface as determined by the vector of the flow of the aerosol stream. Preferably this angle is approximately 45°. The surface 40 has a tendency to be cooled by the at least substantially solid argon or nitrogen which is not a problem in chamber 34. However, it is appropriate to heat the surface to ambient conditions by a heater (not shown) before removing the surface 40 from the chamber 34.
The argon or nitrogen surface cleaner of the present invention differs significantly from the prior art carbon dioxide surface cleaner. The argon or nitrogen surface cleaner uses cleaning agents which are intrinsically purer than carbon dioxide. Argon and nitrogen are inert and therefore less harmful to the microchip fabrication process than carbon dioxide. The argon or nitrogen surface cleaner preferably uses argon or nitrogen to generate a cleaning aerosol. The carbon dioxide cleaner uses carbon dioxide which, in some instances, may be considered a contaminant. The argon or nitrogen surface cleaner operates at substantially lower temperatures than the carbon dioxide cleaner. The argon or nitrogen cleaner uses precooling before the expansion is performed; the carbon dioxide cleaner does not precool the carbon dioxide prior to expansion. The precooling operation assists in the removal of remaining trace molecular impurities in the argon and nitrogen through a process of condensation on the heat exchanger surface. Removal of trace impurities prevents recontamination of the cleaned surface by condensed impurities particles.
The argon or nitrogen surface cleaner affords many advantages over other types of commonly used surface cleaners. The argon or nitrogen cleaning technique leaves no residue, is environmentally compatible and uses ultrapure cleaning agents (argon and nitrogen) which are commonly available in microchip processing facilities. Argon and nitrogen are also lower in cost than many other cleaning agents. The argon or nitrogen cleaning process has been shown to provide approximately 100% removal of submicrometer particles (particles smaller than 10,000 Angstroms) and can remove larger particles also. Other cleaning techniques are either ineffective or less than 100% effective in removing submicrometer contamination. Gases can be filtered to a very high level of cleanliness while liquids typically have relatively high levels of entrained particulate contamination. Therefore, the argon or nitrogen cleaning process uses a considerably cleaner agent than, for example, spray jet or solvent cleaning. Also, since the argon and nitrogen are continuously vented during operation, the process does not suffer from progressive contamination of the cleaning agents as occurs, for example, in solvent or chemical cleaning. The argon or nitrogen cleaning process can operate under vacuum conditions. This makes the process well adapted to future microchip processing techniques which will be performed largely under vacuum conditions. Argon and nitrogen have higher vapor pressures than carbon dioxide under comparable temperature conditions. Therefore, argon and nitrogen can be more easily pumped out of vacuum systems. This makes argon and nitrogen better suited to future microchip processing operations. Since the argon or nitrogen cleaning process is performed in an inert ultrapure atmosphere, recontamination of the surface by molecular impurities after cleaning is completed can be more easily prevented. The argon and nitrogen can be immediately vented to atmosphere after rewarming; no cleanup or conditioning of the vent gas is required. Argon and nitrogen are asphyxiants but are nontoxic and nonflammable. Therefore, the argon or nitrogen cleaning process is inherently safer than most currently used cleaning processes. The argon or nitrogen cleaning process provides flexibility in cleaning intensity. For example, the aerosol intensity can be reduced to permit cleaning without damage to delicate surface features.
The present invention has been set forth with reference to several preferred aspects and embodiments which are utilized for illustrative purposes, however the full scope of the present invention should be ascertained from the claims which follow.
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A method is disclosed for cleaning microelectronic surfaces using an aerosol of at least substantially solid argon or nitrogen particles which impinge upon the surface to be cleaned and then evaporate and the resulting gas is removed by venting along with the contaminants dislodged by the cleaning method.
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BACKGROUND OF THE INVENTION
The present invention relates to jacks for lifting or supporting a roof of a building, to assemblies for securing such a jack between a roof truss and an underlying ceiling joist, and to methods for lifting and supporting a roof.
At times during construction, renovation, or repair of a building it may be necessary to further support or lift the roof. It has been suggested that roofs may be lifted by using a jack, wherein the jack extends from the slanted or angled roof truss to the ceiling joist below. In such circumstances, the base of the jack, which is at an acute angle to the ceiling joist, must be laterally supported. Typically, lateral support is provided by a block of wood which is nailed to the joist. The opposite end of the jack is conventionally not retained in position by any mounting structure, and is only held in position relative to the truss by the weight of the roof.
Since the base of the jack in the aforementioned prior art jacking method is at a sharp angle to the ceiling joist, there is a tendency for the jack to slide along the joist, despite the lateral support provided by the block of wood. Moreover, the lack of any mounting structure at the truss-end of the jack creates the possibility that the jack will slip off the truss during the lifting operation. These deficiencies cooperate to render roof jacking a difficult undertaking, and one which requires more than one person to perform correctly.
Therefore, there exists a need in the art for a device for mounting a jack to a roof truss and to a ceiling joist. There also exists a need for an improved method for lifting and supporting a roof.
SUMMARY OF THE INVENTION
The present invention is directed toward a mounting bracket which solves the problems encountered in the prior art. More specifically, a mounting bracket according to the present invention facilitates mounting of a jack between a roof truss and a ceiling joist and permits lifting and supporting a roof in accordance with the improved method of the present invention.
In accordance with a first preferred embodiment of the present invention, a roof jack mounting bracket includes first and second end sections and a main body section intermediate the end sections. The end sections preferably extend generally perpendicularly to the main body section and are generally parallel to one another.
In further accordance with the first embodiment of the present invention, a ramped mounting portion extends outwardly from, and at an angle to, the main body section. The mounting portion defines an opening which is adapted to receive a jack.
In accordance with a second preferred embodiment of the present invention, a mounting bracket includes planar, oppositely extending end sections and an intermediate mounting section. The mounting section includes a ramped mounting portion which defines an opening adapted to receive the jack.
The present invention also provides a method for lifting a roof including the steps of securing a first mounting bracket to a roof truss, securing a second mounting bracket to a ceiling joist, inserting one end of a jack into an opening in a mounting portion of the second mounting bracket, aligning a second end of the jack with an opening in a mounting portion of the first mounting bracket, operating the jack such that the second end of the jack extends into the opening in the mounting portion of the first mounting bracket, and further operating the jack to lift and support the roof truss.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further features of the present invention will be apparent with reference to the following description and drawings, wherein:
FIG. 1 is a perspective view of a mounting bracket according to a first embodiment of the present invention;
FIG. 2 is a front elevational view of the mounting bracket shown in FIG. 1;
FIG. 3 is a top plan view of the mounting bracket shown in FIG. 2;
FIG. 4 is a perspective view of a mounting bracket according to a second embodiment of the present invention;
FIG. 5 is a front elevational view of the mounting bracket shown in FIG. 4;
FIG. 6 is a top plan view of the mounting bracket shown in FIG. 5;
FIG. 7 is an exploded elevational view of a jack according to the present invention; and
FIG. 8 is an elevational view showing the first embodiment of the mounting bracket and the jack used in lifting a roof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the FIGS. 1-3 and 7-8, a mounting bracket 10 according to a first embodiment of the present invention is used to secure a screw-type jack 12 between a roof truss 14 and a ceiling joist 16. The mounting bracket 10 is preferably formed or stamped from a single piece of metal such as sheet steel, and is generally U-shaped, having a pair of end sections 18, 20 which are parallel to each other and generally perpendicular to an intermediate main body section 22. The main body section 22 includes a ramped mounting portion 24 which receives and retains the jack 12. More specifically, the mounting portion 24 is an outwardly deformed, ramped mid-portion of the main body section 22, as illustrated best in FIGS. 1 and 2. An enlarged opening 26 is formed in the mounting portion 24 and receives an end of the jack 12, as shown best in FIG. 8.
The main body section 22 and each of the end sections 18, 20 includes a plurality of apertures 28 which allow the mounting bracket 10 to be attached to the truss 14 or joist 16 by means of conventional construction fasteners, such as nails (not shown). The end sections are adapted to be attached to lateral sides of a piece of lumber, while the main body section 22 is attached to a face of the lumber perpendicular to and between the lateral sides thereof.
A second preferred embodiment of the mounting bracket 30 according to the present invention is shown in FIGS. 4-6, wherein the mounting bracket 30 is shown to include planar, oppositely extending end sections 32, 34 and an intermediate mounting section 36. The mounting section 36 includes a ramped mounting portion 38 which has an enlarged opening 40 therein for receipt of the jack 12. The ramped mounting portion is an outwardly deformed mid-portion of the mounting section 36, as illustrated. Each of the end sections 32, 34 includes a plurality of apertures 42 which allow the end sections 32, 34 to be attached to the truss 14 or joist 16 by means of conventional construction fasteners, such as nails (not shown).
With reference to FIG. 7, the jack 12 preferably includes a central tubular body 44 having a collar 46 fixed to each end thereof. An adjustment screw 48 is threadably secured to each collar 46 such that rotation of the tubular body 44 in one direction causes the adjustment screws 48 to extend while rotation of the tubular body 44 in the opposite direction causes the adjustment screws 48 to retract. A distal portion 50 of each adjustment screw 48 preferably includes a reduced diameter terminal end 52. The terminal end 52 is sized to extend through the enlarged openings 26, 40 in the mounting bracket 10, 30, while an annular surface 54 surrounding the reduced diameter terminal end 52 will engage the surface of the mounting portion 24, 38 surrounding the enlarged openings 26, 40.
The method of using the mounting brackets 10, 30 and the jack 12 to lift a roof will be discussed hereafter with regard to the first embodiment of the mounting brackets 10 and with specific reference to FIG. 8. It is to be understood that the second embodiment of mounting brackets 30 can be similarly used.
The mounting brackets 10 are attached to appropriate locations on the truss 14 and a downwardly adjacent joist 16. The location chosen for attachment of the mounting brackets 10 will depend upon where support is needed, and the length of the jack 12. It will be apparent to one skilled in the art that the lifting method of the present invention is useful in lifting and supporting roofs in both older and newer construction. For example, in older buildings the ceiling joists are typically nailed at each end to a lateral side of the roof truss and, as such, the lateral sides of the joists are horizontally displaced relative to the lateral sides of the trusses. However, newer buildings, as illustrated in FIG. 8, typically have corner plates 60 to join the trusses 14 to the joists 16 and, as such, the lateral sides of associated trusses and joists are generally co-planar.
Once the mounting brackets 10 are in place on the truss and joist, the lower, reduced diameter end 52 of the jack 12 is inserted into the enlarged opening 26 in the mounting bracket 10 on the ceiling joist 16, and the upper end of the jack 12 is aligned with the enlarged opening 26 in the mounting bracket 10 on the roof truss 14. The tubular body 44 of the jack 12 is rotated to extend the adjustment screws 48 and thereby insert the upper, reduced diameter end 52 of the jack 12 into the enlarged opening 26 in the truss mounting bracket 10. Thereafter, the tubular body 44 of the jack 12 is further rotated to lift and support the roof truss 14 the desired amount.
While the preferred embodiments of the present invention have been described and illustrated herein, it is contemplated that various modifications, rearrangements, and substitutions of parts may be resorted to without departing from the scope of the present invention as defined by the claims appended hereto. For example, it is contemplated that the mounting brackets 10 of the first embodiment may be used in pairs, or individually in combination with the mounting brackets 30 of the second embodiment.
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A system for lifting and supporting a roof including a jack and a pair of jack mounting brackets. One of the mounting brackets is attached to a roof truss and the other of the mounting brackets is attached to a ceiling joist. The jack extends between the mounting brackets, and has reduced diameter ends which are received within enlarged openings in the mounting brackets.
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RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. Patent Application No. 61/173,529, filed Apr. 28, 2009, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to looms and more specifically to a tool for making cloth and jewelry.
[0003] Existing looms lack angles to enable the user to sit in a comfortable position. Users must sit bent over the loom, which causes back pain and discomfort. Existing looms limit the use of jewelry making techniques to one technique. Further more, other looms cause back pain and discomfort while using them.
[0004] It would be desirable to have a loom for multiple uses that is comfortable to use.
SUMMARY OF THE INVENTION
[0005] In one aspect of the present invention, a tool for a cord includes a first fork, having a first anchor point for the cord; a second fork, having a second anchor point for the cord; and a base to retain the first fork and the second fork; wherein the second anchor point is retained at a distance further from the base than the second anchor point, so that the cord lies at a non-zero angle relative to the base.
[0006] In another aspect of the present invention, a loom includes a first fork, having a first interchangeable anchor point for a cord; a second fork, having a second interchangeable anchor point for the cord; and a base to retain the first fork and the second fork at generally perpendicular angles to the base, the first and second anchor points positioned so as to provide an area for a user's hands to be inserted underneath the cord and between the forks to allow the hands to manipulate jewelry items into the cord.
[0007] In yet another aspect of the present invention, a method utilizing a cord, includes anchoring a first portion of the cord to a first anchor point; and anchoring a second portion of the cord to a second anchor point, the second anchor point at a distance from a base that is further than the first anchor point so that the cord lies at a non-zero angle relative to the base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 depicts the components of an embodiment of the present invention;
[0009] FIG. 2 depicts a side view of the embodiment of FIG. 1 ; and
[0010] FIG. 3 depicts a front view of the embodiment of FIG. 1 .
DETAILED DESCRIPTION
[0011] The preferred embodiment and other embodiments, including the best mode of carrying out the invention, are hereby described in detail with reference to the drawings. Further embodiments, features and advantages will become apparent from the ensuing description or may be learned without undue experimentation. The figures are not drawn to scale, except where otherwise indicated. The following description of embodiments, even if phrased in terms of “the invention,” is not to be taken in a limiting sense, but describes the manner and process of making and using the invention. The coverage of this patent will be described in the claims. The order in which steps are listed in the claims does not indicate that the steps must be performed in that order.
[0012] The present invention relates to a 3-in-1 bead weaving, macramé, and braiding loom with comfort angled design for jewelry making projects.
[0013] An embodiment of the present invention generally provides a multi use jewelry making, art and craft tool. Embodiments may include a stable anchor attachment point for the purpose of macramé jewelry making along with braiding and thread weaving. Embodiments may also serve as a seed bead-weaving loom. An embodiment of a tool may be angled to enable the user to sit in a comfortable position instead of having to sit bent over the loom, thereby helping avoid back pain and discomfort. A loom may give the user the ability to sit in a comfortable position eliminating back discomfort and pain. A loom may also serve as a multi purpose tool for three or more different jewelry making techniques.
[0014] A “loom” is generally a frame for interlacing or combining cords, such as threads or yarns, to form a cloth or decorative item. An embodiment of the present invention may include a loom with a universal adaptation to support macramé, weaving, and braiding, with features for the user to comfortably include jewelry into the item. Embodiments may include a tool for seed bead weaving and macramé knot tying and braiding.
[0015] As depicted in FIG. 1 , an embodiment of the present invention may include a loom 10 with a loom base 20 to support a tall fork 12 and a short fork 14 . The forks 12 , 14 may each include a plain macramé dowel 16 that may be replaceably interchanged with a threaded warp bolt 18 . Each fork may have an anchor point 22 that is an adjustable thread/cord attachment. Tall fork 12 may have a tall fork cross support 24 , and short fork 14 may have a short fork cross support 26 . Rubber O ring stoppers 28 may help retain either the warp bolt 18 or macramé dowel 16 when not in use. A fork support bolt 32 with a wing nut 30 may be used to hold the anchor points 22 or fork cross supports 24 , 26 to provide a tool that can be assembled and disassembled.
[0016] As depicted in FIGS. 1 , 2 and 3 , a loom 10 may include a 3-in-1 bead weaving, macramé, and braiding loom with comfort angled design for jewelry making projects. The tall fork 12 may include a surface, which holds the plain macramé dowel 16 or the threaded warp bolt 18 while a person is macramé/weaving/braiding a cord 40 having jewelry 42 , depending on the jewelry technique being used on the loom 10 . Tall fork 12 may have an upper surface that may be rounded or square. The tall fork 12 may include a hard, supportive material, including but not limited to wood, metal and plastic. The tall fork 12 may be shaped as a rectangle. Tall fork 12 may be sized to accommodate the comfortable, working angle, and may have a height of 7-9 inches and a depth of 1¼-1½ inches.
[0017] The short fork 14 may include a surface, which holds the plain macramé dowel 16 or the threaded warp bolt 18 while a person is macramé/weaving/braiding depending on jewelry technique being used on the loom 10 . Short fork 14 may have an upper surface that may be rounded or square. The short fork 14 may include a hard, supportive material, including but not limited to wood, metal and plastic. The short fork 14 may be shaped as a rectangle. Short fork 14 may be sized to accommodate a comfortable, working angle, and may have a height of 4½-5½ inches and a depth of 1¼-1½ inches.
[0018] The plain macramé dowel 16 may include a surface, which attaches cord or thread by looping or tying, to be used as an anchor, for cord/thread to macramé/weave/braid depending on the jewelry technique being used. The plain macramé dowel 16 may include a hard, supportive material, including but not limited to wood, metal and plastic. The plain macramé dowel 16 may be shaped as round, but can take any other shape, such as square, rectangle, or triangle. It may be sized to accommodate the making of jewelry and may have a length of 6-7 inches and a diameter of ½-¾ inch
[0019] The threaded warp bolt 18 may include a surface for accurate spacing between threads for a technique known as warping for loom weaving. The threaded warp bolt 18 may include a hard, supportive material, including but not limited to wood, metal and plastic. The threaded warp bolt 18 may be shaped as round, but can take any other shape, such as square, rectangle, or triangle. It may be sized to accommodate accurate thread spacing and may have a length of 6-7 inches and a diameter of ½-1 inch.
[0020] The loom base 20 may include a surface to provide support for the loom fork assemblies 12 and 14 . It may be sized to accommodate the making of jewelry using a variety of techniques and may have a length of 19 to 22 inches and a width of 3-5 inches and a thickness of ½-1 inch. The loom base 20 may include a hard, supportive material, including but not limited to wood, metal, and plastic. The loom base 20 may be shaped in a rectangle but could take on any other shape such as an oval or square. It may be sized to accommodate a human posture comfortably.
[0021] The adjustable thread/cord attachment 22 may create tension on threads/cords as needed during jewelry making to free a person's hands while working on creating jewelry and proving a support system for the jewelry making process. The adjustable thread/cord attachment 22 may have a round shape, but can take any other shape, such as square, rectangle, or triangle. The adjustable thread/cord attachment 22 may be sized to accommodate the inside width of the tall fork assembly 12 and the short fork assembly 14 with a length of 3½-4½ inches and a thickness of 1 inch in diameter. The adjustable thread/cord attachment 22 may be comprised of a hard, supportive material, including wood, metal, and plastic.
[0022] The tall fork cross support 24 may include a device configured and designed to allow for support to the cross section of the tall fork assembly 12 and measures 4 inches in length and 1¾ to 2 inches high and ½ to 1 inches thick and may comprise of any hard supportive material known to the art including but not limited to wood, metal, and plastic. The tall fork assembly 24 and may be rectangle in shape, but could take any other shape such as square or round.
[0023] The short fork cross support 26 may include a device configured and designed to allow for the best possible support to the cross section of the short fork assembly 14 and may measure 4 inches in length and ½ to ¾ inches high and ½ to 1 inches thick and may comprise of any hard supportive material known to the art including but not limited to wood, metal, and plastic. The short fork assembly 26 may be rectangle in shape, but could take any other shape such as square or round.
[0024] The rubber “O” ring stoppers 28 may apply to the ends of the plain macramé dowel 16 and the threaded warp bolt 18 to secure into place while resting in the short and tall fork assemblies ( 12 and 14 ) and may be ¾ inch in diameter, but can be adjusted to different sized macramé dowel 16 and the threaded warp bolt 18 and may be comprised of any stretchy material known to the art including but not limited to rubber. The rubber “O” ring stoppers may be shaped as a circle, but could take any other shape, such as an oval or square.
[0025] The wing nut 30 may attach to the ends of the fork support bolt 32 to accommodate tightening and hold in place the tall and short fork assemblies ( 12 and 14 ) and the adjustable thread/cord attachment 22 . This tightening will pull the thread/cord to the desired tension to work on the project. The wing nut 30 may include a hard, supportive material, including but not limited to wood, metal and plastic.
[0026] The fork support bolt 32 may give the loom 10 the option to be disassembled for storage. It may include a bolt with a flat head on one end and threaded on the other end which slides through the fork assemblies ( 12 and 14 ) to connect them to the loom base 20 . It may be comprised of a hard material, including but not limited to wood, plastic and metal. The fork support bolt 32 may be sized and shaped to accommodate the length of the fork assemblies ( 12 and 14 ) with a length of 5½-6 inches and a diameter of ¼ inches.
[0027] The tall fork assembly 12 may connect to the adjustable thread/cord attachment 22 in the upper portion of the fork assemblies ( 12 and 14 ) with the fork cross support ( 24 and 26 ) with the other fork connected to the other side (creating an H shape) with the fork cross support ( 24 and 26 ) connecting between the fork assemblies ( 12 and 14 ), fork 12 paired with 12 and fork 14 paired with 14 connecting an inch from the bottom of each fork ( 12 and 14 ) (the bottom being the end not drilled with a hole.) This creates two fork assemblies—one for each end of the loom base 20 . Any connection may include screws, bolts, and adhesives, or other connectors.
[0028] The tall fork assembly 12 may attach at either end of the loom base 20 using the fork support bolt 32 and wing nuts 30 but may use any other nut to tighten at each end of the bolt which will hold the tall fork assembly 12 in place. The short fork assembly 14 may be attached in the same manner at the other end of the loom base 20 . The plain macramé dowel 16 may attach by sliding through both fork assembly holes and securing in place by using the rubber O ring stoppers 28 but may use other ring style stoppers by applying each one to the end of the macramé dowel 16 . The threaded warp bolt 18 may slide into place through the ¾ inch holes in the assembly forks ( 12 and 14 ) at each end of the loom and secured into place by using rubber O ring stoppers 28 but may use other ring stoppers at each end of the threaded warp bolts 16 . The adjustable thread/cord attachment 22 may be permanently or detachably connected and may twist to create thread/cord tension by attaching the threads or cord to the screw in the adjustable thread/cord attachment 22 and twisting to desired tension and tightening into place by using the wing nuts 30 or other nuts on one or both sides.
[0029] An embodiment of the loom 10 may be assembled by sliding metal support bolt 32 through each set of loom forks ( 12 and 14 ) after being placed over each end of the loom base 20 then attaching wing nuts 30 on each end of the metal support bolts 32 and tighten. Once assembly is done the user may choose the plain macramé dowel 16 to create macramé jewelry and braiding or thread weaving and craft items. The dowel 20 may be replaced with the threaded warp bolt 30 and may create seed bead loomed jewelry and craft items.
[0030] An embodiment may be held comfortably between the knees or on the lap of the user while sitting in a comfortable place. Its angled design may allow easy to reach access, with plenty of work space under the project, to help provide proper tension control and easy view of the project. Embodiments may also offer the user multiple jewelry making technique options.
[0031] To use an embodiment, one may begin work on the loom 10 by placing the short fork 14 closest to your body. The tall fork end 12 furthest from the user's body would be the proper working direction. To use loom 10 for macramé jewelry, one may place the plain macramé dowel 16 into both fork ends of the loom 10 . The user may cut a desired length of cord, and create loop or tie cord to macramé dowel, which becomes the anchor point for the cord to be braided, tied, or woven. One or more cords may be tied to the end of the loom 10 at the thread/cord attachment 22 to create the desired tension by twisting the thread/cord attachment 22 , and then the wing nuts 30 tightened to hold in place while working on the project. The plain macramé dowel 16 can then be changed to the threaded warp bolt 18 for the purpose of seed bead loom weaving. One may tie a desired thread to the thread/cord attachment 22 then begin stringing threads over each threaded warp bolt 18 , allowing each thread to lay in a separate groove in the warp bolt 18 . One may then tie the threads onto thread/cord attachment 22 located at the other end of the loom 10 continuing until the desired amount of thread is in place, and then tying the thread end onto one of the thread/cord attachments.
[0032] To use an embodiment, a person may provide the loom 10 and choose either the plain macramé dowel 16 or the threaded warp bolt 18 to use for her desired jewelry, art or craft project. She would then attach her desired cords or threads to the adjustable thread/cord attachment 22 . She would then find a comfortable place and position to sit and begin work on her desired project utilizing the comfortable angled design and easy to hold size in a manner that would suite her and give her accurate full view of her project as she works.
[0033] An embodiment of a seed bead looming technique may include the following steps. Place thread bolts in the loom and secure with rubber O rings at each end. Tie threads over screws at each end of loom with a slip knot. Wrap around screw several times to anchor the thread and then go across the loom to the screw on the opposite side and wrap around screw to anchor thread. Go back across loom placing threads into the thread guide and continue the process until enough thread is in place for your desired project. If more tension on threads is desired place wood braiding dowel behind threads at the end of the loom just above the screw.
[0034] An embodiment of a macramé technique may include the following steps. Place wood dowels in loom. Measure cord to desired length for your project and tie loop at the end of the cord. Slip loop onto dowel at the higher end of the loom. Pull center cord out and place beads onto cord then tie to the screw at the end of the loom. Use remaining cords to begin macramé knot tying of desired design. A paper clip can also be used as a hook for projects like braiding. Just bend into a hook shape and hook onto wood dowel as an anchor.
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A loom includes a first fork, having a first interchangeable anchor point for a cord; a second fork, having a second interchangeable anchor point for the cord; and a base to retain the first fork and the second fork at generally perpendicular angles to the base. The first and second anchor points are positioned so as to provide an area for a user's hands to be inserted underneath the cord and between the forks to allow the hands to manipulate jewelry items into the cord. A tall fork and a short fork support the attachment points perpendicular to the base. The interchangeable anchor points are selectable between dowels and threaded warp bolts.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
The present application is a U.S. national stage of and claims priority to and the benefit of International Application No. PCT/CN2013/076225, filed May 24, 2013, which claims the benefit of Chinese Application No. 201210169746.6, filed May 24, 2012, both of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to the field of dairy processing, and specifically to an infant formula milk powder capable of preventing and alleviating infant iron deficiency anemia and a preparation method thereof.
BACKGROUND OF THE INVENTION
Iron is a kind of essential trace element which is the most abundant in the human body, and is involved in multiple biological functions, such as substance metabolism, production of red blood cell, cell division and the like. However, iron deficiency is one of the most important nutritional problems in the world, particularly in developing countries, and iron deficiency is an important reason for the occurrence of anemia.
In 1928, Mackay firstly proved that the iron deficiency is the reason for anemia being prevailed in infants; in 1982, Bunge noted that infants are susceptible to iron deficiency. The incidence of iron deficiency anemia in infants in China was higher. According to the “Prevalence investigation of iron deficiency in children in China”, which was published on Chinese Journal of Pediatrics in 2008, overall prevalence of iron deficiency in children aged 7 months to 7 years was 40.3%, and the prevalence of iron deficiency anemia was 7.8%. Among them, the prevalence of iron deficiency and iron deficiency anemia in infants was as high as 44.7% and 20.5%, respectively. The prevalence of anemia in artificially fed babies was almost twice as high as that in breast-fed babies.
Iron deficiency anemia would affect behavior and intellectual development of infants, thereby decreasing the visual and auditory developmental level as well as the learning ability; pica appeared in some infants, such as those who like eating soil block, chalk and other abnormal matters. In addition, when the infants had iron deficiency, the number of brain cells in infants would be reduced or the functions thereof would be lowered, and anemia would lead to insufficient oxygen being carried, as well as hypoxia in cells of brain and other organs, such that iron deficiency might affect mental development of children. Therefore, alleviating the infant iron deficiency has become one of the major nutrition researches in the world.
As well known, babies with exclusive breast-feeding suffer fewer anemia. Breast milk contains various kinds of nutrients required in infants for growth and development. Although breast milk contains a small amount of iron, it is enough for the baby requirements because of the high absorption rate of iron therein. The absorption rate of iron in breast milk (50-75%) is much higher than that in milk powder provided with the enhanced iron (about 4%).
The iron supplementing compound commonly used in the commercially-available infant formula milk powder is non-heme iron, but the absorption rate of non-heme iron is only 2.57%. Although in the case of the iron deficiency in body, the absorption of rate will be slightly increased, but it is still too low. According to the investigation, it is found that the intake of dietary iron in crowd is usually higher than RDA (AI), but the phenomenon of iron deficiency in body, including iron deficiency anemia and hemoglobin being lower than normal level is very common, this is mainly because the formula milk powder and other complementary food comprise phosphates, carbonates, phytic acid, oxalic acid, tannic acid and the like, which can form insoluble salts with iron, and affect the absorption of iron. Even a small amount of the above compounds exist, the inhibition of iron absorption is quite significant. In addition, the milk powder comprises some inhibiting components in a high concentration (such as calcium and phosphate), and lacks iron-absorption enhancing components (such as vitamin C, lactose, lactoferrin and the like), or the proportion of each component is inappropriate.
Although some formula milk powder manufacturers have started to pay attention to problems of infant iron deficiency or anemia, most of them intend to solve the infant iron-absorption insufficiency by increasing the addition amount of iron or excessively increasing the addition amount of vitamin C. On one hand, excessive iron will lead to the imbalanced metabolism of zinc, copper and other trace elements in the body, resulting in loss of appetite, anorexia, growth retardation, low blood pressure, abnormal cholesterol in infants, thereby increasing the risk of inducing heart disease; on the other hand, excess iron deposition may result in the body aging and the occurrence of various epidemic diseases, thereby leading to body injury; furthermore, excess vitamin C will cause the instability in quality of milk powder, and the acidity thereof will be too high after being brewed, resulting in the destruction of other nutrients, etc. Therefore, none of them can improve the current situation of infant iron deficiency.
SUMMARY OF THE INVENTION
The purpose of the present invention is to provide an infant formula milk powder as well as the preparation method thereof, in order to prevent and alleviate infant iron deficiency anemia.
The present invention is achieved by the following technical solutions:
The present invention provides an infant formula milk powder, comprising the following components (parts by weight): 5-20 parts of vegetable oil, 187-427 parts of fresh milk (containing 11.1% of dry matter), 20-35 parts of whey powder, 12.23-21.753 parts of lactose, 2-4 parts of whey protein powder, 1.5-2.5 parts of oligosaccharides, 0.15-0.2 part of complex vitamins, 0.35-0.6 part of complex minerals, 1-1.5 parts of other nutrients allowed in the infant formula milk powder, 0.02-0.1 part of lactoferrin, and vitamin C, wherein the mass ratio of lactoferrin to vitamin C is 1:3 to 1:1.
The present invention provides an infant formula milk powder, comprising the following components (parts by weight): 25-35 parts of vegetable fat powder, 30-42.5 parts of powdered milk, 21.5-30 parts of whey powder, 1.096-8.93 parts of solid glucose syrup, 2-4 parts of whey protein powder, 1.5-2.5 parts of oligosaccharides, 0.15-0.2 part of complex vitamins, 0.35-0.6 part of complex minerals, 1-1.5 parts of other nutrients allowed in the infant formula milk powder, 0.02-0.1 part of lactoferrin and, vitamin C, wherein the mass ratio of lactoferrin to vitamin C is 1:3 to 1:1.
As a preferred embodiment, the complex minerals in the infant formula milk powder contain iron source, and the mass ratio of iron source (calculated as iron):lactoferrin:vitamin C is 1:10:25 to 1:8:10.
As a further preferred embodiment, the mass ratio of iron source (calculated as iron):lactoferrin:vitamin C is 1:10:15.
As an even further preferred embodiment, the amount of iron source (calculated as iron) added in 100 parts of infant formula milk powder is 0.004-0.008 part.
As another preferred embodiment, Fe 2+ :Fe 3+ comprised in the iron source is 2:3 (by mol).
The present invention provides a method for preparing the infant formula milk powder, comprising the following steps:
(1) mixing and stirring the vegetable oil, fresh milk, whey powder, lactose, whey protein, oligosaccharide until completely dissolved, to prepare a mixed solution, of which the temperature is 40-50° C.; (2) homogenizing the mixed solution using a high pressure homogenizer at 15-20 MPa, while the temperature is controlled at 40-50° C.; (3) cooling the mixed solution to 10° C. or lower, and temporarily storing for no more than 12 hours; (4) concentrating and spray-drying the mixed solution to obtain a powdery matrix powder, wherein during the spray-drying process, the inlet air temperature is 150-170° C., and the outlet air temperature is 80-90° C.; (5) adding the complex vitamins, the complex minerals, the lactoferrin and the nutrients, and mixing evenly; (6) packaging.
As a preferred preparation method, during the mixing process in the above step (5), the iron source is further added according to the above-said proportion.
The preset invention provides another method for preparing the infant formula milk powder, comprising the following steps:
(1) mixing the complex vitamins, the complex minerals, the lactoferrin, said other nutrients and an appropriate amount of powdered milk in a mixer for 10-15 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
The present invention has at least the following advantages:
The formula milk powder comprises an appropriate amount of vitamin C and lactoferrin, as well as an appropriate amount of iron source as further provided, and the three are combined according to an appropriate proportion, so that the three substances have a synergistic effect, and the absorption and utilization rate of iron are increased dramatically, thereby not only achieving the desirable iron supplementation effect, but also preventing and alleviating the phenomenon of infant iron deficiency anemia.
It should be emphasized that the vitamin C, iron compound (iron source) and lactoferrin added in the present invention is a synergistic combination, which is in the best proportion range obtained after tremendous trial and verification, and the effect thereof is not the simple sum-up of each single substance, but the synergistic combination thereof.
DETAILED DESCRIPTION
Example 1
An infant formula milk powder, comprising the following components (parts by weight): 20 parts of vegetable oil, 187 parts of fresh milk (containing 11.1% of dry matter), 35 parts of whey powder, 4 parts of whey protein powder, 16.173 parts of lactose, 2.5 parts of oligosaccharides, 0.35 part of complex minerals, 0.14 part of complex vitamins (except vitamin C), 1 part of nutrients, 0.02 part of lactoferrin and 0.06 part of vitamin C.
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) stirring the vegetable oil, fresh milk (containing 11.1% of dry matter), whey powder, lactose, whey protein powder, oligosaccharide until completely dissolved, to prepare a mixed solution, of which the temperature was controlled at 40° C.; (2) homogenizing the above mixed solution using a high pressure homogenizer at 20 MPa, while the temperature was controlled at 50° C.; (3) cooling the mixed solution to 10° C. or lower, and temporarily storing for 12 hours; (4) concentrating and spray-drying the mixed solution to obtain a powdery matrix powder, wherein during the spray-drying process, the inlet air temperature was 150° C., and the outlet air temperature was 90° C.; (5) adding complex vitamins, complex minerals, lactoferrin, vitamin C and nutrients, and mixing evenly; (6) packaging, to obtain the final products.
Example 2
An infant formula milk powder, comprising the following components (parts by weight): 5 parts of vegetable oil, 427 parts of fresh milk (containing 11.1% of dry matter), 20 parts of whey powder, 2 parts of whey protein powder, 21.753 parts of lactose, 1.5 parts of oligosaccharides, 0.567 part of complex minerals (except iron), 0.05 part of complex vitamins (except vitamin C), 1.5 parts of nutrients, 0.033 part of ferrous gluconate (containing 12% of iron), 0.10 part of lactoferrin and 0.10 part of vitamin C.
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) stirring the vegetable oil, fresh milk (containing 11.1% of dry matter), whey powder, lactose, whey protein powder, oligosaccharide until completely dissolved, to prepare a mixed solution, of which the temperature was 50° C.; (2) homogenizing the above mixed solution using a high pressure homogenizer at 15 MPa, while the temperature was controlled at 40° C.; (3) cooling the mixed solution to 10° C. or lower, and temporarily storing for 11 hours; (4) concentrating and spray-drying the mixed solution to obtain a powdery matrix powder, wherein during the spray-drying process, the inlet air temperature was 170° C., and the outlet air temperature was 80° C.; (5) adding complex vitamins, complex minerals, lactoferrin, ferrous gluconate (containing 12% of iron), vitamin C and nutrients, and mixing evenly; (6) packaging, to obtain the final products.
Animal Experiment for Alleviating Iron Deficiency Anemia
Experimental animals: experimental SD rats, weighted 180-210 g, male and female each in half, were taken for the blood before modeling, to measure the normal value of blood cell. 5 male rats and 5 female rats were kept as the normal control, which were fed with ordinary feedstuff, while the other rats were used for preparing the iron deficiency anemia model. Preparation of the iron deficiency anemia model: the rats were fed with low-iron feedstuff, and accompanied by having the tail bleed once every 5 days, the amount of blood was 0.4 ml each time. Equal numbers of male rats and female rats were separately arranged in plastic cages covered with stainless steel mesh, and took food freely. After 20 days, blood was taken from all modeling animals, and Hb and iron contents in whole blood were measured. 40 modeling animals (male and female each in half) with Hb below 90 g/L were taken, and randomly divided into four groups: the control group, the sample group 1 (lacking lactoferrin), the sample group 2 (lacking vitamin C) and the sample group 3, n=10.
Experimental method: rats were fed once a day with the amount of 15% of body weight thereof, freely drank distilled water and ate ordinary feedstuff for 30 days. Hb and RBC contents in blood of animals in each group were recorded before modeling, after modeling and after feeding; the control group was fed with ordinary feedstuff; the model control group was still fed with low-iron feedstuff; the sample group 1 was fed with the formula milk powder according to this example but without lactoferrin; the sample group 2 was fed with the formula milk powder according to this example but without vitamin C; the sample group 3 was fed with the formula milk powder according to this example.
Results:
TABLE 1
Measurement results of RBC and Hb before modeling, after modeling and after
feeding ( x ± s)
RBC (*10 12 /L)
Hb (g/L)
before
after
after
before
after
after
group
modeling
modeling
feeding
modeling
modeling
feeding
Normal
6.36 ± 0.40
6.4 ± 0.41
6.42 ± 0.45
122.7 ± 6.6
121.5 ± 4.9
122.5 ± 5.6
control
group
model
6.39 ± 0.39
5.1 ± 0.43
5.18 ± 0.45
121.5 ± 7.6
77.5 ± 5.5
76.5 ± 5.9
group
sample
6.40 ± 0.41
5.4 ± 0.45
6.89 ± 0.52*
122.5 ± 7.1
79.0 ± 6.1
122.8 ± 5.5*
group 1
sample
6.35 ± 0.42
5.3 ± 0.42
7.02 ± 0.49*
121.5 ± 6.2
78.7 ± 6.2
123.5 ± 5.1*
group 2
sample
6.38 ± 0.41
5.3 ± 0.44
7.30 ± 0.51**
123.9 ± 6.7
79.1 ± 6.5
138.1 ± 5.3**
group 3
Note:
*indicates that compared with the model group, P < 0.05;
**indicates that compared with the sample groups 1 and 2, P < 0.05
From the results in Table 1, it can be known that after feeding the modeling animals with different samples for 3 weeks, the recovery of RBC and Hb of rats in sample groups 1, 2 and 3 were evidently enhanced with a significant difference, compared to that in the control group; and said recovery of rats in sample group 3 also had a significant difference compared to that in sample groups 1 and 2. This illustrates that with regard to the effect for alleviating the iron deficiency anemia, the formula milk powder comprising lactoferrin and vitamin C in a certain proportion was better than the formula milk powder provided with lactoferrin or vitamin C alone.
Example 3
An infant formula milk powder, comprising the following components (parts by weight): 6 parts of vegetable oil, 400 parts of fresh milk (containing 11.1% of dry matter), 22 parts of whey powder, 3 parts of whey protein powder, 21.699 parts of lactose, 1.8 parts of oligosaccharides, 0.5 part of complex minerals (except iron), 0.075 part of complex vitamins (except vitamin C), 1.5 parts of nutrients, 0.10 part of lactoferrin, 0.125 part of vitamin C and 0.104 part of ferrous gluconate (containing 12% of iron).
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) stirring the vegetable oil, fresh milk (containing 11.1% of dry matter), whey powder, lactose, whey protein powder, oligosaccharide until completely dissolved, to prepare a mixed solution, of which the temperature was 45° C.; (2) homogenizing the above mixed solution using a high pressure homogenizer at 18 MPa, while the temperature was controlled at 45° C.; (3) cooling the mixed solution to 10° C. or lower, and temporarily storing for no more than 12 hours; (4) concentrating and spray-drying the mixed solution to obtain a powdery matrix powder, wherein during the spray-drying process, the inlet air temperature was 160° C., and the outlet air temperature was 85° C.; (5) adding complex vitamins (except vitamin C), complex minerals (except iron), vitamin C, ferrous gluconate (containing 12% of iron), lactoferrin and the nutrients, and mixing evenly; (6) packaging, to obtain the final products.
Clinical Experiment for Alleviating Iron Deficiency Anemia
Experimental subjects: 90 cases of children patients with iron deficiency anemia diagnosed clinically were chosen by using random-sampling grouping method, and divided into 3 groups (common diet, the ordinary formula milk powder, the formula milk powder of Example 3), n=30. The children patients were 0.5-1.5 years old, and the difference of clinical information of the children patients in three groups had no statistical significance (P>0.05).
Method: group 1 was fed with common diet; group 2 was fed with the formula milk powder in other brands (prepared by wet process); group 3 was fed with the formula milk powder prepared by this example. The Hb of the children patients in the three groups were measured after two months, to evaluate the alleviating effects (when the hemoglobin was increased and the average increase was >15 g/L, it was judged as effective), and contrastively analyze the adverse reaction rates.
Results: clinical information and data of children patients were analyzed by using statistical software, and it was considered as statistically significant when P<0.05. As seen from Table 2, the anemia symptoms of the children patients with anemia cannot be changed by common diet, the effect of alleviating the symptoms of iron deficiency anemia in children patients in group 3 was better than that in children patients in the other two groups, and the difference thereof was statistically significant (P<0.05); the alleviating effect of the formula milk powder of this example was better than that of the ordinary formula milk powder, and the difference therebetween was statistically significant (P<0.05); adverse reaction rate of the children patients in the three group was 0.0%, 3.3% and 3.3%, respectively, and the difference thereof was not statistically significant (P>0.05). See Table 2 and Table 3.
TABLE 2
Comparison of the treatment effects [n (%)]
Hb (g/L)
number of
Before
After
Overall
Group
cases (n)
feeding
feeding
effective
Ineffective
Group 1
30
93.7 ± 5.2
91.7 ± 4.5
4
26
Group 2
30
93.5 ± 5.6
103.5 ± 5.2*
14*
16
Group 3
30
93.4 ± 5.8
123.2 ± 5.1**
23**
7
Note:
*indicates that compared with the control group, P < 0.05;
**indicates that compared with groups 1 and 2, P < 0.05
TABLE 3
Comparison of adverse reactions [n (%)]
number of
poor
Group
cases (n)
emesis
diarrhea
constipation
appetite
allergy
Group 1
30
0
0
0
0
0
Group 2
30
0
0
0
1
0
Group 3
30
0
0
1
0
0
Note:
P > 0.05
Example 4
An infant formula milk powder, comprising the following components (parts by weight): 10 parts of vegetable oil, 325 parts of fresh milk (containing 11.1% of dry matter), 28 parts of whey powder, 3 parts of whey protein powder, 18.827 parts of lactose, 2.0 parts of oligosaccharides, 0.52 part of complex minerals, 0.014 part of complex vitamins (except vitamin C), 1.3 parts of nutrients, 0.088 part of lactoferrin, 0.176 part of vitamin C
The preparation method of the above infant formula milk powder was the same with that in Example 1.
Example 5
An infant formula milk powder, comprising the following components (parts by weight): 10 parts of vegetable oil, 325 parts of fresh milk (containing 11.1% of dry matter), 28 parts of whey powder, 3 parts of whey protein powder, 18.822 parts of lactose, 2.0 parts of oligosaccharides, 0.48 part of complex minerals (except iron), 0.013 part of complex vitamins (except vitamin C), 1.3 parts of nutrients, 0.10 part of lactoferrin, 0.167 part of vitamin C, 0.043 part of ferrous lactate (containing 19.4% of iron).
The preparation method of the above infant formula milk powder was almost the same with that in Example 2, except for in step (5), adding complex vitamins, complex minerals, lactoferrin, ferrous lactate (containing 19.4% of iron), vitamin C and nutrients, and mixing evenly.
Example 6
An infant formula milk powder, comprising the following components (parts by weight): 12 parts of vegetable oil, 350 parts of fresh milk (containing 11.1% of dry matter), 30 parts of whey powder, 3 parts of whey protein powder, 12.23 parts of lactose, 2.0 parts of oligosaccharides, 0.475 part of complex minerals (except iron), 0.045 part of complex vitamins (except vitamin C), 1.2 parts of nutrients, 0.025 part of ferrous sulfate (containing 20% of iron), 0.05 part of lactoferrin, 0.125 part of vitamin C.
The preparation method of the above infant formula milk powder was almost the same with that in Example 5, except for in step (5), adding complex vitamins, complex minerals, lactoferrin, ferrous sulfate (containing 20% of iron), vitamin C and nutrients, and mixing evenly.
Example 7
An infant formula milk powder, comprising the following components (parts by weight): 12 parts of vegetable oil, 350 parts of fresh milk (containing 11.1% of dry matter), 30 parts of whey powder, 3 parts of whey protein powder, 12.2 parts of lactose, 2.0 parts of oligosaccharides, 0.475 part of complex minerals (except iron), 0.095 part of complex vitamins (except vitamin C), 1.2 parts of nutrients, 0.03 part of ferrous sulfate (containing 20% of iron), 0.06 part of lactoferrin and 0.09 part of vitamin C
The preparation method of the above infant formula milk powder was the same with the steps in Example 6.
Example 8
An infant formula milk powder, comprising the following components (parts by weight): 30 parts of vegetable fat powder, 40 parts of skim powdered milk, 13 parts of whey powder, 4 parts of whey protein powder, 8.93 parts of liquid glucose syrup, 2.5 parts of oligosaccharides, 0.35 part of complex minerals, 0.14 part of complex vitamins (except vitamin C), 1 part of nutrients, 0.02 part of lactoferrin, and 0.06 part of vitamin C
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals, lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 10 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Animal Experiment for Alleviating Iron Deficiency Anemia
The iron-deficiency animal model was prepared according to the animal experiment research scheme and method of Example 2, 40 modeling animals (male and female each in half) with Hb below 90 g/L were taken, and randomly divided into four groups: the model control group, the sample group 1 (lacking lactoferrin), the sample group 2 (lacking vitamin C) and the sample group 3 (this example), n=10.
Experimental method: rats were fed once a day with the amount of 15% of body weight thereof, freely drank distilled water and ate ordinary feedstuff for 30 days. Hb and RBC contents in blood of animals in each group were recorded before modeling, after modeling and after feeding; the model control group was still fed with low-iron feedstuff; the sample group 1 was fed with the formula milk powder according to this example but without lactoferrin; the sample group 2 was fed with the formula milk powder according to this example but without vitamin C; the sample group 3 was fed with the formula milk powder according to this example.
Results:
TABLE 4
Measurement results of RBC and Hb before modeling, after modeling and after
feeding ( x ± s)
RBC (*10 12 /L)
Hb (g/L)
before
after
after
before
after
after
group
modeling
modeling
feeding
modeling
modeling
feeding
model
6.54 ± 0.40
5.6 ± 0.45
5.85 ± 0.45
127.5 ± 11.0
78.5 ± 5.8
79.5 ± 9.8
group
sample
6.54 ± 0.39
5.5 ± 0.49
6.92 ± 0.50*
127.5 ± 11.0
78.0 ± 7.1
132.8 ± 9.3*
group 1
sample
6.55 ± 0.41
5.2 ± 0.51
7.10 ± 0.52*
126.5 ± 11.2
78.5 ± 7.2
133.5 ± 9.1*
group 2
sample
6.52 ± 0.42
5.4 ± 0.46
7.29 ± 0.53**
126.9 ± 10.9
78.3 ± 7.5
145.1 ± 9.5**
group 3
Note:
*indicates that compared with the control group, P < 0.05;
**indicates that compared with the sample groups 1 and 2, P < 0.05
From the results in Table 4, it can be known that after feeding the modeling animals with different samples for 30 days, the recovery of RBC and Hb of rats in sample groups 1, 2 and 3 were evidently enhanced with a significant difference compared to that in the control group, and higher than that in the control group; said recovery of rats in sample group 3 also had a significant difference compared to that in sample groups 1 and 2. This illustrates that with regard to the effect for promoting iron absorption, the formula milk powder comprising the iron-absorption enhancing compositions was significantly better than the formula milk powder provided with lactoferrin or vitamin C alone.
Example 9
An infant formula milk powder, comprising the following components (parts by weight): 25 parts of vegetable fat powder, 28 parts of skim powdered milk, 14.5 parts of whole powdered milk, 21.5 parts of whey powder, 2 parts of whey protein powder, 1.5 parts of oligosaccharides, 5.15 parts of solid glucose syrup, 0.567 part of complex minerals (except iron), 0.05 part of complex vitamins (except vitamin C), 1.5 parts of nutrients, 0.10 part of lactoferrin, 0.10 part of vitamin C and 0.033 part of ferrous gluconate (containing 12% of iron).
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins, complex minerals, lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 15 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Example 10
An infant formula milk powder, comprising the following components (by weight): 35 parts of vegetable fat powder (containing 45% of lactose), 30 parts of skim powdered milk, 26 parts of whey powder, 3 parts of whey protein powder, 2.5 parts of oligosaccharides, 1.096 parts of solid glucose syrup, 0.5 part of complex minerals (except iron), 0.075 part of complex vitamins (except vitamin C), 1.5 parts of nutrients, 0.10 part of lactoferrin, 0.125 part of vitamin C and 0.104 part of ferrous gluconate (containing 12% of iron).
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals (except iron), lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 12 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Example 11
An infant formula milk powder, comprising the following components (parts by weight): 35 parts of vegetable fat powder, 30 parts of skim powdered milk, 26 parts of whey powder, 3 parts of whey protein powder, 1.5 parts of oligosaccharides, 2.402 parts of solid glucose syrup, 0.52 part of complex minerals, 0.014 part of complex vitamins (except vitamin C), 1.3 parts of nutrients, 0.088 part of lactoferrin and 0.176 part of vitamin C.
The preparation method of the above infant formula milk powder was the same with the steps in Example 8.
Example 12
An infant formula milk powder, comprising the following components (parts by weight): 25 parts of vegetable fat powder, 28 parts of skim powdered milk, 21.5 parts of whey powder, 14.5 parts of whole powdered milk, 2 parts of whey protein powder, 2.0 parts of oligosaccharides, 4.897 parts of solid glucose syrup, 0.48 part of complex minerals (except iron), 0.013 part of complex vitamins (except vitamin C), 1.3 parts of nutrients, 0.10 part of lactoferrin, 0.167 part of vitamin C and 0.043 part of ferrous lactate (containing 19.4% of iron).
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals (except iron), lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 10 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Example 13
An infant formula milk powder, comprising the following components (parts by weight): 28 parts of vegetable fat powder, 30 parts of whole powdered milk, 30 parts of whey powder, 4 parts of whey protein powder, 4.08 parts of solid glucose syrup, 2.0 parts of oligosaccharides, 0.475 part of complex minerals (except iron), 0.045 part of complex vitamins (except vitamin C), 1.2 parts of nutrients, 0.025 part of ferrous sulfate (containing 20% of iron), 0.05 part of lactoferrin and 0.125 part of vitamin C.
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals (except iron), lactoferrin, other nutrients and an appropriate amount of milk powder in a mixer for 15 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Clinical Experiment for Alleviating Iron Deficiency Anemia
Experimental subjects: 60 cases of children patients with iron deficiency anemia diagnosed clinically were chosen by using random-sampling grouping method, and divided into 3 groups (common diet, other formula milk powder, the formula milk powder of this example), n=20. The children patients were 1-3 years old, and the difference of clinical information of the children patient in three groups had no statistical significance (P>0.05).
Method: group 1 was fed with common diet; group 2 was fed with the formula milk powder in other brands (prepared by dry process); group 3 was fed with the formula milk powder prepared by this example. The Hb of the children patients in the three groups were measured after two months, to evaluate the alleviating effects (when the hemoglobin was increased and the average increase was ≧15 g/L, it was judged as effective), and contrastively analyze the adverse reaction rates.
Results: clinical information and data of children patients were analyzed by using statistical software, and it was considered as statistically significant when P<0.05. It can be seen from the following Table 5 that, the effects of the two formula milk powders were better than that of the common diet group, and the effect of alleviating the symptoms of iron deficiency anemia in children patients in group 3 was better than that in children patients in the other two groups, and the difference thereof was statistically significant; the alleviating effect of the formula milk powder of this example was better than that of the formula milk powder in other brands, and the difference therebetween was statistically significant (P<0.05); the adverse reaction rate of the children patients in the three group was 0.0%, 5.0% and 5.0%, respectively, and the difference thereof was not statistically significant (P>0.05). See Table 5 and Table 6.
TABLE 5
Comparison of the treatment effects [n (%)]
Hb (g/L)
number of
Before
After
Overall
Group
cases (n)
feeding
feeding
effective
Ineffective
Group 1
20
90.5 ± 4.6
93.2 ± 4.6
5
15
Group 2
20
91.2 ± 4.5
107.4 ± 4.8*
11*
9
Group 3
20
91.3 ± 4.7
129.1 ± 5.0**
17**
3
Note:
*indicates that compared with the control group, P < 0.05;
**indicates that compared with the groups 1 and 2, P < 0.05
TABLE 6
Comparison of adverse reactions [n (%)]
number of
poor
Group
cases (n)
emesis
diarrhea
constipation
appetite
allergy
Group 1
30
0
0
0
0
0
Group 2
30
0
0
0
1
0
Group 3
30
0
0
1
0
0
Note:
P > 0.05
Example 14
An infant formula milk powder, comprising the following components (parts by weight): 35 parts of vegetable fat powder, 30 parts of skim powdered milk, 26 parts of whey powder, 3 parts of whey protein powder, 1.5 parts of oligosaccharides, 2.893 parts of solid glucose syrup, 0.34 part of complex minerals (except iron), 0.065 part of complex vitamins (except vitamin C), 1 part of nutrients, 0.01 part of ferrous sulfate (containing 20% of iron), 0.012 part of ferric pyrophosphate (containing 25% of iron), 0.045 part of lactoferrin and 0.135 part of vitamin C.
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals (except iron), lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 13 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Example 15
An infant formula milk powder, comprising the following components (parts by weight): 25 parts of vegetable fat powder, 28 parts of skim powdered milk, 21.5 parts of whey powder, 14.5 parts of whole powdered milk, 2 parts of whey protein powder, 2.5 parts of oligosaccharides, 2.276 parts of solid glucose syrup, 0.45 part of complex minerals (except iron), 0.1 part of complex vitamins (except vitamin C), 1 part of nutrients, 0.024 part of ferric pyrophosphate (containing 25% of iron), 0.09 part of vitamin C and 0.06 part of lactoferrin.
The complex minerals of the present invention comprise calcium carbonate, zinc sulfate, potassium iodide, copper sulfate, sodium selenite, manganese sulfate, and maltodextrin. The complex vitamins of the present invention comprise vitamin A, vitamin D, vitamin E, vitamin K1, vitamin B1, vitamin B2, vitamin B6, vitamin B12, pantothenic acid, biotin, folic acid, nicotinic acid, taurine and a small amount of maltodextrin. The nutrients of the present invention comprise DHA, AA, lutein, nucleotide and maltodextrin.
As described in the Example 15, the amount of complex minerals (0.4 part of calcium carbonate, 0.011 part of zinc sulphate, 0.000072 part of potassium iodide, 0.0012 part of copper sulfate, 0.000024 part of sodium selenite, 0.00012 part of manganese sulfate and balance maltodextrin) was 0.45 part; the amount of complex vitamins (0.0005 part of vitamin A, 0.000009 part of vitamin D, 0.005 part of vitamin E, 0.000055 part of vitamin K1, 0.00045 part of vitamin B1, 0.0009 part of vitamin B2, 0.0003 part of vitamin B6, 0.000002 part of vitamin B12, 0.003 part of pantothenic acid, 0.00002 part of biotin, 0.00009 part of folic acid, 0.003 part of nicotinic acid, 0.045 part of taurine and balance maltodextrin) was 0.1 part; and the amount of nutrients (0.03 part of DHA, 0.06 part of AA, 0.0003 part of lutein, 0.025 part of nucleotides, and balance maltodextrin) was 1 part.
Obviously, the components comprised in the above complex minerals, vitamins, nutrients can be appropriately adjusted according to the specific circumstances.
The preparation method of the above infant formula milk powder was achieved by the following steps:
(1) mixing the complex vitamins (except vitamin C), complex minerals (except iron), lactoferrin, other nutrients and an appropriate amount of powdered milk in a mixer for 15 min, to obtain a mixture; (2) adding the rest of raw materials, mixing for 20 min, to obtain a mixture; (3) packaging.
Example 16
Experiment for Alleviating Iron Deficiency Anemia
Experimental animals: experimental SD rats, weighted 180-210 g, male and female each in half, were taken for the blood before modeling, to measure the normal value of blood cell. 5 male rats and 5 female rats were kept as the normal control, which were fed with ordinary feedstuff, while the other rats were used for preparing the iron deficiency anemia model. Preparation of the iron deficiency anemia model: the rats were fed with low-iron feedstuff, and accompanied by having the tail bleed once every 3 days, the amount of blood was 120 drops/kg each time for 4 times. Equal numbers of male rats and female rats were separately arranged in plastic cages covered with stainless steel mesh, and took food freely. After 20 days, blood were taken from all modeling animals, and Hb and iron contents in whole blood were measured. 40 modeling animals (male and female each in half) with Hb below 90 g/L, and iron contents in whole blood below 430 ng/ml were taken, and randomly divided into four groups: the control group, the sample group 1 (iron), the sample group 2 (vitamin C+iron) and the sample group 3 (vitamin C+iron+lactoferrin), n=10.
Experimental method: rats were fed once a day with the amount of 15% of body weight thereof, freely drank distilled water for 21 days. Hb and RBC contents in blood of animals in each group were recorded before modeling, after modeling and after feeding; iron contents in whole blood of animals in all groups were measured by using atomic absorption spectrometry, and the total iron content in hemoglobin (BHb-Fe) and relative absorption rate of iron (RBA) were calculated. BHb-Fe=weight (g)*7%*Hbg %*3.4 (mgFe/gHb), wherein the amount of blood was as 7%, Fe content in Hb was as 3.4 mg/g.
The control group was fed with ordinary feedstuff; the sample group 1 was fed with the formula milk powder according to Example 15 but without lactoferrin and vitamin C; the sample group 2 was fed with the formula milk powder according to Example 15 but without lactoferrin; the sample group 3 was fed with the formula milk powder according to Example 15. The iron contents in the three samples were 6 mg/100 g.
Results:
TABLE 7
Measurement results of RBC and Hb before modeling, after modeling and after
feeding ( x ± s)
RBC (*10 12 /L)
Hb (g/L)
before
after
after
before
after
after
group
modeling
modeling
feeding
modeling
modeling
feeding
control
6.55 ± 0.40
6.6 ± 0.45
6.85 ± 0.50
127.5 ± 11.0
128.5 ± 12.0
129.5 ± 11.8
group
sample
6.54 ± 0.39
5.1 ± 0.49
7.02 ± 0.52
126.5 ± 10.6
78.0 ± 7.1
142.8 ± 11.3
group 1
sample
6.51 ± 0.41
5.0 ± 0.51
7.41 ± 0.59*
127.5 ± 11.2
77.5 ± 7.2
147.5 ± 12.1*
group 2
sample
6.59 ± 0.42
5.1 ± 0.46
7.65 ± 0.62**
126.9 ± 10.9
78.0 ± 7.5
149.8 ± 12.5**
group 3
Note:
*indicates that compared with the sample group 1, P < 0.05;
**indicates that compared with the sample group 2, P < 0.05
TABLE 8
The relative bioavailability of iron (RBA %) ( x ± s)
BHb-Fe (mg)
BHb-Fe (mg)
BHb-Fe (mg)
group
Before feeding
After feeding
Increased
RBA %
sample
3.68 ± 0.37
6.75 ± 0.62
3.07 ± 0.50
100
group 1
sample
3.65 ± 0.35
6.94 ± 0.69*
3.29 ± 0.49
107
group 2
sample
3.74 ± 0.38
7.18 ± 0.72**
3.44 ± 0.53
112
group 3
Note:
*indicates that compared with the sample group 1, P < 0.05;
**indicates that compared with the sample group 2, P < 0.05
From the results in Tables 7 and 8, it can be known that after feeding the modeling animals with the samples comprising the same amount of iron for 3 weeks, the recovery of RBC and Hb of rats in sample groups 2 and 3 were evidently enhanced with a significant difference compared to that in control group and sample group 1, and higher than that in the control group, while the absorption and utilization rate of iron were improved; said effects in sample group 2 also had a significant difference compared to that in sample group 1, and said effects in sample group 3 also had a significant difference compared to that in sample groups 1 and 2. This illustrates that with regard to the effect for promoting iron absorption, the formula milk powder comprising the iron-absorption enhancing compositions was significantly better than the formula milk powder added with iron or vitamin C alone.
Finally, it should be noted that, the part according to the present invention was all calculated by weight. The components comprised in complex minerals, vitamins and nutrients can be appropriately adjusted according to actual requirements. In addition, the complex minerals can comprise the iron source directly, alternatively, the iron source can be additionally added; the complex vitamins can comprise the vitamin C directly, alternatively, the vitamin C can be additionally added. Regardless which way is to be used, the mass ratio between lactoferrin and vitamin C, as well as the mass ratio of iron source (calculated as iron), lactoferrin and vitamin C must satisfy the ratio relationship pointed out by the present invention.
Certainly, the components listed above are only the specific examples of the present invention. Obviously, the present invention is not limited into the above examples, but can have many variations. All variations that can be derived from or associated directly with the contents disclosed in the present invention by one of ordinary skill in the art should be considered as falling within the scope of the present invention.
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The present invention relates to an infant formula milk powder capable of preventing and alleviating infant iron deficiency anemia and a preparation method thereof. The formula milk powder comprises components such as vegetable oil, fresh milk, whey powder, lactose powder, whey protein powder, oligosaccharides, complex vitamins and complex minerals, wherein the lactoferrin and vitamin C, or alternatively, an iron source (calculated as iron), lactoferrin and vitamin C are maintained in the appropriate mass ratios, and the formula milk powder of the present invention is obtained by performing mixing, homogenizing, cooling, concentrating and spray-drying, packaging or directly using a step-by-step mixing method. The formula milk powder comprises appropriate amounts of vitamin C and lactoferrin, as well as an appropriate amount of iron source as further provided, and the three are combined according to an appropriate proportion, so that the combination of the three kinds of the substances have a synergistic effect, and the absorption and utilization rate of iron are increased dramatically, thereby not only achieving the desirable iron supplementation effect, but also preventing and alleviating the phenomenon of infant iron deficiency anemia.
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[0001] This invention relates generally to computer systems and networks and deals more particularly with systems and methods by which a single computer can control the operation of a plurality of other computers in a coordinated way.
[0002] One of the simplest ways in which humans can interact with computers is by way of line-mode commands and responses. This interaction begins with the human typing a command into the computer using a keyboard. The PC-DOS command “DIR”, the Unix command “Is”, and the CMS command “LISTFILE” are examples of such commands. The computer processes the command and then might print one or more lines of response text on a screen or on a roll of paper. The computer then issues a prompt (such as a question mark), indicating that it is ready for the next command.
[0003] Early computer networks extended this mode of interaction by offering the human operator the ability to use a local terminal and its associated local computer to issue commands to, and receive responses from, a remote computer. In such networks, a telecommunications protocol such as Telnet connects the local computer to the remote one. The data exchanged on the telecommunications link consists of the commands entered by the human operator on the local terminal and the responses generated by the remote computer. The local computer acts as intermediary between the human operator and the remote computer, forwarding commands from the local operator's terminal to the remote computer and printing the remote computer's responses on the local terminal. In this way the human operator conducts command-and-response interaction with the remote computer, the remote computer appearing to be local.
[0004] Telnet and similar protocols are often implemented on top of a generalized data exchange method, such as a TCP/IP socket connection. In such a case, a program running on the local computer can replace the local terminal and the local operator. The local program, being cognizant of the Telnet protocol, can use TCP/IP to connect to the remote computer, send it commands, and receive its responses. Further, the local program can decode those responses and condition subsequently transmitted commands on them. In other words, the local program controls the remote computer as a human operator might. The remote computer is unable to detect that it is being operated by a program running on the local computer, instead of by a human operator at the local terminal. In this scenario, when the local computer is exerting control over the remote computer, we call the local computer the “master” computer or “control” computer, and we call the controlled computer the “subordinate” computer.
[0005] One reason it is desirable for a master computer to operate a subordinate computer in this way is for the testing of programs within the subordinate computer for program debugging and other purposes. U.S. Pat. No. 5,371,883 discloses a method of testing programs in a distributed environment. A central repository is associated with a control computer for one of several computers to be tested. Test cases are stored in the central repository. The test cases are specific sequences of inputs or items of data which are designed to exercise a test program running in a test computer. A control program in the control computer forwards instructions from a test case to one or more test programs to be executed. In this manner, the control program maintains control of the sequence of execution. The results of the execution by the test programs are reported back to the control program which determines whether the results are correct. The control program may send additional instructions to the test programs depending on the foregoing results and startup parameters. In summary, the test program logs the results of the test cases, tracks the test cases that were performed and coordinates the test cases.
[0006] It is occasionally necessary to use the master computer to control a plurality of subordinate computers to operate in a concurrent, coordinated manner, instead of in a serial manner or in a concurrent but unrelated manner. For example, it might be desirable for the master computer to operate a suite of cooperating programs intended to run concurrently on the plurality of subordinates. If a human operator were performing this task, he might first type a “start” command on one subordinate, wait for said subordinate to indicate that it has started, and then type a corresponding “start” command on another subordinate. When a program replaces the human operator in this scenario, the program must issue the commands to the subordinates in the correct sequence, conditioning its actions on the timing of the receipt of appropriate responses from the subordinates.
[0007] Accordingly, an object of the present invention is to provide a program at a master computer to concurrently operate a plurality of cooperating programs at other computers in a manner which emulates human operation.
[0008] Another object of the present invention is to conduct such operation without requiring special coordination software in the subordinate computers.
SUMMARY OF THE INVENTION
[0009] The invention resides in a computer program product for execution at a first computer to emulate manual user input at a first computer to operate second and third computers. The program product includes a computer readable medium and the following programming recorded on the medium. A first program segment requests initialization of communication between the first computer and the second and third computers. A second program segment interacts with the second computer. A third program segment interacts with the third computer. The second program segment and the third program segment are executed effectively concurrently. According to the second program segment, execution of the second program segment is suspended pending the third computer reaching a certain state and the state being communicated to the second program segment. Such a state emulates human operator decisions and time that would be spent by the human operator in making operation decisions based on current events.
[0010] According to one feature of the present invention, the computer programming includes
[0011] a first command to send a first request to the second computer and a second command subsequent to the first command to send a second request to the second computer. There is a third command, between the first and second commands, to wait a predetermined time until executing the second command. The predetermined time emulates a time that the human operator would wait before sending the second request to the second computer.
BRIEF DESCRIPTION OF THE FIGURES
[0012] [0012]FIG. 1 is a block diagram illustrating a master computer, multiple interconnected subordinate computers, and key functions within the master computer according to the present invention.
[0013] FIGS. 2 ( a - e ) form a flow chart of a Script Processing function within the master computer of FIG. 1, according to the present invention.
[0014] [0014]FIG. 3 illustrates scripts embodying various features of the present invention.
[0015] [0015]FIG. 4 is a timing diagram illustrating timing of events resulting from the scripts of FIG. 3.
[0016] [0016]FIGS. 5, 6, and 7 illustrate scripts embodying various features of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now to the drawings in detail, wherein like reference numbers indicate like elements throughout, FIG. 1 illustrates a distributed computer system generally designated 10 embodying the present invention. System 10 comprises a master computer 14 , subordinate computers 16 , 18 , 20 , etc. and communication medium there between. By way of example, the communication medium is Telnet although other known protocols and interfaces will also suffice. Master computer 14 includes several functions pertaining to the present invention. The functions together comprise an interpreter for a script which a user writes with an ordinary text editor such as Notepad.
[0018] The script begins with initialization as illustrated in FIG. 5. Initialization step 501 identifies each subordinate to which the master computer is to connect. For each such subordinate, the initialization step gives the name by which the subordinate will be known in the rest of the script (in 501 , “SUB 1” and “SUB2”). Further, continuing the Telnet example, the initialization section identifies each subordinate by IP address, so as to let the master establish a connection to the subordinate (connection parameters associated with other protocols would be appropriate if the other protocols were used in place of Telnet). Finally, for each subordinate, the initialization step names a later “script segment”. A script segment 502 a or 502 b is a programmatic sequence of commands, expected responses, and other control words which collectively describe how the master is to interact with a subordinate. In many cases the programmatic sequence contains control words describing how the progress of the interaction with a subordinate is to depend on the progress of the interactions with other subordinates. In general, a script will consist of one initialization section and one or more script segments. The master computer executes the script to exercise the subordinate computers 16 , 18 , and 20 as if the commands had been input by human operators seated at terminals directly attached to each of those subordinates.
[0019] It is important to realize that depending on the content of initialization step 501 , a script segment 502 a might apply to more than one subordinate although there would be a different instance of the script for each subordinate. For example, if the script author wanted the master computer to conduct exactly the same command-and-response conversation with 100 subordinates concurrently, he or she would write initialization step 501 to name each of the 100 subordinates and point each one to the very same script segment 502 a. In this case the master computer would instantiate script segment 502 a on each of the 100 subordinate connections. This is analogous to what happens on a Unix or Windows computer when the same program file runs concurrently in a plurality of processes.
[0020] Each script segment comprises one or more lines of code. Each script line includes a control “verb” and one or more parameters as appropriate for the verb. For example, a “Send” verb is a command to transmit a line of text to the respective subordinate. The line of text is indicated by a parameter associated with the verb. A “Wait” verb indicates that a certain text string must be received from the respective subordinate computer before interaction with the subordinate can continue. The text string is indicated by a parameter associated with the “Wait” verb. Other verbs, as described below, influence the ordering or timing of the transmissions to the subordinates. In other words, these other verbs define prerequisites for sending commands to the respective subordinate computers. These prerequisites includes the passage of time or the receipt of requisite responses from one or more other subordinate computers.
[0021] The ordering and timing of the processing of “Send” verbs emulates the decision-making process of a single human operator controlling the subordinate computers manually. For example, when attempting to generate computing load on a single subordinate, a human operator might type a command to start a load-inducing program, wait for the program to finish, delay some amount of time, and then type the load-inducing command again. A script segment emulating this would contain the “Send” and “Wait” verbs described earlier. The segment would contain an additional verb, “Delay”, that caused the master to wait a certain amount of time before proceeding. Finally, the segment would contain some iteration verbs, perhaps to cause the master to enter the load-inducing command 1000 times. In another example, in operating a distributed application, a human operator might need to type commands on a plurality of subordinates, in a specific sequence, so as to operate the distributed application correctly. The operator might need to type “start_server” on subordinate 16 , wait for subordinate 16 to respond “server started”, and only then type “start_client” on subordinate 18 . A script emulating this human operator's behavior would contain two script segments, one for subordinate 16 and the other for subordinate 18 . Each segment would include “Send” and “Wait” verbs. The subordinate 18 segment would also contain a “SemWait” verb (described in more detail below), to cause interaction with subordinate 18 to be suspended until a semaphore has been signaled. The subordinate 16 script would also contain a “SemSignal” verb (described in more detail below), to signal the semaphore and thereby restart the interaction with subordinate 18 at the appropriate moment. FIG. 6, described below, with script segments 601 and 602 illustrates this.
[0022] Master computer 14 's processing of a script begins when Parsing function 40 reads the script from a file, identifies the initialization section of the script, identifies each script segment, and determines the names of the subordinates and the correspondence between subordinates and script segments. Next, an Establish Connection function 42 ( a ) establishes Telnet connections between master computer 14 and each of the subordinate computers identified in the initialization section, for example, subordinate computers 16 , 18 and 20 . Telnet connection establishment is well known and comprises the following steps. First, a TCP socket is obtained. The socket is used to connect to the Telnet port on the subordinate computer. Then, a small amount of data is sent to the subordinate computer to negotiate the Telnet connection parameters. As noted above, other communication protocols and interfaces can also be used. After these connections are established, a Script Processing function 44 begins using the Telnet connections to interact or “converse” with each subordinate according to the verbs in its designated script segment. The conversations with the subordinates are conducted concurrently. This concurrent execution can occur on different “threads” of a multithreaded master computer, if desired. Alternatively, this concurrent execution can be carried out by a single, serial thread on the master computer, provided the master computer thread effectively divides its attention among the subordinates, in which case the execution is effectively concurrent. Script Processing function 44 sends commands to the subordinate computers according to the verbs defined in the script segments.
[0023] Occasionally a subordinate conversation reaches a point where, in accordance with the verbs in its designated script segment, the conversation must wait for an event, such as the lapse of a timer or the receipt of a signal from some other subordinate conversation. When such a point occurs, the master computer suspends its conversation with the subordinate and continues conversing with the others.
[0024] The Script Processing function 44 is further illustrated by the flowchart of FIG. 2 which is executed for each subordinate computer concurrently with that of the other subordinate computers. The general strategy of the Script Processing function is to advance each conversation with the respective subordinate computer as far as possible. When a subordinate conversation can no longer advance (for example, because its script segment requires a wait for a certain response text from the subordinate or a signal from another subordinate conversation), the master computer will suspend its interaction with that subordinate until the requisite event occurs.
[0025] For each subordinate conversation, the Script Processing function begins at step 100 , where the conversation has just been started and is therefore advanceable. The Script Processing immediately moves to step 102 , reading a line of the corresponding script segment to determine the nature of the line (step 104 ). This line will be the first line of the script segment if the conversation is just beginning or will be the next line for subsequent iterations of the flow chart of FIGS. 2 ( a ) through 2 ( e ). As noted above, each line from the script segment will consist of a verb and any parameters appropriate for the verb.
[0026] Each line from a script segment will contain one of the following dispatch control commands or “verbs”:
[0027] “Send” instructs the Script Processing function to send a line of text to the respective subordinate computer.
[0028] “Wait” instructs the Script Processing function to wait for the respective subordinate computer to emit a certain text string before proceeding. For example, if a human operator would ordinarily wait for a prompt string “Password:” before typing a logon password, the script segment would contain “WAIT Password:” to cause the master to wait for the string “Password:” before sending the password.
[0029] “TimedWait” instructs the Script Processing function to wait a certain amount of time before processing the next line of the script segment. The duration of the timer is specified as a parameter to the “TimedWait” verb. The “TimedWait” verb may be used in a script segment which emulates user think time. For example, the user may request data which is presented on a screen at his terminal, and the user must read the screen and decide what to do next before entering a new command. In this example, the “TimedWait” emulates the time required by the user to read the screen and decide what to do next.
[0030] “RandomWait”, like TimedWait, instructs the Script Processing function to wait some amount of time before processing the next line of the script segment. Unlike “TimedWait”, the amount of time to wait is random within a range prescribed by parameters to the “RandomWait” verb. A function within the master computer generates the random time. Like “TimedWait”, the “RandomWait” verb may be used in a script segment which emulates user think time because different (human) users will require different think times for any given scenario. “RandomWait” is probably more realistic than “TimedWait” for emulating think time, but nevertheless both verbs are provided.
[0031] “SemWait” instructs the Script Processing function to wait for a named signal from some other subordinate conversation before processing the next line of the script segment containing the “SemWait”. The identity of the subordinate conversation on which to wait and the name of the signal for which to wait are given as parameters to the “SemWait” verb. The “SemWait” verb may be used in a script which emulates a single user concurrently using two different keyboards to control two different subordinate computers. In this scenario, the user may wait on sending a command to one subordinate computer via one keyboard until having received and evaluated a response from another subordinate computer. The “SemWait” verb can emulate the decision making process of the user in sequencing the sending of commands through the two different keyboards.
[0032] “SemSignal” instructs the Script Processing function to provide a named signal so that one or more other subordinate conversations can proceed. Typically these other subordinate conversations are suspended waiting for this named signal pursuant to the foregoing “SemWait” verb. The provision of the “SemSignal” might enable these other subordinate conversations to proceed. The name of the signal to provide is given by a parameter to SemSignal. Typically, a script author will use SemSignal to let one or more subordinate conversations proceed after an appropriate response has been received from a certain subordinate. Each waiting subordinate conversation uses SemWait to listen for the named signal and proceed to the next line of its corresponding script segment only after it receives the signal. Step 601 of FIG. 6 illustrates the login of an emulated human operator named “bkw” and then the SemSignal verb. Step 602 of FIG. 6 illustrates the login of an emulated user “arthur” and then the corresponding SemWait verb. Thus, script segment 601 illustrates the use of SemSignal to provide signal “FRED” to script segment 602 . Script segment 602 illustrates the use of SemWait to wait for subordinate SUB1 to provide signal “FRED”.
[0033] “MultiWait” instructs the Script Processing function to wait for all subordinate conversations sharing a given name prefix to provide a certain signal. The name prefix and the signal name are given by parameters to the MultiWait verb. The “MultiWait” verb is used to let one or more subordinate conversations wait for a whole class of subordinate conversations to reach a certain point, and only then do the waiting subordinate conversations continue processing. For example, in reference to FIG. 7, initialization step 701 defines five “STUDENT” subordinates, named STUDENT1, . . . , STUDENT5, all running script segment 702 . Initialization step 701 also defines three “TEACHER” subordinates, named TEACHER1, . . . , TEACHER3, all running script segment 703 . After emulation of login of user “bkw” with a password for all STUDENT and TEACHER subordinates, all STUDENT subordinates must finish “Is -al” before any TEACHER subordinate issues “uname -a”.
[0034] “MultiSignal” instructs the Script Processing function to provide the named signal, for capture by one or more other subordinate conversations' MultiWait verb. FIG. 7 also illustrates the use of MultiSignal, wherein each TEACHER subordinate is waiting for the “DONE” signal from each STUDENT subordinate before advancing.
[0035] Each “control directive” may also include one of the following control words or verbs which changes the Script Processing function's flow through the script segment, but is not directly related to advanceability of a subordinate conversation or the sending or receiving of data thereon:
[0036] “If” instructs the Script Processing function to branch within the script segment based on a condition specified as a parameter to the “If” directive. Processing either continues at the next line of the segment or branches to the corresponding “EndIf”, depending on the veracity of the specified condition.
[0037] “Do” instructs the Script Processing function to iterate over a portion of a script segment a certain number of times. The end of the sequence is marked by a corresponding “End” directive. The requisite number of iterations is given by a parameter to the “Do” verb.
[0038] “IfRun” instructs the Script Processing function to branch within the script segment based on whether the name of the subordinate conversation matches one of the subordinate name prefixes specified as a parameter to “IfRun”. If the subordinate name matches one of the prefixes, processing continues at the next line. If there is no match, control transfers to the corresponding “EndIfRun” directive.
[0039] Each “control directive” may also include one of the following control words or verbs which causes the Script Processing function to take specific immediate actions which do not bear on the interaction with the subordinate computers:
[0040] “Say” which instructs the Script Processing function to display specified text to a user of the master computer.
[0041] “Checkpoint” which instructs the Script Processing function to write to persistent storage (for example, a disk file) all of the subordinate responses it has received so far, so that in the event of a failure, some responses will have been saved.
[0042] As noted above, in step 104 the Script Processing function examines the “verb” in the script line. If the verb is “Send” (decision 106 ), then the Script Processing function sends the associated line of text (indicated by the parameter for the Send verb) to the subordinate (step 108 ). Then, the Script Processing function returns to step 102 to process the next line of this script segment. However, if the current line of the script segment does not contain a “Send” verb, then step 108 is bypassed, and the Script Processing function determines if the verb is “Wait” (decision 110 ). If so, the Script Processing function waits for some text to arrive from the subordinate associated with the script segment (step 112 ). To wait for some text, the Script Processing function uses the “wait for data” and “read data” functions provided by the data transport protocol being used. (In the Telnet example, the Script Processing function uses the TCP socket function “select( )” to wait for data to arrive from the subordinate, and it then uses the TCP socket function “read( )” to collect the arrived data. Those skilled in the art will recognize that other data transport means will have corresponding primitives which should be used in place of select( ) and read( ).) Whenever data arrives, the Script Processing function examines it to determine whether the desired text has arrived yet (step 114 ). When the desired text arrives, the Script Processing function loops back to step 102 to process more lines from the script segment.
[0043] If the line of the script segment does not contain any of the foregoing verbs, then the Script Processing function determines if the verb is “TimedWait” (decision 120 ). If so, the Script Processing function records the wakeup time for this subordinate conversation (step 122 ). The “wakeup” time for a “TimedWait” verb is based on a timer value specified as a parameter to the “TimedWait” verb. Next, the Script Processing function waits until the specified timer has expired (decision 124 ). At that time, the Script Processing function loops back to step 102 to process more lines from the script segment.
[0044] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function determines if the verb is “RandomWait” (decision 130 ). If so, the Script Processing function records the wakeup time for this subordinate conversation (step 132 ). The “wakeup” time for a “RandomWait” verb is based on a random time (within a specified range) generated by the Script Processing function. Next, the Script Processing function waits until the specified time has been reached (decision 134 ). At that time, the Script Processing function loops back to step 102 to process more lines from the script segment.
[0045] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function determines if the verb is “MultiWait” (decision 140 ). Such a script segment line will also specify the name prefix for the set of subordinates for which this conversation is waiting and the name of the signal all of these subordinates must provide before the script segment bearing the MultiWait can proceed. If the verb is a “MultiWait”, the Script Processing function checks whether all of the specified subordinates have already provided the named signal (step 142 ). If so, the Script Processing function loops back to step 102 to process the next line of the script segment. However, if at least one of the subordinates of the named set has not yet provided the named signal, the Script Processing function repeats step 142 . When all subordinates of interest provide the named signal, the Script Processing function loops back to step 102 to process more lines from the script segment.
[0046] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function determines if the verb is “SemWait” (decision 150 ). Such a script segment line will also specify the name of the subordinate which will provide the signal and the name of the signal the subordinate will provide. If the verb is a “SemWait”, the Script Processing function checks whether the named subordinate has already provided the named signal (decision 152 ). If so, the Script Processing function loops back to step 102 to process the next line of the script segment. However, if the named subordinate has not yet provided the named signal, processing returns to decision 152 . When the named subordinate provides the named signal, the Script Processing function loops back to step 102 to process more lines from the script segment.
[0047] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function determines if the verb is “SemSignal” (decision 160 ). If so, the Script Processing function records (step 162 ) that this subordinate conversation has provided the named signal. This will directly end the waiting of any subordinate conversation using SemWait (decision 152 ) to wait on this subordinate to emit this signal. The Script Processing function then loops back to step 102 to process more lines from the script segment.
[0048] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function determines if the verb is “MultiSignal” (decision 170 ). If so, the Script Processing function records (step 172 ) that this subordinate conversation has provided the named signal. Like SemSignal (step 162 ), this will contribute toward the advancement of one or more other subordinate conversations which were suspended at a MultiWait verb (decision 142 ). The Script Processing function then loops back to step 102 to process more lines from the script segment.
[0049] If the line of the script segment does not contain any of the foregoing verbs, then the Script Processing function determines if the verb is a conditional verb—“If”, “IfEnd”, “Do”, “End”, “IfRun” or “EndIfRun” (decision 180 ). If so, the Script Processing function evaluates the condition (step 182 ). In the case of an “If” verb, the script segment will also state the requisite condition. The Script Processing function will determine if the requisite condition has been satisfied and locate the appropriate next line of the script segment (step 184 ). The appropriate line is either the very next line of the script or the first line after the corresponding “EndIf”. In the case of a “Do” verb, the script segment will also state a number of iterations of a step or loop of steps to be performed, and the Script Processing function will iteratively execute them. The end of the block of script segment statements is marked by “End”. In the case of an “IfRun” verb, the script segment will also state the class of subordinates to which the steps apply. The Script Processing function will determine if the requisite condition has been satisfied and locate the appropriate next line of the script segment (step 184 ). The appropriate line is either the very next line of the script or the first line after the corresponding “EndIfRun”. For any of these conditionals, once it has located the appropriate next line, the Script Processing function returns to step 104 to evaluate the line.
[0050] If the line of the script segment does not contain any of the foregoing verbs, then the Script Processing function determines whether the verb is one of the minor verbs, such as “Say” or “Checkpoint” (decision 190 ). If so, the Script Processing function handles the verb accordingly (step 192 ) and then returns to step 102 to process more lines from the script segment.
[0051] If the line of the script segment does not contain any of the foregoing verbs, the Script Processing function displays an error message for the user of the master computer, halts its interactions with the subordinate computers, and terminates (step 200 ).
[0052] Based on the foregoing process, master computer 14 advances each subordinate conversation according to the instructions specified in its associated script segment. Subordinate conversations which have no requisite preconditions for completion or whose preconditions are satisfied from the outset may complete without ever waiting. Other subordinate conversations whose script segments include a “Wait” may be executed until reaching this verb, and then be suspended until receiving the requisite response from a subordinate computer. Other subordinate conversations whose script segments include a “TimedWait” or “RandomWait” verb may be executed until reaching these verbs, and then be suspended the requisite time before proceeding. Other subordinate conversations whose script segments include a “MultiWait” or “SemWait” verb may be executed until reaching this verb, and then be suspended until receiving a notification from one or more other subordinate conversations to proceed. Thus, the script and Script Processing function let a script author determine the timing and sequence in which commands will be sent to a plurality of subordinate computers.
[0053] Referring again to FIG. 1, during script processing, the Script Processing function notifies a Logging function 180 of the responses from the subordinates. The Logging function duly records them. After the Script Processing function completes each subordinate conversation, the Script Processing function notifies an End Connection function 42 ( b ) to end the Telnet connection with the respective subordinate computer.
[0054] [0054]FIG. 3 illustrates a sample script that includes Wait, MultiWait, and MultiSignal verbs. The script begins with initialization step 300 which defines four subordinates followed by their respective IP addresses. Three of the subordinates are in class S and are named S 1 , S 2 , and S 3 . The other subordinate is named T. The script segment designated “S” is for each of the subordinates S 1 , S 2 and S 3 . The script segment designated “T” is for subordinate T. Script segment S begins at step 302 a, while script segment T begins at item 304 a. All four script segments, i.e. three instances of script segment S and one instance of script segment T, execute concurrently. To process this script, the master computer runs its Parsing function 40 (from FIG. 1) so as to determine the identities of the subordinates and the script segments they are to run. The master computer next runs its Establish Connection function 42 (also from FIG. 1) so as to establish appropriate connections to the four subordinates. Next, the master computer begins its Script Processing function 44 , conversing with the four subordinates concurrently. The Script Processing function advances each of the four subordinate conversations at its own pace, according to network speed, the speeds of the respective subordinate computers, and any wait conditions. With respect to each subordinate conversation S, the Script Processing function performs one or more steps 302 b, whose contents are not relevant to this example, and then performs step 302 c, wherein it waits for the subordinate to respond with text containing a dollar sign “$”. (Unix practitioners will recognize the “$” as the prompt character, indicating the computer is ready to process another command.) After the “$” is received, the Script Processing function moves to step 302 d, at which it records that the respective subordinate has provided the signal “DONE”. With respect to its conversation with subordinate T, the Script Processing function in like manner has worked through steps 304 a and 304 b, and arrived at 304 c. The Script Processing function cannot complete step 304 c on its conversation with subordinate T until it has completed step 302 d for each of its S 1 , S 2 , and S 3 conversations, that is, until each of the S subordinates has emitted the “DONE” signal. Thus the master computer cannot advance its subordinate conversation T to step 304 d until its conversations with S 1 , S 2 , and S 3 have all completed step 302 d. This achieves the synchronization of the operation of each of the four subordinate computers.
[0055] [0055]FIG. 4 illustrates one possible sequence of events that would satisfy the script of FIG. 3. The scenario begins at time t 0 with the master establishing its connections to the four subordinates S 1 , S 2 , S 3 , and T. At times t 1 through t 4 , the master accomplishes intermediate steps 302 b and 304 b with the four subordinates, the relative ordering and function actually performed by these steps not being relevant to the present example. At time t 5 the master receives “$” from subordinate S 3 , thus satisfying the Wait at 302 c, and so at time t 6 accomplishes 302 d for subordinate S 3 , recording provision of signal “DONE”. At time t 7 the master begins step 304 c for subordinate T, but finding the MultiWait condition unsatisfied, can advance its conversation with T no further. At times t 8 through t 11 , the master detects receipt of “$” from subordinates S 1 and S 2 (step 302 c ) and records their provisions of signal “DONE” (step 302 d ). At this moment the conversation with subordinate T becomes advanceable, because all of the S subordinates have emitted “DONE”. However, at time t 12 the Script Processing function continues with subordinate S 1 , accomplishing 302 e, whose actual function is not relevant to the present example. At t 13 the master computer detects that S 1 , S 2 , and S 3 have all emitted the signal “DONE”, and so the Script Processing function completes step 304 c with T. At time t 14 the master computer completes step 304 d with T. Beyond time t 14 the master continues with subordinates S 1 , S 2 , S 3 , and T through the rest of their script segments, description thereof not being relevant in this example.
[0056] Based on the foregoing, a computer system and method embodying the present invention have been disclosed. However, numerous modifications and substitutions may be made without deviating from the present invention. For example, minor verbs other than “Say” and “Checkpoint” could be added, or the “Wait” verb could be enhanced to detect that a subordinate has not emitted the desired response within a specified period of time, or iteration and flow control verbs sensitive to subordinate response texts could be added. Therefore, the present invention has been disclosed by way of illustration and not limitation and reference should be made to the following claims to determine the scope of the present invention.
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A computer program product for execution at a first computer to emulate manual user input at a first computer to operate second and third computers. The program product includes a computer readable medium and the following programming recorded on the medium. A first program segment requests initialization of communication between the first computer and the second and third computers. A second program segment interacts with the second computer. A third program segment interacts with the third computer. The second program segment and the third program segment are executed effectively concurrently. According to the second program segment, execution of the second program segment is suspended pending the third computer reaching a certain state and the state being communicated to the second program segment. Such a state emulates human operator decisions and time that would be spent by the human operator in making operation decisions.
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DESCRIPTION
BACKGROUND OF PRIOR ART
Energy and medical experts are becoming more and more concerned in recent years because of indoor air pollution and undesirable conditions which are becoming prevalent as a result of efforts to conserve energy. As heating costs soar, home owners rush to seal their homes with additional insulation and weatherproofing in order to seal out the cold. Such action, however, at the same time seals in harmful pollutants and creates harmful conditions in the form of an inadequate good air supply. Since most people spend most of their time indoors, such harmful conditions are justifiably of much concern.
Older homes leak sufficient air so that a complete air change takes place every one to one and one-half hours. Builders today, however, have reduced air changes due to leakage in the new homes which they build to about one air change every ten (10) hours. Such limited air entrance, coupled with increased consumption and removal of air by various devices within the home, causes a negative pressure to be built up within relatively new and air-tight homes, along with air pollutants which emanate from various products in the home interior, such as particle board which disseminates formaldehyde fumes. Another pollutant given off by rocks, soil and common building materials and found in home interiors is radon, an odorless radioactive gas which has been implicated as a cause of cancer.
Negative pressure conditions within such an air-tight home are particularly attributable to various devices commonly utilized within the home and which either consume oxygen or expel air to the exterior. Examples of the former are fireplaces, wooden stoves and gas or oil-fired water heaters, stoves and clothes dryers. Examples of the latter are kitchen, attic and bathroom ventilation or exhaust fans which actually reduce the overall supply of air within the house. The latter reduces the supply of oxygen, which in turn results in the formation of deadly carbon monoxide by fireplaces and other oxygen consuming devices, which in recent years has caused many accidental deaths.
In addition to the above, many such air-tight homes, particularly those heated by electricity, have high humidity problems which indicates an inadequate supply of fresh air in the interior.
All of the above evidences a need for a controllable supply of fresh outdoor air upon demand. Various air-conditioning equipment has heretofore been provided for introducing air from the exterior into the interior of a building but all of such are necessarily relatively large and unsightly, are necessarily mounted on the exterior or interior of the walls, and require substantial piping to convey the air. United States Pat. No. 2,787,946; No. 4,072,187; No. 2,820,880; No. 2,882,383; and No. 3,165,625 disclose devices which exemplify efforts which may be relevant but are not directed specifically at these conditions. I have provided a very simple, attractive and inexpensive solution for these problems.
BRIEF SUMMARY OF THE INVENTION
My invention provides a simple, attractive and inexpensive air make-up unit which mounts easily within the confines of a standard exterior wall and between two standard 16" on-center studs, with only the air shield protruding therebeyond. The unit introduces outside air into the interior of the building upon need and demand and, if desired, also conditions same while it is being introduced. It creates and maintains a positive pressure within the interior of the building, thereby ensuring an adequate supply of oxygen and improving the operation of the abovenamed devices which require oxygen and/or withdraw air from the interior of the home. Fresh warmed outside air is introduced automatically by my air make-up unit in response to negative pressure, undue humidity, or low temperature conditions within the room. It also automatically compensates for unusually low temperature conditions outside the building.
It is a general object of my invention to provide a simple, attractive and inexpensive air make-up unit which will be easily and inexpensively mounted within the confines and between the studs of a standard exterior wall of a building to introduce outside air into the latter.
A more specific object is to provide such an air makeup unit which will introduce ample supplies of outdoor air into the building's interior and create and maintain a positive air pressure therein.
Another object is to provide such an air make-up unit which will introduce fresh outdoor air into the interior of such a room whenever negative pressure, unduly low temperature, or high humidity conditions exist therein.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the preferred embodiment of my invention is hereafter described with specific reference being made to the drawings in which:
FIG. 1 is a perspective view of an embodiment of my invention mounted in place between the studs and within the confines of a standard wall;
FIG. 2 is a right side elevational view of the unit shown in FIG. 1 with parts cut away and with the wall structure shown in simplified cross-sectional form;
FIG. 3 is an exploded perspective view of my air make-up unit;
FIG. 4 is a front elevational view of the same with the register panel removed;
FIG. 5 is a rear elevational view of the same with the wind shield removed; and
FIG. 6 is a diagrammatic view of the controls and wiring circuit by means of which the unit is operated.
BETAILED DESCRIPTION OF THE INVENTION
One embodiment of my invention, as shown in FIGS. 1-6, inclusive, includes an air make-up unit identified generally by the numeral 10 mounted within an exterior standard wall 11 of a conventional frame building which is shown only fragmentarily in FIGS. 1-2, inclusive. As shown, such a wall is characterized by a plurality of 16" on-center studs 12 and has a thickness of no less than 5.25-6.0 inches.
As shown, my air make-up unit is comprised of an elongated metal casing 13 which is rectangular in cross-section and has an open front surrounded by outwardly extending mounting flanges 14, 15, 16 and 17, an an open rear. The latter has inwardly extending flanges 18, 19 and 20, as best shown in FIG. 5. A front register panel 21 is secured to the flanges 14, 16 by screws, as illustrated in FIG. 3, and is provided with vanes 22 which are manually controllable by control level 23.
An air-intake housing 24 has a tubular forward portion 25 which surrounds the casing 13 in close sliding telescoping relation. The tubular portion 25 has an outwardly extending flange 26 which extends therearound. Extending downwardly and outwardly from the tubular portion 25 is an imperforate air shield 27. Extending inwardly from the lower edge of the shield 27 is a screen member 28 which connects at its forward edge with the casing 13, as best shown in FIG. 2.
Pivotally mounted upon the inner surface of the wind shield 27, as at 29, is a damper 30 which extends throughout the width of the casing and pivots between open position, as shown in FIG. 2 and a closed position (not shown) in which it engages the lower rear edge portions of the casing. This can best be seen in FIG. 2. A control rod 31 which pivots about its longitudinal axis to open and close the damper is operated manually by control knob 32.
Side wall structure 33, 34, together with bottom wall structure 35 and top wall structure 36 within the casing 13 define an interior air chamber 37. This wall structure is packed with ceramic fiber insulation, such as is sold by Carborundum Company, P.O. Box 808, Niagara Falls, New York, N.Y. 14302, under the trademark FIBERFRAX. Such insulation is sometimes referred to as condensed insulation and is known for its high insulating qualities.
Dividing the air chamber 37 midway between the front and back thereof is a vertical wall or panel 38 which extends longitudinally of the casing 13 and is likewise packed with such ceramic fiber insulation throughout its length. Mounted within the air chamber 37 rearwardly of this wall 38 is a squirrel-cage type rotary blower 39 which has a tangential discharge 40 extending forwardly through the wall 38 and terminating at the front or inner surface thereof. The blower 39 has a housing 41 which is open at the top, as shown in FIG. 2, at which point air is picked up by the vanes 42 of the blower.
An electric motor 43 is mounted on the end of the blower housing 41 in driving relation and carries a cooling fan 44.
Mounted within the throat discharge 40 of the blower 39 and extending thereacross is a pair of electrical heating elements 45 and 46. Of course, if desired, more of such elements may be utilized. These heating elements are separately wired and connected to a source of electrical supply, as best shown in FIG. 6, and are energized at different temperature levels as hereinafter described.
The axis of the blower 39 extends longitudinally of the casing 13 and is located, as best seen in FIG. 2, in the same vertical plane as the rear edge of the casing. It is also located in substantially the same horizontal plane as the upper heating element 45.
FIG. 6 illustrates the controls and circuits which are used in the operation of my air make-up unit. The electric supply 47 is connected by three separate supply lines 48, 49 and 50 to the heating elements 45, 46 and blower motor 43. Interposed within the supply line 48 is a humidistat 51 which is of the type well known in the art by means of which an electric current is closed when a predetermined humidity level is reached.
Interposed within supply line 49 is an air-pressure-sensitive control 52 of the type sold by Tjernlund Products, Inc., 1620 Terrace Drive, St. Paul, Minn. 55113, and identified as a Pressurestat Control, Model No. P.S. 2501.
Interposed within the supply line 50 is a thermostat 53 of the conventional type well known in the art by means of which an electric circuit is closed when a predetermined temperature level is reached.
Interposed within the circuit for the electric heating element 45 is a conventional thermostat 54 which is located outside the building and, of course, is responsive to the outside air temperature. This thermostat 54 is set to energize the heating element 45 at a relatively high temperature so that it will be energized whenever the outside air is below the temperature desired within the building or room.
Interposed within the circuit for the electric heating element 46 is a second conventional thermostat 55 which is also located outside the building and is also responsive to the outside temperature. It is set so as to energize the thermostat 55 at a considerably lower temperature so that when the outside temperature lowers markedly, this will be compensated for by additional heat being provided as it is discharged from the blower.
The two-speed motor 43 also has a thermostat 56 located outside the building and interposed within its circuit so as to energize the motor at a lower speed whenever the outside temperature drops below the desired level. Thus, when the latter condition prevails, the current will pass through line 57 to cause the motor to run at a lower speed and thus enable the air moved across the heating elements to be more adequately warmed. At higher outside temperatures, the temperature of the moving air will not need to be raised as much and so the circuit is established through high speed line 58.
The air make-up unit described above is wired for 110 volts and will produce 5,100 BTU's of heat per hour when both heating elements are energized. The blower 43 will supply up to 135 cubic feet of air per minute. The selector switch 59 is a manual control to provide blower only operation, or for low heat, high heat, or no heat at all. It is manually controlled through the control knob 60.
From the above, it will be seen that I have provided a novel, simple, attractive and inexpensive air make-up unit which can be installed very simply and easily without any serious modifications to the wall 11. To install, the user merely cuts a hole in the wall between two studs 12 to a height equal to that of the casing 13 and housing 24. The casing is inserted from the inside, the electric wiring is properly connected as described, and the housing 14 is telescoped therearound from the outside until the flange 26 abuts against the outside surface of the wall 11. This provides a very attractive installation which does not interfere with the decor of the building and is relatively inexpensive since no duct work is required. Moreover, it is perfectly safe from a fire danger standpoint in that the insulation described herein more than adequately eliminates danger of overheating of any surface with which the unit comes in contact.
It will also be seen that when the humidity within the building becomes excessive, humidistat 51 will close and blower 43 and heating element 45 will become energized, thereby causing fresh and partially warmed air to be introduced into the building to provide a positive pressure and diminish the humidity gradually, since the outside air will be dryer and some of the inside air will escape.
Similarly, if a negative pressure develops within the building, pressure control 52 will close the circuit and blower 43 will be activated to discharge air into the interior of the building, overcome the deficiency, and eventually produce a positive air pressure within the building.
In the same manner, if the temperature of the room drops below the desired level, thermostat 53 will close the circuit of line 50 and energize the blower 43 and heating element 45, to introduce warm air into the building.
In the event the blower 43 is being operated in any one of the above situations and the outside air proves to be unusually cold, the thermostat 56 will cut out the high speed line 58 and cause the blower to be operated more slowly through line 57 and thereby cause the air moved thereby into the building to be first warmed to a greater extent. Similarly under such conditions, thermostat 55 will close the circuit through heating element 46 so that more heat will be applied to such air.
If desired, the discharge throat of my air make-up unit may be connected directly by a duct to the return air side of a forced-air heating system. This assures an even distribution of air throughout the entire house without any chance of cold air entering the building during severely cold weather. When the blower of the forced-air heating system is on, it will tend to suck air through the make-up unit and will increase the positive air pressure in the house, to thereby ensure movement of air out of the house rather than entrance thereof through infiltration.
In considering this invention it should be remembered that the present disclosure is illustrative only and the scope of the invention should be determined by the appended claims.
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Disclosed is an air make-up unit mounted within the confines of a conventional outside wall of a frame building between the 16" on-center studs. The unit includes a rotary blower with a horizontal tangential discharge, the latter having heating elements therein and being encased in a vertical wall of insulation which extends within an insulated air chamber defined by a telescoping outer casing. Positive air pressure is maintained within the building by air-pressure-sensitive controls located within the building and controlling the two-speed motor. The latter is thermostatically controlled to be operated at a slower speed when colder weather prevails. It is also controlled and energized by a humidistat located within the building to force outside air into the building and diminish the humidity therein when needed.
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TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to production monitoring systems for monitoring production and injection from a configuration of oil and/or gas wells. Moreover, the invention concerns methods of monitoring said oil and/or gas wells for controlling operation and forecasting of the well injection and production. Furthermore, the invention relates to software products recorded on machine-readable data storage media, wherein the software products are executable upon computing hardware for implementing the aforementioned methods.
BACKGROUND OF THE INVENTION
[0002] With reference to FIG. 1 , a contemporary oil and/or gas production system includes multiple production and injection wells 80 through corresponding boreholes 20 penetrating into an underground geological formation 30 bearing an oil deposit 40 and/or a gas deposit 50 . In general a deposit 40 , 50 comprises more or less water in addition to oil and/or gas, or even just water. Often, the geological formation 30 corresponds to one or more anticlines which form a natural containment for the oil deposit 40 and/or gas deposit 50 . The geological formation 30 is usually heterogeneous. The deposits 40 , 50 are often contained within regions of porous rock with multiple fissures, cavities and structural weaknesses which define maximum pressures which can be sustained by the regions during oil and/or gas extraction. The borehole 20 itself is often introducing a structural weakness. Excessive pressure applied to the geological formation 30 , for example via water injection, can risk causing multiple unwanted fractures, namely “out of zone” fractures.
[0003] In the present document some expressions are defined as follows:
[0004] A productivity parameter of a reservoir deposit is a fluid flow of oil and/or gas from a reservoir deposit divided by a differential pressure resulting from the fluid flow.
[0005] An injectivity parameter of a well is a similar parameter as said productivity parameter and is a fluid flow of water into a reservoir deposit divided by a differential pressure resulting from the fluid flow.
[0006] A storativity parameter of a reservoir deposit is a volume change in said reservoir deposit divided by the pressure change in the reservoir deposit.
[0007] A connectivity parameter between two deposits in the underground is a fluid flow between the first and the second of said deposits divided by the differential pressure between said two deposits. This parameter reflects potential hydraulic communication between the two deposits.
[0008] Contemporary industry practice is to decide upon productivity, injectivity and reservoir pressure from episodic tests, i.e. through measuring coherent values of production rates and pressures.
[0009] In the patent application WO2012/039626 (Arild Bøe, Epsis AS), monitoring of a production well is done by identifying temporally slow and temporally fast processes and abstract a parameter representation that is representative of said slow processes and said fast processes to be used for controlling operation of the system.
SUMMARY OF THE INVENTION
[0010] The present invention seeks to provide an improved production monitoring system for providing enhanced control of complex oil and/or gas production systems.
[0011] The present invention seeks to provide an improved method of monitoring a complex production system comprising a plurality of producers and injectors operating in association with a heterogeneous porous medium.
[0012] The present invention uses an alternative method for parameter estimation:
The hydraulic response of a sub-surface production system comprising a number of participating deposits is estimated based upon pressures and production rates as measured variables instead of pressure integrals and production rate dynamics. A parametric model of the production system is used for describing the behavior of the production system. A parameter estimation procedure, such as a Kalman filter, is used to find the model parameters in the parametric representation. The production system involves a well system comprising at least one production well. This production system may comprise a deposit not penetrated by wells but in hydraulic communication with a deposit with a production well or an injection well. The parametric representation is then employed and evaluated based upon measured real time data of flow and pressure. By using an estimation method such as a Kalman filter, all the desired parameters are abstracted as a set of parameters adapted optimally to each other as opposed to traditional modeling where each parameter is developed one by one and thus are not tuned optimally to each other. Provided the evaluation concludes that the model of the production system is not sufficiently accurate, a more complicated parametric representation is considered, comprising maybe a additional deposit not penetrated by wells but in hydraulic communication with other deposits. This parametric representation is then evaluated, based upon the monitored data and the process of selecting a new parametric representation and then evaluating it may be repeated until a sufficiently accurate parametric representation is identified. The simplest parametric representation identified as sufficiently accurate is then used for estimating all parameters defining said representation of the production system. If, after some time has passed, the parametric representation is no longer able to provide a sufficiently accurate reproduction of the measured flow and pressure data, another parametric representation is evaluated and the above method is repeated. Often this new parametric representation is more complicated than the previous one. More than one parametric representation may be developed and evaluated in parallel.
[0020] Because the underground is dynamic and influenced by e.g. the process of retrieving oil and gas from deposits in the underground, the parametric representation used for the production monitoring system is expected to be corrected or altered during the lifetime of the production system. When used for production monitoring, the parametric representation is continuously evaluated if being sufficiently accurate. It is not necessary to stop the production in order to get parameters for the evaluation of the parametric model.
[0021] By using the present invention, some important parameters may be estimated continuously along a timeline with no need to interrupt production:
[0022] Parameters of a well
The productivity of a producing well and the injectivity of an injecting well as functions of time. Through this, one may also continuously monitor alterations of these. Alterations may stem from changes in the flow of fluid or changes in the hydraulic communication properties in a deposit close to the well.
[0024] Parameters of a deposit
Storativity of each deposit involved, i.e. volume of fluid times compressibility Reservoir pressure of each deposit involved
[0027] Parametric representation of the production system
The number of deposits involved in the parametric representation Identifying deposits involving hydraulic communication between each other as well as its strength The extent of cross current between the involved deposits
[0031] This invention is useful for technical reasons:
Continuous control with key parameters in order to optimize the production from a well or reservoir The ability to monitor how these key parameters change over time and thereby also the ability to optimize related to changed conditions
[0034] This invention is useful for operational reasons:
Improved background at any time to optimize related to changed external conditions including limitations Improved reliable prognoses of future production capacity Extended possibility for using scenario technics like “what-if” in order to analyze Consequences of different actions before the actual actions are performed
Problems to be Solved by the Invention
[0039] With the WO2012039626 application, production monitoring is done by identifying a representation of temporally slow and temporally fast processes. In order to identify the parameters of these temporally slow and temporally fast processes, sensors for measuring physical processes occurring in operation in the injection and production wells for generating corresponding measurement signals that are used to apply a temporal analysis.
[0040] A problem with that invention is that it depends on executing periodical tests, involving interruption of the production, in order to get sufficient measurement signals to maintain the representation of the processes sufficiently well.
[0041] The present invention does not depend upon periodical tests or shutdowns in order to maintain a good representation of the well. The invention can be utilized during normal operation of the configuration of oil and/or gas wells, i.e. without planned or not planned interruption of the production. On the other hand, when such events happen, added information from the behavior of the system may be utilized to improve or verify the parametric representation or model being used to monitor the production system.
Means to Solve the Problems
[0042] According to a first aspect of the present invention, there is provided a production monitoring system as defined in claim 1 .
[0043] A production monitoring system for a configuration of oil and/or gas wells, said configuration comprising production and injection wells coupled in operation to sensors for measuring physical processes during normal operation of the production well(s) and injection well(s) and generating corresponding measurement signals for computing hardware, wherein said computing hardware is operable to execute software products for processing said signals, where the software products are adapted for said computing hardware to analyze said measurement signals to abstract at least one parametric representation of said configuration of oil and/or gas wells comprising the following parameters:
one instantaneous productivity parameter for each production well; one instantaneous injectivity parameter for each injection well; one instantaneous storativity parameter for each deposit; and one instantaneous connectivity parameter for the hydraulic communication between each pair of deposits in hydraulic communication with each other and to employ said at least one parametric representation for monitoring the configuration of oil and/or gas wells.
[0048] Optionally, the production monitoring system analysis involves applying a parametric model with an estimation algorithm analyzing characteristics of said measurement signals by using said measurement signals, and determining deviations between said measurement signals and corresponding modeled measurement signals for identifying said parameters for the model.
[0049] Optionally, the estimation algorithm employs a Kalman filter.
[0050] More optionally, the at least one parametric model comprises one of more deposits not penetrated by boreholes, in addition to the plurality of deposits comprising production and injection well(s).
[0051] More optionally, a production monitoring system wherein said at least one parametric model comprises at least two models and the model to be used to model the production monitoring system is selected as the simplest one estimating a correlation coefficient between a measured value and an estimated value of a set of variables in the model sufficiently accurate i.e. with a correlation coefficient greater than 0.93.
[0052] Still more optionally, a production monitoring system wherein the correlation coefficient is greater than 0.95.
[0053] More optionally, a production monitoring system wherein the parametric model to be used to model the production monitoring system is selected by a software product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings wherein:
[0055] FIG. 1 is an illustration of a contemporary oil and/or gas production system including multiple wells and boreholes;
[0056] FIG. 2 is an illustration of a contemporary oil and/or gas production system including multiple wells and boreholes and comprising deposits without any borehole;
[0057] FIG. 3 is an illustration of a contemporary temporal characteristic of the system of FIG. 2 subject to periods of quasi-constant production interspersed with well testing;
[0058] FIG. 4 is a simple representation of a pair of wells of the system of FIG. 1 ;
[0059] FIG. 5 is a more complex representation of a pair of wells of the system of FIG. 2 ;
[0060] FIG. 6 is a complex representation of the system of FIG. 2 with n pairs of injection and production wells as well as deposits without any well;
[0061] FIG. 7 is an illustration of functions included within a method of monitoring and controlling the system of FIG. 2 ; and
[0062] FIG. 8 is an illustration of the system of FIG. 2 coupled to computing hardware operable to execute software products for implementing a method pursuant to the present invention.
[0063] In the accompanying diagrams, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION OF THE INVENTION
[0064] Referring to FIG. 1 , the boreholes 20 A, 20 B are associated with wells 80 A, 80 B respectfully. The well 80 A is employed to inject fluid, whereas the well 80 B is employed to receive fluid from the geological formation 30 comprising oil and/or gas. In the present document, a well 80 comprises the line from a wellhead through a borehole 20 and to a deposit 40 , 50 . An injection rate is denoted r A while a production rate is denoted r B . The geological formation 30 is usually heterogeneous in spatial nature.
[0065] In the underground, oil and gas deposits are located in deposits 30 , 40 that may be in heterogeneous communication with each other. These deposits 30 , 40 have production wells 80 B, injection wells 80 A and often also one or more deposits 30 , 40 without wells but nevertheless communicate with the other deposits.
[0066] FIG. 2 depicts a more detailed well system than in FIG. 1 , now also including a deposit 50 not penetrated by any wells but in hydraulic communication with the rest of the well system. This embodiment enables a more correct parametric representation of a well system.
[0067] In FIG. 3 , an abscissa axis 210 denotes time t, and an ordinate axis 220 denotes a parameter of the system, for example well-head proximate pressure. The tests 200 conventionally involve applying a step perturbation change in flow rate r by applying a step change in one or more of the flow resistance h A and/or h B , or by changing the proximate wellhead pressures p AU , p BU A response of the system to the step change perturbation at each well 80 provides insight into the flow resistances k A , k B , and also the capacity c G for each well 80 , namely for a portion of the geological region 30 associated with the wells 80 A, 80 B. For example, a time constant associated with an exponential pressure response to a step change in flow rate r provides an indication of the capacity c G , and a magnitude of the pressure response provides an indication of the flow resistances k A , k B associated with the wells 80 . However, such a quasi-constant measurement is only approximate when the geological formation 30 is extensive, porous and is intersected by multiple sets of boreholes 20 . Such tests are not necessary for implementing the present invention, but conveniently may improve the parameters involved in the estimated parametric representation.
[0068] FIG. 4 is a parametric representation of an oil well production system which is a gross simplification of a real oil and/or gas well production system. Flow resistance is indicated with k A , k B while spatial capacities are indicated with C G .
[0069] FIG. 5 is also a parametric representation of an oil well production system which is a gross simplification of a real oil and/or gas well, but now includes a deposit not penetrated by any well but in hydraulic communication with the rest of the well system. k C denotes flow resistance to/from the indicated two deposits. r B denotes the related flow to/from said deposit. Parameters with a (t) suffix indicate time dependent parameters.
[0070] In practice, pressures can be conveniently measured at top and bottom regions of the wells 80 ; these pressures will be referred to as p AU and p AL for the well 80 A, and p BU and p BL for the well 80 B. Moreover, the wells 80 A, 80 B will themselves represent flow resistance h A , h B respectively to fluid flow therethrough.
[0071] It will be appreciated that optimal control of system as depicted in FIG. 6 is highly complex, for example on account of the pressure p G within the geological formation 30 being a function of spatial location within formation 30 . Conveniently, the pressure p G within the formation 30 is defined by P G (x, y, z, t) wherein z, y, z are Cartesian coordinates for defining a region including the formation 30 , and t denotes time.
[0072] The present invention employs, in overview, a form of algorithm 300 as depicted in FIG. 7 . The algorithm 300 includes:
[0000] (a) a first function 310 concerned with historical values of measured parameters, for example flow rate “Q” (which is representative of the flow rate r), pressure P (representative of one or more of the pressures p AU , p AL , p BU , p BL );
(b) a second function 320 concerned with a conversion of measured parameters from the first function 310 to corresponding working indirect or abstract parameters, e.g. p CL , c G and k C for use in the algorithm 300 ;
(c) a third function 330 concerned with employing in the parametric representation an estimation algorithm for estimating the behaviour of the facility 10 by processing converted parameters from the second function 320 ; and
(d) a fourth function 340 concerned with response modelling and prediction based upon parameters from the third function 330 .
[0073] The functions 310 , 320 , 330 , 340 are optionally executed concurrently and feed data between them on a continuous basis. Alternatively, the functions 310 , 320 , 330 , 340 are executed in sequence which is repeated by way of a return 350 from the fourth function 340 back to the first function 310 .
[0074] A Kalman filter is a mathematical method which uses measurements that are observed in respect of time t that contain random variations, namely “noise”, and other inaccuracies, and produces values that tend to be closer to true values of the measurements and their associated computed values. The Kalman filter produces estimates of true values of measurements and their associated computed values by predicting a value, estimating an uncertainty of the predicted value, and then computing a weighted average of the predicted value and the measured value. Most weight in the Kalman filter is given to the computed value of least uncertainty. Estimates produced by Kalman filters tend to be closer to true values than the original measurements because the weighted average has a better estimated uncertainty than either of the values that went into computing the weighted average.
[0075] Referring to FIG. 8 , the algorithm 300 is based on a Kalman filter formulation of an oil and/or gas production system having N i injectors and N p producers. Downhole distal pressure measurements p LA , p LB as well as wellhead proximate pressure measurements p UA , p UB in the injector and producer wells 80 A, 80 B are made available to the algorithm 300 . In certain situations, only wellhead proximate pressures p UA , p UB are measured and corresponding data is supplied to the algorithm 300 . The algorithm 300 is also provided with measurements of injection and production flow rates r A , r B as a function of time t. The injection and production flow rates r A , r B are beneficially measured using at least one of: ultrasonic measurement sensors, electromagnetic measurement sensors, pressure difference sensors associated with a flow resistance (for example a flow orifice or section of pipe).
[0076] The algorithm 300 is thus operable, via its Kalman filter, to compute estimates of parameters including:
(i) productivities and injectivities of the wells 80 of the gas and/or oil production system; (ii) storage characteristics and/or change in average reservoir pressure of the geological formation 30 ; (iii) interactivities between wells 80 of the system; and (iv) aquifer influx and/or “out-of-zone” outflux in respect of the geological formation 30 and its associated wells 80 .
[0081] The algorithm 300 , namely implemented in computing hardware 400 and sensing instruments 410 coupled thereto, has technical effect in that it senses physical conditions of the system as sensed signals, analyses the signals, and then generates outputs which can be used for controlling operation of the system to improve its productivity, increase operating safety and/or reduce maintenance costs. Improved operating safety is achieved by more appropriate control which assists to avoid blowouts, fractures and similar. Enhanced productivity is achieved by employing a more suitable injectivity strategy. Reduced maintenance can be achieved by maintaining appropriate productivity rates and/or injectivity rates for avoiding sedimentation which can block wells 80 and which is costly and time-consuming to rectify.
[0082] Although use of the algorithm 300 is described in relation to oil and/or gas production, it can also be used for controlling other types of industrial processes and also mining operations, for example continuous seabed suction systems for extracting valuable minerals from ocean floor sediments and silt; such ocean mining processes must maintain appropriate flow rates and move extraction nozzles to most valuable mineral deposits in a dynamic real-time basis, namely activities which are advantageously controlled by using computing hardware executing the algorithm 300 .
[0083] The present invention is susceptible to being used with existing contemporary injection and production wells 80 , both in on-shore applications and also in off-shore applications.
[0084] Defining a parametric representation or model as presented herein is made possible by introducing the presumption that mass exchange between different deposits in hydraulic communication between them is proportional with the difference in reservoir pressure in the deposits concerned. This makes also possible monitoring cross flow between different deposits and the development of reservoir pressure in participating deposits not being penetrated by wells (“passive deposits”) and consequently do not involve direct pressure measurements.
[0085] There are several advantages with this approach, among these are:
Since this invention results in a continuous and concurrent estimation of both well parameters (e.g. productivity and injectivity) and reservoir parameters (e.g. storativity, reservoir pressure and hydraulic communication), estimated well parameters are likewise corrected according to changes in reservoir parameters (e.g. reservoir pressure) The use of direct measurements as opposed to derived parameters Availability of the strength of hydraulic communication and the extent of mass transport between different deposits that are comprised in the parametric representation of the sub surface production system Availability of estimated reservoir pressure in participating deposits that are not penetrated by wells (“passive deposits”) and consequently do not have directly measured pressure measurements available Availability of indications if the sub surface production system changes character, i.e. novel hydraulic communications to new deposits as well as development of known deposits
[0091] The present invention utilizes some novel approaches to enable said parameter estimation:
A multi well and multi deposit parametric description of the hydraulic responses of the variables comprised in a sub-surface production system. This is defined as a plurality of deposits, each participating deposit may have none, one, or a plurality of wells and may be in hydraulic communication with any one of the other deposits. A parametric description of the relation between pressure differences in different deposits and related transportation of mass between the same deposits. This makes possible formulating the hydraulic responses of the wells in a parametric representation with said parameters and employing an estimation algorithm, such as a Kalman filter, in the parametric representation. For each relevant system description, depending on the number of deposits and how many wells in each deposit being included in the system description in question, and how the different deposits are connected, control theoretical estimation methods (Kalman filter or similar) are used for continuously to select the best estimate from the different parameters and variables comprised in the system description in question. Measured and estimated values of the variables involved are thereafter compared with each other for different descriptions of the multi well reservoir. Testing of different hypothesis is used to determine a parametric representation which is the least complex one of the evaluated parametric representations capable of estimating the observed variables, such as production rate and pressure, sufficiently accurate. Observed indirect variables are expected to change as time goes on, and in that case often from a less complex parametric representation to one with greater complexity. The precise definition of “sufficiently accurate” may vary, depending on the actual application, but is always defined by the operator in terms of the correlation coefficient R̂2 being larger than a given threshold value. The fall back value is R̂2>0.95. The simplest parametric representation meeting the accuracy criterion is selected as the system model. If none of the available parametric representations meets the accuracy criterion, a monitor presenting the results displays e.g. “No accurate system model found” and then the resulting parametric representation is taken as the parametric representation giving the best fit.
[0096] The present invention utilizes similar real time measurement data as in prior art monitoring systems, e.g. WO2012/039626. In a database comprising real time measurement data, such as related values of pressure and production rate for each producing well and similar for each injector. Pressure measurements may be down hole measurements as well as different pressure measurements by the well head. Corresponding to this, the production rate of each single well be measured (e.g. by using multiphase meters) or calculated based upon other measured variables. The physical measurements and storage of such variables and access to them are prerequisites for utilizing the present invention. Most recently employed wells having some production capacity will nevertheless comprise this type of data access and will consequently be candidates for using the method revealed by the present patent application.
[0097] One preferred embodiment of the present invention involves a set of parametric representations describing a subsurface production system. Each of these parametric representations involve one or more deposits that may be in hydraulic communication with other deposits comprised in the parametric representation. Each deposit may have none, one or more producing wells or injector wells connected.
[0098] A preferred embodiment utilizes mathematical methods such as Kalman filters or similar for estimation of variables and parameters such as e.g. pressure, rate, productivity or injectivity, the storativity of the deposits involved, reservoir pressure and the strength of hydraulic connection, all of which is involved in each of the characterization of each parametric representation describing the production system.
[0099] Statistical methods, like e.g. hypothesis testing, are used to select the simplest description of the system, i.e. the simplest parametric representation, presenting a sufficiently accurate and thus an acceptable relationship between measured and estimated values of one or more sets of variables over time.
[0100] In one preferred embodiment, measured and estimated values of a variable involved is sufficiently accurate if the correlation coefficient of the estimated value vs. the corresponding measured value has a correlation coefficient larger than 0.93.
[0101] In a more preferred embodiment, measured and estimated values of a variable involved is sufficiently accurate if the correlation coefficient of the estimated value vs. the corresponding measured value has a correlation coefficient larger than 0.95.
[0102] In all embodiments of the present invention, the production system which is being modeled, may change as time passes. It may then be important to retest a chosen hypothesis in order to find a parametric representation that is sufficiently accurate. This may be the same parametric representation with different parameters or another parametric representation with a different set of deposits and parameters. Hydraulic communication to new deposits may develop over time, or existing hydraulic communication between deposits may change.
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A production monitoring system comprises a plurality of production and injection wells coupled in operation to sensors for measuring physical processes occurring in operation in the production and injection wells and generating corresponding measurement signals for computing software. The computing hardware is operable to execute software products to analyze said measurement signals to abstract a parameter representation of said measurement signals, and to apply said parameters to estimate at least one parametric model of said plurality of injection and production wells, and to employ one of these models for monitoring the system.
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FIELD OF THE INVENTION
The present invention relates generally to magnetic disk drives and, more particularly, to active vibration cancellation within a disk drive using a multitude of accelerometers.
BACKGROUND OF THE RELATED ART
Magnetic disk drives generally read and write data on the surface of a rotating magnetic disk with a transducer or “head” that is located at the far end of a moveable actuator. A servo control system uses servo control information recorded amongst the data, or on a separate disk, to controllably move the transducer from track to track (“seeking”) and to hold the transducer at a desired position (“track following”). A detailed discussion of servo control systems is unnecessary because such systems are well known as set forth, for example, in patent application Ser. No. 09/138,841 that was filed on Aug. 24, 1998, entitled “DISK DRIVE CAPABLE OF AUTONOMOUSLY EVALUATING AND ADAPTING THE FREQUENCY RESPONSE OF ITS SERVO CONTROL SYSTEM,” and is commonly owned by the assignee of this application.
The industry has previously mounted various kinds of accelerometers on the disk drive in order to sense external forces.
One example is U.S. Pat. No. 5,426,545 entitled “Active Disturbance Compensation System for Disk Drives.” This patent discloses an angular acceleration sensor 22 that comprises an opposed pair of linear accelerometers 22 a and 22 b . The invention is intended for use with balanced actuator assembly 26 . The overall sensor package 22 is mounted to the HDA 10 or drive housing, as shown in FIG. 1, in order to detect and correct for angular acceleration about the axis 27 of the balanced actuator assembly 26 that would otherwise produce a radial position error 30 (FIG. 2) due to the actuator's inertial tendency to remain stationary in the presence of such acceleration.
U.S. Pat. No. 5,521,772 entitled “Disk Drive with Acceleration Rate Sensing” discloses a variation on that theme in that it uses an “acceleration rate sensor” 50 rather than a linear acceleration sensor (conventional accelerometer) or angular acceleration sensor. The sensor 50 is mounted to the disk drive housing 9 .
U.S. Pat. No. 5,663,847 is yet another patent disclosing an angular accelerometer in a disk drive. It is entitled “Rejection of Disturbances on a Disk Drive by Use of an Accelerometer.” In FIG. 1, the '847 patent discloses an angular accelerometer 102 that is mounted to the drive's base plate 104 in order to sense rotational motion 110. The '847 patent is similar to the '545 patent in that both are addressing the problem that when the disk drive containing a balanced actuator is bumped rotationally in the plane of the disk 112, a position error will arise because “the actuator 114 will retain its position in inertial space . . . ” (4:19-21).
PCT Application WO 97/02532 discloses another apparent use of an accelerometer that is described therein as a “shock sensor” 46 (See FIG. 3 ). This application is entitled “Disk Drive Data Protection System”. The WO 97/02532 application appears similar to the remainder of the presently known art in that it appears to disclose a single sensor that is mounted to the drive housing. According to the disclosure, the shock sensor 46 detects “physical shocks to the disk drive which may compromise data being transferred . . . ”
Conventional systems mount a single accelerometer to the overall disk drive and disable reading and/or writing when the output of the accelerometer surpasses a threshold. The '545 patent discussed above is different in that it uses a angular acceleration sensor mounted to the overall disk drive to indicate when the drive is being shocked or vibrated about the pivot axis of a balanced actuator. However, it is only sensitive to rotational motion and it assumes that the actuator is a perfectly balanced actuator.
The foregoing uses of accelerometers are incapable of accurately detecting a motion of the head relative to the remainder of the disk drive and are subject, therefore, to an off-track condition due to acceleration of an imbalanced actuator. There remains a need, therefore, for a disk drive that detects the motion of the actuator relative to the disk drive and implements active vibration cancellation using a multitude of sensors.
SUMMARY OF THE INVENTION
The invention may be regarded as a disk drive comprising a head disk assembly 20 including a base 21 , a rotating disk 23 , and a rotary actuator 50 that pivots relative to the base; a first motion sensor 35 rigidly mounted relative to the base for sensing motion of the head disk assembly; and a second motion sensor 55 mounted to the rotary actuator for sensing motion of the rotary actuator relative to the motion of the head disk assembly. In a more particular embodiment, the first motion sensor is rigidly mounted relative to the base to output a first sense signal, the second motion sensor is mounted to the rotary actuator to output a second sense signal, and the disk drive further includes a means for controlling a disk function in response to a comparison of the first and second sense signals.
The invention may also be regarded as a method of controlling a disk drive having a head disk assembly 20 including a base 21 , a rotating disk 23 , and a rotary actuator 50 that pivots relative to the base, in order to achieve improved track following performance by reducing off-track error caused by shock and vibration, the method comprising the steps of: generating a first sense signal corresponding to a motion of the head disk assembly; generating a second sense signal corresponding to a motion of the rotary actuator relative to the motion of the head disk assembly; comparing the first and second sense signals in order to detect off-track movement of the rotary actuator while track-following; and compensating for the off-track movement. In a preferred embodiment of the method, the step of generating a first sense signal corresponding to a motion of the head disk assembly is accomplished by mounting a first motion sensor 35 rigidly relative to the base and the step of generating a second sense signal corresponding to a motion of the rotary actuator relative to the motion of the head disk assembly is accomplished by mounting a second motion sensor 55 to the rotary actuator that pivots relative to the base.
BRIEF DESCRIPTION OF THE DRAWINGS
The just summarized invention can be best understood with reference to the following description taken in view of the drawings of which:
FIG. 1 is an exploded perspective view of a magnetic disk drive 10 according to a preferred embodiment of the invention, the disk drive having a head disk assembly 20 (“HDA”) that contains a magnetic disk 23 , a rotary actuator 50 , a first acceleration sensor 35 that moves rigidly with the HDA 20 and a second acceleration sensor 55 that rotates with the rotary actuator 50 ;
FIG. 2 is a simplified plan view of the disk drive 10 showing how a head 80 carried by the rotary actuator 50 moves through a first arc 58 and how the second sensor 55 carried by the rotary actuator 50 moves through a second arc 56 ;
FIG. 3 is a simplified plan view of the disk drive 10 showing the PCBA 30 that carries the first sensor 35 below the rotary actuator 50 that carries the second sensor 55 ;
FIG. 4 is a simplified plan view of the disk drive 10 showing that the second sensor 55 is preferably located over the first sensor 35 when the rotary actuator 50 is at a middle diameter of the disk 23 ; and
FIG. 5 is schematic diagram of a simplified system model for a microprocessor-based embodiment wherein the first and second sensors 35 , 55 are used to compensate for motion that is otherwise undesirably imparted to the rotary actuator 50 by shock and vibration;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a preferred embodiment of a disk drive 10 according to this invention. As shown, the disk drive 10 comprises a head disk assembly (“HDA”) 20 including a base 21 , a rotating disk 23 , and a rotary actuator 50 that pivots relative to the base 21 . In this first embodiment, the disk drive 10 further comprises a first motion sensor 35 rigidly mounted relative to the base 21 for sensing motion of the HDA 20 , and a second motion sensor 55 mounted to the rotary actuator 50 for sensing motion of the rotary actuator 50 , both with and relative to the motion of the HDA 20 .
There are preferably two sensors 35 , 55 , but it is possible to use more than two sensors in a more complicated differential arrangement. The preferred sensors 35 , 55 are linear accelerometers with a single sense axis 35 s , 55 s (see FIG. 2 ), but multi-axis sensors and other types of motion sensors altogether may also be used in a differential mode in accordance with this invention.
In the preferred embodiment, a PC Board Assembly (PCBA) 30 that contains suitable control electronics is rigidly mounted to an underside of the base 21 . The disk 23 is rotated by a spindle motor 22 . The rotary actuator 50 rotates about a pivot axis extending through a center of a pivot cartridge 51 that secures the actuator 50 to the base 21 , adjacent to the disk 23 . An actuator arm 54 extends to one side in order to carry a head 80 over the disk 23 for reading and writing data therefrom and a voice coil 52 extends from the other side for interacting with a pair of permanent magnets 60 . The voice coil 52 and magnets 60 are frequently regarded as a “voice coil motor”, or VCM 40 . A cover plate 24 encloses the foregoing components in a cavity within the base 21 .
The first sensor 35 is rigidly coupled to the base 21 . In the preferred embodiment, it is indirectly mounted to the base 21 by being mounted to the PCBA 30 that is itself rigidly mounted to the base 21 . It is possible, of course, to mount the first sensor 35 directly to the base 21 , or to mount it to any other structure that is, in turn, fixed to the base 21 . The second sensor 55 is mounted to the rotary actuator 50 . It is desirable to provide maximal sensitivity to rotational actuator motion. As such, the second sensor 55 is preferably positioned on the actuator arm 55 , as far as possible from the pivot cartridge 51 . The second sensor 55 , however, may be located elsewhere on the actuator 50 , such as on the voice coil 52 . Such placement however must be done while maintaining vertical registration with first sensor 35 as discussed below.
As shown in FIG. 5, discussed in more detail below, the first sensor 35 that is rigidly mounted relative to the base 21 outputs a first sense signal and the second sensor 55 that is mounted to the rotary actuator 50 that pivots relative to the base 21 outputs a second sense signal 56 . The preferred embodiment further comprises suitable means for controlling a motion of the actuator in response to a comparison of the first and second sense signals 36 , 56 . The preferred means for controlling uses suitable hardware and/or firmware on the PCBA 30 to implement the control system shown in FIG. 5, but other more or less complicated control means are possible.
FIG. 2 is a simplified plan view of the disk drive 10 showing how the head 80 that is carried by the rotary actuator 50 moves through a first arc 58 , while the second sensor 55 moves through a second arc 56 , as the rotary actuator 50 moves from the inner diameter (ID), to the middle diameter (MD), to the outer diameter (OD), and back again. The second sensor 55 is preferably mounted on the actuator arm 50 such that its sense axis 55 s is perpendicular to the long axis of the actuator 50 As such, the sense axis 55 s is perpendicular to the length of the actuator 50 and tangential to the arc 56 that is traversed by the sensor 55 and the arc 58 that is traversed by the head 80 . In this manner, any component of acceleration that tends to move the head 80 off-track, is maximally imparted to the second sensor 55 .
The second sensor's sense axis 36 is preferably aligned with the first sensor's sense axis when the actuator is at the MD. The angular extent of the arc 58 is relatively small, but it is still necessary to consider the fact that the second sensor's sense axis 55 s will sometimes be aligned and sometimes be skewed relative to the first sensor's sense axis 35 s throughout the actuator's range of motion. At the ID and OD, or course, the sense axis 55 s is slightly skewed from the ideal and the gain of the second sensor will be reduced relative to the first sensor 55 . As discussed below, however, the preferred embodiment compensates for the skew between the sense axes 35 s , 55 s when the actuator 50 is at the ID or the OD, and not at the MD.
FIG. 3 is a simplified plan view of the disk drive 10 showing the PCBA 30 that carries the first sensor 35 vertically registered with the second sensor 55 carried by the rotary actuator 50 when the rotary actuator is at the MD. In this preferred arrangement, the first sensor 35 is located below the second sensor 55 , but their respective sense axes 35 s , 55 s are substantially perpendicular to the long axis of the actuator 50 and aligned with one another when the actuator 50 is as the MD.
FIG. 4 is a simplified plan view of the preferred disk drive 10 showing that the second sensor 55 preferably moves over the first sensor 35 as the actuator 50 moves from the ID, to the MD, to the OD, and back again. The second sensor's arc of motion 56 , in other words, preferably travels over the first sensor 35 . FIG. 4 also further shows that the second sensor 55 is located directly over the first sensor 35 when the rotary actuator 50 is at the MD of the disk 23 . It is possible, however, that the sensors 35 , 55 are located in such places that they are never in vertical alignment at any point in the actuator 50 's range of motion. In such case, however, larger gain adaptations will be required to maintain comparable signals, thereby increasing the likelihood of errors.
FIG. 5 is simplified diagram of a control system model that is used for controlling a disk drive 10 in order to achieve improved track following performance by reducing off-track error caused by shock and vibration. A preferred method of controlling a disk drive comprises the steps of generating a first sense signal corresponding to a motion of the head disk assembly; generating a second sense signal corresponding to a motion of the rotary actuator relative to the motion of the head disk assembly; comparing the first and second sense signals in order to detect off-track movement of the rotary actuator while track-following; and compensating for the off-track movement.
The preferred method may be readily understood by referring to FIG. 5 in conjunction with FIGS. 1-4. In operation, the first and second sensors 35 , 55 are used to generate the first and second sense signals 36 , 56 in the presence of shock and vibration, those sense signals are compared by a junction 150 to detect any resulting off-track motion, and suitable hardware and firmware is used to compensate for torque that is otherwise undesirably imparted to the rotary actuator 50 by the shock and vibration.
In normal operation, the control system 100 receives a digital target position 101 in accordance with a request from a host computer (not shown). An indicated position 103 is also available on a periodic basis by virtue of servo control signals that are periodically read by the head 80 , processed through a servo channel demodulator 110 , and converted to a digital value by an A/D converter 11 a.
A summing junction 102 subtracts the indicated position 103 from the target position 101 to produce a position error signal PES that is provided to a suitable compensator 120 to produce a nominal digital command 121 that, ordinarily, would be provided without any compensation for vibration, to a digital-to-analog converter DAC that produce an analog current “i” for accelerating the VCM 40 (see FIG. 1) in accordance with the magnitude of the PES.
As suggested by the gain block 131 , the drive current “i” is nominally converted to a torque T according to a torque conversion factor, K T , where T=i*K T . The applied torque, of course, accelerates the rotary actuator 50 at an angular acceleration 2 θ t 2
that is a function of the applied torque T and the actuator's angular moment of inertia J. Over time, as suggested by the simplified 1 S
system blocks 141 , 142 , the acceleration 2 θ t 2
results in an angular velocity θ t
and an angular position θ. A change in the angular position Δθ causes the head 80 to move by along the arc 58 (see FIG. 2) as a function of the radial distance R h from the pivot cartridge 51 to the head 80 . Ultimately, the head 80 is located a particular track position POS over the disk 23 and, as already discussed, that position POS is detected and returned for comparison with the target position 101 .
The rotary actuator 50 shown in FIGS. 1-4 is a “balanced actuator” in that the center of mass is designed to be located precisely at the pivot axis such that external accelerations will not generate a relative acceleration between the actuator 50 and the base 21 . As a practical matter, however, many rotary actuators 50 are shipped with an operational or effective imbalance even though they are nominally balanced.
As suggested by block 150 , an actuator 50 with an effective imbalance has a center of mass located at some distance d from the pivot axis. Such an actuator 50 is detrimentally subject to an angular acceleration whenever a linear shock or vibration imparts a force to the off-axis mass. The result is the injection of an undesired torque T vib that tends to cause the head 80 to move off-track even while the servo control system is in a track-following mode. An inability to control the actuator 50 in the face of such undesired vibration detrimentally requires a coarser track pitch design than might otherwise be used, makes it possible that the system will have to re-read a data track, and worse yet, makes it possible that the head 80 will over-write an adjacent track when recording data.
In accordance with the present invention, however, two sensors 35 , 55 may be uniquely used in order to detect and compensate for such undesired acceleration of the actuator 50 . Moreover, because of the differential approach, the system is also capable of detecting motion due to both linear and rotational shock and vibration.
As shown in FIG. 5, accelerations a 1 , a 2 imparted to the first and second sensors 35 , 55 results in two corresponding sensor signals 36 , 56 that, subject to suitable gain adjustments, are differentially compared at a junction 150 . Accordingly, if the disk drive 10 were subject to a linear shock or vibration that resulted in the head 80 moving with the disk 23 (as it would were the actuator 50 perfectly balanced), then the sensors would also move together, the sensor signals 36 , 56 would be identical, and the output of the junction 150 would be zero, i.e. no compensation would be needed and none would take place. On the other hand, if the actuator has an effective imbalance, then a linear shock or vibration that causes the head 80 to move relative to the disk 23 would be reflected as a difference between the first and second signals 36 , 56 . As such, the junction 150 would produce a net value and that value, after suitable treatment though an acceleration compensator 160 to produce a compensated signal 161 , would be combined (added or subtracted as appropriate) with the nominal digital command 121 , at junction 170 , to produce an adjusted digital command 171 . Preferably an adaptive gain stage G 4 is coupled between junction 150 and acceleration compensator 160 for adjusting signal gain on the basis of the formula: a 1 G 1 −(a 2 G 2 )G 3 .
As a result of this approach, the system 100 will actively work to cancel shock and vibration that would otherwise undesirably move the actuator 50 and the head 80 away from a desired track-following position.
As shown in FIG. 5, the preferred system 100 includes a gain adjust block G 3 that accounts for skewing between the sense axis of the two sensors 35 , 55 . In particular, the gain block G 3 adaptively modifies the gain of the second sensor 55 that is mounted on the actuator 50 based on the location of the actuator 50 . When the actuator is located at the MD, the gain would be 1.0, whereas the gain at the ID or OD would increase to a larger amount (e.g. 1.2) in order to account for skew.
As can now be understood by reference to FIGS. 1-5 and the above description, the preferred method of generating a first sense signal 35 corresponding to a motion of the head disk assembly 20 is accomplished by mounting a first motion sensor 35 rigidly relative to the base 21 and the preferred method of generating a second sense signal 56 corresponding to a motion of the rotary actuator 50 relative to the motion of the head disk assembly 20 is accomplished by mounting a second motion sensor 55 to the rotary actuator 50 that pivots relative to the base 21 .
The compensating step is preferably accomplished, as shown in FIG. 5, by modifying a nominal digital command 121 in a servo control loop with a digital value 161 corresponding to the result of the comparing step.
As discussed above, the step of generating a first sense signal is preferably accomplished with a linear accelerometer 35 that has its sense axis 35 s substantially, tangentially aligned with an arc 86 that is traversed by a head 80 carried by the rotary actuator 50 . In such case, the step of mounting the second linear accelerometer 55 on the rotary actuator 50 is preferably accomplished with its sense axis 55 s substantially aligned with the sense axis 35 s of the first linear accelerometer 35 when a read/write head 80 supported by the rotary actuator 50 is located over a middle diameter of the rotating disk 23 .
Finally, the preferred method includes the further step of adjusting a compensation factor G 3 to account for skew that exists between the sense axes 35 s , 55 s of the first and second linear accelerometers 35 , 55 when the read/write head 80 supported by the rotary actuator 50 is located at the inside or outside diameter of the rotating disk 23 .
The preferred system 100 of FIG. 5 is a microprocessor implementation characterized by translation from digital-to-analog using a DAC, and back again using A/D converters 37 , 57 , 111 . In this particular embodiment, the vibration compensation is accomplished digitally because it is most convenient. It is possible, of course, that the vibration cancellation could be implemented in a purely analog system, or in an analog portion of a hybrid system.
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A disk drive that includes a base, a magnetic disk, a rotary actuator that carries a head for reading and writing data from the disk in a track-following mode under the control of a servo control system, and at least two sensors—one fixed sensor rigidly coupled to the overall disk drive and one mobile sensor mounted to the rotating actuator—for differentially detecting accelerations of the rotary actuator relative to the overall disk drive and its disk. The disk drive detects and actively compensates for accelerations imparted to a balanced actuator that has an effective imbalance. The fixed sensor is preferably mounted to a PCBA that is secured to the base. The mobile sensor is preferably mounted to an actuator arm of the rotary actuator, as far outboard as possible, and so as to align with the fixed sensor as the rotary actuator swings through its range of travel. The preferred sensors are linear accelerometers.
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BACKGROUND OF THE INVENTION
This invention relates to a friction device for use in car radios.
Car radios usually have a tuning slider which carries the cores of the variable-inductance coils of the local oscillator of the tuning device, thereby a tuning frequency change is obtained by correspondingly moving the tuning slider in its axial direction. The user may move the tuning slider by means of a convenient rotatable knob.
Furthermore, it is known to provide car radios, in addition to the conventional tuning knob, with keyboard type tuning devices in which each preselection key of a keyboard corresponds to a different transmitter station to which the key can be preset, whereby the radio can be tuned to said station by simply depressing this key. Such tuning devices generally employ a friction clutch, which is interposed between the tuning knob and the tuning slider and has to be released to disengage the manual knob control, when tuning is effected by using the keyboard in lieu of the knob.
A known type of such a releasable friction clutch employs a friction element with a high coefficient of friction, such as rubber, cork of the like. Therefore, the tuning devices of this known type of clutch have in general the disadvantage that the changes in tuning brought about by the rotation of the knob are non uniform, since the friction element of the clutch has a certain elasticity. Consequently, the tuning accuracy in these tuning devices is limited.
Furthermore, these known friction clutches are relatively cumbersome, because the friction element must be sufficiently large to transmit the torque necessary for moving the tuning slider.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a friction device which is extremely small and still very accurate and uniform in the transmission of the motion from the tuning knob to the slider.
According to the invention there is provided a friction device comprising a reciprocable element secured to the tuning slider and a rotatable element driven by the tuning knob, said elements being releasably urged against each other into frictional contact and their surfaces of mutual contact being shaped in such a manner that the surface of one element is wedged into the surface of the other element.
This device converts therefore the rotational motion of the rotatable element into a rectilinear motion of the reciprocable element and consequently also of the tuning slider secured to it, without the need of any intermediate means. In fact, the wedging of one element into the other eliminates the need of the interposition of high friction coefficient materials between the driving and the driven element.
The device of the present invention is particularly but not exclusively suitable for the control of the transducers used in the tuning devices of radio sets, since it allows a fine and sensitive search of transmitter stations.
The friction device according to the invention is particularly suitable for use in car radios because it occupies a relatively small volume, an important factor in the design of car radios, since the space available for the installation of a radio in car dashboards is usually at a premium.
Preferably the reciprocable element is a rod and the rotatable element a pulley. The rod may have a circular cross-section and the pulley a V-shaped groove. These two elements of the device may be urged against each other by any suitable means, such as a roller resiliently biased against the reciprocable element.
In general the tuning slider moves between two end stops which determine two positions which correspond to the two limits of the frequency range of the radio set. Consequently also the rod, which is secured to said slider, stops when either end stop of the slider is reached. If the knob is inadvertently rotated after either of these two end stops has been reached by the slider, the pulley driven by said knob will continue rotating on the corresponding end of the rod and will wear it thinner.
This wear results in an irregular jerky motion of the tuning slider when they are moved back, preventing an accurate tuning-in to a station near the ends of the tuning scale.
When then the wear at the rod ends becomes very severe, the friction between them and the pulley may become insufficient to remove the rod from its end positions.
This disadvantage has been overcome according to another aspect of this invention by providing the cylindrical rod with at least one conical end portion.
The rod may be pivotally connected to an element controlling the tuning slider and may have a single conical end portion when spring means are provided to urge it in a predetermined direction.
BRIEF DESCRIPTION OF THE DRAWINGS
Three embodiments of the invention will now be described for a purely illustrative and in no way limitative purpose with reference to the accompanying draings, in which:
FIG. 1 is a diagrammatic front view of a device according to a first embodiment of the invention;
FIG. 2 is a side view of the device of FIG. 1;
FIG. 3 is a diagrammatic front view of a device according to a second embodiment of the invention; and
FIG. 4 is a diagrammatic front view of a device according to a third embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and in particular to FIG. 1, a friction device according to the invention is shown mounted on a frame 7 of a car radio.
A rotatable element of the friction device consists of a pulley 11 having two flanges 10 defining a circumferential groove having a V-section (FIG. 2).
A reciprocable element, in the form of a cylindrical rod 1, is resiliently wedged between the flanges 10 of the pulley 11 by a small roller 8, freely rotatable around a pivot pin 9 and engaging the external surface of the rod 1.
The pivot pin 9 is rigid with one arm of a bellcrank lever 5, fulcrumed on a pivot pin 6 integral with the frame 7.
In order to engage the friction device, the bellcrank lever 5 is urged anticlockwise, as viewed in FIG. 1, around the pivot pin 6, by a movable bar 4, which is biased axially by a helical spring 3, one end of which is fixed to the bar 4 and the other end of which is anchored to the frame 7.
When the friction device has to be disengaged, it suffices to move the bar 4 axially (to the left as viewed in FIG. 1) against the action of the spring 3: such movement disengages the rod 1 from the flanges 10 of the pulley 11, so that the pulley 11 ceases to be coupled to the rod 1.
As known, the bar 4 is generally shifted to disengage the friction device each time a preselection key is actuated.
The pulley 11 is rigidly connected to a gear 12, which meshes with a pinion 13 integral with the shaft 14 of the tuning knob (not shown).
The rod 1 is connected to an element 2 which controls a conventional tuning slider, so that a rotation of the pulley 11 by means of the tuning knob causes the tuning slider to move to the right or to left, as viewed in FIG. 1, to tune-in a desired transmitter station.
The tuning shaft 14 is supported by the frame 7 and, in addition to its rotation about its axis, the shaft 14 is capable of an inward axial movement in order to release a previously depressed preselection key, thereby engaging the friction device and permitting a manual search of a transmitter station.
The pulley 11 and the gear 12 are rigid with a shaft 15, rotatable in the frame 7 about an axis parallel to that of the tuning shaft 14.
In order to avoid that the rod 1 may transmit motion to the pulley 11, for instance by a spring acting on said rod 1 or on the tuning slider, the gear 12 is pressed against the frame 7 by a spring 16 in the form of a belleville washer or spider.
The friction between the gear 12 and the frame 7 can be increased by interposing between them a washer of a suitable material, such as cardboard or fibre.
As already stated, the wedging of the rod 1 between the flanges 10 of the V-shaped groove of the pulley 11 ensures the maximum positive transmission of motion from the pulley 11 to the rod 1 and therefore a very smooth rectilinear motion of the rod 1 and consequently a very accurate setting of the tuning slider.
This wedging action permits that both the pulley 11 and the rod 1 can be made of metal, although keeping within the usual limits the pressure applied by the roller 8.
In operation, when the bar 4 comes under the action of the spring 3, it rotates the bellcrank lever 5 anticlockwise thereby to wedge the rod 1 between the flanges 10, so that by rotating the tuning knob the pinion 13 drives the gear 12 and thus rotates the pulley 11 to displace the rod 1 and therefore the tuning slider axially by an amount precisely related to the rotation of the tuning knob.
When it is desired to release the friction device, for instance in order to effect tuning by means of a preselection key, the depression of the selected key causes a shifting of the bar 4, to the left as viewed in FIG. 1, against the action of its biasing spring 3, thereby drawing the roller 8 away from the rod 1 and disengaging the rod 1 from the pulley 11. The rod 1, together with the tuning slider secured to it, is thereby left free to move axially.
It will be understood that the rod 1 can have any cross-sectional shape, such as a triangular, polygonal or other shape.
In particular, if the rod 1 has a V-shaped cross-section, the rotatable element could have the shape of a disc with rounded edges.
In the embodiment of FIG. 3 the cylindrical rod 1 is provided with two conical end portions 21, 22.
The tuning slider is designed in such a manner as to permit it to move beyond the scale ends, where the conical end portions 21, 22 of the rod 1 enter the groove of the pulley 11.
In this way only the cylindrical portion of the rod 1 serves for the tuning control.
Owing to their greater thickness, it takes these conical portions a longer time to be worn so thin as to render their frictional engagement with the pulley groove insufficient to move the rod.
As long as the conical end portions 21, 22 are not worn thinner than the cylindrical portion by the pulley 11, the motion of the rod 1 remains uniform. In this way, the life time of the present device is notably extended.
Furthermore, even if the contact portion betweeen the conical portion or portions and the pulley groove does not produce a uniform motion of the rod 1, this is of no importance because this portion or portions are outside the scale ends.
It will be noted that the rod 1 is pivoted to the element 2 which controls movement of or forms part of the tuning slider, through a pivot pin 23: this pivotal connection allows a better relative positioning between the moving parts.
A rod 1 with only one conical end portion 21 is shown in FIG. 4.
A tension spring 24 has one end fixed to a hook 25 fastened to the control element 2 and the other end anchored to the frame 7.
In this way the spring 24 biases the element 2 and therefore the rod 1 towards the right as viewed in FIG. 4, that is away from any worn right terminal portion, in which no friction between the pulley 11 and said rod end could take place and consequently a rotation of the pulley 11 would no more cause a rectilinear motion of the rod. Thanks to the provision of this spring 24 only one end of the rod 1 need be made conical, namely that opposite the direction of the bias exerced by said spring.
It will be noted that the bias action, as caused by the spring 24, could be also produced by a tension spring having one end anchored to the frame 7 and the other end directly connected to the rod 1 or to the tuning slider.
It will be apparent that other numerous and different variations can be made by those skilled in the art to the disclosed forms of embodiment, without departing from the scope of this invention.
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A friction device for coupling the manual tuning knob of a keyboard (pushbutton) radio to a reciprocal tuning slidebar is disclosed. The friction device comprises a cylindrical rod attached to the tuning slidebar which selectively is drivingly engaged by a peripheral V-shaped groove in a pulley rotated by the manual tuning knob.
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BACKGROUND OF THE INVENTION
An accurate guiding system suitable for obtaining precise movement of the carriage of a machine tool is disclosed in U.S. Pat. No. 3,578,827. In this arrangement, two bearings are carried by one component of the system and positioned adjacent two opposed walls of a second component with respect to which their is to be relative movement. One of the bearings is rigidly mounted on the first component and positioned adjacent one of the walls, which is made to an accurate dimension. The other bearing is adjacent the opposite wall and is connected by a spring to the first component. This provides the second bearing with freedom to float, so that as the components move relative to each other, the path of movement is controlled by the rigidly mounted bearing and the first wall as the second bearing floats to accommodate dimensional differences. The resulting system allows a very accurate and relatively long path of movement to be achieved at a reasonable expense.
There are certain limitations to the prior art construction, however. The use of a spring provides a varying force, not necessarily entirely uniform, as the bearing floats and the spring deflects. The bearing shoe has uniform loading on one side where the air is discharged at the bearing surface, while the other side has a point or localized load where it is engaged with the spring in one case or the rigid mounting means in the other. This means that the bearing shoe tends to deform, unless made quite heavy. Even then, some distortion is unavoidable. Deformation of the bearing can result in variation in the lift height accomplished by the air discharged through the bearing. Contact between the bearing and the wall may result if the lift height is too small, thereby resulting in failure of the bearing to perform its function. This design requires a relatively high degree of parallelism between the two opposed surfaces to avoid changes in the lift of the bearings and the risk of contact between a bearing and the adjacent surface.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improved bearing system overcoming the difficulties of the prior art noted above. In this arrangement the bearings are more uniformly loaded, and the floating bearing has a considerably higher increment of permissible travel without incurring any change in the amount of lift, than is characteristic of prior art designs.
When the system is applied to a machine with a movable carriage, the floating bearing includes a cylinder in the carriage which receives a sleeve that extends from the bearing, so that the area encompassed by the sleeve provides a piston. Air is discharged into the cylinder, reacting against the piston, biasing the bearing outwardly. A portion of this air also bleeds outwardly through openings in the bearing to form a film of air at the bearing surface, so that the air which loads the floating bearing also provides the lift for that bearing. The cylinder is relatively large in volume so as to form a plenum at constant pressure for supplying the air to the bearing surface. When deviations in contour are encountered, the bearing can move outwardly or be displaced inwardly against the biasing force of the air.
Preferably, there is a cylinder for the second bearing, with a sleeve from the bearing shoe extending into that cylinder. The cylinder of the second bearing is smaller so that the piston head of the second bearing is of lesser area than that of the floating bearing and the outward biasing force is not as great. Discharge openings through the second bearing provide an outlet for the air within the plenum of the second cylinder so that it can form a film between the bearing surface and the wall. The bearing area of the second bearing equals that of the first, and the air discharge openings have the same size and pattern. An adjustable stop limits the inward travel of the second bearing. The air supply to the second bearing is at the same pressure and preferably from the same source as that of the floating bearing.
When the system is in use, the compressed air against the piston heads provides a reaction on the carriage with a net force away from the floating bearing. This causes the bearing adjacent the accurate wall of the table to bottom out against its stop. The other bearing then is free to float inwardly and outwardly as deviations in contour are encountered. Because the bearing surface areas of the two bearings are the same, as are their orifice outlets, equal lifts are provided at the two bearings, and the carriage assumes a position of equilibrium.
Relatively large amounts of variations in wall contour and angle may be accommodated by the floating bearing, which at all times maintains the same lifting force. There is no danger of contact between the bearings and the walls. The bearings are uniformly loaded on both sides throughout major portions of their areas so that there is little tendency to distort them and they need not be made excessively thick and stiff. The increased amount of surface variation that may be tolerated means that is less expensive to form the opposed walls of the table, because not as much care is necessary in the formation of the wall along which rides the floating bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a machine tool carriage, movable with respect to a support table and guided by the air bearing system of this invention;
FIG. 2 is an enlarged transverse sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a further enlarged transverse section view of the air bearing arrangement; and
FIGS. 4 and 5 are sectional views taken along lines 4--4 and 5--5, respectively, of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown, the air bearing system of this invention is used in guiding the carriage 10 of a machine tool in a rectilinear path with respect to a fixed table 11, which may be made from a slab of granite. Bearings, not shown, support the carriage vertically with respect to the table 11. A channel 12 with a flat bottom wall 13 and opposed substantially parallel flat sidewalls 14 and 15 is formed in the table 11. In the construction of the table 11, the channel sidewall 15 is made to precise dimensions so that it is close to being exactly planar. The surface 14, however, is not made to such close tolerances and so is not as close to being planar as is the surface 15. This means that there are slight differences in the spacing and angularity of the surfaces 14 and 15 throughout the lengths of these surfaces, and that the surfaces 14 and 15 are approximately, but not entirely, parallel.
Four bearings are used in guiding the carriage 10 in its fixed horizontal path, two on one side and two on the other. The two bearings on each side are identical so only one of each is shown and described in detail.
The carriage 10 includes depending flanges 17 and 18 along its sides adjacent the surfaces 14 and 15, respectively. Extending inwardly from the wall 19 of the flange 17, which is adjacent the table sidewall 14, is a cylinder 20. The axis of the cylinder 20 is perpendicular to the wall 19 and hence to the channel sidewall 14. The circumferential wall of the cylinder 20 is stepped, having a short entrance portion 21 which is slightly smaller in diameter than the inner portion 22. An annular recess 23 in the entrance portion 21 receives an O-ring 24. The latter element engages and seals against a cylindrical sleeve 25, one end of which is slidably received in the cylinder 20. The outer end of the sleeve 25 fits within an annular groove 26 in the inner surface 27 of a bearing shoe 28. The latter member is a flat, circular plate having an outer bearing surface 29 adjacent the table sidewall 14. The outside diameter of the bearing shoe 28 is somewhat larger than that of the sleeve 25. Several small spaced openings 30 extend through the bearing shoe 28 within the circumference of the sleeve 25, providing communication between the cylinder 20 and the outer surface 29 of the bearing.
Compressed air is supplied to the cylinder 20 through a line 31 which connects to a passageway 32 in the carriage flange 17 that empties into the cylinder at its inner end 33. This means that air can flow from the line 31 into the cylinder 20 to be discharged through the restricted openings 30 in the bearing shoe for providing a film of air between the bearing surface 29 and the table wall 14. The cylinder 20 and interior of the sleeve 25 are of relatively large volume and so form a plenum for the air so that there is a constant supply at a predetermined pressure for the openings 30.
The portion of the inner surface 27 of the bearing shoe 28 within the sleeve 25, and the inner end edge 34 of the sleeve 25, act as a piston head, so that the pressure of the air within the cylinder 20 biases the bearing shoe 28 outwardly toward the table sidewall 14. An equal and opposite reaction is exerted on the carriage 10, urging it away from the wall 14.
On the opposite side of the carriage 10 at the flange 18 is a second cylinder 35, which has an entrance 36 and a larger inner circumferential wall 37. The axis of the cylinder 35 is aligned with the axis of the cylinder 20 and is perpendicular to the sidewall 15 of the table. The entrance 36 and inner wall 37 of the cylinder 35 are of smaller diameter than the corresponding walls 21 and 22 of the cylinder 20. An annular recess 38 in the entrance wall 36 receives an O-ring 39. This provides a seal around a sleeve 40 of cylindrical shape which is movable axially relative to the cylinder 35. The sleeve 40 is smaller in diameter than the sleeve 25 in the cylinder 20.
A bearing shoe 41 has an annular recess 42 in its inner surface 43 which receives the outer end of the sleeve 40. Openings 44, within the sleeve 40, extend through the bearing shoe 41, providing communication between the inside of the sleeve 40 and the outer surface 45 of the bearing shoe which is adjacent the table wall 15. The openings 44 are the same in number, size and spacing as are the openings 30 in the bearing shoe 28. The outside diameter of the bearing shoe 41 is the same as that of the bearing shoe 28, which means that the bearing surfaces 29 and 45 have the same area.
The inner end of the sleeve 40, within the cylinder 35, carries an end plate 46 which has a domed surface 47 exteriorly of the sleeve. A passage 48 extends through the end plate 46. This allows for the transmission of air to the bearing shoe 41 from a line 49 that connects to a passageway 50 in the carriage flange 18, which in turn communictes with the cylinder 35 at its inner end wall 51. Therefore, air can flow from the line 49 through the passageway 50 and the opening 48 in the end plate 46 into the space within the sleeve 40. Air from this plenum can flow outwardly through the restricted openings 44 and the bearing shoe 41 to form a film between the outer bearing surface 45 and the table wall 15.
Air from the line 49 also reacts against the piston head formed by the portion of the bearing shoe within the sleeve 40 and the peripheral area of the domed surface 47 beyond the sleeve end to bias the bearing 41 toward the table wall 15. This force is less than the biasing force on the bearing 28 because the sleeve 25 is of greater diameter than the sleeve 40 and results in a piston head of larger area for the bearing 28. The equal and opposite reaction against the carriage 10, urging it away from the wall 15, therefore, is less than the reaction biasing the carriage away from the wall 14.
A threaded opening 52 in the carriage flange 18 communictes with the inner end wall 51 of the cylinder 35 at its center and receives a threaded stud 53. The end 54 of the stud 53 within the cylinder 34 is engagable with the center of the domed outer surface 47 of the end plate 46. Therefore, the stud and end plate 46 act as a stop which limits the travel of the sleeve 40 and the bearing shoe 41 toward the inner end 51 of the cylinder 35. The axial position of the end 54 of the stud 53 is adjustable by rotation of the stud, and the stud is held in its adjusted position by a nut 55 on the stud. An O-ring 56, beneath the washer 57, seals around the periphery of the stud 54 to prevent air flow.
In use of the air bearing system of this invention in guiding the carriage 10, a common source of compressed air is used to supply the lines 31 and 49 so that the same pressure is realized in the two cylinders 20 and 35. This air flows from the plenums formed inside the pistons within these cylinders through the restricted air outlet openings 30 and 44. This produces a thin film of air between the outer surface 29 of the bearing 28 and the table wall 14 and a similar film between the outer surface 45 of the bearing 41 and the table surface 15. Because the air orifices and the bearing surface areas of the two bearings 28 and 41 are the same, equal lifts are produced by the two bearings, and the carriage 10 assumes lateral equilibrium between the table walls 14 and 15.
Internally, however, the larger piston area within the sleeve 25 of the bearing 28, compared with that within the sleeve 40 of the bearing 41, produces a net lateral reaction on the carriage 10 biasing it in the direction of the wall 15. This force on the carriage causes the sleeve 40 to be pressed into the cylinder 35 so that the end plate 46 of the bearing 41 bottoms out against the stud 54, as shown in FIG. 3. Thus, there is a solid connection between the carriage 10 and the bearing 41 through the stud 54, the end plate 46, and the sleeve 40.
The other bearing 28, however, is free to float, as the sleeve 25 can move inwardly and outwardly. The bearing 28 also can tilt slightly relative to the carriage 10 by virtue of the clearance between the axially short entrance wall 21 of the cylinder 20 and the exterior surface of the sleeve 25. As a result, as the carriage 10 moves axially of the channel 12, it is guided entirely by the accurately formed wall 15, as the bearing 28 floats to accommodate any irregularities in contour, angle, or parallelism found in the wall 14. The air pressure is maintained at a constant value so that the lift and reactive force will remain constant, regardless of any variations in the channel walls.
Each of the bearing shoes 28 and 41 is uniformly loaded by air pressure along its inner surface within the sleeve. This load balances the pressure on the outer bearing shoe surface and assures that the bearing is virtually undistorted.
Inasmuch as the end plate 46 bottoms out against the stud 54 to form a solid connection as the bearing system is in use, the device may be constructed without a cylinder for the bearing 41, using a solid mounting istead. However, the use of a cylinder with uniform loading on both sides of the bearing contrasts with the point-type loading normally where a solid bearing mounting is used, with resulting distortion of the bearing shoe. Also, a relatively simple construction follows from the use of a pressure cylinder for the bearing 41, facilitating manufacture of the system.
Instead of being positioned against opposite walls of a channel, as described above, the bearings may be on opposite sides of an intermediate member, such as a beam. In that case the bearings face each other and the bearing surfaces are the opposite sides of the beam. The beam between the bearings may be the movable element while the bearings and their cylinders remain stationary, except for the movement of the pistons associated with the bearings. In that event, one of the beam walls is made to an accurate dimension and the opposite wall is not, so that the path of the beam is controlled by the accurate wall and the floating bearing responds to deviations in the opposite wall.
The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.
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This invention provides an air bearing system for guiding along one of two opposed walls by a piston-mounted air bearing. A second piston-mounted air bearing is adjacent the other of the opposed walls, having a larger piston to exert a greater force and cause the first piston to bottom against a stop. The bearings receive air pressure along their inner surfaces for balancing the load on them and avoiding distortion.
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BACKGROUND OF THE INVENTION
Field of the invention
The present invention relates to a novel process for producing oxetanocin G. The present invention also relates to intermediates for synthesis of oxetanocin G.
Description of the Prior Art
Oxetanocin G is a compound which is expected to be useful as an antiviral agent, etc. and is disclosed in EP-A-0291917, together with a process for production thereof. This known process comprises either performing microbiological conversion with respect to the steps of starting from oxetanocin A to obtain oxetanocin X and then performing chemical synthesis up to 2-amino-oxetanocin A, or applying chemical synthesis to all of the steps up to 2-amino-oxetanocin A and finally performing enzymatic conversion to obtain oxetanocin G.
However, this known process involves problems that in the case of the microbiological conversion, large amount of microbial cells are required, its reaction time is prolonged, etc. On the other hand, the overall chemical synthesis encounters a problem in yield so that such a process is not suited for industrial production.
Therefore, the present inventors have made extensive investigations on a process for producing oxetanocin G suitable for mass production and as a result, have accomplished the present invention.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a process for producing oxetanocin G (hereinafter merely referred to as OXT-G) which is suited for industrial production.
The present invention provides a process for producing OXT-G which comprises hydrogenolizing an alkoxylated 2-amino-oxetanocin A (referred to as alkoxy-2-amino-OXT-A) represented by formula (I) to obtain 2amino-oxetanocin A (referred to as 2-amino-OXT-A) and then converting ##STR2## at the 6-position thereof into >C═O.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process for producing OXT-G (including salts thereof) which comprises hydrogenolizing alkoxy-2-amino-OXT-A (including salts thereof) represented by general formula (I): ##STR3## (wherein R 1 represents a lower alkyl group) to remove the alkoxy group and obtain 2-amino-OXT-A (including salts thereof) represented by the following formula: ##STR4## and then converting ##STR5## at the 6-position thereof into 22 C═O.
The present invention also relates to oxetanocin derivatives represented by general formula (II): ##STR6## wherein Y represents: ##STR7## (wherein R 1 represents a lower alkyl group)] which are used as intermediates for synthesis of OXT-G.
The hydrogenolysis of the alkoxy-2-amino-OXT-A represented by general formula (I) can be carried out by catalytic reduction in a solvent.
Any solvent is usable so long as it does not inhibit the reaction; however, a polar solvent, for example, a polar organic solvent, water or a solvent mixture of water and the polar organic solvent is generally used. As the polar organic solvent, it is preferred to use a lower alcohol such as methanol, ethanol, etc.
As the catalyst, there may be used catalysts used for ordinary catalytic reduction, for example, platinum type catalysts, palladium type catalysts, nickel type catalysts, cobalt type catalysts, etc. In general, palladium type catalysts such as Pd-C, etc. are used.
The reaction is carried out generally in the presence of hydrogen at about 0° C. to about 150° C. under normal pressure to under pressure, e.g., at about 1 to about 20 atoms.
The reaction time can vary depending upon kind of catalyst or reaction temperature and is not limited to a certain period but about 1 to about 10 hours are sufficient for the reaction.
For forming the slats of 2-amino-OXT-A, the following procedure applies.
2-Amino-OXT-A is suspended in water and an acid is added to the suspension to dissolve 2-amino-OXT-A. Then, a suitable solvent is added to the solution to crystallize the salts. Any acid can be used for forming the salts as long as it is a pharmacologically acceptable acid. Preferred examples are hydrochloric acid, sulfuric acid, phosphoric acid, etc.
Examples of the lower alkyl group in general formula (I) or (II) include an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms such as methyl, ethyl, propyl and butyl, etc.
In order to convert ##STR8## at the 6-position to >C═O, either the chemical method or the enzymatic method may be used but the enzymatic method is generally used. As the enzyme, adenosine deaminase, adenylic acid deaminase or the like may be used. These enzymes may be those commercially available, for example, EC 3.5.4.4 manufactured by Sigma Co. as adenosine deaminase and, as adenylic acid deaminase, 5'-adenylic acid deaminase (Catalogue No. A-1907) manufactured also by Sigma Co., or DEAMIZYME® (trademark) manufactured by Amano Pharmaceutical Co., Ltd., etc. These enzymes may not be pure but the culture of microorganism and treated matters thereof or products collected from animal tissue may also be used so long as they contain these enzymes.
For producing OXT-G from 2-amino-OXT-A using these enzymes, 2-amino-OXT-A and these enzymes are reacted with each other in an aqueous solvent, for example, water or a solvent mixture of water and a polar solvent (a lower alcohol or the like) at pH of about 5 to about 9, preferably about 6 to about 8, at a temperature of about 10° C. to about 70° C., preferably about 20° C. to about 50° C., more preferably about 20° C. to about 40° C. As the solvent, it is preferred to use a buffer solution, preferably, phosphate buffer solution for pH stabilization. In general, there may be used about 0.05 to about 2.5 M, preferably about 0.1 to about 2.0 M of phosphate buffer (pH of about 5 to about 8).
It is difficult to a set a general range for the quantity of enzyme to be used since the quantity varies depending upon purity of enzyme, etc. but it is preferred that for example, A-1907 (adenylic acid deaminase) manufactured by Sigma Co. be used in a quantity of about 10,000 to about 50,000 units per 1 mole of 2-amino-OXT-A. The optimum quantity to be used is approximately 20,000 to 30,000 units.
In the case of EC 3.5.4.4 (adenosine deaminase) manufactured by Sigma Co., it is preferred to use 2,000 to 200,000 units per 1 mole of 2-amino-OXT-A. The optimum quantity used is approximately 25,000 to 50,000 units. In this case, the enzymatic method can be carried out according to the process described in EP-A-0291917.
To isolate the product from the reaction solution, a convertional manner may be applicable. For the isolation, a method for utilizing difference in solubility in water or an organic solvent, adsorption-desorption method using activated charcoal, adsorbing resin or ion exchange resin, and the like can be used in a suitable combination.
For example, colorless crystalline OXT-G can be obtained by reacting 2-amino-OXT-A with the enzyme, passing the reaction solution through a column packed with porous resin to adsorb the product thereto, then either eluting the product with water, concentrating and evaporating off to dryness or eluting with a solvent mixture of water-lower alcohol (methanol, ethanol or the like), concentrating the desired fraction and evaporating off to dryness. If necessary and desired, the obtained OXT-G can be further purified using Sephadex® or the like.
The alkoxy-2-amino-OXT-A represented by general formula (I) which is used as the raw compound in the present invention can be produced by the following steps. (I) Process for producing alkoxy-2-amino-OXT-A; ##STR9## That is, after oxetanocin A (OXT-A) is converted into the N-oxide, cyano group is substituted on the amino group via the oxadiazole ring. The resulting N-oxide compound is alkylated and then subjected to ring-opening, rearrangement and ring closure to obtain alkoxy-2-amino-OXT-A (Compound ○1 ). Hereafter, the respective steps are described in more detail.
Step 1
Oxetanocin A (OXT-A) is N-oxidated with an appropriate oxidizing agent. Examples of the oxidizing agent include m-chloroperbenzoic acid, peracetic acid, hydrogen peroxide, etc. The oxidizing agent may be used in about 0.5 to about 5 equimolar amounts based on OXT-A. The reaction may be carried out at a temperature in the range of from about 0° C. to about 100° C.
The reaction described above is carried out generally in an appropriate solvent. As the reaction solvent, there may be used a polar organic solvent such as acetic acid, acetone, dioxane, methanol, ethanol and the like which may include water. The reaction may also be carried out in the dual layer solvent system consisting of a non-polar organic solvent such as chloroform, ethyl acetate, etc. and water. N-oxide of OXT-A (Compound ○1 ) can be purified by removing the reagents by extraction with ethyl acetate followed by column chromatography.
Step 2
In this step, a cyanogen halide is reacted with Compound ○1 to form the oxadizole ring. Examples of the cyanogen halide include cyanogen bromide, cyanogen iodide, etc. The cyanogen halide may be used in approximately 0.5 to 10 equimolar amounts. The reaction temperature is generally between about 0° C. and about 100° C.
Step 3
In this step, the hydrogen chloride is removed from the hydrogen chloride salt of Compound ○2 with ammonia-saturated alcohol. As the solvent, it is preferred to use an organic solvent such as methanol, ethanol, etc. The reaction is carried out at a temperature in a range of from about 0° C. to about 60° C.
Step 4
The Compound ○3 is alkylated in a suitable solvent at a temperature of about 0° C. to the boiling point of a solvent (about 150° C.) in the presence of a base. The reaction is carried out generally under normal pressure but may be under pressure. As the solvent, a polar organic solvent such as N,N-dimethylformamide, acetone, pyridine, etc. are preferred. Examples of the base include mono, di or tri lower alkyl amines such as triethylamine, diisopropylethylamine, etc. As the alkylating agent, an alkyl halogenide such as methyl iodide, ethyl iodide, etc. can be used.
Step 5
In this step, the base moiety of Compound ○4 is subjected to ring-opening with a base, rearrangement and then ring closure by heating in a polar solvent. As the base, there may be used an alkali metal hydroxide, for example, sodium hydroxide, potassium hydroxide, and an alkaline earth metal hydroxide, etc. In addition thereto, an organic base such as triethylamine or the like may also be used. As the polar solvent, an alcoholic solvent such as aqueous methanol, aqueous ethanol, etc. are preferred. The heating is effected in a range of from about 30° C. to about 150° C. but generally in a range of from about 50° C. to about 80° C.
In the steps 1 through 5, the product may not be isolated at each step, unless inconvenience is involved. Alternatively, these steps may be performed continuously several steps in one batch. For example, the steps 2 to 4 may also be carried out in one batch, using a polar solvent such as dimethylformamide, etc.
EXAMPLE 1
(1) Synthesis of 2-amino-OXT-A
To a solution of 53.8 g of alkoxy-2-amino-OXT-A (Compound ○5 ) (R 1 =ethyl) in 50% aqueous ethanol, 16 g of 10% Pd-C was added to hydrogenolize for 4 hours in the presence of hydrogen at 95° to 105° C. under 12 to 14 atms. After the catalyst was filtered off, the solvent was concentrated. The residue was crystallized from 500 ml of hot water to give 34.4 g of crude 2-amino-OXT-A. By washing the crude product with 150 ml of hot water, 32.7 g of 2-amino-OXT-A.1/2H 2 O was obtained. 2Amino-OXT-A.1/2H 2 O: FE-MS /mz; 266 (M) +
UV: λH 2 O/max nm; 256, 278
NMR (200 MHz, DMSO-d 6 , TMS) ppm; 8.30 (1H, s, 8-H). 6.80 (2H, bs, NH 2 ), 6.23 (1H, d, J=5.84Hz, 1'-H), 5.88(2H, bs, NH 2 ), 5.39(1H, t, OH), 5.0(1H, t, OH), 4.48(1H, m, 3'-H), 3.50-3.80 (3H, m)
Element analysis: Calcd: C: 43.94%, H: 5.49%, N: 30.90%. Found: C: 43.63%, H: 5.30%, N: 30.53%.
(2) Synthesis of 2-amino-OXT-A salt (hydrochloride)
In 33 ml of water was suspended 5.0 g of 2-amino-OXT-A-1/2H 2 O and, 3.42 ml of hydrochloric acid (hydrogen chloride: 20%) was added to the suspension to dissolve the salt and then 33 ml of ethanol was added to the solution. The mixture was allowed to settle at 5° C. for 20 hours. The precipitated crystals were filtered and washed with a small quantity of 50% aqueous ethanol and then with a small quantity of ethanol. After drying under reduced pressure, 29.3 g of 2-amino-OXT-A.HCl was obtained. 2Amino-OXT-A.HCl: molecular formula: C 10 H 14 N 6 O 3 HCl
Elemental analysis: Calcd: C: 40.04%, H: 5.02%, N: 28.48%, Cl: 10.31%. Found: C: 39.68%, H: 5.00%, N: 27.76%, Cl: 11.71%.
NMR (200 MHz, D 2 O) ppm; 8.30(1H, s, 8-H), 6.29(1H, d, J=4.8Hz, 1'-H), 4.65(1H, m, 3'-H). 3.60-3.95(5H, m)
(3) Synthesis-1 of OXT-G
After 2.0 g of 2-amino-OXT-A was dissolved in 300 ml of 1/10 M phosphate buffer (pH 6.5), 200 units of 5'-adenylic acid deaminase (manufactured by Sigma Co., A-1907) were added to the solution followed by stirring at 37° C. for 50 hours. After the reaction solution was passed through a column packed with MCI® GEL CHP 20 (300 ml) and the reaction products were adsorbed onto it, the products were eluted by water. Fractions showing an Rf value of about 0.42 in silica gel TLC [developing solvent: n-butanol-acetic acid-water (4:1:2)] were collected and concentrated to dryness under reduced pressure to give 1.8 g of OXT-G as colorless crystals (yield, 90%).
FE-MS: 268 (M+H) +
UV : λpH 6.0/max (log ε) 253.5 nm (4.09)
NMR (400 MHz, D 2 O) ε ppm: 3.69-3.87(5H, m), 4.66-4.69(1H, m), 6.29(1H, d), 8.17(1H, s)
(4) Synthesis-2 of OXT-G
After 2.0 g of 2-amino-OXT-A was dissolved in 300 ml of 1/10 M phosphate buffer (pH 6.5), 8.0 g of 5'-adenylic acid deaminase (manufactured by Amano Pharmaceutical Co., Ltd. DEAMIZYME®) was added to the solution followed by stirring at 37° C. for 70 hours. After insoluble matters of the reaction solution were removed by filtration, the filtrate was passed through a column packed with 50 ml of activated charcoal powders (manufactured by Wako Pure Chemical Industry K.K., for chromatography). After washing with water, elution was performed with 50% aqueous methanol. By concentrating the desired fraction to dryness, crude OXT-G was obtained. The crude powders were dissolved in 50 ml of water and the OXT-G in the solution was adsorbed onto MCI® GEL CHP 20 (300 ml) followed by elution with water. The desired fraction was concentrated and evaporated to dryness under reduced pressure to give 1.5 g of OXT-G as colorless crystals (yield, 75%).
The alkoxy-2-amino-OXT-A used as a starting material was synthesized as follows.
Synthesis of alkoxy-2-amino-OXT-A (Compound ○5 ) form OXT-A
(a) Synthesis of Compound ○1
After 150 g of OXT-A was dissolved in a mixture of 2.2 liters of water and 1 liter of methanol, 0.75 liter of a solution of 139 g of m-chloroperbenzoic acid in methanol was added to the solution. Under light shielding, the mixture was stirred at room temperature for 18 hours and 0.15 liter of a solution of 28 g of m-chloroperbenzoic acid in methanol was further added to the reaction mixture. Stirring were performed for further 5 hours.
After insoluble matters were filtered off, the filtrate was concentrated to 2.0 liters and the concentrate was extracted twice with 1.5 liters of ethyl acetate. After the aqueous phase was concentrated to 1.5 liter, 0.5 liter of water was added to the residue. The mixture was passed through a column packed with 2.0 liters of MCI® GEL CHP 20. The passing liquid and washing liquid (8.2 liters) were collected and concentrated to dryness to give 146.4 g of Compound ○1 (yield, 91.7%).
Compound ○1 : FAB-MS m/z; 268 (M+H)
NMR (60 MHz, D 2 O) pm; 8.87(1H, s), 8.73(1H, s), 6.71(1H, d), 4.70(1H, m), 3.99-4.30(5H, m), 4.66(1H, m, 3'-H)
(b ) Synthesis of Compound ○2.sup.[
After 129.3 g of Compound ○1 was dissolved in 5.7 liters of methanol, 0.45 liters of a solution of 55.5 g of cyanogen bromide in methanol was added to the solution. The mixture was stirred at room temperature for 2 hours.
Compound ○2 was precipitated but for further precipitating the compound, 3.0 liters of ethyl acetate were added to the mixture followed by stirring for 20 minutes. The precipitated crystals were filtered and washed with ethyl acetate. After drying under reduced pressure, 146.48 g (yield, 81.1%) of Compound ○2 was obtained as colorless crystals. The method liquid was concentrated and crystallized from 1 liter of methanol and 1 liter of ethyl acetate. By performing the same procedure, 13.26 g (yield, 7.3%) of Compound ○2 was obtained as colorless crystals.
Compound ○2 : FD-MS m/z; 294 (M+H-Br) + ,
IR (KRr); 1720 cm -1 (C═NH)
NMR (200 MHz, DMSO-d 6 TMS) ppm; 10.70(1H, bs, NH), 10.13(1H, s, 8-H), 9.35(1H, s, 2-H), 6.61(1H, d, J=4.84Hz, 1'-H), 4.70(1H, m), 2.50(3H, m)
UV λH 2 O/max nm: 223, 283
(c) Synthesis of Compound ○3
After 159.6 g of Compound ○2 was suspended in 6 liters of methanol, 1.6 l of ammonia-saturated methanol was added to the suspension (the compound ○2 was dissolved). The solution was stirred at room temperature for 1.5 hour. The reaction solution was concentrated to the half volume an the precipitated colorless crystals were filtered. After washing with a small quantity of methanol, the crystals were dried under reduced pressure to give 118.1 g (yield, 94.6%) of Compound ○3 .
Compound ○3 : FD-MS m/z; 293 (M+H) + ,
IR (KBr); 2170 cm -1 (N--C.tbd.N), 1220 cm -1 (N--O)
UV λH 2 O/max nm; 247, 293
NMR (200 MHz, D 2 O) ppm: 8.55 (1H, s, 8-H), 8.42(1H, s, 2-H), 6.46(1H, d, J=5.49Hz, 1'-H) 4.70 (1H, m, 3'-H), 3.72-4.00 (5H, m)
(d) Synthesis of Compound ○4
After 109.06 of Compound ○3 was suspended in 1.1 liter of N,N-dimethylformamide, 85.2 ml of triethylamine and 60.6 ml of ethyl iodide were added to the suspension. The mixture was stirred at room temperature for 2 hours. The solvent was concentrated under reduced pressure. After the residue was dissolved in 1.4 liter of hot water, the solution was allowed to stand at room temperature and the resulting gel-like precipitates were filtered to give 118.47 g (yield, 99.2%) of crude Compound ○4 .
Compound ○4 : FD-MS m/z; 320 (M) +
IR (KBr); 2180 cm -1 (C N)
UV λMeOH/max mm: 220, 285
NMR (200 MHz, CD 3 OD, TMS) ppm: 8.84(1H, s, 8-H) 8.68(1H, s, 2-H), 6.52(1H, d, J=5.78 Hz, 1'-H), 4.69(1H, m, 3'-H), 4.43(2H, q, J=7.01 Hz, --CH 2 --CH 3 ), 3.65-3.97 (3H, m), 1.44(3H, 5, J=7.01 Hz, --CH 2 --CH 3 )
(e) Synthesis of Compound ○5
After 107.6 g of Compound ○4 was suspended in 2.3 liters of water, 86 ml of 5 N sodium hydroxide was added to the suspension. The mixture was stirred at room temperature for 2.5 hours. A pH of the reaction solution was adjusted to 7.3 with Dowex® 50 (H + ) and the resin was filtered off. To the filtrate was added 2.3 liters of ethanol. The mixture was heated to reflux for 30 minutes and the resulting reaction solution was used in the following step as it was.
Compound ○5 : FD-MS m/z; 310 (M) +
UV λH 2 O/max nm; 280
NMR (200 MHz, DMSO-d 6 , TMS) ppm; 9.70(1H, bs, NH). 8.07(1H, s, 8-H), 6.60(2H, bs, NH 2 ), 6.11 (1H, d, J=5.95 Hz, 1'-H), 5.20(1H, t, OH), 4.96(1H, t, OH), 4.46(1H, m, 3'-H), 3.98(2H, q, J=7.04 Hz, OCH 2 --CH 3 ), 3.40-3.70 (5H, m), 1.05(3H, t, J=7.04 Hz, --OCH 2 --CH 3 )
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The present invention provides a novel process for producing oxetanocin G by hydrolysis of alkoxylated 2-amino-oxetanocin A thereby to convert ##STR1## at the 6-position thereof into >C═O. Oxetanocin G is expectedly useful as an antiviral agent.
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CLAIM OF PRIORITY
This application claims priority from U.S. provisional application 61/624,669, filed on Apr. 16, 2012, the contents of which are fully incorporated by reference.
FIELD OF THE INVENTION
The invention relates to a watercraft utility harness and more particularly relates to a watercraft utility harness that may be attached to boat guardrail cables to carry supplies such as fuel containers.
BACKGROUND OF THE INVENTION
Watercrafts, such as sailboats, fishing boats and yachts, are widely used for practical and entertaining purposes. It is desirable that the watercraft is capable of housing ample supplies such as fuel, drinkable water, and foodstuff to sustain a trip. However, due to limitations on board a watercraft, the ability to carry more supplies is in most occasions insufficient. In particular, having an extra supply of fuel, such as diesel, may enable the navigator to extend a trip and prepare for unanticipated conditions such as bad weather or accidents, thus improving the level of safety and enjoyment. Moreover, also due to the limited space on a watercraft, it is desirable to have a storing device that does not occupy too much space and that is easy to implement and access.
The current invention addresses such concerns by providing a watercraft utility harness that may be attached to the cables, especially the horizontal guardrail cables on a watercraft. Moreover, the utility harness introduced here may have broad usage aside from carrying supplies on a watercraft. With multiple advantageous designs in its attachment assembly and the materials used, the utility harness may be used in other environments as long as appropriate anchoring positions may be provided. In addition, the current invention provides the benefit of lightweight, portability, easy attachment, durability, and being inexpensive.
Some devices and systems have been developed for additional storage on a watercraft. These designs, however, show shortcomings in one aspect or another. For example, U.S. Pat. No. 4,756,455 discloses a utility saddlebag which has a top, sides, and ends and, of woven fabric attached together by seams of thread configured to cover the engine compartment enclosure of a jet-propelled watercraft. The saddlebag is held in place by the use of an elastic member sewn into a bead on the skirt or periphery of the device allowing it to be stretched over and held in place by tucking the ends under the edges of the housing. A number of pockets on the sides and on rear provide storage compartments, and strap assures closure on the sides. The invention provides storage for a watercraft, without any modification or alteration.
This design, however, requires the attachment of the saddlebag to the engine of the watercraft, making the usage of the saddlebag rather limited. Other various implements are also known in the art, but fail to address all of the problems solved by the invention described herein. The preferred embodiment of this invention is illustrated in the accompanying drawings and will be described in more detail herein below.
SUMMARY OF THE INVENTION
The present invention discloses a watercraft utility harness having a hanging piece and a utility pocket. The hanging piece has an upper edge, a front side and a back side. The utility pocket has a top opening, a front piece, a back piece, and side pieces. The back piece of the utility pocket is attached to the front side of the hanging piece. There are one or more front straps attached to the front side of the hanging piece and releasably connect to the front piece of the utility pocket. There is a back top flap having a top edge and a lower portion, the top edge being permanently attached to the back side of the hanging piece and the lower portion releasably attached to the back side of the hanging piece. Moreover, there are one or more back straps each having an upper point and a lower part, wherein the upper point is permanently attached to the back side of the hanging piece and the lower part of the first back strap is releasably connected to the back side of the hanging piece. When the front strap is connected to the front piece of the utility pocket, it partially covers the top opening of the utility pocket, preventing the items stored in the utility pocket from falling out.
The watercraft utility harness may be attached to the horizontal guardrail cables on a watercraft. In almost all the watercrafts, guardrail cables are used to serve as a fence at the edge of the watercraft and prevent accidental falling of persons or items into the water. The guardrail cables are attached to the guardrails and form horizontal barriers. The structure of the guardrails is generally robust and the guardrail cables are strong and well-positioned. These are the ideal places to hang extra supplies, especially when the proper devices like the utility harness introduced in the current invention are available.
In most occasions, there are two guardrails cables attached to the guardrails and these two cables are aligned horizontally parallel to the floor of the watercraft, with one cable positioned higher than the other. The back top flap of the hanging piece of the utility harness may embrace the upper guardrail cable when the lower portion of the back top flap is connected to the back of the hanging piece. Similarly, the back straps may embrace the lower guardrail cable when the lower parts of the back straps are connected to the back of the hanging piece. The back flap and back straps provide the support to hang the utility harness or at least anchor the utility harness by preventing it from falling down or tilting over. The two-guardrail-cable design is particularly suitable for the latter purpose. It should be noted that with proper selection of materials that make up the hanging piece and proper design for the thickness and robustness of the back flap and back straps, it is possible to hang the utility harness on a single guardrail cable. However, it is preferred to utilize both upper and lower guardrail cables to hang the utility harness.
The utility harness may be used to store anything. It is particular useful for the carrying and storing of watercraft supplies such as fuel, drinkable water, food stuffs, and safety devices. The specific design of the hanging piece and utility pocket may vary according to the type of watercraft and the items and substances that will be carried. For example, the utility harness may be designed specifically to carry fuel containers with a fixed size. The extra fuel may enable the user of the watercraft to prolong a trip and deal with unanticipated events such as bad weather and accidents.
The utility pocket may be used as a unitary structure, or it may be divided by separators into sub-pockets that may be individually useful for storing the same or different items. For example, two separators may be disposed in the utility pocket to divide it into three sub-pockets, with each sub-pocket being sized to carry a fuel container. The fuel container may have a handle and the front strap may be threaded under the handle before being attached to the front piece of the utility pocket, ensuring that the fuel container is firmly placed in each sub-pocket.
The hanging piece and utility pocket may be made from various kinds of materials. Preferably, the hanging piece and the utility pocket are made from lightweight materials that are robust and durable. Such a design not only improves the portability of the utility harness and makes the implementation particularly easy, but also ensures that the utility harness is safe, reliable, and may be used for a long period of time. In addition, it is preferable that the utility harness is made from waterproof and porous materials, preventing the accumulation of water in the utility pocket and preventing damping of the utility harness.
In general, the present invention succeeds in conferring the following, and others not mentioned, desirable and useful benefits and objectives.
It is an object of the present invention to provide a watercraft utility harness that is safe and easy to use.
It is another object of the present invention to provide a watercraft utility harness having multiple sub-pockets or compartments for storage.
It is another object of the present invention to provide a watercraft utility harness that may be easily attached to cables.
It is another object of the present invention to provide an embodiment of a watercraft utility harness that may be easily attached to the guardrail cables on a watercraft.
Yet another object of the present invention is to provide a watercraft utility harness that may be used to house one or more fuel containers.
Still another object of the present invention is to provide a watercraft utility harness that does not cause water accumulation.
It is another object of the present invention to provide a watercraft utility harness that is robust and durable.
Still another object of the present invention is to provide a watercraft utility harness that is inexpensive.
Still another object of the present invention is to provide watercraft utility harness having different sizes and dimensions to fit the needs for different watercrafts, different storing requirements and different conditions.
It is a further object of the invention to provide a watercraft utility harness that is easy to manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top back perspective view of a preferred embodiment of the watercraft utility harness when it is hung on the guardrail cables.
FIG. 2 shows a top front perspective view of a preferred embodiment of the watercraft utility harness when it is hung on the guardrail cables.
FIG. 3 shows a top front perspective view of a sub-pocket when a fuel container is stored therein.
FIG. 4 shows a top front perspective view of the details of a snap fastener assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will now be described with reference to the drawings. Identical elements in the various figures are identified, as far as possible, with the same reference numerals.
Reference will now be made in detail to embodiments of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto without deviating from the innovative concepts of the invention.
FIG. 1 shows a top back perspective view of a preferred embodiment of the watercraft utility harness when it is hung on the guardrail cables. Shown in FIG. 1 is the watercraft utility harness 1 comprising a hanging piece 10 and a utility pocket 20 ; the hanging piece 10 has a back side 18 and an upper edge 21 ; the utility pocket 20 has a back piece 25 and side pieces 22 . Also shown in FIG. 1 are the back top flap 90 having a top edge 93 and a lower portion 96 , the top edge 93 of the back top flap 90 being aligned with and permanently attached to the upper edge 21 of the hanging piece 10 and the lower portion 96 of the back top flap 90 being releasably attached to the back side 18 of the hanging piece 10 with a plurality of snap fastener assemblies 70 . In addition, FIG. 1 also shows a first back strap 100 , a second back strap 110 , and a third back strap 120 , each having an upper point 121 and a lower part 122 , the upper points 121 are permanently attached to the back side 18 of the hanging piece 10 and the lower parts 122 are releasably connected to the back side 18 of the hanging piece 10 with snap fastener assemblies 70 . For clarity purposes, not all snap fastener assemblies 70 are marked.
“Permanent attachment,” as used herein, refers to the type of attachments that may not be broken without damaging the integrity of the basic structures of the connecting mechanism or the parts being connected. On the other hand, a “releasable attachment” refers to an attachment that may be broken without the destruction of the connecting mechanism or the connected parts.
In FIG. 1 , the watercraft utility harness 1 is hung on guardrail cables comprising an upper guardrail cable 150 and a lower guardrail cable 160 . When the lower portion 96 of the back top flap 90 is connected to the back side 18 of the hanging piece 10 , the back top flap 90 and the hanging piece 10 embrace the upper guardrail cable 150 . Similarly, when the lower parts 122 of the back straps are releasably connected to the back side 18 of the hanging piece 10 , the back straps and the hanging piece 10 embrace the lower guardrail cable 160 . These structures provide the necessary forces that hang the watercraft utility harness 1 on the guardrail cables. At the very least, even if the watercraft utility harness 1 is not fully suspended, the hanging piece 10 , the back top flap 90 , and back straps anchor the watercraft utility harness 1 and prevent it from fall down or tilting over.
In addition to the back top flap 90 and the back straps, there are anchoring holes 125 on the hanging piece 10 , wherein attachment cords 180 may be used to thread through the anchoring holes 125 to provide more stability to the watercraft utility harness 1 . Preferably, the anchoring holes 125 are located on the corners of the hanging piece 10 , allowing easy access by the attachment cords 180 , which may be connected to the guardrails or other stable structures on the watercraft.
FIG. 2 shows a top front perspective view of a preferred embodiment of the watercraft utility harness when it is hung on the guardrail cables. Shown in FIG. 2 is the watercraft utility harness 1 having a hanging piece 10 and a utility pocket 20 , wherein the hanging piece 10 has an upper edge 21 and a front side 15 and the utility pocket 20 has a top opening 24 , a front piece 27 and side pieces 22 . Also shown in FIG. 2 are a first front strap 55 , a second front strap 60 , a third front strap 65 , with one end of the front straps being permanently attached to the front side 15 of the hanging piece 10 (not shown in FIG. 2 ) and the other end of the front straps being releasably attached to the front piece 27 of the utility pocket 20 with snap fastener assemblies 70 . For clarity purposes, not all snap fastener assemblies 70 are marked. Also shown in FIG. 2 are the upper guardrail cable 150 and the lower guardrail cable 160 being used to hang watercraft utility harness 1 , the anchoring holes 125 on the hanging piece 10 and the attachment cords 180 threaded through the anchoring holes 125 . The basic usages of such structures are discussed above in FIG. 1 .
In FIG. 2 , the utility pocket 20 is divided by a first separator 35 and a second separator 45 into three sub-pockets. The first separator 35 and the second separator 45 are disposed in the utility pocket 20 and are generally parallel to the side pieces 22 , dividing the utility pocket 20 into a first sub-pocket 30 , a second sub-pocket 40 , and a third sub-pocket 50 . Three fuel containers 200 are kept in the three sub-pockets. Each fuel container 200 has a handle 210 and the front straps thread under the handles 210 to connect to the front piece 27 , ensuring that the fuel containers are properly secured in the utility pocket 20 .
It should be noted that the utility pocket 20 does not necessarily have to be separated, nor is it paramount that the utility pocket 20 be divided into three sub-pockets. The utility pocket 20 may be a single pocket or it may be divided into two or more sub-pockets having similar or different sizes and locations. The compartmentalization of the utility pocket 20 may be adjusted according to the size and weight of the supplies to be carried, the durability of the guardrails and cables, and the actual necessities of the user.
The key function of the front straps is to prevent whatever that is stored in the utility pocket to fall out. The possible tumultuous environment a watercraft may encounter, such as storms and heavy rain, requires that some enclosing mechanism be employed to secure the storage in the utility pocket. However, the design shown in FIG. 2 is not the only possibility. The precise format of the enclosing mechanism may be altered according to the specific needs of the user and the likelihood of falling out. For example, a cover completely enclosing the top opening 24 of the utility pocket 10 may be used to ensure full closure.
In terms of materials, the hanging piece 10 and the utility pocket 20 may be made from the same or different materials. More particularly, the various components of the watercraft utility harness may be made from the same or different materials. The materials that may be used include but are not limited to: metal, rubber, and plastic such as, but not limited to, polyethylene (PE), high-density polyethylene, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyesters, vinyl, (HIPS) and polycarbonate (PC), mesh fabric, or paperboard coated with a suitable waterproof coating such as, but not limited to, polyethylene, or some combination thereof. The material is preferred to be safe, strong, flexible, and waterproof. Moreover, it would be desirable that the material is inexpensive and easy to manufacture.
It is preferred that the utility pocket 20 is made porous so that water does not accumulate in the utility pocket 20 . Due to waves, splashes, and rain, it is very likely that water may get access to the utility pocket 20 when the utility harness is installed on a watercraft. However, the accumulation of water may cause deterioration of the substances stored in the utility pocket 20 . Moreover, the accumulated water adds to the weight that needs to be sustained by the hanging piece, making it more likely to collapse. Therefore, it is preferred that the utility pocket 10 is made from porous material. The preferred material for the hanging piece and utility pocket is Phifertex® mesh fabrics.
The dimension of the utility harness may be adjusted according to the supplies being carried, the necessities of the user, and the actual conditions likely to be encountered. The variations for the dimensions of the components of the utility harness are almost limitless. As shown FIG. 1 and FIG. 2 , this particular preferred embodiment is designed to carry fuel containers. The width, height, and depth of the sub-pocket here may range from 1 to 100 inches (2.5-2500 cm), with the dimension of approximately 13×16×8 inches (33×40×20 cm). As shown in FIG. 2 , the fuel containers 200 have container handles 210 that are exposed. The front straps may be threaded under the container handles 210 to ensure that the containers are properly secured.
As to the size of the hanging piece 10 and the utility pocket 20 as a whole, there are also many variations. It is preferred that the width of the hanging piece 10 is similar to, but not smaller than the width of the utility pocket 20 . In the preferred embodiment, the width of the hanging piece 10 and the utility pocket 20 may range from 5-100 inches (12.5 to 1250 cm), with the preferred width to be approximately 50 inches (127 cm). The space between the back strap and the back flap is another essential dimension of the utility harness. In particular, it is preferred that the distance between the top edge 93 of the back flap 90 and the first point 121 of the back straps is similar to the distance between the top guardrail cable 150 and the bottom guardrail cable 160 . With such a design, both the back straps and back flap structures are put to use when the hanging piece is properly attached to the guardrail cables.
It should also be noted that although the preferred embodiment is designed to hang from guardrails cables on a watercraft, it is still possible that the utility harness introduced by the current invention may be hung on other structures on a watercraft. Moreover, it is also possible that the current invention be used in other settings not a watercraft. As long as the key structures are the same, the use of the utility harness may vary according to the user's needs.
FIG. 3 shows a top front perspective view of a sub-pocket when a fuel container is stored therein. Shown in FIG. 3 are the second sub-pocket 40 , the first separator 35 , the second front strap 60 , the front piece 27 of the utility pocket 20 , the snap fastener assembly 70 , and the fuel container 200 having a handle 210 , the fuel container 200 being stored in the second sub-pocket 40 . FIG. 3 provides a more detailed depiction of how the fuel container 200 is being secured in the utility pocket 20 .
FIG. 4 shows a top front perspective view of the details of a snap fastener assembly 70 . The snap fastener assembly 70 shown here is just one of the possible ways to releasably attach the front straps to the front piece 27 of the utility pocket 20 . It is also one of the many possible options to releasably attach the lower part 93 of the back flap 90 to the back side 18 of the hanging piece 10 . Similarly, it is one of the options to releasably attach the second point 122 of the front straps to the front piece 27 of the utility pocket 20 . Other possible options include but are not limited to: cross snaps, rivets, magnets, and hook-and-loop structures. Here in FIG. 4 the example demonstrates the snap fastener assembly 70 used to attach the second front strap 60 to the front piece 27 .
As shown in FIG. 4 , the snap fastener assembly 70 comprises an oval ring 85 encircling an oval opening 80 , the oval ring 85 and the oval opening 80 are located on the second front strap 60 (not shown in FIG. 4 ). The snap fastener assembly 70 further comprises a fastening fin 75 rotatably disposed on a base platform 72 , the base platform 72 being secured to the front piece 27 (not shown in FIG. 4 ). The length of the fastening fin 75 is shorter than the long diameter of the oval opening 80 but longer than the shorter diameter of the oval opening 80 . Thus, the fastening fin 75 may be inserted through the oval opening 80 when the fastening fin 75 is aligned with the longer diameter of the oval opening. After insertion, the fastening fin 75 may be rotated to secure the fastening fin 75 on the oval ring 85 .
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.
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A watercraft utility harness having a hanging piece and a utility pocket attached to the hanging piece. Separators may be disposed in the utility pocket to divide the utility pocket into sub-pockets that may house necessary items. There are attachment straps and flaps on the back of the hanging piece, allowing the watercraft utility harness to be hung on watercraft guardrail cords. There are front straps on the front side of the utility harness, preventing the items stored in the utility pocket from falling out. The utility harness is particularly suitable to store fuel containers and provide backup fuel supply for the watercraft. The utility pockets and sub-pockets may be sized specifically for this purpose.
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This is a continuation of application Ser. No. 190,608 filed Sept. 25, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an electronic keyboard musical instrument capable of inputting rhythmic patterns by keyboard operation.
In a conventional electronic keyboard musical instrument such as an electronic organ, a plurality of rhythmic patterns are stored in advance for rhythmic performance. By suitably operating a selection switch, a desired rhythmic pattern among the stored patterns is specified to be read out for rhythmic performance.
The rhythmic patterns which are commonly stored are waltz, rock, march, rhumba, beguine and so on.
However, the electronic organ of this type is defective in that the kind and number of rhythmic patterns available are limited. Therefore, the performance becomes very monotonous.
Recently, rhythm boxes and rhythm machines have been proposed in which a rhythmic pattern is stored by an input operation of the performer, so that the rhythmic performance is effected based on the set rhythmic pattern.
In this case, the input operation is effected by turning on or off predetermined switches by fingers or foot. However, the device for this is separated from the electronic musical instrument. As a result they require more space for installation. Since the device is separated from the electronic musical instrument, synchronous performance therewith has been generally difficult. Synchronism between the keyboard performance and the rhythmic performance has been difficult.
The present invention has been made to overcome these problems and has for its object to provide an electronic keyboard musical instrument which enables a performer to input a rhythmic pattern by keyboard operation.
SUMMARY OF THE INVENTION
To the above and other ends, the present invention provides an electronic keyboard musical instrument comprising a keyboard; a mode changeover switch for changing over between setting of rhythmic patterns and general performance, each key of the keyboard being changed over between a setting for general performance and a setting for inputting of rhythmic pattern; a memory in which a rhythmic pattern is set by manipulation of predetermined keys of the keyboard when the mode is set by the changeover switch for setting rhythmic patterns; and a percussive sound generating circuit for generating percussine sounds based on the rhythmic patterns set in the memory.
With an electronic keyboard musical instrument of the present invention, it is possible for a performer to set desired rhythmic patterns in an internal memory circuit for providing a desired rhythm with an extremely simple input operation using keys of the keyboard. It is advantageous in that it does not require an additional device separate from the musical instrument since the rhythmic pattern is set in the memory circuit inside the electronic keyboard musical instrument itself. Further, rhythmic performance of various patterns is possible since the operation may be effected in cooperation with various switches of the electronic keyboard musical instrument. Further, the desired rhythm may be used in combination with a rhythmic pattern set in advance in the electronic keyboard musical instrument. For example, rhythms based on a rhythmic pattern set by the manual operation of a performer may be utilized as fill-in rhythms.
BRIEF DESCRIPTION OF THE Drawings
FIG. 1 is a perspective view illustrating the outer appearance of an electronic organ in accordance with the present invention;
FIG. 2 shows a circuit block diagram of the electronic organ shown in FIG. 1;
FIG. 3 is a view showing the correspondence of respective keys of the manual keyboard with the rhythm instrument and the function of the key C2 of a pedal;
FIGS. 4A to 4C are views illustrating the successive input operation for setting the rhythmic pattern in memories M1 to M3; and
FIGS. 5A to 5C are views illustrating the manner in which percussive sounds such as the sounds of cymbals, snare-drums, and bass-drums are outputted according to the rhythmic patterns set as in FIGS. 4A to 4C.
DETAILED DESCRIPTION
An embodiment of the present invention as applied to an electronic organ will be described referring to the accompanying drawings. In FIG. 1, an electronic organ 1 comprises support legs 2, a machine body 3 supported by these support legs 2, and a pedal keyboard 4 electrically connected to the machine body 3 through a cable 5. A manual keyboard 6, a music stand 7, an operation unit 8, and a loud-speaker 9 are arranged on the machine body 3 as shown in the figure. The manual keyboard 6 has 49 keys from tones C1 to C6 for normal performance. Twelve keys of tones C2 to B2 correspond to rhythmic instruments of 12 kinds such as bass-drums, snare-drums, guiro and so on as shown in FIG. 3, and are used to store in a memory desired rhythmic patterns of a rhythmic instrument by operating these keys. The correspondence between the keys of the tones C2 to B2 and each rhythmic instrument indicated by symbols is displayed on the music stand 7 as shown in FIG. 1. The pedal keyboard 4 has 13 keys of tones C3 to C2. The key of the tone C2 is used for inputting timing for the rhythmic patterns of the keys of the tones C2 to B2. In this case, a tempo lamp 10 disposed on the music stand 7 is lit at the start of every measure, according to the tempo set by a tempo setting knob 11 disposed on the operation unit 8. Tempo sounds are thus produced from the loud-speaker 9. The operation of the key of the tone C2 of the pedal keyboard 4 while confirming the timing with the flashing of the lamp 10 and the tempo sounds are thus enabled.
In addition to the tempo setting knob 11, on the operation unit 8 are disposed a power source switch 12, a start/stop switch 13, a volume switch 14, a tone color setting knob 15, a mode changeover switch 16, and a memory changeover switch 17. The start/stop switch 13 starts or interrupts the rhythmic performance to be described hereinafter. The mode changeover switch 16 sets the electronic organ 1 to either the performing mode or the rhythmic pattern inputting mode. The memory changeover switch 17 specifies one of three memories M1, M2 and M3 (Random access memory, RAM) to be described hereinafter, when inputting the rhythmic patterns.
The circuit construction will be described referring to FIG. 2. The key operation signals of the respective keys of the pedal keyboard 4 and the manual keyboard 6 are inputted to a switching circuit 20. The mode changeover signals are inputted by the mode changeover switch 16 to the switching circuit 20. When the mode chageover switch 16 is changed over to the performing mode, the switching circuit 20 sends the key operation signals to a tone generating unit 21. When the mode chageover switch 16 is changed over to the rhythmic pattern inputting mode, the switching circuit 20 transmits the key operation signals to a memory control circuit 22. The tone generating unit 21 is a circuit for generating a tone corresponding to the inputted key operation signal, and it outputs a tone waveform signal and an envelope control signal corresponding to each of the keys of the tones C3 to C2 of the pedal keyboard 4 and each of the keys of the tones C2 to C6 of the manual keyboard 6. The memory control circuit 22 is a circuit for controlling the reading and writing of rhythmic patterns in three memories M1, M2 and M3 (the data stored in these memories may be simultaneously read out, so that a complex rhythmic pattern may be inputted while dividing it into parts) which freely read and write the data. To the memory control circuit 22 are inputted a rhythm start/stop signal from the start/stop switch 13, a memory chageover signal from the memory changeover switch 17, and a tempo signal from a tempo signal generating unit 23. For storing a rhythmic pattern in the memories M1 to M3, one of the memories M1 to M3 is specified by the memory changeover signal; a writing command is outputted to the memories M1 to M3; and the key operation signals of the keys of the tones C2 to B2 of the manual keyboard 6 are inputted with the timing of the key operation of the tone C2 of the pedal keyboard 4 to a specified storage area within the specified memory of the memories M1 to M3 through the switching circuit 20 and the memory control circuit 22, for storing a desired rhythmic pattern. On the other hand, for reading out the rhythmic pattern data from the memories M1 to M3, a reading command is outputted to the memories M1 to M3, and rhythmic pattern data are simultaneously read out from the memories M1 to M3 to be transmitted to a rhythm source percussive sound generating means or 24 when the rhythmic start/stop signal is set to "start".
In addition to the mode changeover signal, a tempo setting signal is inputted to the tempo signal generator 23. The tempo signal generator 23 outputs to the memory control circuit 22, a tempo signal corresponding to the tempo setting signal, it flashes the lamp 10 at the start of every measure, and produces a tempo sound from the loud-speaker 9 in synchronism therewith. Reading and writing of the rhythmic patterns from and in the memories M1 to M3 are performed at a speed controlled by the tempo signal.
The percussive sound generating means or rhythm source 24 generates rhythmic sound signals of 12 kinds in response to the rhythmic pattern data. The rhythmic sound signal generated by the rhythm source 24 are inputted to a mixer 27. To the mixer 27 are further inputted a tempo signal, and a tone waveform signal provided with an envelope at a multiplying circuit 25 and converted into an analog signal at a digital/analog (D/A) converter 26. The mixer 27 mixes these three kinds of signals inputted as needed, and its output is amplified by an amplifier 28 and sounded at the loud-speaker 9.
The operation of the above embodiment will be described. For performing music by operating the keys, the power source switch 12 is turned on and the mode changeover switch 16 is operated to set the electronic organ 1 to the performing mode. When the keys of the pedal keyboard 4 and the manual keyboard 6 are operated, key operation signals are transmitted to the tone generating unit 21 through the switching circuit 20. The tone generating unit 21 outputs a tone waveform signal and an envelope control signal corresponding to the inputted key operation signal. The tone waveform signal is multiplied with the envelope control signal by the multiplying circuit 25, converted into an analog signal by the D/A converter 26, amplified by the amplifier 28 through the mixer 27, and sounded by the loud-speaker 9.
The operation for setting a rhythmic pattern in the memories M1 to M3 will be described with reference to FIGS. 4A to 4C. The mode changeover switch 16 is operated for setting the mode to the rhythmic pattern inputting mode. The memory M1, for example, is specified by the memory changeover switch 17 and the tempo setting knob 11 is operated for setting a desired tempo. Then, according to the set tempo, the lamp 10 is lit, a tempo sound is produced by the loud-speaker 9, a tempo signal (clock pulse) is transmitted as a time measuring data to the memory control circuit 22 in synchronism with the tempo sound and so on. The rhythmic pattern data with sounds of a cymbal and a snare-drum is inputted in the memory M1 as shown in FIG. 4A. According to the tempo sound and the lighting of the lamp 10, the inputting operation of the first measure is initiated. First, the key of the tone D2# in the manual keyboard 6 corresponding to the cymbal is depressed, and the key of the tone C2 of the pedal keyboard 4 is operated for inputting the timing. The operation signals of the keys of the tones D2# and C2 are transmitted to the memory control circuit 22 through the switching circuit 20. By the control operation of the memory control circuit 22, data specifying cymbal and data specifying the duration of the cymbal sound from the starting point are stored in the first storage area of the memory M1. At the second beat, the key of the tone C2# in the manual keyboard 6 corresponding to the snare-drum is operated, and the timing is inputted by the key of the tone C2 of the pedal keyboard 4. Then in a similar manner as described above, under the control of the memory control circuit 22, data specifying the snare-drum and data specifying the duration from the preceding cymbal sound to the snare-drum sound are stored in the next storage area of the memory M1. In the third beat, similarly as in the case of the second beat, data specifying the snare-drum is stored in the above-mentioned storage area of the memory M1. Then, when the lamp 10 is lit again and a tempo sound is produced, by the same key operation as in the first beat of the first measure, the data of the cymbal sound is written in the memory M1. The same key operation is performed at the second and third beats as in the second and third beats of the first measure, and the data of the snare-drum is written in the memory M1.
The desired rythmic pattern data of the cymbal and the snare-drum is stored in the memory M1 by the desired key operation for the third and succeeding measures.
When the setting of the rhythmic pattern in the memory M1 is terminated, the memory changeover switch 17 is changed over to the memory M2, and the rhythmic pattern data of, for example, a bass-drum is stored in the corresponding storage area of the memory M2 as shown in FIG. 4B. For this purpose, at the first beat of each measure, the key of the tone C2 of the manual keyboard 6 corresponding to the bass-drum and the key of the tone C2 of the pedal keyboard 4 for inputting the tempo are operated. Then, the memory changeover switch 17 is changed over to the memory M3 as needed, and a desired rhythmic pattern data of other rhythmic instruments is inputted to the memory M3 in a similar manner. In the case of the embodiment described, no data is inputted in the memory M3 as shown in FIG. 4C. The rhythmic performance utilizing the rhythmic patterns set in the memories M1 to M3 will be described. The mode changeover switch 16 is operated for setting the electronic organ 1 to the performing mode, and the tempo setting knob 11 is operated for setting the desired tempo. A tempo signal (clock pulse) is transmitted from the tempo signal generator 23 to the memory control circuit 22. Production of sounds will be performed according to this tempo.
The rhythm start/stop switch 13 is operated to output a "start" signal which is transmitted to the memory control circuit 22, and output of a reading command to all of the memories M1 to M3 is initiated. Thus, after the "start" signal has been outputted, the rhythmic pattern data of the cymbal, the bass-drum, and the snare-drum is read out from the memories M1 to M3 in synchronism with the start of the next measure, to be supplied to the rhythm source 24. Consequently, the rhythm source 24 is operated in response to the inputted rhythmic pattern data, and the output of the source 24 is supplied to the mixer 27. Thus, the tones of the combination of the melody and chord accompaniment which are manually performed and the rhythmic sounds according to the rhythmic pattern data read out from the memories M1 to M3 are produced from the loud-speaker 9. FIGS. 5A to 5C show the condition of the rhythmic performance in this case. FIG. 5A shows the output timing of the cymbal; FIG. 5B, of the snare-drum; and FIG. 5C, of the bass-drum. For stopping the rhythmic performance, the rhythm start/stop switch 13 is operated again to output a "stop" signal which is transmitted to the memory control circuit 22 for stopping the production of the rhythm sounds.
The present invention is not limited to the particular embodiment described above. For example, areas of the memories M1 to M3 may be arranged in correspondence with two continuous measures so that the rhythmic performance may be performed by reading out the rhythmic patterns of these two measures in repetition.
For setting the rhythmic pattern in the memories M1 to M3, the input rhythmic pattern may be read out under the control of the memory control circuit 22, and the new rhythmic pattern may be superposed on it while listening to the rhythm sounds based on the rhythmic pattern read out.
Although the key of the tone C2 of the pedal keyboard is the key for inputting timing in the above embodiment, the timing of the operated keys C2 to B2 for specifying the rhythm source may be stored as a sound generating timing.
A rhythm source other than the rhythm source shown in the above embodiment may be similarly used. The kind and number of rhythmic instruments may arbitrarily be selected.
A plurality of rhythmic patterns may be set permanently in an ROM (Read Only Memory) or the like for combination with the rhythmic pattern set by the performer for still better effects. In this case, the rhythmic pattern set by the performer may be used as a fill-in rhythmic pattern. In addition, a plurality of sets of rhythmic patterns may be set, and a desired rhythmic pattern may be selected for rhythmic performance. It is further possible, by the addition of a simple circuit, to automatically start the set rhythmic performance in synchronism with the manual performance or to automatically perform rhythmic accompaniment in synchronism with the chord output.
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An electronic keyboard musical instrument is capable of inputting rhythmic patterns by setting desired rhythmic patterns in memory circuits using the keys of keyboards. The set rhythmic patterns operate a rhythm source circuit when read out from the memory circuits during performance and thereby output rhythm sounds.
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INTRODUCTION
This invention relates to anodized aluminum articles and more particularly to anodizing aluminum to provide a surface for adhesive bonding.
In U.S. Pat. Nos. 4,127,451 and 4,085,012, there is disclosed a method of preparing an adhesive bond wherein an aluminum article is anodized in phosphoric acid and then bonded to join aluminum articles together. Anodizing time can be as high as 30 minutes. U.S. Pat. No. 4,127,451 discloses a method for forming a honeycomb structure using aluminum foil which is anodized in phosphoric acid, then primed, cured before an adhesive is applied, cured and formed into a honeycomb structure.
Japanese Patent Publication 83006639 discloses a production method for a printing plate in which an aluminum alloy is anodized using an electrolyte containing phosphorous acid.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a new process for adhesively bonding aluminum members.
It is another object of the present invention to provide a new anodizing process as a pretreatment for adhesively joining aluminum components.
Yet it is another object of the present invention to provide a new surface treatment on aluminum for adhesive bonding purposes.
A further object of the present invention is to provide an adhesively bonded aluminum structure or article employing a new finish or anodic coating on the aluminum structure.
These and other objects will be apparent from the specification, drawings and claims appended hereto.
In accordance with these objects, there is provided an article and a process for making an article comprised of adhesively bonded aluminum, the process comprising the steps of anodizing an aluminum alloy member surface in a phosphorous acid (H 3 PO 3 ) electrolyte to form an anodic coating on said surface, the coating suitable for providing a high strength environmentally stable adhesive bond and capable of being formed in the electrolyte in two minutes or less. An adhesive is applied to the anodized surface for bonding to another surface to form the article.
FIGS. 1a and 1b show graphs comparing phosphorous acid anodizing to other treatments to 7075-T6 aluminum alloy for adhesive bonding.
FIGS. 2a and 2b show graphs comparing phosphorous acid anodizing to other treatments to 2024-T3 aluminum alloy for adhesive bonding.
FIGS. 3a and 3b show graphs comparing phosphorous acid anodizing, with subsequent priming, to 2024-T3 aluminum alloy for adhesive bonding.
FIGS. 4a and 4b show the effect of anodizing time in phosphorous acid on the strength and stability of adhesive joints.
FIG. 5 shows a graph comparing the stability of phosphorous acid formed using adhesive bonds and phosphoric acid anodized substrates, which substrates were anodized under potentiostatic conditions with all treatment variables equivalent.
FIG. 6 shows a graph comparing the stability of adhesive bonds formed using phosphorous acid anodized and phosphoric acid anodized surfaces, which surfaces were anodized under galvanostatic conditions in solutions with the same conductivities and all treatment variables equivalent.
FIGS. 7a-c transmission electron micrographs of an anodic oxide film formed in phosphoric acid in 2 minutes and 20 minutes and the film formed in phosphorous acid in two minutes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, aluminum articles to be prepared for bonding may be first vapor degreased and then subjected to an alkaline or acid cleaner. This may be followed by a deoxidizing treatment with appropriate rinsing in between the steps.
The aluminum article is then subjected to an anodizing treatment in an electrolyte containing phosphorous acid (H 3 PO 3 ). The electrolyte preferably is comprised of water and phosphorous acid (H 3 PO 3 ). The electrolyte can contain from 1 to 30 wt. % H 3 PO 3 acid, preferably 5 to 15 wt. % H 3 PO 3 acid. During anodizing, the electrolyte should be kept at a temperature in the range of 3° to 60° C. Anodization can be carried out in a time period of about 0.1 to 60 minutes. Preferred time periods for anodization range from about 0.75 to 5 minutes with typical times being about 1 to 3 minutes.
The anodization can be carried out at a current density of 0.5 to 50 mA/cm 2 and preferably 1 to 10 mA/cm 2 . While direct current is preferred, alternating or pulsed current or combinations of AC/DC may be used. The voltage for anodizing should be maintained in the range of 2 to 100 V and preferably 5 to 40 V. Further, a continuous method or a batch method may be used in anodizing. One of the advantages of the present system resides in the very short anodizing times required to produce an anodic coating which has equal or superior bonding properties when compared to conventional anodizing approaches in phosphoric acid (H 3 PO 4 ) or chromic acid. After anodizing, the anodized surface may be rinsed free of electrolyte.
The anodic film produced in accordance with the present invention can have a thickness in the range of 10 nm to 10 μm and a density in the range of 2.5 to 3.2 gms/cc. Although the cell and pore geometry of coatings formed anodically in phosphorous acid at 23° C. is comparable to that of coatings formed in phosphoric acid (FIG. 7), there are significant differences in the atomic arrangement or coordination. Nuclear Magnetic Resonance (NMR) measurements show that the coordination number of aluminum bonded to phosphorus through oxygen (Al-O-P) in the oxide layer is four and six in phosphoric acid formed coatings, while a coordination number of four predominates for Al-O-P in phosphorous acid formed films. The Al-O-Al coordination is predominantly octahedral (sixfold) in both phosphoric and phosphorous acid formed anodic oxides, with about 20% tetrahedral coordination of Al-O-Al in phosphorous acid coatings vs. only 10% in phosphoric acid coatings. The coordination number of an atom or ion in a lattice is the number of near neighbors to that atom or ion.
In the instant invention, the anodized article may be primed or the adhesive may be applied directly to the anodized finish. A primer is selected according to the adhesive used in the bonding process. A suitable epoxy primer is available from American Cyanamide Corporation under the designation BR127 and requires a 250° F. cure.
An adhesive such as an epoxy acrylic, phenolic polysulfone or polyimide resin can be applied either to the cured primer or to the anodized articles. A suitable adhesive is available, e.g., from 3M Corporation under the designation AF163. After application of the adhesive to aluminum articles, they are arranged in a composite arrangement and the joint held firmly and cured or permitted to set at the designated temperature to provide for the proper bond between the articles. By setting or set as used herein is meant the bonding of the adhesive to anodized coating where a thermosetting or thermoplastic adhesive or mixtures thereof are used. Cure as used herein can include cooling of thermoplastic to permit it to harden and bonding thereof.
Alloys which may be joined or bonded together in this manner include AA1000, AA2000, AA5000, AA6000 or AA7000 series alloys, e.g., AA2024, AA6061 or AA7075, although most aluminum alloys, including clad alloys which can be anodized in phosphorous acid (H 3 PO 3 ) , can be used. Further, other metallic, polymeric or ceramic materials may be joined to the aluminum article with an appropriate adhesive.
Joints formed in this manner have been found to have a high level of stability in high temperature humidity tests according to ASTM 3762-79 (wedge test), as shown in FIGS. 1-6. The crack extension for joints formed in phosphorous acid is consistently as low as or lower than for joints formed from aluminum treated with more time consuming treatments in other electrolytes. Minimal crack growth in the wedge test is an indication of good environmental stability.
In another aspect of the invention, aluminum sheet processed or anodized in accordance with the invention can be used in laminates of sheet metal and polymer or adhesive with or without fiber reinforcement. That is, two, three, four or more sheets of aluminum may be bonded together with an adhesive. The adhesive may or may not have reinforcing fibers embedded or dispersed therein. The aluminum sheet is treated and anodized as disclosed herein. After rinsing and drying, an adhesive or a prepreg consisting of a film adhesive containing reinforcing fibers may be applied to one side of the sheet and the second anodized sheet placed on top thereof. Several layers may be set up in this way as desired. Thereafter, layers are pressed together firmly and cured to form a bonded laminate having outstanding fatigue properties and hydrothermal stability.
While reference has been made herein to individual layers of adhesive and reinforcing media, it will be appreciated that the fibers may be discontinuous and dispersed in the adhesive or the reinforcing fabric may be impregnated with adhesive. Further, the adhesive may be of the thermoplastic or thermosetting type. Further, a laminate may be formed having a single metal sheet having both sides coated with a polymer with or without fibers.
Any alloy product may be pretreated and adhesively bonded in this manner. However, the alloy may be selected depending on the application. For aircraft use, AA7000 series or AA2000 series may be used. For example, AA7075, AA7475, AA2024 or AA2090 may be used to provide high strength structural joints and laminates. The alloy may be provided in plate, sheet, castings or extrusions, for example. The use of sheet herein is intended to include foils (thickness from 5 to 250 μm, for example) and a laminate which may include a single metal sheet with a polymer layer on each side.
Fibers which may be used in the laminate include glass, carbon, graphite, boron, steel, titanium carbide and the like. Fibers such as homo- or copolymers of aramids are particularly suitable, more particularly, poly-paraphenylene terephthalamide, or of aromatic polyamide hydrazides or fully aromatic polyesters are suitable. The amount of fiber in the adhesive layer can range from 1 to 80, preferably 40 to 60, wt. %, based on the weight of both components. It is preferred that the adhesive/fiber layer in the laminate be thinner than the metal sheet thickness.
The adhesive may be of thermoplastic or thermosetting type as noted herein. Adhesives that are suitable for use in the laminates include, e.g., AF163 epoxy adhesive and XA-3498 epoxy adhesive available from 3M.
For making a pre-stressed product, the laminate is stretched an amount greater than the specific elastic elongation of the aluminum sheet and less than the specific break elongation of the fibers and the aluminum sheets. Typically, a 0.01 to 5% stretch is suitable. The fibers may be stretched prior to curing the adhesive such that after curing the aluminum sheet is in compression stress and the fibers remain in tensile stress. Fibers which respond to the stretching condition include aramids. Pre-stressing is disclosed in U.S. Pat. No. 4,489,123, incorporated herein by reference.
Laminates in accordance with the invention are suitable for use in aircraft application such as wing panels or where there is required high fatigue properties. Further, adhesively bonded articles in accordance with the invention are suitable for applications such as vehicular uses where high strength bonding is necessary. By vehicular is meant to include all automotive applications, including body panels and frame components, and refers also to automobiles, bicycles, motorcycles, trucks, off-road vehicles, transport vehicles, as well as boats, ships, aircraft and spacecraft applications, such as rockets, missiles and the like.
EXAMPLE 1
Adhesive bonding data comparing different surface preparation techniques are shown in FIGS. 1a and 1b. All samples were prepared for anodizing as follows: Unclad AA7075-T6 was machined to appropriate dimensions for the lap shear test (ASTM D-1002) and for the wedge test (ASTM D-3762-79). The surfaces were vapor degreased by exposure to the vapors of trichloroethylene for 5 minutes at 87° C. Upon cooling, the surfaces were then etched in a non-chromate acidic bath for 1.5 minutes at 23° C. After acid etching, the aluminum surfaces were rinsed with flowing tap water for 30 seconds to remove residual etchant, dried at 50° C., divided into four groups and anodized as follows: One quarter of the samples were anodized at 10 V in 10% (w/w) phosphoric acid solution for 20 minutes at 23° C. (A, FIG. 1a, A', FIG. 1b). One quarter of the samples were anodized at 6.5 mA/cm 2 in 10% (w/w/) phosphoric acid solution for 2 minutes at 23° C. (B, FIG. 1a, B', FIG. 1b). One quarter of the samples were anodized at 20 V in 10% (w/w) phosphorous acid (H 3 PO 3 ) solution for 2 minutes at 23° C. (C, FIG. 1a, C', FIG. 1b). One quarter of the samples were anodized in 0.5M chromic acid solution at 38° C. using a step voltage schedule which consists of anodizing at 4 V for 2 minutes then increasing the voltage 4 V/min to 40 V, holding at 40 V for 20 minutes, increasing to 42 V for 2 minutes, then increasing 2 V/min to 50 V, and holding at 50 V for 5 minutes (D, FIG. 1a, D', FIG. 1b).
All anodized samples were rinsed for 30 seconds in flowing deionized water and dried at 50° C. The samples were then assembled, within 24 hours of anodization, using AF163 epoxy resin film adhesive manufactured by Minnesota Mining and Manufacturing Company. This adhesive is typically used for aerospace applications. The adhesive bondline thickness of the lap shear specimens was controlled at 0.51 mm using a lap shear bonding fixture. The lap shear assemblies were cured in the lap shear fixture at 121° C. for 1 hour. Breaking strength was determined on an Instron Model 1127 equipped with a 222.4 KN load cell, using a cross-head speed of 1.27 cm/min.
The adhesive bondline thickness of the wedge test assemblies was controlled at 0.38 mm using stainless steel shims. The assemblies were cured in a platen press for 1 hour at 121° C. with 310.3 KPa pressure and then cut into 2.54 cm wide specimens. Thereafter, the specimens were cracked according to ASTM D-3762-79, the initial crack length was marked, and the specimens then were placed in condensing humidity at 52° C. Crack progression in the humidity chamber was checked periodically.
The lap shear data of FIG. 1a show that the 2 minute anodization in phosphorous acid results in bonded joints with strengths equivalent to joints assembled from samples anodized by a 20 minute phosphoric acid process or a 40 minute chromic acid process.
Furthermore, the wedge test data of FIG. 1b show that the joints assembled from substrates which were anodized for 2 minutes in phosphorous acid (H 3 PO 3 ) exhibited the smallest crack extension (<3 mm) of all the assemblies studied. Minimal crack extension is an indication of good joint hydrothermal stability. Joints formed from the 20 minute phosphoric acid anodization had the next best hydrothermal performance whereas the 2 minute phosphoric acid anodization and the 40 minute chromic acid anodization provided joints with inferior hydrothermal durability.
EXAMPLE 2
The example is similar to Example 1 except that unclad 2024-T3 was used. Furthermore, the acid etch used prior to anodization consisted of 50 g/L chromic trioxide and 250 g/L of 95% (w/w) sulfuric acid. The samples were etched at 63° C. for 14 minutes. Furthermore, phosphorous acid (H 3 PO 3 ) anodization of 2024-T3 alloy was done at 10 V, as opposed to 20 V, used for 7075-T6.
The lap shear data of FIG. 2a show that joints formed from substrates anodized for 2 minutes in phosphorous acid (H 3 PO 3 ) solution (G) had significantly superior strength compared with the 20 minute phosphoric acid (E) anodization and the 40 minute chromic acid anodization (H). While the strength of the joints formed from substrates anodized for 2 minutes in phosphoric acid (F) approached that of the phosphorous acid anodized joints, the variability in strength for the 2 minute phosphoric acid anodized joints was unacceptable.
The wedge test data of FIG. 2b show that there is no significant difference in crack extension, and therefore, hydrothermal durability for joints formed from substrates anodized for 2 minutes in phosphorous acid (H'), 20 minutes in phosphoric acid (E'), or 40 minutes in chromic acid (H'). Anodizing unclad 2024-T3 for 2 minutes in phosphoric acid (F') yields joints with significantly inferior hydrothermal durability.
EXAMPLE 3
This examples is similar to Example 2 except that after anodizing and drying, and prior to bonding, the samples were primed with a 5 μm thick coating of BR127, an epoxy-modified phenolic primer manufactured by American Cyanamide.
The lap shear data of FIG. 3a show that the 2 minute phosphorous acid anodization (K) yielded joints with the highest lap shear breaking strength (44 MPa). The joints formed for substrates anodized in the other acids had slightly lower strengths (40-42 MPa) I, J and L, 20 min, H 3 PO 4 , 2 min., H 3 PO 4 , 40 min, CrO 3 , respectively. It was noted that priming had a significant positive effect on the lap shear breaking strength of joints formed from substrates treated in phosphoric and chromic acid. The effect was to raise the strengths closer the strength of joints with phosphorous acid anodized substrates. Priming had no effect on the strength of joints formed with phosphorous acid anodized substrates.
The wedge test data for joints formed from anodized and primed substrates (FIG. 3b) show that there is a slight improvement in joint hydrothermal durability as a result of priming, and that there is no significant difference in the performance of joints anodized for 2 minutes in phosphorous acid (K') or 20 minutes in phosphoric acid (I'). The 40 minute chromic acid (C') anodizing and the 2 minute phosphoric acid (J') anodizing were shown to be inferior with respect to enhancing joint hydrothermal stability.
EXAMPLE 4
In this example, all substrates were anodized in phosphorous acid solution, and the time of anodization was either 0.5 (P'), 1 (M or M'), 2 (N or N'), S (O or O') or 10 minutes.
The lap shear data of FIG. 4a show that optimum joint strength is achieved at a 2 minute anodization in phosphorous acid.
The wedge test data of FIG. 4b show that a 2 minute anodization in phosphorous acid (N') is an optimal time of anodization for providing good hydrothermal durability to an adhesive joint.
EXAMPLE 5
In this example, specimens were prepared as follows: Unclad aluminum alloy 6061-T6 was machined to appropriate dimensions for the wedge test (ASTM D-3762-79). The surfaces were vapor degreased by exposure to the vapors of trichloroethylene for 5 minutes at 87° C. Upon cooling, the surfaces were then etched in an acidic bath for 1.5 minutes at 23° C. After acid etching, the aluminum surfaces were rinsed with flowing tap water for 30 seconds to remove residual etchant, dried at 50° C. and divided into two groups and then anodized as follows: One half of the samples were anodized at 20 V in 10% (w/w) phosphoric acid solution for 2 minutes at 23° C. One half of the samples were anodized at 20 V in 10% (w/w) phosphorous acid (R and T) (H 3 PO 3 ) solution for (S and U) 2 minutes at 23° C. All anodized samples were rinsed for 30 seconds in flowing deionized water and dried at 50° C. One half of each acid anodized samples were then assembled, within 24 hours of anodization, using AF163 epoxy resin film adhesive manufactured by Minnesota Mining and Manufacturing Company. Curing conditions were the same as for Example 1. The other half of each acid anodized samples were assembled using an epoxy paste adhesive, XA-3498, an experimental adhesive manufactured by Minnesota Mining and Manufacturing Company. This adhesive is intended for automotive applications. Bondline thickness was controlled as in Example 1. The XA-3498 wedge test assemblies were cured in a platen press at 149° C. for 30 minutes with 22.24 KN applied force.
FIG. 5 shows wedge test data for joints assembled from substrates receiving a 2 minute, 20 V phosphoric acid anodization, and from substrates receiving a 2 minutes, 20 V phosphorous acid anodization. The joints formed from substrates receiving the phosphorous acid anodization exhibited superior hydrothermal durability as compared with joints formed from substrates receiving the phosphoric acid anodization. The better performance of the phosphorous acid anodized joints was observed for both the aerospace epoxy film adhesive, and the automotive epoxy paste adhesive.
EXAMPLE 6
In this example, specimens were prepared as follows: Unclad aluminum alloy 2024-T3 was machined to appropriate dimensions for the wedge test (ASTM D-3762-79). The surfaces were vapor degreased by exposure to the vapors of trichloroethylene for 5 minutes at 87° C. Upon cooling, the surfaces were then etched in a solution consisting of 50 g/L chromic trioxide and 250 g/L of 95% (w/w) sulfuric acid at 63° C. for 14 minutes. After acid etching, the aluminum surfaces were rinsed with flowing tap water for 30 seconds to remove residual etchant, dried at 50° C., then divided into two groups and anodized as follows: One half of the samples were anodized at a current density of 7 mA/cm 2 in phosphoric acid solution having a conductivity of 103.6 mS for 5 minutes at 23° C. The remaining samples were anodized at a current density of 7 mA/cm 2 in phosphorous acid solution having a conductivity of 103.6 mS for 5 minutes at 23° C. All anodized samples were rinsed for 30 seconds in flowing deionized water and dried at 50° C.
The samples were then assembled, within 24 hours of anodization, using AF163 epoxy resin film adhesive. The adhesive bondline thickness of the wedge test assemblies was controlled at 0.35 mm using stainless steel shims. The assemblies were cured in a platen press for 1 hour at 121° C. with 310.3 KPa pressure and then cut into 2.54 cm wide specimens. The specimens were cracked according to ASTM D-3762-79, the initial crack length was marked, and the specimens were placed in condensing humidity at 52° C. Crack progression in the humidity chamber was checked periodically.
The wedge test data of FIG. 6 show that under equivalent conditions, joints formed from substrates anodized in the phosphorous acid solution had smaller crack extensions than those anodized in the phosphoric acid solutions, and thus have a higher degree of hydrothermal stability. Since phosphorous acid has a greater pKa 1 value than phosphoric acid, the ionic concentration of the solutions were made equivalent by preparing solutions of equivalent conductivities. By anodizing under galvanostatic conditions in solutions with equivalent conductivities, oxides of similar thicknesses and structures are formed.
EXAMPLE 7
In this example, specimens were prepared as follows: Unclad aluminum alloy 6061-T6 was machined to appropriate dimensions for the wedge test (ASTM D-3762-79). The surfaces were vapor degreased by exposure to the vapors of trichloroethylene for 5 minutes at 87° C. Upon cooling, the surfaces were then etched in an acidic bath for 1.5 minutes at 23° C. After acid etching, the aluminum surfaces were rinsed with flowing tap water for 30 seconds to remove residual etchant, dried at 50° C., and anodized as follows: One sample was anodized at 20 V in 10% (w/w) phosphorous acid solution for 2 minutes at 23° C. One sample was anodized at 6.5 mA/cm 2 in 10% (w/w) phosphoric acid solution for 2 minutes at 23° C. One sample was anodized at 10 V in 10% (w/w) phosphoric acid solution for 20 minutes at 23° C. All samples were rinsed for 30 seconds in flowing deionized water and dried at 50° C. and then the surface was scribed into 2 mm×2 mm squares. The samples were immersed in a saturated mercuric chloride solution in order to remove the oxide films which were subsequently rinsed three times in fresh distilled water. The oxide films were put onto transmission electron microscope grids and examined with transmission electron microscopy.
FIG. 7 shows the aluminum oxide morphology of the 2 minute phosphorous acid anodic film. The film has a well-developed porous cell structure with an average pore diameter of 40 nm. FIG. 7 also shows the aluminum oxide morphology of the 2 minute phosphoric acid anodic film. The cell structure is not well developed. The porous structure evident on the 2 minute phosphorous acid anodic oxide is not evident on the 2 minute phosphoric acid anodic oxide; only incipient porosity is observed after a 2 minute anodization in phosphoric acid. Well developed cell structure with open pores is believed to be critical for good adhesive bonding performance.
FIG. 7 also shows the aluminum oxide morphology of the 20 minute phosphoric acid anodic film. It is seen that this image is similar to the 2 minute film formed in phosphorous acid.
EXAMPLE 8
In this example, specimens were prepared as follows: High purity, 99.99%, aluminum surfaces were vapor degreased by exposure to the vapors of trichloroethylene for 5 minutes at 87° C. Upon cooling, the surfaces were then etched in an acidic bath for 1.5 minutes at 23° C. and then rinsed with flowing tap water for 30 seconds to remove residual etchant. The samples were dried at 50° C. and anodized as follows: One sample was anodized at 20 V in 10% (w/w) phosphorous acid solution for 2 minutes at 23° C. One sample was anodized at 10 V in 10% w/w) phosphoric acid solution for 20 minutes at 23° C. Both samples were rinsed for 30 seconds in flowing deionized water, and dried at 50° C. The samples were randomly scribed and immersed in a solution of 10% (v/v) Br 2 in absolute methanol until the aluminum metal dissolved. The remaining anodic oxides were rinsed with methanol followed by two rinses with deionized water. The clean anodic oxides were examined with Al 27 solid state nuclear magnetic resonance (NMR). The results of the NMR analyses are presented in Table 1.
TABLE 1______________________________________NMR Analyses of Phosphoric andPhosphorous Anodic Aluminum Oxides Peak Peak Ratio Height Position Peak Height to Height ofElectrolyte (ppm) Assignment (mm) Peak at 7 ppm______________________________________Phosphoric 61 Tetrahedral 4 0.08Acid Al--O--Al 30 Tetrahedral 15 0.32 Al--O--P 7 Octahedral 48 1 Al--O--Al -17 Octahedral 18 0.38 Al--O--PPhosphorous 65 Tetrahedral 11 0.21Acid Al--0--Al 30 Tetrahedral 32 0.60 Al--O--P 7 Octahedral 53 1 Al--O--Al -17 Octahedral 0 0.00 Al--O--P______________________________________
The data of Table 1 show that the anodic oxide formed in phosphorous acid is different from that formed in phosphoric acid. The major differences are first that the phosphorous acid anodic aluminum oxide has no octahedral Al-O-P structure (-17 ppm). This structure is evident in the phosphoric acid anodic oxide. Secondly, the phosphorous acid anodic aluminum oxide has more tetrahedral Al-O-P (30 ppm). While not being held to any particular theory, it is possible that the tetrahedral Al-O-P structure enhances adhesive bonding, as the tetrahedral Al is less coordinated than octahedral Al, resulting in higher energy sites for adhesive bonding.
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Disclosed is a process for anodically oxidizing aluminum alloy surfaces as a pretreatment for structural adhesive bonds or laminates. The process is comprised of anodically oxidizing aluminum and its alloys in phosphorous acid containing electrolyte to form a porous film comprised of Al, O and P. This film provides a very effective substrate for adhesively bonding aluminum articles and laminates.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to autoinjection devices and, in particular but not exclusively, to such devices intended for multiple use.
DESCRIPTION OF THE RELATED ART
[0002] Although single use autoinjection devices are common there are many instances where the autoinjection device is designed for reuse by the user or clinician and this is becoming more frequent due to environmental awareness. Where an autoinjection device is to be reused, it is important that the loading, priming, firing and unloading of the syringe is achieved simply and consistently by a wide range of potential users and also that there are safeguards against inadvertent operation.
SUMMARY OF THE INVENTION
[0003] According to one aspect of this invention there is provided an autoinjection device comprising:
[0004] a housing including a main body portion and a front body portion moveable longitudinally between a closed position and an open position allowing access to enable in use a syringe to be loaded into said housing, the syringe having a body, a plunger and a needle at a forward end of the body;
[0005] a drive member and a drive bias means disposed in said housing, the drive member being moveable against said drive bias means to a primed position and operable in use when released from said primed position to urge the syringe forwardly to an injection position, and to expel a dose therefrom; and
[0006] trigger means for releasably retaining said drive member in its primed position,
[0007] the device being operable to move said drive member to its primed position as the main body and the front housing portion are moved to their closed position.
[0008] In this way preferred arrangements of the device may be opened to insert a syringe and then closed to prime the drive mechanism.
[0009] To provide a safety feature, at least one of said front housing portion and said drive member is preferably moveable between an inactive configuration, in which closing movement of the front housing portion does not cause engagement with said drive member, and an active configuration, in which closing movement of said front housing portion applies directly or indirectly a rearward force to said drive member to move it to said primed position.
[0010] Thus the front housing portion may include a drive face adapted to be moved to cooperate with a drive face on the drive member.
[0011] An externally operable actuating member may be disposed on the main body portion and actuable to urge the drive faces into lateral engagement against a bias.
[0012] Conveniently, said front housing portion is operable to apply directly or indirectly a force to release said trigger means on movement of the front housing portion rearwardly from said closed position.
[0013] Again, for safety, at least one of said front housing portion and said trigger means may be changeable between an inactive configuration in which rearward movement of said front housing to engage said trigger means is prevented, and an active configuration, wherein, on rearward movement from said closed position, said front housing portion releases said trigger means.
[0014] An externally operable actuating member may be disposed on the main body portion and operable to switch the front housing portion and the trigger means to their active configuration.
[0015] A dual function actuating member may be provided for activating the priming stroke and for freeing the front housing portion for rearward motion to release the trigger means.
[0016] This safety feature may be provided by providing releasable safety latch means for preventing rearward movement of said front housing portion to release said trigger means until after said safety latch has been released.
[0017] Still further, to ensure that the needle is shrouded after an injection a lock out latch means may be provided for latching the forward housing portion against retracting means when it returns to a forward position on completion of an injection.
[0018] Both latching functions may be performed by a common releasable latching means. Indeed, in a particularly preferred arrangement a common actuating member and latching means may be provided.
[0019] To facilitate the injection, the housing may have an associated injection site contacting element having two lobes spaced to either side of the longitudinal axis of the needle and adapted in use, when the contact element is pressed against the user's flesh, to compress the flesh at spaced locations to either side of the injection axis and thereby to cause a bulge at the injection site.
[0020] Preferably said injection site contact element has only two lobes, and the contact element has a profile comprising a central concave region with two convex regions to either side thereof to define said lobes. In one arrangement said lobes are adapted to move towards each other as pressure is applied to said device, thereby to exert a pinching action to enhance said bulging effect.
[0021] In another aspect, this invention provides an autoinjection device comprising:
[0022] a housing having a main body portion, containing a drive mechanism, and
[0023] a front body portion moveable longitudinally between a closed position and an open position allowing access to enable a syringe to be loaded therein for an autoinjection cycle, wherein closing of said housing is operable to energise the drive mechanism for the autoinjection cycle, and rearward movement of said front body portion beyond the closed position releases said drive mechanism.
[0024] The device advantageously includes an externally operable actuating member, operarable to affect at least one of the following functions:
[0025] to engage and/or disengage a load path between the forward body portion and a prime mover in the drive mechanism,
[0026] to engage and/or disengage a load path between the forward body portion and a trigger for the drive mechanism,
[0027] to prevent and/or allow rearward movement of the forward body portion prior to release of said trigger,
[0028] to prevent and/or allow rearward movement of the forward drive portion from a shrouding position after completion of said injection operation.
[0029] In yet a further aspect, this invention provides an injection device comprising:
[0030] a housing including a main body portion and a front body portion relatively moveable longitudinally;
[0031] the housing being openable to provide access to allow a syringe to be loaded into the housing in use, the syringe having a body, a plunger and a needle at its forward end;
[0032] a drive member disposed within the housing and moveable against a drive spring bias to a primed position and operable in use when released from said primed position to urge the syringe forwardly within the housing to an injection position in which the syringe needle projects from the front end of the housing and to expel a dose therefrom;
[0033] a trigger for latching said drive member in its primed position;
[0034] said front body portion further being moveable against a housing spring bias rearwardly from a closed position to a fire position in which it unlatches said firing latch to free said drive member for forward movement under the influence of said drive spring bias;
[0035] wherein as said housing is moved away from the injection site following an injection, said housing spring bias urges said front body portion forwardly back towards its closed position to shroud said needle;
[0036] a releasable safety latch preventing rearward movement of said front body portion from its closed position until release of the safety latch, and
[0037] a latch for latching said forward body portion in its extended, shrouding, position.
[0038] Preferably said front body portion is movable longitudinally relative to said main body portion from said closed position to an open position providing access for said syringe. The front housing portion may include a drive face adapted to be moved to cooperate with the drive member to move the drive member to its primed position as the housing is moved from its open position to its closed position. An actuating member may be disposed on the main body portion for urging the drive face on the front body portion laterally into engagement with the drive member.
[0039] The said actuating member may also be operable to unlatch said safety latch whereby, at different phases of operation of the device, said actuating member is operable
[0040] to urge said drive face on the forward drive portion into engagement with the drive member
[0041] to release said forward body portion to allow it to move from said closed position to its firing position, and
[0042] to lock out the forward drive portion on completion of an injection.
[0043] Preferably said front body portion includes a unitary element slideably mounted for telescopic movement relating to said main body portion. Said unitary front body portion may include a shroud region for said needle, a latch surface for cooperating with said releasable safety latch, and a drive face resiliently moveable into engagement with said drive member. The drive member is preferably longitudinally slideably mounted within said housing, with said drive spring bias comprising at least one spring. The drive spring bias preferably comprises two co-acting springs, which advantageously each comprise a constant force spring.
[0044] Conveniently, said housing includes at its forward end thereof an interchangeable nose element, the contact nose element being interchangeable to adjust the penetration depth of the injection.
[0045] In another aspect, this invention provides an injection device comprising:
[0046] a housing;
[0047] said housing being adapted in use to receive a syringe having needle at its forward end;
[0048] a drive member moveable against a spring bias to a primed position and releasable in use to urge said syringe to a forward position and to expel a dose;
[0049] a trigger for latching said drive member in its primed position;
[0050] an actuating member having a shroud portion at a forward region thereof and moveable between a forward position and a rearward position;
[0051] actuating member bias means biasing said actuating member towards its forward position;
[0052] said actuating member being adapted in use when moved to its rearward position to release said firing latch to free said drive member for movement;
[0053] the actuating member thereafter being movable forward under the influence of said actuating member bias means to return to its forward position with said shrouding region in use shrouding the needle when the needle is at its forward position, and
[0054] releasable latch means for locking said shroud member against movement from its forward position.
[0055] In yet another aspect this invention provides an injection device comprising a needle through which a dose is delivered and, adjacent said needle, a skin contact surface, said skin contacting surface comprising two lobes spaced to either side of the longitudinal axis of the needle and, adapted in use, when the contact element is pressed against the skin, to compress the flesh space locations to cause a bulge at the injection site.
[0056] In still a further aspect, this invention provides an autoinjection device comprising a housing for receiving a syringe, and having a drive mechanism for releasable to urge the syringe forwardly to an injection position and to expel a dose therefrom, said drive mechanism comprising a drive member mounted for sliding movement within said housing and acted upon by two constant force spring arrangements.
[0057] Whilst the invention has been described above, it extends to any inventive combination or sub-combination of the features set out above, or in the following description or claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0058] The invention may be performed in various ways, and embodiment thereof will now be described by way of example only, reference being made to the accompanying drawings in which:
[0059] FIG. 1 is a top perspective view of the injection device when closed;
[0060] FIG. 2 is a top perspective view of the injection device when open for insertion of a syringe;
[0061] FIG. 3 is a bottom perspective view when closed;
[0062] FIG. 4 is an exploded view of the injection device;
[0063] FIGS. 5( a ) and ( b ) are a view of the injection device when closed in a primed condition with the top cover removed, and a detail showing the latch mechanism respectively;
[0064] FIG. 6 are respective views of the injection device at the start of a priming action with the multi-function button depressed and urging the rear part of the drawer into engagement with the drive member, a detail on said view, and a detailed section view respectively;
[0065] FIG. 7 is a part-assembled view of the injection device;
[0066] FIG. 8 is a view from the underside of the injection device with the lower body removed showing interaction of the button and the drawer;
[0067] FIG. 9 is a schematic view showing the effect of the wide footprint of the nose of the injection device when applied to a user's skin;
[0068] FIGS. 10( a ) and ( b ) are schematic section views of a modified form of nose designed actively to exert a pinching action on the injection site, and
[0069] FIGS. 11( a ) to ( f ) illustrate successive stages during operation of the device of FIGS. 1 to 8 .
DETAILED DESCRIPTION OF THE INVENTION
[0070] Referring initially to FIGS. 1 to 4 the reusable auto injector of the present invention is designed to have a slim compact rectangular form closed of length not much greater than that of the syringe and needle cap.
[0071] The auto injector indicated generally at 10 comprises a main body portion 12 made up of a lower casing part 14 and an upper casing part 16 to define a body of generally rectangular form open at one end to receive slideably a drawer or front body portion 18 . On the forward end of the drawer 18 is a nose piece 20 . The nose piece may be interchangeable so as to provide a number of options for the injection depth. Typically injection depth may be 8, 10 and 12 mm penetration depth. On the underside of the housing, as seen in FIGS. 3 and 4 , there is a multi-function button 22 having an integral forwardly extending arm 24 and being mounted for rocking movement in the lower casing part 14 .
[0072] Turning more specifically to FIG. 4 , the drawer 18 comprises a main transverse web 26 from which extends forwardly a cylindrical tubular portion 28 . From the front end of the tubular portion 28 extends first laterally then rearwardly two spring arms 30 with finger pads 32 that align with apertures 34 in the nose piece 20 . At their rearward ends, the spring arms 30 terminate in barbed portions 33 which latch behind abutment surfaces inside an inner lip 36 of the main body portion 12 releasably to latch the drawer in its closed position. Extending rearwardly from the main web 26 are two side webs 38 between which there is a floor 40 extending well to the rear of the webs 38 . The drawer in this embodiment is formed integrally from a single plastic moulding. In the floor, just to the rear of the side webs 38 is a latch aperture 42 that cooperates with the arm 24 of the multi-function button 22 in a manner to be described below.
[0073] At the rear end the floor 40 has a cut out to accommodate a pivot post 46 upstanding from the lower casing 14 . Upstanding from the spaced edges of the floor 40 to either side of the cut out portion 44 are upwardly projecting ribs 48 . Slideably received in the inside of the tubular portion 28 of the drawer 18 is a compression spring 50 and the forward end of a part cylindrical syringe carriage 51 cut away to allow a syringe to be introduced as to be described below. The drawer 18 is urged forwardly by twin drawer springs 52 which are received inside pockets on the lower body casing and act against the main web 26 of the drawer to push it forwardly so that the barbs 33 are normally in engagement with the lip 36 on the housing.
[0074] Slideably mounted in the lower casing part 14 is a drive member 54 , the forward extent of movement of the drive member 54 being limited by horns 56 on the drive member abutting internal ribs 58 on the lower casing 14 . The drive member is urged forwardly relative to the lower casing by a pair of constant spring arrangements each comprising a drum 58 rotatably mounted on the drive member around which is wrapped a constant force spring 60 whose apertured free end is anchored to the lower casing 14 by a peg 62 . By using twin constant force spring arrangements the loading on the drive member is symmetric and also the size of the springs required can be reduced thereby giving a flatter, more compact arrangement. The lower casing 14 may be provided with ‘end of dose’ apertures through which part of the drive member 54 is visible only when it is in its fully forward position with the horns 56 adjacent the abutments 58 . The drive member 54 has a latching aperture 64 which cooperates with a T-shaped latch 66 which is mounted for pivoting movement on the pivot post 48 . At the base of the T of the latch 66 is a barbed latch surface which engages the latch aperture 64 releasably to retain the drive member in a primed position against the bias afforded by the constant force springs 60 . One of the cross limbs of the latch 66 is anchored in the lower casing 14 and acts as a resilient bias 70 urging the barb 68 to its latching position. The other cross piece of the latch comprises an abutment surface 72 that is engageable by one of the ribs 48 on the rear end of the drawer when suitably deflected upwards by the multi-function button 22 .
[0075] Referring now to FIGS. 11( a ) to ( f ) operation of the device will now be described. From a closed position as shown in FIGS. 1 and 3 , the device is moved to an open position by squeezing the finger pads 32 thus pulling the barbs 33 out of engagement with the lip 36 and pulling the drawer forwardly to allow access to the syringe carriage 51 ( FIG. 11( a )). A syringe may then be inserted into the carriage 51 and dropped into place ( FIG. 11( b )). In doing this the needle cap is trapped by the keyhole shaped opening 21 in the nose piece 20 , thus holding the syringe forwardly in the drawer against the bias of the carriage spring 50 ( FIG. 11( c )). When the needle cap is removed, the syringe springs back to become captive inside the device thereby shrouding the needle.
[0076] In order to prime the device, the multi-function button 22 is pressed which in turn presses the floor 40 of the drawer away from the opposed surface of the lower casing 14 so that the ribs 48 are aligned with a transverse surface of the drive member 54 . At the same time the device is pushed down on a flat surface ( FIG. 11( d )) to push the drawer 18 back into the main body and at the same time pushing the drive member 54 rearwardly until it is latched in the primed position by means of the latch 66 . As the drawer returns to its closed position, the barbs 33 move past the inward lip 36 and prevent forward movement of the drawer. At the same time the arm 24 on the multi-function button 22 latches in latch aperture 42 in the floor 40 of the drawer 18 , to prevent rearward movement. It will be noted that the device cannot be primed without the compound action of both pressing the multi-function button 22 and pushing the nose against a firm surface to move the drive member 54 rearwardly to latch it.
[0077] In order to fire the device it is offered up to the injection site ( FIG. 11( e )) and the multi-function button 22 depressed to exert two functions; firstly, it lifts the arm 24 out of the latching recess 42 so allowing the drawer to move back into the housing towards the firing position and secondly, it again lifts the floor 40 of the drawer away from the internal surface of the lower casing so that the right hand rear rib 48 as viewed in FIG. 4 is aligned with the abutment surface on the trigger and so as the drawer reaches its rearmost position, it pivots the latch 66 thus releasing the drive member 54 . The drive member moves under the influence of the constant force springs firstly to drive the syringe forwardly and thereafter to expel a dose as the plunger moves relative to the syringe. It is to be noted that, unless the button 22 is pressed to lift the floor of the drawer 40 upwardly, the rib 48 will simply pass underneath the abutment 72 and thus not trip the latch. This embodiment therefore requires that, for an injection to occur, there must be sustained pressure applied to the multi-function button 22 not only to release the drawer for rearward movement but also to ensure that the rib 48 engages the release abutment.
[0078] When the user releases pressure from the main body portion on completion of an injection, the drawer 18 moves back forwardly to its initial position under the influence of the drawer springs 52 and in so doing, shrouds the needle of the syringe. As it nears the rest position, the finger 24 again latches into the latch aperture 42 on the drawer thus effectively locking the drawer against retraction movement and ensuring that the needle remains shrouded.
[0079] Finally, to unload the device, the finger pads 32 are pressed and the drawer moved forwardly to allow access to the syringe which is removed.
[0080] Referring to FIGS. 9 and 10 , the traditional method of administering a subcutaneous injection with a syringe (without an auto injector) is to pinch the flesh skin at the injection site and to insert the needle at the centre of the pinched fold of skin. This creates depth in the subcutaneous layer ensuring the needle does not enter the muscle layer below, it also relieves pressure under the skin thereby making it easier to inject the drug. With some known types of auto injector, the surface area of the device contacting the skin is typically relatively small and immediately adjacent the injection axis. Such devices can therefore have the effect of actually thinning the subcutaneous layer due to the pressure and increasing pressure under the skin, especially if the footprint is small. However in the present embodiments it will be noted that the nose 20 has a rounded ‘w’ profile where it contacts the injection site, defining two lobes 72 to either side of the injection axis. Applying pressure to two spaced locations to either side of the injection axis provides an effect similar to the pinching action commonly used when injecting into the subcutaneous layer.
[0081] It will be appreciated that this contact surface may be used on a wide variety of different devices beyond the embodiments described herein.
[0082] FIGS. 10 ( a ) and ( b ) describe a variation of this technique where the lobes of the injection contact surface instead of being static are defined on the ends of flexible arms which are configured such that as pressure is applied to the arms, the contact surfaces tend to move together thus enhancing the pinch effect. Thus in these Figures, the forward end of the housing is provided with two inwardly facing L-shaped members with rounded contact surfaces designed to roll inwards as pressure is applied.
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An autoinjection device includes a main body in the front end of which is slideably mounted a drawer or front body portion. The drawer can be opened to remove or insert a syringe. Closing the drawer whilst pressing a multifunction button primes the drive mechanism by latching it against trigger latch. Pressing the button gain whilst urging the front end causes the drawer to release the trigger latch. After the injection the drawer shrouds the used needle and can be released only by pressing the button.
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RELATED U.S. APPLICATION
This application claims the benefit of U.S. Provisional Application No. 61/556898 filed Nov. 8, 2011.
FIELD OF THE INVENTION
This invention relates to a mobile support device for supporting and moving concrete spreading hoses.
BACKGROUND
In the construction industry it is common for concrete to be used and conveyed to the job site via hoses. Concrete is typically either delivered by transit mix trucks or mixed on site. The problem is that these sources of mixed concrete are typically at some distance from the actual site where the concrete is needed. Typically, uncured concrete is pumped from a mixing truck to the area to be filled utilizing a pumping device which feeds a flexible hose. Mixed but uncured concrete has a slurry-like consistency, and is difficult to deliver by hose. A common solution to this problem is to use a large diameter hose, which may range from about three inches in diameter to about ten inches in diameter, with about five inches being typical. When filled with uncured concrete, this hose may weigh up to 30 pounds per foot. With tens of feet of hose being a typical installation, devices which support and move the hose are advantageous. In order to facilitate distribution of the uncured concrete, it is desirable to position the hose off the ground, and provide a structure to support the hose so that it is easily movable, even though carrying substantial weight.
Devices have been developed which attempt to perform these functions. U.S. Pat. No. 5,219,175 (Woelfel) and U.S. Pat. No. 6,209,893 (Ferris) disclose support devices for concrete hoses. Both of these devices use a single, short support to hold the hose resulting in the hose only being supported for less than one foot of its length. In addition, these supports both arrange the supports so that the weight of the supported hose is centered below the tops of the wheels, thereby making the devices more stable. The present designs, however, are still inherently unstable, allowing the supports to rock in relation to the hose, and allowing the hose to contact the ground. Further, surges and collapses in the flexible hose can result in tipping of the hose supports in relation to the hose, which can sometimes impede the pumping process. Another shortcoming in the prior art is the relatively short portion of the support which underlies the hose. This abbreviated dimension allows the hose to flex excessively unless many separate support assemblies are employed. These design features mean that multiple supports may be needed to support a significant length of concrete spreading hose. Likewise, the low center of gravity means that these supports have very low ground clearance and therefore must be lifted over obstacles. In addition, the placement of the lifting handles is such that operators must place their feet on either side of the wheels in order to lift the device, placing the operator's feet in danger of being rolled over by the wheels.
It is desirable then, that a mobile support device for supporting and moving concrete spreading hoses be available which overcomes these limitations. In particular, it is desirable to provide a concrete pumping flexible hose support which resists tipping as it is moved from one distribution location to the next, which discourages buckling or collapsing, which provides readily accessible handles for repositioning, and which elevates the hose above the work site, while at the same time providing improved support along the longitudinal axis of the hose.
SUMMARY OF THE INVENTION
Aspects of the present invention provide for a mobile support device for supporting and moving concrete spreading hoses. Disclosed herein is a mobile support system for supporting a concrete spreading hose, comprising two or more supports spaced apart so as to support a length of concrete spreading hose; at least four large-diameter casters; a frame arranged to rotatably fixture the casters and to position the supports above the casters; and a hand hold arranged around the perimeter of the mobile support system above the wheels and below the supports. It is an object of the invention to provide an improved wheeled support for flexible concrete carrying hoses which provides stability for the flexible hose in all three dimensions, while still allowing a high degree of mobility. It is a further object of the invention to provide such a support which prevents or inhibits collapses of the hose during the concrete pumping and distribution process. It is a further object of the invention to provide such a support which offers increased clearance between the flexible hose and the work surface over which it is suspended, and to provide convenient hand holds for positioning the support and improved safety for the operator in positioning the support.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an embodiment of this invention;
FIG. 2 is a side view of an embodiment of this invention;
FIG. 3 is a front view of an embodiment of this invention; and
FIG. 4 is a top view of an embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Aspects of the present invention provide for a mobile support device for supporting and moving concrete spreading hoses. FIGS. 1-4 show a mobile support assembly 10 for supporting a concrete spreading hose 12 . The assembly is preferably constructed as a metal framework having sufficient strength to support the anticipated loads, while the hose 12 as above described is generally flexible. It will be appreciated that the preset invention will also function effectively when used with rigid or semi-rigid pipes or similar conduits. The mobile support assembly 10 comprises two or more holders 14 spaced apart on a support beam 15 so as to support a length of concrete spreading hose 12 . The holders 14 are preferably in the configuration of a semi-cylindrical section, open at the upper end and affixed by fasteners or weldment to a support beam 15 . Elongated support beam 15 is of rigid solid or tubular construction and may be of circular or polygonal cross-section. The support beam 15 is affixed to hand hold 28 , which in turn is affixed to frame 18 at tubular sockets 32 . The frame 18 , hand hold 28 and sockets 32 form a box-like structure which imparts rigidity to the assembly 10 . The ends 30 of support beam 15 extend outward from opposing sides of the rigid frame 18 to facilitate manipulation of the assembly 10 as will be further described herein.
The assembly 10 further comprises at least four large-diameter casters 16 , where large diameter is defined as 16 inches in diameter or greater. Large casters 16 are preferable in the typical work environment, where small, commonly occurring debris, such as gravel, nails, and the like may interfere with the operation of smaller wheels. The casters 16 may be provided with either solid or pneumatic tires 20 , which pivot on caster mounts 22 in the conventional fashion. The invention incorporates a frame 18 arranged to position legs 24 and casters 16 and to position the support beam 15 above the casters 16 . The frame 18 is preferably constructed of solid bar stock or hollow metal tubing, and is in the form of a rectangular structure to which is attached a plurality of legs 24 constructed of like material. The legs 24 extend downwardly and outwardly of said frame 18 , and at their distal ends are provided with the caster mounts 26 above described. A hand hold 28 is arranged above the frame 18 of the mobile support assembly 10 , above the wheels 16 and below the supports 14 , so that operators can lift or move the mobile support assembly 10 without placing their feet in danger from the casters 16 . Although the mobile support assembly 10 , by virtue of having the hose supports 14 well above the casters 16 , has a high center of gravity, the four casters 16 are located at the corners of the mobile support assembly 10 so as to provide adequate stability during use. In addition, the location of the elongated support beams 15 extending beyond the perimeter of the mobile support assembly 10 helps to keep the operator away from the hose 12 during use and permits operators to have additional safe and effective hand holds. To provide rigidity to the frame 18 and legs 24 , diagonal brace 38 is provided which extend from one corner 34 of the support frame 18 to a diagonally opposed corner 34 of said frame, and an additional brace 38 extends from one corner 34 of hand hold 28 to a diagonally opposed corner 34 of said hand hold. Preferably said braces 38 are constructed of solid bar stock, or hollow tubing.
Legs 24 are preferably constructed in pairs and each pair is interconnected by lateral brace 37 . Frame 18 is provided with tubular sockets 32 attached to the frame 18 and held hold at corners 34 . The upper end 36 of leg 24 are sized to removably fit within sockets 32 , where legs 24 may be secured with fasteners (not shown). Likewise, legs 24 may fit into sockets 32 utilizing only a slide fit, whereby the weight of frame 18 and hand hold 28 serves to hold the sockets 32 in engagement with the upper ends 36 of legs 24 . In this fashion, the assembly may be disassembled for compact storage.
With reference to FIG. 4 , it will be appreciated that support beam 15 extends laterally across hand hold 28 , and extends distance “A” beyond the track “B” of the support assembly. This facilitates manipulation of the entire assembly by the operator, reducing risk that the casters 16 will interfere with the operator's person during re-positioning of the hose 12 .
Embodiments of this invention use four supports 14 to support about ten feet of hose 12 and clear obstructions less than two feet high and two feet wide, permitting the hose 12 to be supported and moved forward, backward or side to side. Each assembly has a supporting beam 15 that typically supports 10 to 16 feet of hose. The normal gap between the support assemblies is between four and six feet. Therefore a set of four mobile support assemblies 10 can support over 80 feet of hose and keep it clear of the work surface. A typical pumping hose weighs over 30 pounds per foot when filled, giving the operators over 2400 pounds of concrete to transport.
Concrete pouring generally proceeds from areas distant from the concrete source to the source. As the pour proceeds, a way to handle the decrease in distance from the source is to remove sections of hose, a time-consuming and messy task. Aspects of this invention permit the mobile support assemblies carrying the hose sections to be moved in opposite directions thereby folding the hose back on itself, thereby shortening the effective hose length and reducing the need to remove sections of hose. In addition, the placement of the last section of hose on the mobile support system permits the operator to distribute the concrete directly from the hose on the mobile support system thereby reducing the burden on the operator to lift and move the end of the hose while distributing concrete.
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A mobile support system for supporting a concrete pouring hose supports ten to sixteen feet of hose while providing sufficient ground clearance to avoid common obstacles. The mobile support system features large castors and conveniently placed hand holds to permit the mobile support system to be moved safely and easily. The system provides for socketed leg attachment, thereby allowing for ease of disassembly and storage.
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This application is a division of application Ser. No. 06/919,871 filed on Oct. 16, 1986, now abandoned which was a division of application Ser. No. 06/628,611 filed on July 6, 1984, now U.S. Pat. No. 4,620,699.
FIELD OF THE INVENTION
Our invention relates to an assembly for registering a sheet prior to feeding it to a subsequent location such as the image-transfer station of an electrophotographic copier. Our invention relates further to apparatus for deforming the leading edge of such a sheet to facilitate its separation from a member such as a photoconductor from which the sheet receives a developed image.
BACKGROUND OF THE INVENTION
Electrophotographic copiers of the image-transfer type, or plain-paper copiers as they are, generally called, are well known in the art In copiers of this type, an electrostatic latent image is first formed on a photoconductor by uniformly charging the photoconductor and then exposing the photoconductor to a light image of an original document to discharge portions of the photoconductor in a pattern corresponding to the graphic matter on the document The photoconductor bearing the latent image is then subjected to the action of a developer, or toner, to form a developed toner image, which is transferred to a carrier sheet such as paper. Generally, in electrophotographic copiers employing the process described above, the photoconductor comprises an endless member, usually in the form of a drum, that is continuously moved at a predetermined velocity throughout the entire copy cycle. To transfer the developed toner image from the photoconductor to the carrier sheet, the sheet is brought into close proximity or actual contact with the photoconductor, while moving at the same velocity, in a transfer station.
In order to ensure that the leading edge of the carrier sheet is advanced to the transfer station in synchronism with the arrival of the leading edge of the developed toner image, the carrier sheet is first fed to a registration station, where it is momentarily held. As the leading edge of of the developed image approaches the transfer station, feed members are actuated to advance the sheet from the registration station. By prefeeding the carrier sheet to the registration station in this manner, one avoids the loss of synchronism that may occur if the sheet slips relative to a feed member as it is initially fed from a stack.
Generally, in registration stations of the prior art, the leading edge of the carrier sheet is advanced to a registration position defined by a pair of opposing friction feed rollers, which remain stationary while the sheet is being held. One disadvantage of registration systems of this type is that the registration position depends on the sheet thickness, as well as the longitudinal extent of the registration nip. The longitudinal extent of the registration nip depends in turn on such factors as the compliance of the registration rollers and the normal nip force. Since these factors cannot be precisely controlled, the exact registration position of the carrier sheet remains uncertain.
Another problem encountered with registration systems of this type involves the acceleration of the carrier sheet to the photoconductor velocity when the registration rollers are actuated. Even a momentary slippage between the carrier sheet and the registration rollers will result in loss of synchronism between the leading edge of the sheet and that of the developed toner image. Further, if unequal slippage occurs across the width of the sheet, skewing will result. It is known in the art to advance a carrier sheet a sufficient distance from the stack so as to create a buckle in the registration nip, thereby urging the leading edge into the nip, so as to minimize slippage upon actuation of the registration rollers. However, even this expedient does not entirely eliminate the possibilities for slippage. Slippage is particularly likely to occur if the leading edge of the sheet is registered against a gate which is intermittently moved into the sheet path slightly upstream of the rollers.
Still another problem, inherent in image-transfer electrophotographic copiers generally, is that of separating the carrier sheet from the photoconductor surface following transfer of the developed image. A common expedient is to use a pickoff blade which intercepts the leading edge of the carrier sheet as it emerges from the transfer station to separate the adjacent edge portion of the sheet from the photoconductor. However, if such a blade is allowed to contact the photoconductor drum it will damage the drum surface over time. Further, the blade will become contaminated with remnant developer from the drum surface, producing streaks on the passing surface of the copy sheet.
It is known in the art, as shown in Hukuda et al 4,408,861, to deform a portion of the leading edge of the carrier sheet at the registration station so that the deformed edge portion remains spaced from the photoconductor at the transfer station. In such a system, the pickoff blade may be spaced slightly from the drum surface so as to avoid abrasion of the drum surface or contamination of the contacting blade portion. However, in the apparatus disclosed in the patent, all or a substantial portion of the leading edge of the sheet is bent away from the photoconductor, producing a corresponding void in the leading edge portion of the transferred image. Further, in the disclosed apparatus, in which a rotating deforming member urges the leading edge of the sheet against a resilient roller, the extent of sheet deformation remains uncertain.
OBJECTS OF THE INVENTION
One object of our invention is to provide a registration system that ensures accurate registration of a sheet prior to its feeding to a subsequent location, such as the transfer station of an electrophotographic copier.
Another object of our invention is to provide a registration system that advances a sheet to a subsequent station without slipping or skewing.
Still another object of our invention is to provide a registration system for an electrophotographic copier that allows the use of a pickoff member that is spaced from the photoconductor.
A further object of our invention is to provide a registration system that does not produce large image voids along the leading edge of the sheet.
A still further object of our invention is to provide a registration system that is simple and inexpensive.
Other and further objects of our invention will be apparent from the following description.
SUMMARY OF THE INVENTION
In one aspect, our invention contemplates apparatus for registering a copy sheet prior to feeding the sheet to the image-transfer station of an electrophotographic copier in which opposing pairs of relatively rigid feed rollers are arranged on shafts in alternating relationship with opposing pairs of relatively compliant feed rollers, which are of somewhat larger diameter than the rigid rollers so as to form nips of appreciable extent in the direction of feed. Registration gates mounted for rotation on one of the roller shafts through slipping couplings are selectively restrained against rotation with the roller shaft either in a non-blocking position out of the feed path or in a blocking position within the nip area of the compliant rollers but upstream of the nip area of the rigid rollers.
In another aspect, our invention contemplates a sheet crimper comprising an anvil rotating with one of the registration gates and a hammer supported by the anvil for movement into a recess in the anvil. The crimper deforms a leading edge portion of the carrier sheet as the sheet is advanced from the registration rollers to facilitate separation of the sheet from the photoconductor after image transfer by a pickoff element spaced from the photoconductor.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which form part of the instant specification and which are to be read in conjunction therewith, and in which like reference numerals are used to indicate like parts in the various views:
FIG. 1 is a fragmentary section of the processing and sheet-feeding portions of an electrophotographic copier incorporating our registration assembly.
FIG. 2 is a fragmentary section of the registration assembly of the copier shown in FIG. 1, along line 2--2 thereof.
FIG. 3 is an enlarged section of the registration assembly shown in FIG. 2, taken along line 3--3 thereof with the registration gates held in a blocking position.
FIG. 4 is an enlarged section of the registration assembly shown in FIG. 2, taken along line 3--3 thereof, with the registration gates held in a non-blocking position.
FIG. 5 is an enlarged section of the sheet crimper of the registration assembly shown in FIG. 2, taken along line 5--5 of FIG. 2, with the registration gates in the blocking position shown in FIG. 3.
FIG. 6 is an enlarged section of the sheet crimper of the registration assembly shown in FIG. 2, at a stage in the copy cycle subsequent to that in which a sheet is blocked.
FIG. 7 is an enlarged fragmentary section of the sheet crimper of the registration assembly shown in FIG. 6, taken along line 7--7 thereof.
FIG. 8 is a greatly enlarged fragmentary view of the pickoff area of, the copier shown in FIG. 1.
FIG. 9 is a greatly enlarged fragmentary section of the pickoff area of the copier shown in FIG. 1 along line 9--9 thereof.
FIG. 10 is a greatly enlarged fragmentary section of the pickoff area of the copier shown in FIG. 1 along line 10--10 of FIG. 8.
FIG. 11 is a schematic diagram of the control circuit for the sheet-feeding and registration portions of the copier shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a copier, indicated generally by the reference numeral 10, incorporating our registration assembly includes an electrophotographic imaging drum, indicated generally by the reference numeral 12, having a peripheral photoconductor 14 supported by a conductive substrate 16. Drum 12 is mounted on a shaft 18 for rotation therewith, and is driven in the counterclockwise direction as viewed in FIG. 1 at a uniform velocity by any suitable means (not shown). In a manner well known in the art, the drum photoconductor 14 is rotated first past a charging station 20 at which the surface of the photoconductor receives a uniform electrostatic charge, then past an exposure station 22 at which the electrostatically charged surface is exposed to a flowing light image of an original document (not shown) to form an electrostatic latent image, then past a developing station 24 at which a carrier liquid containing a suspension of charged toner particles is applied to the latent-image-bearing surface to form a developed toner image. Upon emerging from the developing station 24, the developed-image-bearing surface 14 moves past a metering roller 26, which is disposed at a slight spacing from the surface 14 and rotated in a reverse direction of surface movement at a high speed to reduce the thickness of the liquid layer (not shown) on the surface 14. Thereafter, the surface 14 moves past a transfer station 28 at which the developed toner image is transferred from the photoconductor to a carrier sheet 34, past a cleaning station 30 at which the surface 14 is cleaned of any remaining toner particles or developer liquid, and finally past an erasing corona 32 which neutralizes any remaining electrostatic charge on the surface 14.
In the sheet-feeding portion of copier 10, a friction separator roller 38 bearing against the upper sheet of a stack 36 of carrier sheets is momentarily driven at the proper time in the copy cycle, in a manner to be described, to advance the top sheet 34 to the left as viewed in FIG. 1 to a pair of opposing feed rollers 40 and 42. Rollers 40 and 42 continue to feed the sheet 34 upwardly between a pair of spaced guides 44 and 46 to a registration assembly, indicated generally by the reference numeral 48, that is the subject matter of our invention.
Referring now also to FIG. 2, in the registration assembly 48, an upper shaft 66 rotatably supported by respective front and rear side plates 70 and 72 of the copier 10 supports a plurality of axially spaced friction feed rollers 50, 52, 54 and 56, formed of a solid, or noncellular, elastomer such as polyurethane. Feed rollers 50 to 56 oppose a corresponding plurality of axially spaced lower feed rollers 58, 60, 62 and 64, preferably formed of the same noncellular elastomer material as upper rollers 50 to 56, supported on a lower shaft 68 rotatably received by the same side plates 70 and 72. Shafts 66 and 68 are driven continuously by any suitable means (not shown) at such a speed that rollers 50 to 64 move at the peripheral velocity of the drum 12.
Referring now also to FIGS. 3 and 4, we arrange respective rotary registration gates 74, 76, 78 and 80 on lower shaft 68 at locations just inboard of respective rollers 58 to 64. Respective clutches 82, 84, 86 and 88 of any suitable type known to the art provide slipping couplings between gates 74 to 80 and shaft 68. As shown in FIGS. 3 and 4 for gate 78, each of the gates 74 to 80 has a sector 90, smaller in diameter than solid rollers 58 to 64, as well as a sector 92 of appreciably larger diameter than rollers 58 to 64. Larger-diameter sector 92 has a radially extending trailing edge 94 that serves as a registration edge for copy sheets 34 approaching the nip formed by rollers 50 to 64.
The leading edges 96 of gate sectors 92 serve a stops for controlling the positions of the gates 74 to 80. Referring also to FIG. 2, respective control latches 98, 100, 102 and 104, supported by a shaft 106 rotatably received by side plates 70 and 72, are selectively actuated to arrest gates 74 to 80 either in a blocking position, shown in FIG. 3, in which registration edges 94 are about 2 to millimeters upstream of the nips formed by rollers 50 to 64, or in a nonblocking position, shown in FIG. 4, in which sectors 92 are held at a position remote from the sheet path. Referring now particularly to FIGS. 3 and 4, each of the latches 98 to 104 has an upwardly extending arm 108, as well as a lower arm 110 formed with a catch 112. A tension spring 118 extending between the copier frame and an arm 116 carried by shaft 106 normally biases shaft 106, and hence latches 98 to 104, counterclockwise to the position shown in FIG. 3, in which the upper arms 108 arrest registration gates 74 to 80, causing them to slip relative to shaft 68, in the blocking position shown in FIG. 3. In this position, gates 74 to 80 hold the leading edge of sheet 34 in a registered position about 2 to 3 millimeters upstream from the nip of solid rollers 50 to 64.
When it is desired to feed sheet 34 through the nip, a solenoid 120 is actuated to rotate the latches 98 to 104 clockwise, against the action of the spring 118. This retracts the upper arms 108 from gates 74 to 80, allowing the gates to rotate with shaft 68. Gates 74 to 80 continue to rotate until gate sectors 92 reach catches 112, which bear against gates 74 to 80 under the action of solenoid 120. At this point, gates 74 to 80 again slip relative to shaft 68 in the non-blocking position shown in FIG. 4, with the gate sectors 92 remote from the sheet path. After the trailing edge of a sheet 34 has cleared the registration assembly 48, solenoid 120 is again deactuated to allow gates 74 to 80 to rotate along with shaft 68 until they reach the registration position shown in FIG. 3, in preparation for the next copy sheet 34.
To ensure against momentary slippage of sheet 34 relative to solid rollers 50 to 64 as the sheet is fed forward from the roller nip, we also provide upper shaft 66 with axially spaced foam feed rollers 122, 124, 126 and 128 inboard of respective registration gates 74 to 80. Likewise, we provide lower shaft 68 with respective foam feed rollers 130, 132, 134 and 136 at locations opposite upper foam rollers 122 to 128. Rollers 122 to 136, which are formed of any suitable elastomeric cellular material such as polyurethane, are of appreciably larger diameter than solid rollers 50 to 64. Accordingly, in the blocking position shown in FIG. 3, the registration edges 94, while lying upstream of the nips of solid rollers 50 to 64, lie within the nip region of foam rollers 122 to 136. Thus, rollers 122 to 136, which rotate continuously, grip a sheet 34 with sufficient force to ensure that the sheet is fed forward without slipping when the sheet is advanced from the registration assembly 48 to the transfer station 28. At the same time, rollers 122 to 136 do not press against sheet 34 with sufficient force to crumple the leading edge of the sheet against registration edges 94.
Referring now particularly to FIGS. 5 to 7, the crimper of the registration assembly 48, indicated generally by the reference numeral 164, includes a rotary anvil 166 having a rounded sheet-receiving portion substantially the same diameter as solid rollers 58 to 64. A reduced-diameter sleeve 168 of anvil 166 forms an interference fit with a counterbore 170 formed in registration gate 76, so that crimper 164 rotates with gate 76 and is controlled in a like manner by solenoid 120. A pin 176 received by anvil 166 supports a hammer 174 for pivotal movement into a slot 172 formed in the anvil 166. Hammer 174 is formed at the end remote from pin 176 with an oblique clamping surface 178 movable against the corner portion 180 of a metal insert 182 received by anvil 166. A compression spring 188 received in a bore 190 formed in slot 172 urges hammer 174 partly out of the slot 172 to an open position defined by a limit stop 192 of hammer 174 which abuts anvil 166. Preferably, slot 172 is formed with chamfers 184 along its outer edges, while metal insert 182 is formed with a slot 186 of the same width as the chamfered portion of slot 172.
Crimper 164 is so arranged angularly relative to registration gate 76 that in the blocking position shown in FIG. 3, crimper 164 is in the position shown in FIG. 5, with the clamping surface 178 just above the registered leading edge of the sheet 34 and with the hammer 174 in its open position. As the crimper 164 rotates with gate 76 upon actuation of solenoid 120, a leaf spring 194 carried by hammer 174 bears against upper shaft 66 to urge hammer 174 into the recess 172. By the time crimper 164 reaches the position shown in FIG. 6, spring 194 has urged hammer 174 fully into the recess 172 to sandwich the leading edge portion of the sheet 34 between surface 178 and corner portion 180 to form a crimp 196 in the sheet 34. As the crimper 164 continues to rotate beyond the position shown in FIG. 6, leaf spring 194 clears upper shaft 66, allowing compression spring 188 to urge hammer 74 out of the recess 172, releasing the sheet portion 34. Crimper 164 thereafter continues to rotate along with gate 176 until the gate reaches the non-blocking position shown in FIG. 4, in which it is held by catch 112. With the crimper thus retracted from the sheet path, the sheet 34 continues to advance toward the transfer station 28, without interference either from the hammer 174 or from the registration gates 74 to 80. When the trailing edge of the sheet clears the registration assembly 48, solenoid 120 is again deactuated to return gates 74 to 80 to the position shown in FIG. 3, and hence crimper 164 to the position shown in FIG. 5, in preparation for the arrival of another sheet.
Referring again to FIG. 1, the transfer and pickoff assembly of the copier 10, indicated generally by the reference numeral 138, is located in the transfer station 28. Assembly 138 is supported by a transversely extending shaft 140 for pivotal movement relative to the side plates 70 and 72 of the copier 10. Torsion springs 144 bias the assembly 138 upwardly to a position defined by spacer rollers 146 carried by respective side plates 142 of the assembly 138 at locations opposite the edges of the drum surface 14. As a copy sheet 34 enters the transfer station 28 from the registration assembly 48, it moves first along a lower guide 148 of assembly 138. Lower guide 148 directs the sheet 34 past a transfer corona 152 which provides sheet 34 with an electrostatic charge opposite in polarity to that of the developed image on the drum 12, so as to attract the image electrostatically from the drum 12 to the paper 34.
Referring also to FIGS. 8 to 10, a pickoff blade 154, aligned axially with crimper hammer 174 and carried by assembly 138 at a location slightly downstream of transfer corona 152, engages the crimped portion 196 of the sheet 34 to initiate the separation of the sheet from the drum surface 14. Pickoff blade 154 directs the separated leading portion of the sheet 34 toward a set of axially spaced foam rollers 156, which rotate at the velocity of the drum surface 14 to direct the sheet along an exit guide 158 to an exit path A leading to an output tray (not shown). A vacuum source 162 coupled to the underside of rollers 156 and guide 158 by way of a port 160 at the rear of the transfer assembly 138 attracts the separated portion of the sheet 34 toward the rollers and guide so as to prevent smearing of the image by prolonged contact with the blade 154.
Rollers 146 space pickoff blade 154 a distance from the photoconductor surface 14 which is preferably greater than the thickness of the layer (not shown) of remaining toner material and carrier liquid on the surface, but less than the depth of the crimp 196 at the leading edge of the sheet 34. Further, the thickness of the pickoff blade 154 should be less than the width of the crimp 196. As a particular example, the pickoff blade 154 may be spaced 0.2 to 0.3 millimeter from the surface 14 and have a thickness of 0.5 millimeter, while the hammer 174 and slot 172 may be so formed as to produce a crimp 2 millimeters wide, 0.5 millimeter deep at the leading edge of the sheet 34, and 4 to 5 millimeters long.
Referring now to FIG. 11, the control circuit for the registration assembly 48, indicated generally by the reference numeral 200, includes a digital counter 202 receiving a clock input from a disk encoder 204 that produces a train of pulses synchronous with the rotation of the drum 12 in a manner known in the art. Counter 202 also receives a reset input from a switch 206 that is momentarily closed at a predetermined point in the copy cycle, also in a manner known in the art. Switch 206 may be closed either in response to the rotation of the drum 12 to a predetermined angular position or in response to movement of a document scanning element (not shown) past a predetermined point.
Initially, registration gates 74 to 80 and crimper 164 are in the positions shown in FIGS. 3 and 5, and feed rollers 40 and 42 rotated by a drive 222. At a predetermined point in the copy cycle, a decoder 208 responsive to counter 202 supplies a timing pulse tl to the set (S) input of an RS flip-flop 216 to set the flip-flop. Flip-flop 216 actuates a separator roller drive 218 to initiate the feeding of a sheet 34 from stack 36. Feed rollers 40 and 42 continue to direct the sheet 34 toward the registration assembly 48.
As the leading edge of the sheet 34 approaches the registration assembly 48, an optical sensor 198 disposed on the feed path immediately downstream of the assembly supplies a signal to a delay circuit 210. Upon the lapse of a sufficient time period to permit the leading edge of the sheet 34 to enter the nips of foam rollers 122 to 136 and abut registration gates 74 to 80, the delay circuit 210 supplies a signal to the reset (R) input of flip-flop 216, disabling the separator roller drive 218. Delay circuit 210 also supplies a signal at that time to the R input of an RS flip-flop 220 controlling the feed roller drive 222 to disable the latter drive.
At a predetermined later point in the copy cycle, decoder 208 produces a pulse t2, which is supplied to the S inputs of flip-flop 220 and of another RS flip-flop 224 controlling the gate solenoid 120. As a result, gate solenoid 120 is actuated to permit registration gates 74 to 80 to rotate along with shaft 68 to a position clear of the sheet path, allowing rollers 50 to 64 to advance the sheet 64 to the transfer station 28. In the course of movement of gate 76 and crimper 164 from the position shown in FIG. 5, hammer 174 clamps a leading edge portion of sheet 34 against corner 180 to form a crimp 196, as shown in FIG. 6. Simultaneously with the actuation of solenoid 120, feed roller drive 222 is actuated to drive the feed rollers 40 and 42. Feed roller drive and gate solenoid 120 remain actuated until the trailing edge of the sheet 34 clears the gate sensor 198, at which time an inverter 212 supplies a high-level logic signal to a delay circuit 214. Upon the lapse of a predetermined period of time sufficient, to permit the trailing edge of the sheet to clear the registration assembly 48, delay circuit 214 supplies a high-level logic signal to the R input of flip-flop 224, disabling gate solenoid 120. As a result, registration gates 74 to 80 are again allowed to rotate until they reach the blocking position shown in FIG. 3, in preparation for another cycle similar to the one just described.
It will be seen that we have accomplished the objects of our invention. Our registration system ensures accurate registration of a sheet prior to its feeding to a subsequent location, such as the transfer station of an electrophotographic copier. Our registration system advances a sheet to a subsequent station without slipping or skewing, and allows the use of a pickoff member that is spaced from the photoconductor. Moreover, our registration system permits the use of such a spaced separator member without producing large image voids along the leading edge of the sheet. Finally, our registration system is simple and inexpensive.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.
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Apparatus for registering a copy sheet prior to feeding the sheet to the image-transfer station of an electrophotographic copier. Opposing pairs of relatively rigid feed rollers are arranged on shafts in alternating relationship with opposing pairs of relatively compliant feed rollers, which are of somewhat larger diameter than the rigid rollers so as to form nips of appreciably greater extent in the direction of feed. Registration gates mounted for rotation on one of the roller shafts through slipping couplings are selectively restrained against rotation with the roller shaft either in a non-blocking position out of the feed path or in a blocking position within the nip area of the compliant rollers but upstream of the nip area of the rigid rollers. A crimper comprising an anvil rotating with one of the registration gates and a hammer supported by the anvil for pivotal movement into a recess in the anvil deforms a leading edge portion of the copy sheet as it is advanced from the registration rollers to facilitate separation of the sheet from the photoconductor after image transfer by a pickoff element spaced from the photoconductor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. Pat. No. 08/228,668 filed Apr. 18, 1994, now abandoned.
TECHNICAL FIELD
The present invention relates to a diffuser having a container through which cellulose pulp is arranged to be transported, nozzle arms for delivering a fluid, such as washing liquid, to the pulp, concentrically disposed screen surfaces and screen arms disposed on and connected to the screen surfaces for withdrawal of the fluid.
BACKGROUND OF THE INVENTION
A diffuser is shown and described in Swedish patent SE-B-342 271, which relates to a device for bleaching cellulose pulp. The withdrawal of the bleaching liquid is carried out through boxes which are disposed on the outer side of the container and into which there extend the screen arms provided, at their outer ends, with withdrawal pipes. Recesses in the wall of the container are covered by plates disposed on the boxes. This construction of the diffuser gives rise to heavy leakage from the container. Moreover, a raising and lowering device for a screen pack having screens mounted on screen arms is disposed on the bottom sides of each screen arm. The raising and lowering device includes a piston and cylinder assembly having a piston rod connected to the piston, and the piston rod is fixed to a pull rod that is fastened via a ball joint to the screen arm. The alignment of the screen pack is controlled in the upward and downward direction by a bushing around the withdrawal pipe or by a separate control system. There is herein a strong risk of the entire screen pack becoming tilted or skewed, resulting in the pull rod being bent with the stuffing box as the breaking point, such that the control bushing is exposed to bending forces. The damage which can arise if the screen pack should tilt increases the wear on the equipment, leading rapidly to operating breakdowns.
Swedish patent SE-B-340 216 has previously disclosed a cellulose-bleaching tower having an axially movable screen pack, in which devices in the form of hydraulic cylinders for raising and lowering the screen packs are disposed above the screen arms. In the case of this previously known bleaching tower, the piston rod of the hydraulic cylinder is guided through a bushing as a result of which leaking hydraulic liquid can trickle down in the bushing. Withdrawal of the fluid is further carried out by means of boxes disposed on the contacting surface of the container, as is also known from Swedish patent SE-B-342 271.
SUMMARY OF THE INVENTION
The above-stated drawbacks of the prior art are eliminated by a diffuser in accordance with the present invention. A diffuser in accordance with the present invention is the subject of Swedish Patent Application No. 9400215-1, entitled Diffuser, filed Jan. 24, 1994, from which priority has been claimed and which is incorporated herein by reference thereto. In a preferred embodiment, the diffuser includes a container through which cellulose pulp is transported, a nozzle arm having nozzles positioned in the container for delivering fluid to the pulp, a pulp outlet connected to the container for directing a portion of the pulp away from the container, and a scraper arm having a scraper movably positioned in the container to direct a portion of the pulp to the pulp outlet. The nozzle arm and scraper arm are spaced apart from each other with the scraper arm being above the nozzle arm to allow a seal-forming cap of pulp to form in the space between the nozzle and scraper arms. The nozzle and scraper arms are rotatable relative to the container, and the container has anti-rotation plates positioned below the scraper arm to resist the pulp from rotating within the container.
Screen arms are movably positioned in the container and connected to screen surfaces such that the screen arms and screens are movable vertically as a unit within the container. The screen surfaces are concentrically disposed about a central axis in the container, and the screen arms are coupled to the screens for withdrawal of the filtrate. A vertically directed withdrawal pipe is rigidly and non-pivotally attached to an outer end of the screen arms. The withdrawal pipe is telescopically extended into the filtrate opening and is sealably connected to the filtrate during vertical movement of the screen arms to substantially resist rotational movement of the screen arms relative to the container.
The screen arms extend radially outward from the center axis of the container and terminate at the withdrawal pipe. The screen arms have an interior withdrawal space that is coupled to the screens for channeling the filtrate from the screens, through the withdrawal space to the withdrawal pipes. The screen arms are constructed with the withdrawal space having a substantially continuously increasing cross-sectional area as the screen arm extends toward the withdrawal pipe.
In one embodiment of the invention, the screen arms have an upper member between the screen surfaces and the withdrawal area, and the upper member includes restriction holes therethrough for transmitting the filtrate from the screen surfaces to the withdrawal space. Plugs extend through the upper member and extend toward the restriction holes. The plugs include long plugs that extend into the restriction holes to reduce the flow of filtrate through the respective restriction hole, and short plugs that do not reduce the filtrate flow. Accordingly the flow rate of filtrate from the screens to the withdrawal space in the screen arms is controllable by selectively installing the long and short plugs in the upper member.
In a preferred embodiment, the diffuser includes a raising and lowering device connected to one of the screen arms for vertically moving the screens in the container. The raising and lowering device is positioned above the withdrawal pipe and substantially coaxially aligned with the withdrawal pipe. The container has an outwardly directed bulge with a bushing through which the withdrawal pipe is guided, and the raising and lowering device is positioned above the bulge and extends through an upper wall of the bulge.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail below with reference to appended drawings showing preferred embodiments, in which:
FIG. 1 is a cross-sectional view along a longitudinal axis of a diffuser according to the present invention.
FIG. 2 shows a cross-sectional view through a screen assembly having screen arms of FIG. 1, in which connected screen rings and other parts of the diffuser according to the invention have been omitted for the sake of clarity.
FIG. 3 is a cross-sectional view through a screen ring pack taken substantially along the line III--III in FIG. 2.
FIG. 4 is a cross-sectional view through the screen ring pack taken substantially along the line IV--IV in FIG. 2.
FIG. 5 shows a partial section of the diffuser according to the invention through the end of one of the screen arms.
FIGS. 6A and 6B show a cross-section through a screen ring and illustrate a way to change the capacity in the diffuser according to the invention.
FIG. 7 shows a cross-section through a first embodiment of a stuffing box.
FIG. 8 shows a cross-section through a second embodiment of a stuffing box.
FIG. 9 is a cross-sectional view of our prior diffuser design, which is prior art.
DETAILED DESCRIPTION OF THE INVENTION
A diffuser 1 according to a preferred embodiment of the present invention, shown in FIG. 1, includes a container 2, a screen pack having upper and lower screen rings 3 and 4 and screen arms 5, and upper and lower nozzle arms 6 and 7 having nozzles 6' and 7', respectively, for delivering fluid, such as washing liquid, to cellulose pulp in the container. The diffuser 1 also includes a scraping arm 8 of the ring-scraper type having scrapers 9, and a hydraulic piston and cylinder assemblies 10 distributed along the periphery of the container 2 for axial raising and lowering of the screen pack. A drive device 11, indicated by dashed lines, is mounted atop the container 2 for rotation of a center axle 12 and of the nozzle and scraper arms 6, 7 and 8 which are fixed on the center axle. One of the piston and cylinder assemblies 10 for axial raising and lowering of the screen pack is preferably disposed at the outer end of, and above, each screen arm 5. As best seen in FIGS. 1 and 2, the screen pack includes six screen arms 5 disposed on the diffuser 1 and the screen arms are in fluid connection with the screen rings 3, 4 (FIG. 1) in the screen pack. The screen arms 5 are radially directed from an annular hub 13. The number of screen arms 5 is not limited to the number shown in the preferred illustrative embodiment, but can be varied within the scope of the present invention. The same also applies, of course, to the number of screen rings 3, 4 and number of nozzles 6' and 7'.
As best seen in FIG. 1, the scraping arm 8 having scrapers 9 is not provided with nozzles and has been designed merely to transport cellulose pulp radially outwardly to pulp outlets 9' of outlet chutes 9" connected to the container. This scraping arm construction enables the scraping device to be optimized for pulp transportation. The upper nozzles 6' are placed on the separate upper nozzle arm 6 below the scraping arm 8. Prior art diffusers such as is shown in FIG. 9, include a container 100 with a combined scraper and nozzle arm 102 having scrapers 104 and nozzles 106 connected to the same arm at the upper end of the container.
Between the nozzle and scraping arms 6 and 8 of the present invention there is formed a space 14. In this space 14, the inner wall of the container is provided with anti-rotation plates 15 to prevent the pulp from being brought into rotation by the rotating nozzle and scraping arms. During operation, a pulp layer is formed in the space to produce a reduced change in level during back-flushing and during a return stroke of the screen pack. The unbroken pulp layer also dampens the formation of gas at the screen rings. By virtue of the upper nozzle arm 6 and the scraping arm 8 being separated, the nozzles 6' are therefore unable to cut grooves in the pulp as occurs in the prior art diffuser of FIG. 9. This is particularly important in the case of high pulp concentration, where air is able to force its way down through the pulp and reach the screen pack. The pulp layer forms an effective cap that remains unbroken and prevents air from reaching the screen rings 3, 4 and the screen arms 5, which is very important when operating with a relatively high pulp concentration. As a result of separate nozzle and scraper arms 6 and 8, the upper and lower screen rings 3, 4 in the screen pack operate under equivalent conditions, which, in turn, produces more stable operation of the diffuser.
The lower nozzle arm 7 having the nozzles 7' is matched to the intended flow of fluid and at each end there is formed at least one opening. This means that the entire arm is flowed through by fluid and the risk of blockage at the outer opening is minimized. In addition, the nozzles 7' are shorter, which reduces the load on them.
As best seen in FIGS. 1 and 3, the screen arms 5 of the screen pack have an inner withdrawal space 16 that receives filtrate from the screen rings 3, 4 and channels the filtrate radially outward. Each screen arm 5 is provided internally with guide plates 16', which demarcate the withdrawal space 16 for the fluid. The guide plates 16' are angled such that the withdrawal space 16 has an increasing cross-sectional area as the screen arm 5 extends outwardly from the annular hub 13. In the preferred embodiment, each of the screen arms 5 is a generally conical shaped arm with a larger cross-sectional area adjacent to the annular hub 13 and a smaller cross-sectional area at the arm's outer end. Three of the screen arms 5 form the filtrate withdrawal spaces 16 for the upper screen rings 3 and are configured as shown in the right portion of FIG. 3, and the three other screen arms are configured as shown in the left portion of FIG. 3 and form the withdrawal spaces for the lower screen rings 4. The screen arms 5 are distributed along the periphery of the diffuser in such a way that the withdrawal space 16 in every other screen arm is connected to the upper 3 and every other to the lower 4 screen rings. The diameters of the screen rings 3, 4 are matched to the diameters belonging to the screen rings in a screen pack having only upper screen rings.
In the screen pack, the screen arms 5 include a plurality of headers 17 that provide a collecting space for the filtrate along the edge of the upper and lower screen rings 3 and 4 which faces the withdrawal space 16. The headers 17 provide for efficient flow of the filtrate from the screen rings 3, 4 to the withdrawal spaces 16. The headers 17 also allow the screen rings 3, 4 to be quickly and easily mounted to the screen arms during assembly of the diffuser at a selected diffuser site. The headers 17 are positioned to define the location and spacing of the screen rings upon assembly of the screen pack. As a result, the screen packs can be transported as smaller units to the diffuser site and welded or otherwise assembled by local workers.
In the preferred embodiment the diameter of each screen ring 3 and 4 is equal for a diffuser having a screen pack having only upper or lower screen rings. The dimensions of the screen pack are adapted according to the particular flow. The withdrawal space 16 can be placed under or over the screen ring or, in the case of a double screen pack illustrated in FIGS. 1 and 3, between the screen rings. This construction of the screen pack results in the flow-paths being optimized, so that the liquid volume and gas volume in the screen pack are minimal. In the preferred embodiment, a double screen pack has been provided and the screen arms 5 disposed therebetween are provided with the internal withdrawal spaces 16 as discussed above.
As best seen in FIGS. 6A and 6B the screen pack has restriction holes 19, 20 through which the filtrate flows as it enters the screen arms 5. The restriction holes 19, 20 are adapted to receive plugs 24, 25 that alter the capacity of the restriction holes of the screen pack. In the event production is below the diffuser's maximum capacity, selected restriction holes 19, 20 are plugged, as shown in FIG. 6A to reduce the filtrate flow. In the preferred embodiment, the screen arm 6 has a circumferential part 18 located between the screen ring 3, 4 and the header 17. The circumferential part 18 has the restriction holes 19, 20 formed between the screen ring and the header, and the holes, as can be seen from FIGS. 6A and 6B, connect to the inner spaces 21 and 22 of the screen ring, which are divided by means of a partition 23. Depending upon the desired capacity, the diffuser is configured with a predefined number of the restriction holes 19, 20, for example every other hole, plugged up by an elongated plug 24 according to FIG. 6A. The elongated plug 24 extends through an aperture in the circumferential part 18 transverse to the restriction hole 19 and across the restriction hole to substantially prevent filtrate from flowing through the restriction hole. The diffuser is thereby matched to a capacity from the start amounting to around half of its maximum capacity. As requirements increase, these elongated plugs 24 are exchanged with short plugs 25 that do not extend across the restriction holes 19, 20, whereupon the flow through the screen pack can be increased up to the diffuser's maximum capacity according to FIG. 6B.
As best seen in FIG. 1, the diffuser includes nozzles 6" and 7" which are disposed on the center axle 12 of the lower nozzle arm 7 at the center of the diffuser and are fed with fluid directly from the center axle 12 and not via the nozzle arms 6 and 7. The flow of liquid, such as the wash liquid, through these nozzles 6" and 7" can thus be made independent of the flow of liquid through the nozzle arms 6 and 7 and, preferably, a higher flow of liquid is produced than through other nozzles 6' and 7' to enable the pulp to pass easily through those screen rings 3' and 4' disposed nearest the center axle 12. This design minimizes the risk of the screen pack, i.e., the screen rings 3, 4 and the screen arms 5, and the center axle 12 arresting each others' movements when the pulp is fed forward therebetween.
The diffuser according to the invention, as shown in FIGS. 1-5, having eight upper and lower screen rings and having six screen arms, is dimensioned for a capacity in the order of magnitude of 2000 tons of cellulose pulp throughput every 24 hours. In a diffuser of this kind, the screen rings 3, 4 each have a height of between 1000 and 1500 mm, preferably 1100 mm in the case of a single diffuser and 1450 in the case of a double diffuser. The diffuser 1 according to the invention is preferably made from stainless steel containing at least 12% Cr and can also contain at least 10% Ni and/or at least 1% Mo.
In previously known diffusers as is shown in FIG. 9, the hydraulic piston and cylinder assemblies 10 for the movement of the screen pack are normally placed under the arm of the screen pack. This placement means that the cylinders are exposed to leakage from the above-situated stuffing box. By moving the piston and cylinder assemblies to the top side in accordance with the embodiment of the present invention illustrated in FIGS. 1, 3 and 5, they are placed in a sheltered position. The hydraulic drive assembly is expediently placed on an upper servicing level. By virtue of a divided casing at the center of the screen pack, an assembly unit is obtained, complete with hydraulics and drive. This unit can be fitted and tested prior to final assembly.
A withdrawal pipe 26 of the preferred embodiment is rigidly and non-pivotally connected to the outer end of each screen arm 5 and is directed substantially downwards. The withdrawal pipes 26 are guided telescopically through bearing bushings 27 disposed in recesses formed in the casing of the container 2, so that the withdrawal pipes open out into an outlet for filtrate. The rigid mounting of the withdrawal pipes 26 resist rotational forces that are transferred from the rotating nozzles by the pulp to the screen arms. The withdrawal pipes of the prior art diffuser illustrated in FIG. 9 is pivotally attached at the upper and lower ends, so they are unable to resist the rotational forces as is done by the embodiment of the present invention.
The outer ends of the screen arms 5 of the present invention extend into an annular bulge 28 in the wall of the container 2, and the withdrawal pipe within the bulge extends substantially vertically downwards through the bushing 27. It is also possible to configure a separate bulge 28 in the wall of the container 2 right in front of each screen arm rather than an annular bulge. The hydraulic piston and cylinder assemblies 10 are positioned above the annular bulge 28 which allows the bulges around the container to be smaller and have a smaller diameter. The smaller annular bulge 28 which contains at least a portion of the vertical withdrawal pipes 26 of the present invention is easier to construct during assembly, and it provides for improved access to components for maintenance and repair.
As can be seen from the drawings, the withdrawal pipes 26 and the piston and cylinder assemblies 10 are disposed on either side of the outer ends of the screen arms 5. It is also possible, within the scope of the present invention, to direct the withdrawal pipes 26 upwards and mount them in control bushings arranged at the top of the annular bulge 28, in which case the piston and cylinder assemblies 10 are disposed under or over the screen arms. As a result of the pressure from the pulp located above the screen pack, a flow-pressure is generated upon the filtrate. The withdrawal pipes 26 can thereby readily be placed above the screen arms 5 and the longitudinal section of the withdrawal spaces does not have to be adapted for the running-off of filtrate, but rather the filtrate is forced automatically out of the withdrawal outlets of the diffuser at the bushings 27. It is most advantageous, on the other hand, for the withdrawal pipe 26 and piston and cylinder assembly 10 to be arranged as illustrated in FIGS. 1, 3 and 5, this by virtue of the fact that a stable raising and lowering of the screen pack can thereby occur, at the same time as the filtrate cannot significantly enter into contact with the bearing bushings through which the withdrawal pipes are guided. Moreover, leakage from the diffuser does not reach the hydraulic cylinder when this is mounted above the screen arm.
Pull rods 29, which are connected by means of a coupling 30 to the piston rod 31 in each piston and cylinder assembly 10, are flexibly connected at their lower end, by means of a ball joint 32, to the outer ends of each screen arm 5 within the bulge 28 in the wall of the container 2. Each pull rod 29 passes through the wall of the container via a seal-forming stuffing box 33, described in greater detail below, which is floatingly mounted, i.e., accompanies any movement of the rod 29 in the lateral direction whenever the screen pack is raised or lowered, and which is arranged in a pipe which is disposed on and is joined to the bulge 28. As a result of the arrangement of the floating stuffing box 33, no bending forces are transmitted to the cylinder or pull rod in the event the screen pack moves laterally. The piston and cylinder assemblies 10 are flexibly connected at their upper end, by a ball joint 34, to the outer side of the container. The control and vertical movement of the screen pack allows the screen pack to tilt as needed corresponding to the stroke length, without damage to machine parts.
In FIGS. 7 and 8 there is shown, on a larger scale, two embodiments of the stuffing boxes 33 and 33', which are mounted such that the pull rod 29 can be displaced in the lateral direction if the pull rod is acted upon by radial forces.
In the case of the stuffing box 33 according to the embodiment in FIG. 7, the cylindrical fixture 35 of the stuffing box, which cylindrical fixture bears against the pull rod, is constituted by an inner part 35A which seals against the rod and an outer part 35B, having an outer spherical contacting surface 36, which is mounted in a spherical bearing shell 37 belonging to a lower, circumferential supporting part 38, this being provided with a circumferential, radially directed, lower flange 39. An upper, circumferential supporting part 40 is fixed to the lower supporting part 38 at 41 and comprises a circumferential, radially directed, upper flange 42. Between the lower and upper flanges 39 and 42, there is formed an annular space 43, in which there is inserted a circumferential, radially directed bearing flange 44. The circumferential flange is fixed at its outer circumferential edge, by means of a bolt connection 45, to the wall of the container 2.
A collecting box 46 for the collection of leak fluid is disposed right around the pull rod above the stuffing box 33 The stuffing box 33 can, of course, be mounted differently from the arrangement shown in the drawings, the main point being that it is able to move freely and in sealing arrangement in the radial direction, at the same time as the pull rod guided through the stuffing box is allowed to perform a rocking movement in all directions. A rotary movement of the rod extending through the stuffing box is also possible. The two parallel flanges 39 and 42 can thus be fixed to the wall of the container, or to a stationary frame, and the circumferential, radially directed bearing flange can constitute a part of or be fixed to a supporting part provided with an inner spherical bearing, which supporting part is mounted on the inner part.
As can be seen from the embodiment of the stuffing box 33' according to FIG. 8, the spherical bearing can be relinquished, in which case the fixture 35' is directly connected to upper and lower supporting parts 40' and 38', which are fixed to each other at 41' and bear flanges 42' and 39', respectively. The radially directed, circumferential bearing flange 44' is fixed by means of a bolt connection 45' to the wall 2 of the container and extends into the space 43' between the upper and lower flanges 42' and 39'. Here too, a collecting box 46' for leak fluid is disposed around the pull rod 29.
From the two embodiments of the stuffing box 33 and 33' according to FIGS. 7 and 8, it can be seen that circumferential grooves 48, 49 and 50 and 48', 49' and 50' are formed for seal-forming 0-rings. 51, 52 and 51', 52' denote upper and lower sliding elements. An annular seal 53 or 53' is disposed, for sealing of the rod, in the fixture 35 or 35', which bears and seals against the rod and is mounted such that it is slidably displaceable. The upper and lower supporting parts, as indicated above, are fixed to each other as shown in the drawings. It is possible, of course, within the scope of the appended patent claims, instead of two supporting parts, to have the stuffing box comprise just one supporting part.
The stuffing box shown in the drawings is not limited to use in a diffuser according to the invention, but can find other applications as a stuffing box designed for a rod, which stuffing box shall be able to perform a forward and reverse and/or rotary movement and which shall be able to absorb lateral forces acting against the rod. A predefined rocking movement in respect of the rod guided through the stuffing box can also be possible.
The diffuser according to the invention is not limited of course, to the embodiment described above and shown in the drawings, but can be modified within the scope of the appended patent claims.
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The invention relates to a diffuser having a substantially cylindrical container through which cellulose pulp is arranged to be transported, nozzle arms for delivering a fluid to the pulp, a scraper arm with scrapers spaced apart from the nozzle arms, and concentrically disposed screen surfaces and screen arms disposed on and connected to the screen surfaces for withdrawal of the fluid. The screen arms are provided, at their outer ends, with fixed, non-pivotal withdrawal pipes that are slidably controlled and are connected in sealing arrangement to filtrate outlets. The screen arms have interior withdrawal areas with increasing cross-sectional areas as the screen arms extend toward the withdrawal pipes. The screen arms also include long and short plugs for controlling the filtrate flow capacity of the diffuser. The invention relates also to a stuffing box designed to receive a rod, preferably a pull rod for raising and lowering a screen pack having screen surfaces in a diffuser, the rod being guided in sealing arrangement and slidably through a fixture which is mounted in a bearing for free movement in a plane substantially perpendicular to the rod. The bearing comprises a radially directed bearing flange extending around the fixture, which bearing flange is mounted between two radially directed retaining flanges extending around the fixture.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to plow blades for snow plows, earth working devices, and the like, and more particularly to a plow blade having carbide inserts along the bottom forward edge of the plow blade for improved impact and wear resistance.
[0003] 2. Background
[0004] Graders and snowplows are both well known and each has a relatively long moldboard which extends generally laterally of the surface being worked and is moved over the surface in a direction generally perpendicular to the length of the moldboard. Such support members are typically concave on the forward side and adapted for mounting beneath or in front of a power device, such as a truck or tractor. Such plows also typically include a detachable blade which may be attached, typically by bolting, to the lower edge of the support member so as to project downwardly from the support member. Such blades normally withstand most of the impact and abrasive wear to which the plow blade is subjected and as a result are typically made from a quality grade of steel. A lower edge of the blade forms the working surface of the blade.
[0005] Grader blades made of steel have the advantage of being relatively inexpensive, but also the disadvantage of wearing out extremely rapidly. Because blade edges are subjected to abrasive wear and impact damage, the wear rate can be extremely high at times. When a blade edge wears down beyond a predetermined point, it must be replaced with another blade edge. The replacement of blade edges is, of course, time consuming, represents down time for the equipment, and requires the maintenance of a replacement parts inventory. If a worn blade edge is not replaced, wear at the lower edge of the blade edge would continue until the support member suffers damage by exposure to the surface being worked on.
[0006] Thus, over the years, various techniques, such as impregnation and hardfacing of the blade cutting edge with carbide particles, and attachment of cemented carbide inserts into or onto the blade edge have been employed in attempting to prolong the life of the steel blade.
[0007] Blades with cemented carbide inserts, generally referred to as buttons in the industry, have a compact cylindrical shape. These compact inserts are disclosed in U.S. Pat. No. 5,813,474, for instance. The compact insert in FIG. 4 of U.S. Pat. No. 5,813,474 is at one end generally semispherical and at the other end has a blunt stepped section 46 . The semispherical section is more resistant to impact damage. In FIG. 2 of '474, a drilled hole in the steel blade body 24 with a compact insert 16 brazed therein is illustrated. As is shown at 38 in U.S. Pat. No. 5,813,474, the bottom of the drilled bore was drilled out by a standard drill bit and is conical. Braze material is placed into the drilled out bores and, next, the compact button is inserted into the bore and then the blade is heated, forming a braze between the compact button and the steel body. The bore does not cooperate with the compact insert like-a-glove, as seen in FIG. 2 of '474. At the bottom of the bore a generally conical space remains after insertion of the compact insert. This remaining conical space is filled with braze material. In this prior art design after the brazing process is complete, voids are much more likely to be present in this conical space in comparison to tight fitting members. Efforts at solving this problem in the industry have included manufacturing the bores with an end mill that forms a cylindrical bore having a flat circular bottom and have been successful in forming a tighter fit between the compact inserts and bores. Although successful in preventing the propensity of voids in the connecting braze, cutting out the bore with an endmill is a much more expensive and more time consuming machining operation in comparison to drilling out the bores with a standard drill.
[0008] The use of protruding lane marker reflectors on highways has grown significantly in popularity over recent years. These lane markers are typically attached to the road surface and extend slightly above the road surface. While these reflectors greatly improve lane visibility, they present a problem when the road must be plowed. When typical prior art carbide block/bar inserts within prior art blade edges impact the reflector lane markers, the carbide block/bar inserts, which are more susceptible to impact damage than steel, are sometimes damaged. Furthermore, because such prior art carbide block inserts are typically brazed adjacent to each other, carbide inserts adjacent to the damaged insert are susceptible to crack propagation damage. The same type of damage may also occur when such typical prior art carbide block inserts strike irregularities in the road surface, such as potholes or ruts.
[0009] In prior art blades, uniform cemented tungsten carbide bar inserts have been employed on blades to reduce and limit damage to the steel blades. Such blades are disclosed in the sales brochure “Kennametal snowplow blades and accessories” (1995), published by Kennametal Inc., AM95-17(5)F5. The cemented tungsten carbide bars are aligned side by side across the width of the blade. Steel blade edges having cemented wear resistant hard metal carbide block/bar inserts distributed along the lower edge of the blade edge have been employed in an attempt to prolong the life of the blade edge. Other examples of such block/bar inserts are disclosed in U.S. patents to Stephenson et al. (U.S. Pat. No. 3,934,654) and Stephenson (U.S. Pat. No. 3,529,677). The tungsten carbide bars/blocks brazed onto the steel body are positioned side-by-side across the width of the blade and are brazed to each other at their sides. A cemented tungsten carbide bar on these prior art blade designs would sometimes fracture/crack on account of an unusually large impact force. The crack in a cemented tungsten carbide bar of the prior art often was not limited to just a single bar, but would propagate into bars adjacent thereto along large portions of the width of the blade.
[0010] Generally speaking, the use of the two sets of tiered cemented tungsten carbide inserts in the bottom edge of a grader blade is known, for instance, in U.S. Pat. No. 4,770,253, to Hallissy et al. The blade in the front recess in Hallissy is made from tungsten carbide having a high cobalt content, 18%-22% cobalt by weight, so as to adapt it for impact wear resistance during use of the grader blade. The intermediate slot contains a second insert composed of cemented tungsten carbide containing 10% to 13% weight percent cobalt. The inserts are brazed to the steel blade body including the intermediate and rear sections thereof. However, in contrast to the construction of the grader blade of the present invention, the prior art Hallissy grader blade has tiered inserts and does not have an independent intermediate slot spaced from the front recess, with the inserts respectively disposed in the recess and the slot. In the present invention the front recess is formed along the forward bottom edge of the blade, whereas the intermediate slot is formed along and opens toward the bottom edge of the blade and is separated from the front recess of the steel blade body. In Hallissy '253 and other prior art, the cemented tungsten carbide bars are brazed together in side-by-side relation. These brazed together tungsten carbide bars function to form a unitary piece of cemented tungsten carbide that spans the width of the blade. If one of the cemented tungsten carbide inserts fractured due to an excessive impact force, a crack would propagate into adjacent carbide inserts across the connecting braze joints.
[0011] In the above discussed tiered insert designs, as shown in U.S. Pat. No. 4,770,253, the rearline row of insert bars is brazed into a recess in the steel blade and the frontline of insert bars is brazed onto the rearline row of inserts. The brazing together of the frontline and rearline inserts results in an inherent disadvantage in tiered insert designs. Whenever a front line insert is pried off, for instance by contact with an obstruction on the road whenever the vehicle is placed in reverse, the adjoining rear line insert typically is knocked off together with the front line insert. Not only is the loss of two insert bars of tungsten carbide expensive, the less wear resistant steel portion of the blade becomes exposed.
[0012] The use of the two lines of hard material spaced apart from each other along the bottom edge of a grader blade is also known in the prior art, Kengard A grader blade made and sold by Kennametal, see sales brochure “Kengard A grader blades,” Kennametal Inc., Latrobe, Pa., publication B84-19(5)A4;B83-145 (1983) discloses spaced hard material inserts. This prior art Kengard A grader blade has a front recess, and an intermediate slot spaced from the front recess, with the inserts respectively disposed in the recess and the slot. The front recess is formed along the forward bottom edge of the blade, whereas the intermediate slot is formed along and opens toward the bottom edge of the blade. The slot is defined between and spaced from the front recess and a rear surface of the blade by intermediate and rear bottom end sections of the steel blade body. The front recess contains a first insert composed of Kengard A material, a metal composite of tungsten carbide particles in a matrix of tough, work-hardening stainless steel. The intermediate slot contains a second line of inserts composed of cemented tungsten carbide containing 10 to 13 weight percent cobalt. The inserts are brazed to the steel blade body. However, the prior art Kengard A grade blade of such construction frequently experienced binder washout between the carbide particles in the composite metal matrix, braze failure due the inherent porosity of the matrix, and overall was not cost effective. The grader blade construction of the present invention eliminates these problems.
[0013] While many of these prior art blades would appear to operate reasonably well under the limited range of operating conditions for which they were designed, most seem to embody one or more shortcomings in terms of complexity, performance, reliability and cost effectiveness which make them less than an optimum design. Consequently, a need exists for a different approach to grader blade design, one which will more adequately address the kinds of wear and forces encountered by the lower end of the grader blade.
SUMMARY OF THE INVENTION
[0014] The present invention provides a grader blade designed to satisfy the aforementioned needs. The blade of the present invention is based on two sets of cemented carbide principle—the one forward cemented carbide for face wear resistance primarily to impacts and the other rearward cemented carbide for downpressure wear resistance. In particular, the blade of the present invention has a bottom edge with a forward portion thereof incorporating a pair of elongated cemented carbide inserts. A frontline of inserts is composed of, for instance, a cemented carbide composition of high cobalt content adapting it for impact wear resistance and a rear one of compact buttons is composed of, for instance, a cemented carbide composition of lower cobalt content adapting it for downpressure wear resistance.
[0015] Another object of the invention is to separate the cemented tungsten carbide block/bar inserts from each other by positioning a steel alloy spacer/shim therebetween, reducing the potential for impact damage cracks formed on the edge of the blade propagating along the width of the blade to other cemented tungsten carbide bars.
[0016] In the present invention, the compact inserts have a convex end that is inserted into a bore formed into the steel body of the blade with a standard drill bit. The convex end more closely approximates the conical inner end of the blind bore and significantly lessens the possibility of voids in the braze between the blade steel body and compact insert.
[0017] In an alternative embodiment, the improved blade edge comprises an edge body having a lower edge with a recess and separate slot in the bottom surface of the edge. Within the blade recess and blade slot are positioned generally cylindrical inserts separated by notched spacer means made from a ductile material.
[0018] These and other advantages and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] While various embodiments of the invention are illustrated, the particular embodiments shown should not be construed to limit the claims. It is anticipated that various changes and modifications may be made without departing from the scope of this invention.
[0020] [0020]FIG. 1 is a front view of a blade constructed according to the present invention.
[0021] [0021]FIG. 2 is bottom view of the blade illustrated in FIG. 1.
[0022] [0022]FIG. 3 is an enlarged view of the circled section of the blade shown in FIG. 2.
[0023] [0023]FIG. 4 is an enlarged partial cross sectional view of the one circled section of the blade shown in FIG. 1.
[0024] [0024]FIG. 5 is a cross-sectional view of the blade taken along lines 5 - 5 shown in FIG. 1.
[0025] [0025]FIG. 6 illustrates a front view of second embodiment of the present invention.
[0026] [0026]FIG. 7 is bottom view of the blade illustrated in FIG. 6.
[0027] [0027]FIG. 8 is an enlarged view of the circled section of the blade shown in FIG. 6.
[0028] [0028]FIG. 9 illustrates a bottom view of a third embodiment of the present invention.
[0029] [0029]FIG. 10 is an enlarged view of the circled section of the blade shown in FIG. 9.
[0030] [0030]FIG. 11 illustrates a front view of a fourth embodiment of the present invention.
[0031] [0031]FIG. 12 is bottom view of the blade illustrated in FIG. 11.
[0032] [0032]FIG. 13 is an enlarged view of the circled section of the blade shown in FIG. 12.
[0033] [0033]FIG. 14 is an enlarged view of the one circled section of the blade shown in FIG. 11.
[0034] [0034]FIG. 15 illustrates a bottom view of a fifth embodiment of the present invention.
[0035] [0035]FIG. 16 is a cross-sectional view taken along lines 16 - 16 in FIG. 14.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0036] The present invention generally relates to blades for graders, snowplows and the like and, more particularly, is concerned with a grader blade which incorporates a pair of rows of inserts adapting its bottom forward edge for improved impact and downpressure wear resistance.
[0037] One embodiment of the plow blade invention is shown in FIGS. 1 - 5 . The plow blade 10 includes a plurality of openings 12 for receiving bolts or other connecting means to fix the blade to the blade support mold. While any suitable bolts may be used, the bolts may be in the form of plow bolts in which the heads are substantially flush with the working side of the blade and provide substantially no obstruction to the sliding of material over the edge front work surface of the blade edge. The use and spacing of such bolts with self-locking nuts are generally known in the art and will not be discussed in further detail here. The blade 10 is connected to a support mold board, having a member front work surface up to 18 feet long or longer and can be mounted beneath or in front of a power device such as a truck or tractor. The configuration of the front surface of a support member may be concave, flat, partially flat and partially concave, or may have any other suitable or desired configuration.
[0038] A support member for the blade 10 is typically mounted so that the length of the support member is generally parallel to the surface being worked on and is typically moved along the surface being worked on in a direction generally perpendicular to the length of the support member. Additionally, the support member is typically mounted such that it can be raised and lowered relative to the surface and tilted relative to the surface in the fore and aft direction and also in the lateral direction.
[0039] The blade has a steel body section 14 including a blade bottom edge section 16 including a bottom surface 41 generally perpendicular to the front work face of the bottom edge section. The blade body 14 may be made from any appropriate material, such as AISI 1020 to 1045 grade steel or AR 400 steel. The blade bottom edge section 16 in the embodiment illustrated in FIGS. 1 - 5 has attached thereto a plurality of hard material inserts 18 , 20 fixed thereto. The frontline inserts 20 are fixed within a recess 35 as best shown in FIGS. 3 & 5 and the rearline inserts are fixed within a plurality of holes 28 . The hard material inserts can be manufactured from cemented tungsten carbide, a diamond composite or other wear-resistant hard materials well-known in the industry. The front line inserts 20 on the forward section of the blade can be made from a different hard material than the rearline inserts. U.S. Pat. Nos. 4,715,253 and 4,715,450, for instance, disclose a frontline of insert bars being made from a cemented tungsten carbide composition with a large amount of cobalt in comparison to the rearline of bar inserts which are formed of cemented tungsten carbide with relatively less cobalt, providing for greater resistance to downward pressure. U.S. Pat. Nos. 4,770,253 and 4,715,450, both to Hallissy et al., are hereby incorporated into the specification in their entirety. Such a combination of hard materials in combination exhibits better durability than selecting just one composition for both the frontline and rearline inserts.
[0040] The rearline insert bars positioned into the slot in this prior art design, as discussed above, are made from a cemented tungsten carbide material with a lower percentage of cobalt so as to be more resistant to downward forces which, however, also makes it more brittle and likely to fracture. Fractures in brittle material also have a greater propensity to propagate. These fractures often propagate into and along adjacent bars brazed thereto resulting in catastrophic failure. The inserts on the frontline are made from a tougher, more ductile material with a higher percentage of cobalt in comparison to the rearline inserts and are not as likely to fracture and/or propagate said fracture. Accordingly, the present invention addresses this particular problem with brittle rearline inserts by using generally cylindrical compact inserts 18 for the rearline inserts. In FIG. 4 of the invention the compact inserts 18 are shown positioned in bores 28 drilled in the bottom section 16 of the blade body. In the present invention, the rearline inserts are not brazed together but are separated from each other by sections of the bottom edge section of the steel body 14 . In the present invention, whenever a fracture occurs in a rearline insert 18 , a crack will not propagate into the next closest rearline insert. The crack will dissipate at the boundary between the bottom edge section 16 of the steel body 14 and rearline insert 18 . The steel body 14 is made of a ductile steel alloy material that is less brittle than the hard material used for the rearline inserts 18 , generally cemented tungsten carbide with a low percentage of cobalt.
[0041] The bore 28 is formed by a standard drill bit creating a bore with a conical tip 29 at its most inner end 29 . While the insert holes may have any suitable configuration, the insert holes 28 in this embodiment have a generally cylindrical configuration, the typical shape in the industry. Accordingly, the hard material inserts may have any suitable configuration so long as the shape of the insert hole and hard material insert generally correspond in shape and size.
[0042] The semispherical end 19 of the rearline insert 18 is placed into the bore, in reverse fashion to the manner in which the insert is fitted into the bore in U.S. Pat. No. 5,813,474. The semispherical portion 19 more closely approximates the inner conical end 29 of the bore. The closer fit lessens the possibility of voids in the braze between the blade and inserts. While not shown, the end 19 could alternatively constitute a paraboloid, an ellipsoid or other convex configuration that more accurately approximates the inner end drill point configuration 29 of the hole. The exterior blunt end 17 of the rearline insert, it is admitted, is less resistant to impact damage than an insert having an exterior end that is convex. However, such prior art insert designs with an exterior end having a convex surface, as illustrated in U.S. Pat. No. 5,813,474, quickly flatten during blade use and become similar in shape to the exterior end 17 of the present invention.
[0043] In addition to the benefit of reducing voids in the braze by placing the convex end of the insert into the hole, an added benefit in assembly is also achieved. During assembly, it is easier for a person to position the semispherical end of the compact insert into the bore than attempting to place the blunter opposite end of the compact insert into the hole. The semispherical shape of the hard material insert helps self-center itself as it is manually positioned into the bore for brazing. In contrast to positioning the blunt end of the insert into the bore, see U.S. Pat. No. 5,813,474, which requires more precise manual alignment of the compact insert with the hole before it can be inserted into the hole.
[0044] FIGS. 6 - 8 illustrate a second embodiment of the invention. As shown in FIG. 7, the rearline inserts are generally cylindrical compact inserts 18 that are placed and brazed into cylindrical bores formed into the bottom edge of the steel body. The frontline inserts 20 in the second embodiment are not however directly brazed to each other as in the first embodiment. The tungsten carbide insert bars 20 are spaced from each other by steel body spacer means 34 . Spacer means 34 and frontline insert bars 20 are brazed together in recess 35 at the very bottom corner of the front face and bottom edge of the blade 10 . The spacer means 34 are made from a ductile steel alloy similar to the blade. The ductile spacer means 34 prevent crack propagation along inserts 20 . Any fracture to an insert is limited by the ductile steel spacer means and does not propagate beyond the boundary 36 formed at the interface between a spacer means and frontline insert.
[0045] FIGS. 9 - 10 disclose a third embodiment of the invention. In the third embodiment, both the frontline inserts 20 and rearline inserts 18 are cemented tungsten carbide bars separated by spacer means 34 . The spacer means 34 and bar inserts 20 are positioned in the recess 35 and brazed therein. Similarly, spacer means 34 and rearline bar inserts 18 are positioned inside a uniform slot 37 having a flat inward surface parallel to the bottom surface 41 of the blade, the slot 37 that spans the width of the blade and brazed therein. The center of the rearline insert bars is positioned directly behind the spacer means 34 in the frontline. It is believed that such an arrangement is likely to assist in reducing undesirable washout, as discussed below with respect to a similar embodiment shown in FIGS. 11 - 14 .
[0046] FIGS. 11 - 14 and 16 illustrate a fourth embodiment of the invention. In the fourth embodiment of the invention, generally cylindrical compact inserts are employed for both the frontline inserts 120 and the rearline inserts 118 . Spacer means 134 having semispherical notches at both ends are adapted to receive the inserts 118 and 120 . The tungsten carbide insert bars 120 are spaced from each other by steel body spacer means 134 . Spacer means 134 and frontline cylindrical inserts 120 are positioned in a recess 135 at the bottom of the front work face that forms a corner with the bottom edge of the blade 110 and brazed together onto the blade steel body 114 .
[0047] The uniform slot 137 and recess 135 , as illustrated in FIG. 16, both have a flat inward surface 138 parallel to the bottom surface 141 of the blade that spans the width of the bottom edge of the blade steel body. The spacer means 134 and inserts 118 are inserted within the slot 137 and recess 135 . The spacer means 134 and rearline cylindrical inserts 120 are positioned and brazed together into the slot 137 or recess 135 . This assembly method of placing inserts and spacer means into a slot and/or recess that spans the width of the blade is less expensive than drilling blind holes and manually inserting rearline cylindrical inserts into each bore.
[0048] An additional benefit to this method of assembly is that the compact inserts are not inserted into drilled out blind holes, but along with the spacers are placed into a slot having a flat horizontal inward bottom surface as illustrated in FIG. 16. The blunt end 117 of the insert 118 can be placed into the slot or recess into cooperation with the flat horizontal inward surfaces 138 / 139 . The blunt end 117 of the insert forms better contact with a flat inward surface 138 / 139 than the blunt surface does with the prior art inward conical shape of drilled out blind bores as discussed above. This more closely corresponding fit enables for improved brazing and precludes the braze void problem with drilled out blind bores. In this embodiment it is not necessary to reverse the orientation of the cylindrical compact insert 18 as discussed above to preclude voids. Accordingly, the convex 19 portion of the insert 18 can be oriented outward for improved impact resistance.
[0049] The frontline inserts 120 are uniformly spaced apart along the width of the blade. Gaps of uniform size accordingly span the width of the blade. During operation of the blade, material/snow flows around the inserts through the gaps, causing the steel body material within the gaps to wear “wash out” at a greater rate than accompanying steel on the bottom surface of the blade. The rearline inserts 118 are centrally positioned to help plug these high flow areas and redisperse the material/snow flow helping reduce accelerated “wash out.”
[0050] [0050]FIG. 15 shows a fifth embodiment of the invention that has only one row of hard material wear inserts across the width of the blade. The embodiment shown in FIG. 15, similar to the embodiments shown in FIGS. 7 and 9, includes hard material insert bars 20 . The insert bars 20 are spaced from each other by steel body spacer means 34 . Similar to the embodiment discussed above, the ductile spacer means 34 prevent crack propagation along inserts 20 . In addition, such a design is easier to manufacture and assemble than the single row compact insert blade shown in U.S. Pat. No. 5,813,474. The design shown in U.S. Pat. No. 5,813,479 requires more extensive machining and tooling to form the plurality of holes for receiving the compact inserts. The compact inserts in such a single row blade can be made from a cemented metal carbide, such as tungsten carbide, of a tough grade used in prior art blade designs. More specifically, the inserts 16 are believed suitable if made from a high shock WC grade of tungsten carbide having an 11% to 12.5% cobalt content. U.S. Pat. No. 5,813,474 is herein incorporated in its entirety.
[0051] In the prior art, cemented tungsten carbide bars that are positioned side-by-side with only braze separating them function to form a unitary piece of cemented tungsten carbide that spans the width of the blade. The embodiment of the present invention incorporates hard material inserts that are separated by ductile steel alloys and then brazed together. The ductile spacer means between the hard inserts minimizes the potential for damage to the blade by isolating fractures.
[0052] While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from this invention. It is intended that the following claims cover all such modifications and all equivalents that fall within the spirit of this invention.
[0053] All patents and patent applications cited herein are hereby incorporated by reference in their entirety.
[0054] It is thought that the grader blade of the present invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts and steps thereof without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred or exemplary embodiment thereof.
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The present invention provides for carbide edge snowplow and grader blades that are durable and fracture resistant. The carbide along the blade edge and blade bottom which contacts the surface being treated is designed to limit the degree of fracture of the carbide. Carbide inserts along the edge and/or bottom are separated from each other by a steel alloy spacer/shim along the width of the blade. The spacer/shim reduces the potential for impact damage cracks that form in a carbide insert from propagating into adjacent inserts along the width of the blade. In one embodiment, the improved blade edge comprises an edge body having a lower edge with a recess and separate slot in the bottom surface of the edge. Within the blade recess and blade slot are positioned carbide block/bar inserts separated by spacer means made from a ductile material.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of copending application Ser. No. 15/383,962, filed on Dec. 19, 2016, which is a Divisional of application Ser. No. 14/765,512, filed on Aug. 3, 2015 (now U.S. Pat. No. 9,561,267, issued Feb. 7, 2017), which was filed as PCT International Application Ser. No. PCT/CN2013/071379 on Feb. 5, 2013, all of which are hereby expressly incorporated by reference into the present application.
FIELD OF THE INVENTION
[0002] The present disclosure relates to a vaccine against Mycoplasma spp.; especially to a subunit vaccine against Mycoplasma spp..
BACKGROUND OF THE INVENTION
[0003] Mycoplasma spp. is currently known the tiniest bacteria capable of self-replication outside host cells. Although swine enzootic pneumonia would not cause swine death, it will reduce feeding efficiency and cause growth retardation, inflammation, and immunosuppression as well as make swine more vulnerable to infection of other pathogens, which therefore become economic damage of the industry.
[0004] So far, swine enzootic pneumonia is prevented by three major strategies, including: medicine administration, environment management, and vaccination. Seeing the bad prevention efficiency of antibiotics to Mycoplasma hyopneumoniae , medicine administration can only used for treatment purposes and is hard to meet prevention needs. Furthermore, considering that drug abuse may lead to a larger infection causing by drug-resistant bacteria, medicine administration needs cautious plans and exists a lot of limitations.
[0005] Environment management forms the basis of prevention of Mycoplasma spp. infection. Good piggery sanitation and management would be helpful to reduce occurrence of infection. On the other hand, prevention could be more comprehensive through vaccination.
[0006] The conventional vaccines in the field use inactive/dead bacteria as the active ingredient thereof. However, the price of the conventional vaccines is too high because Mycoplasma spp. is fastidious bacteria and is difficult to be cultured in the laboratory. In order to reduce the cost of Mycoplasma spp. vaccines, scientists continuously try to develop vaccines of different types, such as: (1) attenuated vaccines, (2) vector vaccines, (3) subunit vaccines, and (4) DNA vaccines. Among them, subunit vaccines show the most potential because the advantages of ease in production and high safety.
[0007] To date, there are several potential candidate proteins that could be used for M. hyopneumoniae vaccines; however, there is no further report verifying the proteins suitable for M. hyopneumoniae vaccines.
SUMMARY OF THE INVENTION
[0008] In light of the foregoing, one of the objects of the present invention is to provide antigens suitable for being used in M. hyopneumoniae vaccines and thereby producing novel M. hyopneumoniae vaccines so that the cost of prevention can be reduced.
[0009] Another object of the present invention is to provide a combination of antigens that suitable for being used in M. hyopneumoniae vaccines and thereby provide subunit vaccines with better performance; therefore, there would be more options for prevention tasks.
[0010] In order to achieve the aforesaid objects, the present invention provides a recombination protein for preparing a vaccine for preventing Mycoplasma spp. infection, comprising an amino acid sequence of SEQ ID NO: 08, SEQ ID NO: 09, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or a combination thereof.
[0011] The present invention also provides a vaccine for preventing Mycoplasma spp. infection, comprising: an active ingredient, comprising a protein of PdhA, XylF, EutD, Mhp145, P78, P132, Mhp389, or a combination thereof; and a pharmaceutically acceptable adjuvant.
[0012] Preferably, said active ingredient is of a concentration of 50 to 3500 μg/mL based on the total volume of said vaccine.
[0013] Preferably, said active ingredient comprises at least two proteins selected from a group consisting of PdhA, XylF, EutD, Mhp45, P78, P132, and Mhp389.
[0014] Preferably, said active ingredient comprises PdhA and P78.
[0015] Preferably, said active ingredient comprises XylF and Mhp145.
[0016] Preferably, said pharmaceutically acceptable adjuvant is a complete Freund's adjuvant, an incomplete Freund's adjuvant, an alumina gel, a surfactant, a polyanion adjuvant, a peptide, an oil emulsion, or a combination thereof.
[0017] Preferably, said vaccine further comprises a pharmaceutically acceptable additive.
[0018] Preferably, said pharmaceutically acceptable additive is a solvent, a stabilizer, a diluent, a preservative, an antibacterial agent, an antifungal agent, an isotonic agent, an absorption delaying agent, or a combination thereof.
[0019] The present invention further provides a vaccine for preventing Mycoplasma spp. infection, comprising: an active ingredient, comprising an amino acid sequence of EQ ID NO: 08, SEQ ID NO: 09, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or a combination thereof; and a pharmaceutically acceptable adjuvant.
[0020] Preferably, said active ingredient is of a concentration of 50 to 3500 μg/mL based on the total volume of said vaccine.
[0021] Preferably, said active ingredient comprises at least two amino acid sequences selected from a group consisting of SEQ ID NO: 08, SEQ ID NO: 09, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, and SEQ ID NO: 14.
[0022] Preferably, said active ingredient comprises amino acid sequences of SEQ ID NO: 08 and SEQ ID NO: 12.
[0023] Preferably, said active ingredient comprises amino acid sequences of SEQ ID NO: 09 and SEQ ID NO: 11.
[0024] Preferably, said pharmaceutically acceptable adjuvant is a complete Freund's adjuvant, an incomplete Freund's adjuvant, an alumina gel, a surfactant, a polyanion adjuvant, a peptide, an oil emulsion, or a combination thereof.
[0025] Preferably, said vaccine further comprises a pharmaceutically acceptable additive.
[0026] Preferably, said pharmaceutically acceptable additive is a solvent, a stabilizer, a diluent, a preservative, an antibacterial agent, an antifungal agent, an isotonic agent, an absorption delaying agent, or a combination thereof.
[0027] The present invention more provides an expression vector for preventing Mycoplasma spp. infection, comprising: a plasmid; wherein said plasmid comprises: a nucleotide sequence comprising at least one sequence selected from a group consisting of SEQ ID NO: 01, SEQ ID NO: 02, SEQ ID NO: 03, SEQ ID NO: 04, SEQ ID NO: 05, SEQ ID NO: 06, and SEQ ID NO: 07; and a regulatory element.
[0028] Preferably, said regulatory element comprises a promoter and a ribosome binding site.
[0029] Preferably, said plasmid is pET-MSY, pET-YjgD, pET-D, or pET-SUMO.
[0030] Preferably, said plasmid further comprises a gene encoding a fusion partner.
[0031] Preferably, said fusion partner is msyB of E. coli , yjgD of E. coli , protein D of Lambda bacteriophage, or SUMO of S. cerevisiae.
[0032] Preferably, said expression vector is used for an E. coli gene expression system.
[0033] To sum up, the present invention is related to antigens that are suitable for being used as the active ingredient of a M. hyopneumoniae subunit vaccine and a M. hyopneumoniae subunit vaccine/composition prepared by using the same. The present subunit vaccine not only can be effectively used in prevention task for lowering down the cost thereof, the disclosure of the present invention also shows that a “cocktail” subunit vaccine (i.e. having at least two antigens as active ingredients) using at least two antigens of the present invention has improved induction of immune response.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The patent or application file contains at least one color drawing. Copies of this patent or patent application publication with color drawing will be provided by the USPTO upon request and payment of the necessary fee.
[0035] FIG. 1 shows the result of the two-dimensional gel protein electrophoresis conducted in the 1 st example of the present invention.
[0036] FIG. 2 shows the result of the color reaction of the Western blot conducted in the 1 st example of the present invention.
[0037] FIG. 3 shows the result of the electrophoresis of the PCR products obtained in the 2 nd example of the present invention.
[0038] FIG. 4 shows the records of the challenge experiments conducted in the 3 rd example of the present invention.
DESCRIPTION OF REFERENCE SIGNS IN THE FIGURES
[0039] 1 XylF(xylose-binding lipoprotein)
[0040] 2 XylF(xylose-binding lipoprotein)
[0041] 3 XylF(xylose-binding lipoprotein)
[0042] 4 PdhA(pyruvate dehydrogenase E1-alpha subunit)
[0043] 5 Mhp145 (periplasmic sugar-binding protein)
[0044] 6 EutD(phosphotransacetylase)
[0045] 7 EutD(phosphotransacetylase)
[0046] 8 Mhp389
[0047] 9 P78(lipoprotein)
[0048] 10 P132
DETAILED DESCRIPTION OF THE INVENTION
[0049] One of the core concepts of the present invention is to survey potential candidate antigens suitable for subunit vaccines by using two-dimensional gel protein electrophoresis along with immunological screening technology and to identify the antigens by mass spectrometer. Then, the performance of the present subunit vaccines were verified by animal model experiments.
[0050] Briefly, the progress of the development of the present invention is:
[0051] (1) Inducing immune response of experiment pigs by injecting a conventional M. hyopneumoniae vaccine and obtaining serum containing anti- M. hyopneumoniae to antibodies. (2) Obtaining total proteins of M. hyopneumoniae for two-dimensional gel protein electrophoresis. (3) Conducting hybridization of the result of the two-dimensional gel protein electrophoresis of step (2) by using the serum of step (1) as 1 st antibody, and then collecting proteins showing positive (i.e. candidate antigens) from the gel after amplification by a 2 nd antibody and the following development procedure. (4) Identifying the candidate antigens obtained in step (3). (5) Expressing said candidate antigens in large amounts by using an E. coli gene expression system. (6) Examining the efficacy of the present subunit vaccines in reducing pathological traits in lung by swine challenge experiments and thereby verifying the value of said candidate antigens in being used as active ingredient of a subunit vaccine.
[0052] The present vaccine for preventing Mycoplasma spp. infection comprises an active ingredient and a pharmaceutically acceptable adjuvant.
[0053] In an embodiment of the present invention, said active ingredient may be PdhA, XylF, EutD, Mhp145, P78, P132, or Mhp389. In an alternative embodiment, as long as the antigenic determinant of any of the aforesaid protein is not interfered, said active ingredient may be a fusion protein of any two of the aforesaid proteins. In another alternative embodiment, said active ingredient comprises at least two of the aforesaid proteins; that is, so called a “cocktail” vaccine of the present invention.
[0054] In another embodiment of the present invention, said active ingredient may comprise an amino acid sequence of SEQ ID NO: 08, SEQ ID NO: 09, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or a combination thereof. In an alternative embodiment, as long as the antigenic determinant formed by folding of a peptide of said amino acid sequence is not interfered, said active ingredient may be a fusion protein with at least two said sequences. In another alternative embodiment, said active ingredient comprises two or more proteins respectively comprising one of the aforesaid amino acid sequences; that is, so called a “cocktail” vaccine of the present invention.
[0055] Said pharmaceutically acceptable adjuvant is used for improving the immune effect of said active ingredient, stabilizing said active ingredient, and/or increasing the safety of vaccines. Said pharmaceutically acceptable adjuvant of the present invention includes, but not limits to: a complete Freund's adjuvant, an incomplete Freund's adjuvant, an alumina gel, a surfactant, a polyanion adjuvant, a peptide, an oil emulsion, or a combination thereof.
[0056] The vaccine of the present invention may have one or at least two said active ingredients (i.e. a cocktail vaccine). In an example of the present vaccine, said active ingredient is of a concentration of 50 to 3500 μg/mL based on the total volume of said vaccine. In a preferable embodiment of the present invention, when said vaccine comprises only one said active ingredient, said active ingredient is of a concentration of 50 to 500 μg/mL based on the total volume of said vaccine. In an alternative embodiment of the present invention, the present vaccine comprises at least one said active ingredient; wherein the total concentration of said active ingredient(s) contained in said vaccine is 50 to 1000 μg/mL, 50 to 1500 μg/mL, 50 to 2000 μg/mL, 50 to 2500 μg/mL, 50 to 3000 μg/mL, or 50 to 3500 μg/mL based on the total volume of said vaccine.
[0057] Another aspect of the present invention is to provide an expression vector for preventing Mycoplasma spp. infection. Specifically, said expression vector may be used for an E. coli gene expression system. Nevertheless, without being apart from the spirit of the present invention, those having ordinary skill in the art can modify said vector based on the disclosure of the present invention and make said vector suitable for different gene expression system while still belongs to the scope of the present invention.
[0058] Said expression vector comprises a plasmid. Said plasmid comprises: a nucleotide sequence comprising at least one sequence selected from a group consisting of SEQ ID NO: 01, SEQ ID NO: 02, SEQ ID NO: 03, SEQ ID NO: 04, SEQ ID NO: 05, SEQ ID NO: 06, SEQ ID NO: 07, and a combination thereof; and a regulatory element.
[0059] Said vector is used in an E. coli gene expression system and for producing the antigens of the present invention via E. coli . In other words, said nucleotide sequence can be translated into the amino sequence of the present antigen via an E. coli gene expression system and then the amino acid sequence can fold into the present antigen.
[0060] In an alternative embodiment, as long as the operation of the E. coli gene expression system is not hindered and the production of said nucleotide sequence and the folding of the consequent amino acid sequence thereof are not interfered, said plasmid may comprise two or more said nucleotide sequences.
[0061] Said regulatory element is referred to an element required for initiating the transcription and translation in the expression system. Said regulatory element shall at least comprise a promoter, and a ribosome binding site. Preferably, said regulatory element may further comprise: an operator, an enhancer sequence, or a combination thereof.
[0062] In a preferable embodiment of the present invention, said plasmid further comprises a gene encoding a fusion partner. Said fusion partner includes but not limits to msyB of E. coli , yjgD of E. coli , protein D of Lambda bacteriophage, or SUMO of S. cerevisiae . Said MsyB is rich in acidic amino acid and might be favorable for improving the solubility of the proteins to be produced.
[0063] The following examples recite the trials and experiments of the present invention in order to further explain the features and advantages of the present invention. It shall be noted that the following examples are exemplary and shall not be used for limiting the claim scope of the present invention.
Example 1
Screening for Candidate Antigens Suitable for Being used as Active Ingredient of a Subunit Vaccine
Preparation of Serum Containing Anti-Swine Mycoplasm spp. Antibody
[0064] According to researches, there are seven Mycoplasm spp. can be isolated from swine: Mycoplasm hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, Mycoplasma flocculare, Mycoplasma hyopharyngis, Mycoplasma sualvi, Mycoplasma bovigenitalium (Gourlay et al., 1978; Blank et al., 1996; Assuncao et al., 2005). Among them, M. hyopneumoniae is the major pathogen of swine enzootic pneumonia with an to infection rate of 25 to 93%. Therefore, the present invention used M. hyopneumoniae (PRIT-5 strain) for immune proteomics studies and as sources of genes encoding antigens. Friis medium (Friis et al., 1975) as used for culturing M.hyopneumoniae . According to the experiment design, a proper amount of antibiotic or agar of 1.5% was added to formulating a solid medium.
[0065] Three SPF pigs of 4-week old were brought from Agricultural Technology Research Institute and fed with same feed and kept at same environment and growth condition in piggery before experiments.
[0066] After the pigs were fed to 32-day, 46-day, and 60-day old, the pigs were administrated 2 mL of Bayovac® MH-PRIT-5 ( M. hyopneumoniae PRIT-5) vaccine via intramuscular injection. Then, the pigs were continuously fed to 74-day old and blood was collected from a jugular vein thereof. The collected blood was placed in room temperature for 1 hour and stored in 4° C. In the next day, the collected blood was centrifugated at 1,107×g for 30 minutes and the supernatant was removed to a clean tube and stored in −20° C.
Two-Dimensional Gel Protein Electrophoresis of the Total Protein of Mycoplasm spp.
[0067] ReadyPrep™ protein extraction kit (total protein) (Bio-Rad, CA, USA) was used for extracting the total protein of Mycoplasm spp.. Afterward, the concentration of the protein collected was determined by using a Bio-Rad RC DC Protein Assay Kit (CA, USA). The detailed protocol can be referred from the product description or can be modified from well-known protocols in the field.
[0068] The two-dimensional gel protein electrophoresis was conducted in two steps: isoelectric focusing (IEF) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IEF was to separate proteins in the sample in view of isoelectric point thereof SDS-PAGE was to separate proteins accordance with molecular weight thereof Please see FIG. 1 , which shows the result of the two-dimensional gel protein electrophoresis.
Hybridization
[0069] The serum obtained in step (1) was used as 1 st antibody to hybridize with the result of the two-dimensional gel protein electrophoresis in step (2). After being amplified by 2 nd antibody and developed by the following development procedure, proteins showing positive were collected. Those proteins were recognized by the anti- Mycoplasm spp. antibody and therefore would be suitable as candidate antigens for active ingredient of subunit vaccines.
[0070] The hybridization was conducted by Western blotting. Briefly, the 2D gel after electrophoresis was transferred to a PVDF membrane. Then, the membrane was incubated and hybridized sequentially with 1 st antibody (the serum containing anti- Mycoplasm spp. antibody) and 2 nd antibody (AP-conjugated anti-pig IgG). Afterward, a color reaction was conducted by using NBT/BCIP solution.
[0071] The result of the color reaction of Western blotting was shown in FIG. 2 ; wherein 10 proteins positive to the immuno-hybridization with anti- Mycoplasm spp. antibody were marked as candidate antigens for being used as active ingredients of subunit vaccines.
Identification of the Candidate Antigens Obtained
[0072] According to the color reaction of the Western blotting, the gel corresponding to the positive location on the membrane was cut by micropeptide and analyzed by mass spectrometry. The obtained data of the mass spectrometry was then matched with amino acid sequence and protein database to identify those proteins.
[0073] Please see the following table 1, said 10 proteins positive to the immune-hybridization with anti- Mycoplasm spp. antibody were listed.
[0000]
TABLE 1
the 10 proteins positive to the immune-hybridization with
anti-Mycoplasm spp. antibody and amino sequence thereof.
Candidate
Name
SEQ ID NO
1
XylF (xylose-binding lipoprotein)
SEQ ID NO: 09
2
XylF (xylose-binding lipoprotein)
SEQ ID NO: 09
3
XylF (xylose-binding lipoprotein)
SEQ ID NO: 09
4
PdhA (pyruvate dehydrogenase E1-alpha
SEQ ID NO: 08
subunit)
5
Mhp145 (periplasmic sugar-binding
SEQ ID NO: 11
protein)
6
EutD (phosphotransacetylase)
SEQ ID NO: 10
7
EutD (phosphotransacetylase)
SEQ ID NO: 10
8
Mhp389
SEQ ID NO: 14
9
P78 (lipoprotein)
SEQ ID NO: 12
10
P132
SEQ ID NO: 13
*XylF and EutD have different charge states in cells and therefore become 3 and 2 positive location on the membrane.
Example 2
Expressing of Said Candidate Antigens in Large Amount by E. coli Gene Expression System
[0074] Escherichia coli JM 109 was used as the host cells for cloning and Escherichia coli BL21 (DE3) was used as the host cells for protein expression. The Escherichia coli cells were cultured in LB medium (Luria-Bertani; Difco, Michigan, USA). According to the experiment design, a proper amount of antibiotic or agar of 1.5% was added to formulating a solid medium.
Amplification of the Genes Encoding the Candidate Antigens
[0075] After the candidate antigens were identified, the genes encoding those antigens were searched in the NCBI database (National Center for Biotechnology Information). Specific primers targeting the antigen genes were designed accordingly. Then, the antigen genes were amplified by using the specific primers and the chromosome of M. hyopneumoniae PRIT-5 as template. The specific primers used were listed in the following table 2.
[0000]
TABLE 2
Primer set.
Candidate
Sequences of the primer set
PdhA
PdhAF (SEQ ID NO: 15)
5′-GATATAGGATCCATGGACAAATTTCGCTATGTAAAGCCT G-3′
PdhAR (SEQ ID NO: 16)
5′-CAATATGTCGACTTATTTTACTCCTTTAAAAAATTCAAGCG
CTTC-3′
XylF
XylFF (SEQ ID NO: 17)
5′-GATATAGGATCCATGAATGGAATAAATTTCTTGGCTTAGGC
TTAGTTTTTC-3′
XylFR (SEQ ID NO: 18)
5′-CAATATGTCGACTTAATTTTTATTAATATCGGTAATTAGTT
TGTCTAAGC-3′
EutD
EUTDF (SEQ ID NO: 19)
5′-GATATAGGATCCATGACATACCAAGAATATCTTCAAGCAA
G-3′)
EUTDR (SEQ ID NO: 20)
5′-CAATATGTCGACCTATTTACCTTCTTCAAC
TTGTAGAGCGCT-3′)
Mhp145
Mhp145F (SEQ ID NO: 21)
5′-GATATAGGATCCATAGCTTCAAGGTCGAA TACAACTGC-3′
Mhp145R (SEQ ID NO: 22)
5′-CAATATGTCGACTTAATTTACCTTTTGGAG TATCCCATTTTC-3′
P78
P78F (SEQ ID NO: 23)
5′-GATATAGGATCCTTATCCTATAAATTTAGG CGTTTTTTCC-3′
P78R (SEQ ID NO: 24)
5′-CAATATGTCGACTTATTTTGATTTAAAAGCAGGACCTAA AT-3′
P132
P132F (SEQ ID NO: 25)
5′-GATATAGGATCCATTGGACTAACAATTTTTGAGAAATCATT
TAG-3′
P132R (SEQ ID NO: 26)
5′-CAATATGTCGACTTATTCCTAAATAGCCCC ATAAAGTG-3′
Mhp389
Mhp389F (SEQ ID NO: 27)
5′-GATATAGGATCCATGGACAAATTTTCACGA ACTGTTCT-3′
Mhp389R (SEQ ID NO: 28)
5′-CAATATGTCGACCTAGATTTTAAAGGATTTTTTTAATTCAA
TAATATAATC-3′
[0076] Polymerase chain reaction (PCR) was conducted with the primer sets listed in the table 2 above to amplify the genes of the candidate antigens. The amplified genes were then used in the E. coli gene expression system. The PCR condition was: 5 minutes in 98° C. (one round); 30 seconds in 94° C., 30 seconds in 55° C., X seconds in 68° C. (35 rounds); 5 minutes in 68° C. (one round). Said X was the elongation time for the DNA polymerase and was set depending on the size of the fragment to be amplified. After the PCR reaction, an electrophoresis was conducted to verify if the PCR products contained the DNA fragments of expected size. Please see FIG. 3 , which shows the electrophoresis result of the PCR products; wherein lane 1 was eutD gene; lane 2 was pdhA; lane 3 was xylF; lane 4 was P78 gene; lane 5 was P132 gene; lane 6 was mhp145; lane 7 was mhp389.
Cloning of the PCR Products
[0077] The cloning was conducted by using a CloneJET PCR Cloning Kit, and the ligation mixture was transformed into E. coli ECOS™9-5 (Yeastern, Taipei, Taiwan). The detailed protocol can be referred from the product description or modified from the well-known protocol in the field.
[0078] After transformation, the bacteria were cultured on a solid LB medium containing ampicillin (100 μg/mL) until colony thereof formed. Then, colony PCR was conducted to screen strains success in transformation. The PCR condition was: 5 minutes in 95° C. (one round); 30 seconds in 95° C., 30 seconds in 55° C., X seconds in 72° C. (25 rounds); 7 minutes in 72° C. (one round). Said X was the elongation time for the DNA polymerase and was set depending on the size of the fragment to be amplified. The elongation speed of Taq DNA polymerase (Genomics, Taipei, Taiwan) is 1 kb/min; therefore, if Taq DNA polymerase is used for amplifying a 1 kb DNA fragment, said X shall be set as 1 minute.
[0079] The plasmids of strains, whose recombinant plasmids were verified having the insert DNA, were then proceeded to DNA sequencing (Total Solution Provider of Systems Biology and Chemoinformatics Ltd.). Plasmids containing eutD, pdhA, xylF, P78 gene, P132 gene, mhp145, and mhp389 were named as pJET-eutD, pJET-pdhA, pJET-xylF, pJET-P78, pJET-P132, pJET-mhp145, pJET-mhp389, respectively.
Point Mutation and Cloning of the Antigen Genes of M hyopneumoniae
[0080] Before amplifying the candidate antigens in an E. coli gene expression system, the codon usage in different organisms shall be considered. That said, if the gene contains codon that would be encoded ambiguously between the original organism therefrom and E. coli , the gene shall be modified by point mutation.
[0081] The M hyopneumoniae antigen genes, pdhA, xylF, P78 gene, P132 gene, mhp145, and mhp389, contain TGA codon (eutD does not have the concern in codon usage like others). The TGA codon was translated into tryptophan in Mycoplasma spp. but translated as stop codon in E. coli . In order to prevent from not being able to produce the entire protein in an E. coli gene expression system, primers targeting the TGA site were designed and point mutation replacing TGA with TGG was conducted by using overlapping extension polymerase chain reaction. As a result, the genes to be expressed in the E. coli gene expression system can be truthfully translated into the candidate antigen of the present invention. Besides, the cutting sites of BamHI of P78 gene, P132 gene, and mhp389 were undergone silent mutation for the convenience of cloning.
[0082] The primers used for point mutation was designed to locate the site of point mutation at the central part of the primer and to have a Tm value of higher than 78° C. The Tm value of the primers for point mutation was calculated by using the formula provided by Invitrogene Co.: Tm=81.5+0.41 (% GC)−675/N−% mismatch; wherein % GC is referred as the percentage of GC in view of the total nucleotides contained in the primer concerned; N is referred as the length of the primer concerned; % mismatch is referred as the percentage of the base to be mutated in view of the total nucleotides contained in the primer concerned. The primer sets used for the aforesaid genes were listed in the following Table 3 to Table 8.
[0000]
TABLE 3
The primer sets for point mutation of pdhA.
Primer
DNA sequence (5′ to 3′)
PdhAF
GATATAGGATCCATGGACAAATTTCGCTATGTAAAGCCTG
SEQ ID
NO: 29
PdhAM1
GCTAACAAAAGATGACTGGTTTGTCCCAGCTTTTCG
SEQ ID
NO: 30
PdhAM2
CGAAAAGCTGGGACAAACCAGTCATCTTTTGTTAGC
SEQ ID
NO: 31
PdhAM3
CTTGCAAATGCAATATTGGAATGGTAGCGAAAAAGG
SEQ ID
NO: 32
PdhAM4
CCTTTTTCGCTACCATTCCAATATTGCATTTGCAAG
SEQ ID
NO: 33
PdhAM5
CGAGGCGCTAAATATTGCAAGTATTTGGAAATGGCCAGTT
SEQ ID
GTTTTTTGCGTAAATAAC
NO: 34
PdhAM6
GTTATTTACGCAAAAAACAACTGGCCATTTCCAAATACTT
SEQ ID
GCAATATTTAGCGCCTCG
NO: 35
PdhAM7
GTTTTTTGCGTAAATAACAATCAATGGGCAATTTCAACCC
SEQ ID
CAAATAAATATG
NO: 36
PdhAM8
CATATTTATTTGGGGTTGAAATTGCCCATTGATTGTTATT
SEQ ID
TACGCAAAAAAC
NO: 37
PdhAM9
GTTGAGTTTGTAACTTGGCGTCAAGGTGTTCATACC
SEQ ID
NO: 38
PdhAM10
GGTATGAACACCTTGACGCCAAGTTACAAACTCAAC
SEQ ID
NO: 39
PdhAM11
GAGAACACGAAAAATGGGAACCAATGCACCGG
SEQ ID
NO: 40
PdhAM12
CCGGTGCATTGGTTCCCATTTTTCGTGTTCTC
SEQ ID
NO: 41
PdhAM13
CCGAAAAACAAAAAATTTGGGATGAAGCGCTTGCGATTG
SEQ ID
NO: 42
PdhAM14
CAATCGCAAGCGCTTCATCCCAAATTTTTTGTTTTTCGG
SEQ ID
NO: 43
PdhAR
CAATATGTCGACTTATTTTACTCCTTTAAAAAATTCAAGC
SEQ ID
GCTTC
NO: 44
[0000]
TABLE 4
The primer sets for point mutation of xylF.
Primer
DNA sequence (5′ to 3′)
XylFF
GATATAGGATCCATGAAATGGAATAAATTTCTTGGCTTAGG
SEQ ID
CTTAGTTTTTC
NO: 45
XylFM1
CATTTAACCAATCAAGTTGGGAGGCAATTCAACAACTTGG
SEQ ID
NO: 46
XylFM2
CCAAGTTGTTGAATTGCCTCCCAACTTGATTGGTTAAATG
SEQ ID
NO: 47
XylFM3
CTAATACCAACAAAAATGTTTGGGTACTTTCTGGTTTTCAA
SEQ ID
CACG
NO: 48
XylFM4
CGTGTTGAAAACCAGAAAGTACCCAAACATTTTTGTTGGTA
SEQ ID
TTAG
NO: 49
XylFM5
CGGTGATGCGATCACAAAATGGTTAAAAATCCCTGAAAATA
SEQ ID
AGC
NO: 50
XylFM6
GCTTATTTTCAGGGATTTTTAACCATTTTGTGATCGCATCA
SEQ ID
CCG
NO: 51
XylFM7
TTATCATACTCGGAATTGACTGGACTGATACTGAAAATGTA
SEQ ID
ATTC
NO: 52
XylFM8
GAATTACATTTTCAGTATCAGTCCAGTCAATTCCGAGTATG
SEQ ID
ATAA
NO: 53
XylFM9
GAAGAAGCCGGATGGCTTGCAGGATATGC
SEQ ID
NO: 54
XylFM10
GCATATCCTGCAAGCCATCCGGCTTCTTC
SEQ ID
NO: 55
XylFM11
GGTTATCTAGCCGGAATTAAAGCTTGGAATCTAAAAAATTC
SEQ ID
TGATAAAAAAAC
NO: 56
XylFM12
GTTTTTTTATCAGAATTTTTTAGATTCCAAGCTTTAATTCC
SEQ ID
GGCTAGATAACC
NO: 57
XylFR
CAATATGTCGACTTAATTTTTATTAATATCGGTAATTAGTT
SEQ ID
TGTCTAAGC
NO: 58
[0000]
TABLE 5
The primer sets for point mutation of P78 gene.
Primer
DNA sequence (5′ to 3′)
P78F
GATATAGGATCCTTATCCTATAAATTTAGGCGTTTTTTCC
SEQ ID
NO: 59
P78M1
CAATTAATAAAGTTTTGTTTGGTTGGATGATTAATAAAGC
SEQ ID
ACTTGCTGATCC
NO: 60
P78M2
GGATCAGCAAGTGCTTTATTAATCATCCAACCAAACAAAA
SEQ ID
CTTTATTAATTG
NO: 61
P78M3
GATATTAAAGAAATTGAAAGAATCTGGAAAAAATATGTCT
SEQ ID
CCGATGATCAAGG
NO: 62
P78M4
CCTTGATCATCGGAGACATATTTTTTCCAGATTCTTTCAA
SEQ ID
TTTCTTTAATATC
NO: 63
P78M5
GCCCTTTCAGGAGGCTCCACTGATTCGGCA
SEQ ID
NO: 64
P78M6
TGCCGAATCAGTGGAGCCTCCTGAAAGGGC
SEQ ID
NO: 65
P78M7
GCCGCAAAAGCTTTTGTTAAATGGCTTTTGACAGAAAAAA
SEQ ID
TAGTCT
NO: 66
P78M8
AGACTATTTTTTCTGTCAAAAGCCATTTAACAAAAGCTTT
SEQ ID
TGCGGC
NO: 67
P78R
CAATATGTCGACTTATTTTGATTTAAAAGCAGGACCTAAA
SEQ ID
T
NO: 68
[0000]
TABLE 6
The primer sets for point mutation of P132 gene.
Primer
DNA sequence (5′ to 3′)
P132F
GATATAGGATCCATTGGACTAACAATTTTTGAGAAATCAT
SEQ ID
TTAG
NO: 69
P132M1
CTAACTTCTCTAAAAGGTTGGAAAGAAGAAGATGATTTTG
SEQ ID
NO: 70
P132M2
CAAAATCATCTTCTTCTTTCCAACCTTTTAGAGAAGTTAG
SEQ ID
NO: 71
P132M3
CTTTCTATTACTTTTGAACTCTGGGACCCAAATGGTAAAT
SEQ ID
TAGTATC
NO: 72
P132M4
GATACTAATTTACCATTTGGGTCCCAGAGTTCAAAAGTAA
SEQ ID
TAGAAAG
NO: 73
P132M5
CCCTGAAGGAGATTGGATAACTTTAGGGAG
SEQ ID
NO: 74
P132M6
CTCCCTAAAGTTATCCAATCTCCTTCAGGG
SEQ ID
NO: 75
P132M7
CTACCAGGAACTACCTGGGATTTCCATGTTGAAC
SEQ ID
NO: 76
P132M8
GTTCAACATGGAAATCCCAGGTAGTTCCTGGTAG
SEQ ID
NO: 77
P132M9
GGACAACTAATTTGGAGCCAGTTAGCTTCC
SEQ ID
NO: 78
P132M10
GGAAGCTAACTGGCTCCAAATTAGTTGTCC
SEQ ID
NO: 79
P132M11
GGAACAAAAAAGGAATGGATTCTTGTAGGATCTGG
SEQ ID
NO: 80
P132M12
CCAGATCCTACAAGAATCCATTCCTTTTTTGTTCC
SEQ ID
NO: 81
P132M13
CCAATACGCAAATATGGATAACCCGTCTAGGAAC
SEQ ID
NO: 82
P132M14
GTTCCTAGACGGGTTATCCATATTTGCGTATTGG
SEQ ID
NO: 83
P132M15
CCAAGGGGAAGTTCTCTGGACTACTATTAAATCCAAAC
SEQ ID
NO: 84
P132M16
GTTTGGATTTAATAGTAGTCCAGAGAACTTCCCCTTGG
SEQ ID
NO: 85
P132M17
CAAAAAACTTCACCTTTGGTGGATTGCTAATGATAGC
SEQ ID
NO: 86
P132M18
GCTATCATTAGCAATCCACCAAAGGTGAAGTTTTTTG
SEQ ID
NO: 87
P132R
CAATATGTCGACT TATTCCTAAATAGCCCCATAAAGTG
SEQ ID
NO: 88
[0000]
TABLE 7
The primer sets for point mutation of mhp145.
Primer
DNA sequence (5′ to 3′)
Mhp145F
GATATAGG ATCCAT AGCTTCAAGGTCGAATACAACTGC
SEQ ID
NO: 89
Mhp145M1
AATAATTGCAGAAAAAATTCTTAAAGATCAATGGAAAACA
SEQ ID
AGTAAATATTCTGATTTTTATTCACAAT
NO: 90
Mhp145M2
ATTGTGAATAAAAATCAGAATATTTACTTGTTTTCCATTG
SEQ ID
ATCTTTAAGAATTTTTTCTGCAATTATT
NO: 91
Mhp145R
CAATATGTCGACTTA ATTTACCTTTTGGAGTATCCCATT
SEQ ID
TTC
NO: 92
[0000]
TABLE 8
The primer sets for point mutation of mhp389.
Primer
DNA sequence (5′ to 3′)
Mhp389F
GATATAGGATCCATGGACAAATTTTCACGAACTGTTCT
SEQ ID
NO: 93
Mhp389M1
CAATAGTGACAATGGACCCCCCAAATGTTGGTCG
SEQ ID
NO: 94
Mhp389M2
CGACCAACATTTGGGGGGTCCATTGTCACTATTG
SEQ ID
NO: 95
Mhp389M3
GATAAAGGCGCATCATGGCTTGCGCTTGCACCAAC
SEQ ID
NO: 96
Mhp389M4
GTTGGTGCAAGCGCAAGCCATGATGCGCCTTTATC
SEQ ID
NO: 97
Mhp389M5
GGAAAACTTAAAGGTAAATGGACTTTTGGACTAACCTATTT
SEQ ID
NO: 98
Mhp389M6
AAATAGGTTAGTCCAAAAGTCCATTTACCTTTAAGTTTTCC
SEQ ID
NO: 99
Mhp389R
CAATATGTCGACCTAGATTTTAAAGGATTTTTTTAATTCAA
SEQ ID
TAATATAATC
NO: 100
[0083] The method for the point mutation was briefly explained as follows. The chromosome of M hyopneumoniae PRIT-5 was used as template and DNA fragments was amplified by using the primer sets set forth in the table 3 to table 8 above.
[0084] The 50 μL PCR reaction mixture comprised 1×GDP-HiFi PCR buffer, 200 μM of mixture of dATP, dTTP, dGTP, and dCTP, 1 μM of primers, 100 ng of chromosome of M hyopneumoniae PRIT-5, and 1 U of GDP-HiFi DNA polymerase. The PCR condition was: 5 minutes in 98° C. (one round); 30 seconds in 94° C., 30 seconds in 55° C., X seconds in 68° C. (35 rounds); 5 minutes in 68° C. (one round). Said X was the elongation time for the DNA polymerase and was set depending on the size of the fragment to be amplified. The elongation speed of GDP-HIFI DNA polymerase (GeneDirex, Las Vegas, USA) is 1 kb/15 seconds; therefore, if GDP-HIFI DNA polymerase is used for amplifying a 1 kb DNA fragment, said X shall be set as 15 seconds. After the PCR reaction, an electrophoresis was conducted to verify if the PCR products contained the DNA fragments of expected size. Then, the PCR product was recycled by using a Gel-M™ gel extraction system kit.
[0085] Afterward, the PCR product was used as template and amplified by using the primer sets set forth in the table 2 above. The PCR condition was: 2 minutes in 98° C. (one round); 30 seconds in 94° C., 30 seconds in 55° C., X seconds in 68° C. (35 rounds); 5 minutes in 68° C. (one round). Said X was the elongation time for the DNA polymerase and was set depending on the size of the fragment to be amplified. The elongation speed of GDP-HIFI DNA polymerase (GeneDirex, Las Vegas, USA) is 1 kb/15 seconds; therefore, if GDP-HIFI DNA polymerase is used for amplifying a 1 kb DNA fragment, said X shall be set as 15 seconds. After the aforesaid amplification step, a full length sequence of the candidate antigen genes with point mutation can be obtained.
[0086] Then, the PCR product was recycled by using a PCR-M™ Clean Up system kit (GeneMark, Taichung, Taiwan) and the cloning thereof was conducted by using a CloneJET PCR Cloning Kit. Colony PCR was conducted to confirm the strains after transformation containing plasmid having the insert DNA and then the plasmids therein were isolated for DNA sequencing (Total Solution Provider of Systems Biology and Chemoinformatics Ltd.). Plasmids containing mutated candidate antigen genes were named as pJET-pdhAM, pJET-xylFM, pJET-P78M, pJET-P132M, pJET-mhp145M, pJET-mhp389M, respectively.
[0087] According to the result of sequencing, the DNA sequences of the candidate antigen genes after point mutation were as shown in SEQ ID NO:01 (pdhA), SEQ ID NO:02 (xyiF), SEQ ID NO:03 (eutD, was not point-mutated), SEQ ID NO:04 (mhp145), SEQ ID NO:05 (P78 gene), SEQ ID NO:06 (P132 gene), SEQ ID NO:07 (mhp389).
Construction of the Expression Vectors for Expressing the M. hyopneumoniae Antigens
[0088] In this part of experiments, plasmid pET-MSY was used as backbone for constructing an expression vector for expressing M. hyopneumoniae antigen. pET-MSY is a derivative of pET29a and has a E. coli msyB. Therefore, the expressed recombinant antigen thereby would have a fusion partner MsyB. MsyB is rich in acidic amino acid and is able of increasing the solubility of the protein expressed.
[0089] After pJET-eutD, pJET-pdhA, pJET-xylF, pJET-P78, pJET-P132, pJET-mhp145 and pJET-mhp389 being digested by BamHI and SalI, DNA fragment obtained was inserted into pET-Msy digested previously with the same restriction enzymes by ligase. Then, the pET-Msy with the DNA fragment was transformed into E. coli ECOS 9-5. Colony PCR was conducted to confirm the strains after transformation containing plasmid having the insert DNA and then the plasmids therein were isolated for DNA sequencing (Total Solution Provider of Systems Biology and Chemoinformatics Ltd.). Plasmids verified with correct DNA sequence were named as pET-MSYEutD, pET-MSYPdhA, pET-MSYXylF, pET-MSYP78, pET-MSYP132, pET-MSYMhp145, and pET-MSYMhp389, respectively. Those plasmids obtained were examples of the expression vectors for preventing Mycoplasma spp. infection of the present invention.
Expression and Isolation of the M. hyopneumoniae Antigens
[0090] The vectors for antigen expression were transformed into E. coli BL21 (DE3). Single colony of consequent strains after transformation was inoculated in LB liquid medium containing kanamycin (working concentration: 30 μg/mL). After culture overnight at 37° C., 180 rpm, the suspension of the bacteria was diluted at ratio of 1:100 and inoculated again in another LB liquid medium containing kanamycin (working concentration: 30 μg/mL). The bacteria were cultured at 37° C., 180 rpm until OD 600 therefore achieving about 0.6 to 0.8. Then, 0.1 mM of IPTG was added to induce expression. After induction for 4 hours, pellet was collected by centrifugation (10000×g, 10 minutes, 4° C.) and the expression was examined via protein electrophoresis.
[0091] Afterward, immobilized-metal affinity chromatography (IMAC) was used for protein isolation through the covalent bonding between the His tag of the N-terminal of the recombinant protein and nickel ions or cobalt ions. The protocol of protein isolation was in accordance with the product description of the QIAexpressionist™ (fourth edition, Qiagen). The pellet was suspended in a lysis buffer (50 mM NaH 2 PO, 300 mM NaCl, 10 mM imidazole, pH 8.0) and disturbed by an ultrasonic processer. After centrifugation (8,000×g, 15 minutes), the supernatant was collected to introduce into a column of 1 mL Ni-NTA resin. The recombinant antigens would adhere on said resin. Then, 15 mL wash buffer (50 mM NaH 2 PO 4 , 300 mM NaCl, 20 mM imidazole, pH 8.0) was introduced into the column to wash the resin so that nonspecific proteins adhering thereon can be removed. Lastly, 20 mL elution buffer was added (50 mM NaH 2 PO 4 , 300 mM NaCl, 250 mM imidazole, pH 8.0) to wash off the recombinant antigens on the resin; wherein the imidazole of high concentration can compete the binding site on the resin with the recombinant proteins and thereby cause the recombinant proteins being washed off. The result of isolation was then examined by protein electrophoresis.
[0092] The candidate antigens of the present invention collected by isolation can then be used for the following immune trials to confirm their ability to be used as active ingredient of anti- Mycoplasm spp. subunit vaccines.
Example 3
Swine Immune Challenge Experiments of the Candidate Antigens of the Present Invention
[0093] In this example, the candidate antigens of the present invention were used as active ingredient for preparing subunit vaccines and tested for immune effects thereof in live swine.
Vaccine Preparation
[0094] One isolated recombinant antigen or several isolated recombinant antigens were mixed with alumina gel as an adjuvant to prepare a subunit vaccine or a cocktail subunit vaccine. Every dose of the prepared vaccine was of 2 mL in volume and each kind of antigen contained therein was of 100 μg.
[0095] The following table 9 listed the samples prepared in this example for immune challenge experiments.
[0000]
TABLE 9
Samples of vaccine prepared in Example 3
Sample
Active Ingredient (Antigen)
1
PdhA
2
XylF
3
EutD
4
Mhp145
5
P78
6
P132
7
Mhp389
8
PdhA + P78
9
XylF + Mhp145
[0096] The swine immune challenge experiments would be conducted by using Bayovac® MH-PRIT-5 (made by using M hyopneumoniae PRIT-5, as a positive control group), subunit vaccines (samples 1-7 of the present invention), and cocktail vaccines (samples 8 and 9 of the present invention).
[0097] 33 SPF pigs of 4-week old were brought from Agricultural Technology Research Institute and fed with same feed, environment, and growth condition in piggery before experiments.
[0098] After the pigs were fed to 35-day and 49-day old, the pigs were administrated 2 mL of vaccine above via intramuscular injection.
Challenge Experiments
[0099] The aforesaid pigs being induced immune response were challenged by Mycoplasm spp. at 109-day old to confirm the immune effect of the aforesaid vaccines.
[0100] First of all, a lung collected from pigs infected by Mycoplasm spp. was ground in 20 mL of Friis medium and centrifugated at 148.8×g for 10 minutes. The supernatant was removed to a clean tube and centrifugated again at 7,870×g for 40 minutes. Then, the supernatant was discarded and the precipitation was suspended in 6 mL of Friis medium to obtain a suspension. Afterward, the suspension was filtered by membrane of 5 μm and 0.45 μm sequentially to obtain bacteria solutions required for the challenge experiments.
[0101] The bacteria solution (5 mL) was administrated to narcotized pigs via trachea thereof. After 28 days from administration, the pigs were sacrificed and dissected to collect lung thereof. The immune effect was examined by observing the lung and recorded according to the following criteria: any of meddle upper lobes and upper lobes of any side of the lung observed of pathological trait was scored as 10 points; any of meddle upper lobe and diaphragmatic lobes of any side of the lung observed of pathological trait was scored as 5 points. The full score was 55 points. The observation records were shown in FIG. 4 .
[0102] In comparison with the results of non-injected pigs, the seven candidate antigens of the present invention were able to provide equivalent immune effects as conventional vaccine (Bayovac® MH-PRIT-5). If the higher safety of subunit vaccines is taking into consideration, the vaccines containing the candidate antigens of the present invention shall be valued more.
[0103] On the other hand, it was not common to use two or more antigens that would induce immune effects in one vaccine because the two or more antigens may not provide doubled immune effect. In fact, there is higher chance that the two or more antigens may interfere or against each other and consequently reduce the immune effect of the vaccine. According to the result of this example, sample 8 and sample 9 of the present invention (i.e. cocktail vaccine) unexpectedly provide significant increase in the immune effect. That said, the subunit vaccines of the present invention not only have high safety but also provide better immune effect when the candidate antigens of the present invention are used in combination.
[0104] Those having ordinary skill in the art can readily understand any possible modifications based on the disclosure of the present invention without apart from the spirit of the present invention. Therefore, the examples above shall not be used for limiting the present invention but intend to cover any possible modifications under the spirit and scope of the present invention according to the claims recited hereinafter.
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Provided in the present invention are anti- Mycoplasma spp. subunit vaccines, especially proteins suitable for being used as the active ingredient of the Mycoplasma spp. subunit vaccines, and a vaccine prepared therefrom. Upon experimenting, it is confirmed that the proteins can elicit an immune response having sufficient strength to avoid the infection of Mycoplasma spp. in pigs. The vaccine can comprise one of the aforementioned proteins as an active ingredient, or can comprise two or more of the proteins to form a form of cocktail vaccine. The vaccine of the present invention is not only more safe than conventional vaccines, but also has equivalent or even better immune effects.
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FIELD OF THE INVENTION
This invention relates to the synthesis of hydroxyl-terminated polybutadienes.
More particularly this invention is directed to an improvement in a process for polymerizing 1,3-butadiene selectively to form relatively low molecular weight hydroxyl-terminated polybutadiene oligomers in the presence of an aqueous solution of hydrogen peroxide, said improvement comprising achieving butadiene oligomers having a high degree of OH functionality and suppressing the solid or gel-type insoluble rubber by-products by using a solvent selected from the group consisting of aliphatic glycol ether acetates or aliphatic glycol ether carboxylates.
BACKGROUND OF THE INVENTION
Low-molecular weight homo- and copolymers of 1,3-dienes have been known for a long time. It is advantageous for many uses to alter the properties of the hydrophobic polymers in a controlled fashion by introduction of polar groups. One of these groups is the hydroxyl group because reactions with isocyanates, for example, can be carried out on such a group.
It is also known in the art that hydroxyl-terminated polybutadiene can provide polyurethanes having good hydrolytic stability, chemical resistance and a wide range of mechanical properties.
Processes for the preparation of polyhydroxybutadiene (hydroxyl-containing butadiene homopolymers) are known in the art, and may be prepared, for example, by the methods described in U.S. Pat. Nos. 2,877,212, 3,055,952; 3,333,015; 3,338,861; 3,427,366; 3,673,168 and 3,796,762, incorporated herein by reference. For a review of polymeric butadienes see J. N. Henderson, Encyl. Polym. Sci. Eng. 515-36, 2 (1985) and W. Heitz, Telechelic Polymers: Synthesis and Applications, Chapter 4, p. 61 (1989).
In U.S. Pat. No. 4,460,801 there is disclosed a process for reacting butadiene and water in the presence of a palladium salt and boric acid in a polar, aprotic solvent to prepare an unsaturated fatty alcohol of the formula: ##STR1## where n=2 or 4.
U.S. Pat. No. 4,670,518 discloses a process for the production of low-molecular weight homo- and/or copolymers of 1,3-dienes carrying hydroxymethyl groups partially esterified with formic acid, comprising reacting 1,3-dienes having an average molecular weight of 500-8000 with formaldehyde at temperatures of 150°-300° C. optionally in the presence of a solvent and stabilizer.
Butadiene has been polymerized with four-valence molybdenum catalysts. See M. Zhao et al., C. A. Selects, p. 12, 19 (1986). In other work ∝,ω-hydroxyl-terminated polybutadienes with different molecular weights and microstructures were prepared in nonpolar media using lithium-naphthalene-THF as a catalyst (See U.S. Pat. No. 3,055,952 and Germ. Pat. No. 1,173,658).
In U.S. Pat. No. 4,721,754 there is described a polybutadiene composition useful for the preparation of polyurea and/or polyurethane elastomers comprising a blend of a polyhydroxybutadiene homopolymer and an amine terminated polybutadiene.
A problem has existed in polybutadiene solvent recovery units wherein due to solids formation below the feed trays of the distillation columns, fouling may occur which plugs the trays and downcomers. The fouling is apparently caused by the presence of hydrogen peroxide, low molecular weight polybutadienes, polymeric precursors such as butadiene and vinylcyclohexene formed by the polymerization reaction. Such fouling may occur approximately every 5 to 6 days at high plant production rates thus requiring frequent and expensive shutdowns for cleaning.
U.S. Pat. No. 4,518,770 discloses a method of reducing the fouling in a distillation unit which comprises injecting into the distillation unit, along with the feed stream from which the polyhydroxybutadiene has been removed, an aqueous solution of an alkali metal sulfite or bisulfite.
In a Japanese patent 1012-707-A to Idemitsu Petrochem there is disclosed a method for preparing a liquid diene polymer containing OH groups prepared by reacting the conjugated diene monomer with H 2 O 2 in the presence of carboxylic acid.
It would be extremely desirable in the art if a process were available whereby low molecular weight oligomers could be prepared which possessed a high degree of OH functionality by a method which avoided the formation of solid or gel-type insoluble rubbers that are known to foul the reactor.
SUMMARY OF THE INVENTION
In accordance with certain of its aspects, the novel method of this invention for polymerizing 1,3-butadiene to selectively form relatively low molecular weight hydroxyl-terminated polybutadiene oligomers using a process which minimizes fouling comprises polymerizing the 1,3-butadiene in the presence of an aqueous solution of hydrogen peroxide and a solvent from the group consisting of aliphatic glycol ether acetates and aliphatic glycol ether carboxylates.
This invention demonstrates an improvement over the prior art in that the hydroxyl-terminated butadiene oligomers possess low molecular weight and, at the same time, a high degree of OH functionality. Even more important is the improvement demonstrated by the process of the invention that allows for the formation of the desired oligomers without the accompanying formation of the solid or gel-type insoluble rubbers that may foul the reaction system.
DESCRIPTION OF THE INVENTION
In accordance with this invention there is provided an improved process for the preparation of oligomers of 1,3-butadiene which demonstrates a number of distinct advantages over other processes known in the related art.
The process has the following advantages: 1) The solvent can be easily removed from the system; 2) It does not interfere with the polymerization process; 3) It has miscibility with a diluted aqueous solution of hydrogen peroxide over a wide range of weight ratios; 4) It provides a product with desirable properties; and 5) It minimizes polymer build-up in the reactor system in the form of gel or solid rubber-like oligomers.
The products can be represented by the following structure: ##STR2## where x, y and z are integers.
The hydroxyl-terminated polybutadiene oligomers prepared according to this invention contain hydroxyl groups that are in predominantly primary, terminal positions on the main hydrocarbon chain and are allylic in configuration. Ordinarily, at least about 1.8 hydroxyl groups are present per molecule on the average, and advantageously there are at least 2.1 to say 3 or more hydroxyls per polymer molecule, preferably 2.1 to 2.8. The diene polymer has the majority of its unsaturation in the main hydrocarbon chain, such that x plus z in the general structure (A) is greater than y. This formula (A) should not be understood as implying that the polymers are necessarily in blocks, but the cis-1,4-, trans-1,4 and vinyl(1, 2) unsaturation are usually distributed throughout the polymer molecule. The letter x may represent a number sufficient to give a trans-1,4-unsaturation content of 40-70 percent; y may be a number sufficient to give a 1,2-vinylic unsaturation content to the polymer in the range of about 10-35 percent, while z may be sufficient to provide a cis-1,4-unsaturation of about 10-30 percent. Often the polymer will contain largely trans-1,4-units, e.g. about 50-65 percent and about 15-25 percent cis-1,4-units, with about 15-25 percent 1,2-units. Branching may also occur in the above polymers, especially those prepared at higher temperatures; ether and carbonyl linkages may appear in the lower molecular weight oligomer fractions.
The number average molecular weight of the product oligomers (of general structure A) is ordinarily in the range of about 100 to about 20,000, and the hydroxyl content of said products is in the range of 0.1 to 20 meq/g, or higher. Preferably, the number average molecular weight is in the range 200 to 2000 and the hydroxyl content is in the range of 1 to 10 meq/g. Product oligomers of this type are illustrated by the accompanying examples.
Preparation of the product of this invention may be carried out typically by combining a 30 to 70% aqueous solution of hydrogen peroxide with a glycol ether acetate or carboxylate solvent and then reacting the liquid mix with 1,3-butadiene at a pressure of 0-5000 psig and a temperature of 50°-200° C. to form a one or two layered product and subsequently stripping said product or products to remove lights, solvents, etc.
The dienes which are employed to prepare the polyhydroxybutadienes include the unsubstituted, 2-substituted or 2,3-disubstituted 1,3-dienes of 4 up to about 12 carbon atoms. The diene preferably has up to 6 carbon atoms and the substituents in the 2- and/or 3-position may be hydrogen, alkyl, (generally lower alkyl, e.g., of 1 to 4 carbon atoms), aryl (substituted or unsubstituted), halogen, nitro, nitrile, etc. Typical dienes which may be employed are 1,3-butadiene, isoprene, chloroprene, 2-cyano-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 2-methyl-3-phenyl-1,3-butadiene, etc. The examples demonstrate the particular effectiveness of 1,3-butadiene.
The aqueous solution of hydrogen peroxide is diluted with water. The H 2 O 2 content can be in the range of 10% to 80%. Preferably the aqueous solution is in the range of about 30% to 50% H 2 O 2 . Lower contents can be used if necessary.
The molar ratio of hydrogen peroxide feed to 1,3-butadiene may vary in the range of 1:100 to 100:1, or higher, but in order to prepare desired, highly functionalized, OH-oligomers of low molecular weight, the initial H 2 O 2 :1,3-butadiene should preferably be in the range of 1:10 to 10:1 for an economically attractive process; most preferred are molar ratios of ca. 1:1.
The solvent is the critical factor in the improvement of this invention. The solvent should be able to solubilize the 50% aqueous hydrogen peroxide, the butadiene and the hydroxyl-terminated polymer into a single phase over a wide range of reactant/product ratios. In addition the solvent should be able to adequately solubilize the 1,3-butadiene at the temperature of oligomerization (ca. 50°-200° C.) in order to ensure no polymer build up in the C 4 entrance lines and other cooler portions of the reactor system. It is desirable that the solvent not interfere with the polymerization process nor be incorporated into the polymer product. Such a solvent system should have great commercial potential, especially if the solvent were low cost and had a low enough boiling point such that it could be easily stripped from the desired OH-oligomer product.
It has been surprisingly discovered in the process of the instant invention that certain glycol ether carboxylate solvents, including glycol ether acetates particularly alkylene glycol monoalkyl ether acetates and aliphatic glycol ether carboxylates provide all these advantages in the polymerization process. The glycol ether acetates can be aromatic or aliphatic glycol ether acetates. Aliphatic glycol monoalkyl ether acetates which work in this process include ethylene glycol monoalkyl ether acetates and carboxylates having the general structure: ##STR3## where R and R' are alkyl radicals containing one to ten, preferably 1 to 6, carbon atoms that may, or may not, be different, but which are typically methyl, ethyl, isopropyl, t-butyl and n-hexyl. Typical examples include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol monobutyl ether acetate, ethylene glycol mono-t-butyl ether acetate, ethylene glycol monopropyl ether acetate and ethylene glycol monohexyl ether acetate.
Suitable propylene glycol monoalkyl ether carboxylates would have the general structure: ##STR4## where R and R' are alkyl radicals containing one to ten, preferably 1 to six, carbon atoms that may, or may not, be different, as described above, and R" and R"' are either hydrogen, or the methyl radical. Typical examples include propylene glycol monomethyl ether acetates, propylene glycol monobutyl ether acetates or propylene glycol mono-t-butyl ether acetates. Said propylene glycol monoalkyl ether carboxylates may, or may not, be a mixture of isomeric forms.
Suitable aromatic glycol ether acetates include 2-phenoxylethyl acetate and p-methoxyphenoxyethyl acetate.
Generally, the aliphatic glycol ether carboxylates suitable for the practice of this invention are made from aliphatic carboxylic acids with 1 to 6 carbon atoms. Examples include acetic acid, propionic acid and the butyric acids.
The examples herein demonstrate that good results have been achieved with ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate.
While the hydroxyl components of the product polyhydroxybutadienes are predominantly primary, terminal and allylic in structure, both the ratio of cis-1,4, trans- 1,4 and 1,2-vinyl unsaturation which occurs in the diene polymers prepared by this invention, in addition to the number and location of the hydroxyl groups, and the molecular weight of the polymers, can be a function of polymerization conditions, particularly the temperature, the H 2 O 2 to 1,3-butadiene feed ratio, and the type of addition polymerization system employed in forming the polymer. It has been found that diene polymers of the desired configuration can be obtained using hydrogen peroxide as the initiator for polymerization in a suitable solvent system. This free-radical addition polymerization usually takes place in solution at a temperature above about 50° C. to 200° C.
The polymerization may be conducted batchwise in a continuous slurry reactor, or in a stirred tank, continuous flow reactor.
Polymerization of 1,3 -butadiene in the presence of about 50% H 2 O 2 can generally be conducted at temperatures from 100° C. to 150° C. The operating pressure may be from zero to 5000 psig. The most preferred temperature range is about 110°-130° C. and the preferred pressure range is about 100 psig to 1000 psig.
Example 1 illustrates the syntheses of desired low molecular weight hydroxyl-terminated polybutadiene oligomers having a high degree of hydroxyl functionality using hydrogen peroxide as initiator and ethylene glycol monoethyl ether acetate as solvent.
Advantages to using said solvent include:
a) Its miscibility with 50% aqueous hydrogen peroxide over a wide range of weight ratios.
b) It does not interfere with the polymerization process or the formation of desired hydroxyl-terminated polybutadiene oligomer.
c) It can be easily removed from the desired oligomer product.
Example 2 illustrates the synthesis of desired low molecular weight hydroxyl-terminated polybutadiene oligomers of the same type using propylene glycol monomethyl ether acetate as the solvent of choice.
EXAMPLE 1
To a 300 cc capacity, stirred clave reactor fitted with temperature and pressure controls plus facilities for two continuous feed additions, was charged with ethylene glycol monomethyl ether acetate, and the reactor heated to temperature (120° C.) under pressure (600 psi). A liquid mix of 50% hydrogen peroxide aqueous solution (2 parts) and ethylene glycol monomethyl ether acetate (3 parts) was then fed continuously to said reactor at a rate of 300g/hr (1.76 moles H 2 O 2 /hr), and when the system was lined out, a second feed of 1,3-butadiene was also introduced simultaneously at a rate of 100 g/hr (1.85 moles/hr). After a few hours on stream, typical liquid product was collected under these steady state conditions for about 30 hours.
The two-phase liquid product was allowed to stand and the two layers separated. A sample (1462 g) of the top layer was stripped to remove lights, solvent, etc., and the residue, water-white liquid (1026 g) analyzed as follows:
______________________________________Number Average mw 11.83Weight Average mw 2154Dispersity 1.8Viscosity 2900 cs/25° C.Hydroxyl Number 1.6 meq KOH/g______________________________________
13 C NMR analyses of this product shows the total carbon association with the three major functionalities of this material, olefin, OH and aliphatic, to be about 47, 6.6 and 46%, respectively. A sample (4505 g) of the heavier layer was likewise stripped to remove lights, solvent, etc., and the residual liquid (633 g) analyzed as follows:
______________________________________Number Average mw 246Weight Average mw 543Dispersity 2.2Viscosity 2998 cs/25° C.Hydroxyl Number 8.7 meq KOH/g______________________________________
EXAMPLE 2
Using the same 300 cc capacity, stirred autoclave reactor system of Example 1, as well as the same start-up procedures, said reactor was charged with a mix of 50% hydrogen peroxide solution (2 parts) and 1,2-propylene glycol monomethyl ether acetate (3 parts) at a rate of 300 g/hr (1.76 moles H 2 O 2 /hr), plus 1,3-butadiene at 100 g/hr (1.85 moles/hr). Operating conditions were 120° C. and 600 psi. Liquid product was collected from the unit for about 24 hours under steady state conditions.
The two-phase liquid product was allowed to stand at ambient temperature and the two layers separated. A sample of the top layer (1043 g) was stripped to remove lights, solvent, etc., and the residual liquid (637 g) analyzed as follows:
______________________________________Number Average mw 1534Weight Average mw 2689Dispersity 1.8Viscosity 5352 cs/25° C.Hydroxyl Number 2.2 meq KOH/g______________________________________
A sample of the heavier layer (6865 g) was likewise stripped to remove lights, solvent, etc., and the residual liquid (708 g) analyzed as follows:
______________________________________Number Average mw 251Weight Average mw 643Dispersity 2.6Hydroxyl Number 10.5 meq KOH/g______________________________________
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Disclosed is an improvement in a process for polymerizing 1,3-butadiene selectively to form relatively low molecular weight hydroxyl-terminated polybutadiene oligomers in the presence of an aqueous solution of hydrogen peroxide which comprises the use of a solvent selected from the group consisting of alkylene glycol monoalkyl ether acetates and aliphatic glycol ether carboxylates to produce butadiene oligomers having a high degree of OH functionality and suppression of formation of solid or gel-type insoluble rubber by-products.
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BACKGROUND OF THE INVENTION
[0001] Soap-containing compositions generally need to be protected against decomposition as shown by discoloring, particularly yellowing, of the composition. Such protection usually comes from various opacifying materials present in a soap composition such as titanium dioxide, zinc oxide, and the like. However, certain solid soap-containing compositions are desirably translucent or even transparent. Opacifiers and other materials which bring about opaqueness and behave as discoloration inhibitors are absent from these compositions. Therefore, discoloration, particularly yellowing of the solid soap-containing compositions can be a significant issue. Such discoloration can become even more exacerbated when the container has at least one window through which the translucent or transparent soap bar can be visualized by the human eye, or the entire container is made from a material through which the translucent or transparent soap bar can be viewed.
[0002] Such discoloration of a transparent or translucent soap bar, particularly translucent, has now been essentially overcome through use of an antidiscoloring effective quantity of a specific benzotriazole namely 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol wherein the dodecyl is branched and/or linear with a CAS Number 233,28-53-2/125304-04-3/104487-30-1 and INCI name of benzotriazolyl dodecyl p-cresol. It is available from Ciba Specialty Chemicals as Tinogard TL.
SUMMARY OF THE INVENTION
[0003] In accordance with the invention, there is a solid transparent or translucent cleansing composition comprising a cleansing effective amount of soap and an antidiscoloration effective amount of 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol.
DETAILED DESCRIPTION OF THE INVENTION
[0004] Soap is a long chain alkyl or alkenyl or mixture thereof carboxylate salt wherein the salt is generally alkali metal ammonium or ethanol ammonium such as triethanol ammonium. The long chain alkyl or alkenyl is about 8 to 20 carbon atoms in length counting the carbon of the carboxy group, preferably about 10 to about 18 carbon atoms. The quantity of soap present in the solid composition is at least about 1 wt. %, generally at least about 2, 5, 10, 20, 30, 40, 50, or 60 wt. % of the composition. Generally, the maximum quantity of soap is no more than about 70, 75 or 80 wt. % of the composition. Other surfactants can also be present in the composition, for example, synthetic anionic, amphoteric, nonionic and cationic surfactants, as long as the solid composition remains transparent or translucent. By translucent is meant a finite (non-zero) amount of visible light can be transmitted through the bar. Light transmittance can be measured using a UV-vis spectrophotometer. A one centimeter thick sample of the soap bar is prepared. The % transmittance of light, from 400-800 nm, through this sample is measured. In the opaque soaps, i.e., non-translucent, the transmittance of light through a one centimeter sample is zero. Transparent means 74 print font can be read through a bar sample that is one inch thick.
[0005] The specific benzotriazole effective in controlling discoloration in these soap-containing compositions is present in effective antidiscoloration amounts. Generally such quantities are at least about 0.01 wt. %, desirably at least about 0.03 wt. % and more desirably at least about 0.05 wt. % of the composition. The maximum amount of compound is dependent upon cost and the incidence of undesirable effects, though generally does not exceed about 0.25, desirably about 0.15 wt. % of the composition, and more desirably about 0.10 or about 0.075 wt. % of the composition.
[0006] The solid soap composition has no or essentially no opacifiers as previously mentioned. By opacifiers is meant compounds which limit the quantity of light passing through the solid composition. When opacifiers are present, the solid composition is generally opaque, i.e. “opacification”. Examples of opacifiers include titanium dioxide, zinc oxide and the like.
[0007] The particular solid soap-containing compositions of this invention are desirably bar shaped. They are also at least translucent with respect to light. Such transmission of light through the solid bar is achieved by standard techniques primarily through the use of monohydric alcohol (ethanol) and, desirably, polyhydric substances such as glycerin, sorbitol, mannitol, xylitol, and propylene glycol mixtures thereof and the like. Desirable non-opaque compositions are those with a minimum of about 60 wt. % soap, and generally not more than about 75 wt.% soap, about 4 to about 19 wt. % of an alcohol or mixtures thereof, about 10 to about 25 wt. %, more desirably about 12 to about 20 wt. % water. Various adjuvants and other materials usually found such as preservatives, fragrance(s) and colorant(s) can be present as well. Also, not essentially present in the solid composition, preferably absent altogether are various polymer materials generally plastic such as polyester, polycarbonate, polyester polycarbonate, polyolefin, as well as various wood lacquers.
[0008] Other benzotriazoles are not compatible nor provide the desired stabilization. For example, Uvinul MS-40 from BASF, also known as benzophenone-4, CAS # 4065-45-6, changed the color of the bar during manufacturing. The desired benzotriazole must not only function as an effective discoloration inhibitor but also be safe for use, have ease of handling and be readily incorporated into the composition. Tinogard TL does not cause discoloration (yellowing of the bar). No special handling of this yellow liquid is required. The Tinogard TL is readily soluble into an organic system such as a fragrance.
[0009] The solid soap compositions are prepared in any manner well known in the art. The benzotriazole is solubilized in an organic material, for example, the fragrance, and added to the soap chips. The bars can be pressed from standard machinery.
[0010] The bars are then placed in standard containers or wraps, desirably those types that allow a user to visualize the bar. This can be done by having one or more windows on a solid container or a clear overwrap for the soap bar, preferably with a stiffener. The overwrap is generally a polyethylene terephthalate or a polyolefin. In like manner the see-through windows are of the same or similar plastics.
[0011] Below are examples of the invention. These examples are intended to illustrate the invention and not unduly limit it.
[0012] The subject benzotriazole (Tinogard TL) is solubilized in a fragrance and then added to the soap chips and thereafter preparing a translucent soap bar comprising the following composition and having 0.05 wt. % of the benzotriazole:
High Low Solubilizer Solubilizer COMPONENT (Wt. %) (Wt. %) Soap 64-68 67-72 Glycerin 6-9 2-5 Sorbitol 4-7 2-5 Free Fatty Acid 1-5 1-5 Propylene Glycol 0-3 0-3 Triethanolamine 0.5-1.5 0-1 Water 12-20 12-20
[0013] A control bar is prepared in the same manner but with the benzotriazole Tinuvin 326. Typical colorants which can be employed include blue, peach, green, pink, and raspberry. The antioxidant is particularly useful for stabilization when a red colorant is present.
[0014] The bars (raspberry) are placed on a shelf in direct sunlight with no packaging, which allows light to pass through the bar. After 12 weeks aging, having the benzotriazole Tinuvin 326, the bars showed signs of yellowing (fading) as a result of exposure to direct sunlight. The bars with the Tinogard TL do not show any significant signs of yellowing. As well as visual evaluation, Colorimeter readings are also done on the raspberry bars after 13 weeks of aging in intense sunlight. Values for a and b indicate where the color is in the spectrum, i.e.,
−a green +a red −b blue +b yellow
[0015] Thus, a decrease in a indicates a decrease in the red color, while a 10 decrease in b indicate a decrease in the yellow hue.
[0016] The aging data are shown in the table below:
0.05 wt. % Benzotriazole a b Tinuvin 326 Before aging 11.46 4.65 After aging 4.57 6.62 Change −6.89 1.97 Yellowing Tinogard TL Before aging 12.20 −0.44 After aging 11.33 −1.89 Change −0.87 −1.45 No Yellowing
[0017] The data show that with the addition of Tinuvin 326, the bars faded or became less red (low a values) after aging. The higher b value denotes yellowing. Upon the addition of Tinogard TL, the level of fading was decreased significantly (lower reduction in a). The lower b value denotes no yellowing.
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A solid translucent or transparent soap composition comprising a cleansing effective amount of soap and an antidiscoloration effective amount of the benzotriazole 2-(2H-benzotriazol-2-yl)-6-dodecl-4-methylphenol.
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FIELD OF THE INVENTION
[0001] The invention relates to a prefabrication system for the structural components of a partially pre-assembled frame, in wood or other material, in particular for the construction of interior and exterior walls, floors, roof trusses and roofs of buildings.
BACKGROUND
[0002] The typical platform framing technique, which is also the most common light framing construction technique (in Usa, Canada, Australia, UK) requires the interpretation of blueprints, often designed using a CAD software, and the selection, measurement, marking, cut and assembly of many components, (as studs) that need to be spaced at specific distances. All the work is made on the construction site where weather may impede construction.
[0003] This phase requires the presence on site of highly qualified personnel, it is the most complex and it is subject to errors caused by incorrect interpretation of the drawings or by human error in the marking process or cutting of the components. Moreover, after having correctly positioned the various components to the ground, components as studs typically are repositioned elsewhere for cutting and then placed back in position, an operation which requires additional time.
[0004] There are alternatives to traditional platform framing on-site construction.
[0005] The most known and used is the off-site prefabrication of entire walls or sections of walls, floors, and trusses, which are then transported to the construction site.
[0006] Another system, typically used for kit-homes, requires to process every single stud, plate, joist or other components one at a time, cutting and marking them, then packing and shipping all to the construction site.
[0007] Other less known patented systems require the prefabrication of collapsible light metal frames which are then opened and installed on-site, where the vertical components are hinged with the horizontal components. Sometimes even the studs are collapsible (example U.S. Pat. No. 6,318,044 B1).
[0008] The pre-prefabrication in a factory of complete walls and floors (framework and sheathing) are well known and generally used when there is the need to build on a very short timeframe, on remote sites or with adverse climate. In those cases these system is competitive compared to the traditional platform framing on-site construction but usually they are not very cost-effective and therefore less used.
[0009] For the prefabrication of entire walls and ceiling usually the money saved thanks to the use of better systems within the factory and thanks to a faster installation on-site is often compensated by the fixed costs of the facility where the walls are manufactured, the cost of the equipment used, which is not fully automated, therefore it still requires extensive use of labor in the factory, and transportation costs, much higher than the simple transportation of the lumber needed for traditional on-site construction (which take up only about 25% of prefabricated walls and floors volume during transportation). Furthermore there is the cost of temporary indoor storage space for finished walls and sometimes the crane cost for the installation on-site.
[0010] In addition most of the times contractors does not own the factory, for the manufacturing of walls and floors, and the crane needed for the installation on-site, so they need to pay third-party suppliers, reducing their profit.
[0011] About kit-houses, with all the elements pre-cut in an off-site facility, the transportation cost is not substantially different, but the costs are increased by the need to cut, number, mark and make a schedule of all the components, one by one, and by the fact that on the construction site somebody need to interpret the drawings and the schedule of all the singular components and then find them. This can be quite complex and time consuming, making this system usually not competitive compared to the traditional on-site marking & cutting of the components, especially for the construction of a single home.
[0012] About the patented collapsible light frames hitherto known, if they are in production they are really little used. Probably the drawback of this systems can be the high production cost, due to a higher number of industrial processes required, the greater amount of material required and the transportation cost, more competitive compared to other known types but still greater than the transportation cost of the individual, not yet assembled, components. Moreover, often this systems work only for light gauge metal frames, still far less used than wood.
SUMMARY OF THE INVENTION
[0013] Purpose of the present invention is to provide a prefabrication system that allows the production of inexpensive, high precision, structural frames made out of wood, metal or other materials, a simple and quick installation on site, eliminating completely the manual measuring, marking & cutting operations usually necessary on-site and the need to use a crane for the installation.
[0014] Further, the other purpose of the present invention is to keep transportation cost as low as for traditional construction on-site, with the shipped material occupying the same volume.
[0015] Further, the other purpose of the present invention is to eliminate the need to mark one by one and then schedule all the single pre-cut components in the off-site facility and to have the chance to make the few cuts required without moving or repositioning any component as the studs, so saving time.
[0016] Further, the other purpose of the present invention is to make the production of these frames, which are in fact different one from another, way more efficient, using a fully, or almost fully automated machine, with minimum use of labor, not even necessarily skilled.
[0017] Furthermore, the other purpose of the present invention is the use of low-cost machinery and a relatively small facility for the manufacturing.
[0018] These and other purposes are achieved by the pre-distancing collapsible system according to the invention characterized in that it comprises at least three components of a structural frame and at least two spacers, being said spacers, not part of the supporting structure of the frame, integral with the head of those frame components, and being said spacers foldable.
[0019] These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of example embodiments of the invention, and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of the structural wooden vertical components (or studs) with the spacers fastened on the heads of the studs of a wall frame example with a window opening in the middle, packed with strips and ready for storage and transportation.
[0021] FIG. 2 is a top plan view of the same components in FIG. 1 , without strips and ready to be unfolded, in which the central part is not shown for the sake of drawing simplicity.
[0022] FIG. 3 is a top plan view of the same components of FIG. 1 during the opening, in which the central part is not shown for the sake of drawing simplicity.
[0023] FIG. 4 is a perspective view of the same components of FIG. 1 during the unfolding process. The frame is lying in a horizontal position, as usual in light-frame construction prior to wall erection.
[0024] FIG. 5 is a perspective view of the frame completely unfolded, with its spacers fully unfolded at the maximum extension and the two horizontal components, the top and bottom plates, already end-nailed to the vertical components (studs) and to the two partially-cut studs that still require to be completely cut. The frame is lying in a horizontal position.
[0025] FIG. 6 is a perspective view of the frame completely assembled with all the studs completely cut and with the window sill and window header also assembled. The frame is still lying in a horizontal position.
[0026] FIG. 7 is a top plan view of a variant in which the spacers are wires or cables. The view shows part of two studs, the ends are not shown for the sake of drawing simplicity, and a spacer, packed together for transportation.
[0027] FIG. 8 is a top plant view of the variant of FIG. 7 where the two studs are unfolded.
[0028] FIG. 9 is a top plan view of a variant in which the spacers are rigid bodies with a sliding slot. The view shows two studs, the ends are not shown for the sake of drawing simplicity, and a spacer, packed together for transportation.
[0029] FIG. 10 is a top plant of the variant of FIG. 9 where the two studs are unfolded.
[0030] FIG. 11 is a top plan view of a variant in which the spacers are rigid bodies with two sliding slots. The view shows two studs, the ends are not shown for the sake of drawing simplicity, and a spacer, packed together for transportation.
[0031] FIG. 12 is a top plan view of the variant of FIG. 11 partially unfolded.
[0032] FIG. 13 is a top plan view of the variant of FIG. 11 where the two studs are unfolded.
[0033] FIG. 14 is a perspective view of a variant in which the spacers are rigid and are not fastened to the frame components. The frame components have grooves of different widths cut into the surface. The view shows five studs, one end is not shown for the sake of drawing simplicity, and no spacers, packed together for transportation.
[0034] FIG. 15 is a perspective view of the variant of FIG. 14 with the five studs and two spacers in place for the unfolding, where the studs are shown in partially unfolded configuration.
[0035] FIG. 16 is a top plan view of the a variant scheme with discontinuous spacers in a series that connect couples of studs together.
[0036] FIG. 18 is a top plan view of the variant scheme with the spacers connected in a parallel configuration, with the first stud connected with all the others.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The system, as illustrated in the drawings, comprises the structural vertical components of the wood frame 1 , also called studs, of a wall with a window opening in the middle. The spacers 2 are fastened to each head of the studs by staples or nails 4 . The spacers are made of foldable material (e.g. aluminum sheet 2/10 mm thick) and the length of the portion of foldable material between one stud and the other depends on the distance designed for the frame. The spacers are folded between a stud and the other during storage and transportation as shown in FIG. 1 , where a wall is packed with strips 15 , ready for transportation. The two studs 12 are shorter compared to the others, they are the so called “jack studs”, supporting the window header 10 . The two jack studs 12 are fastened to the adjacent full-height studs 13 , the so called “king studs”.
[0038] In FIG. 5 are also visible the partial cuts 8 in the two studs 14 , and the two horizontal components of the frame 6 and 6 ′ (called top and bottom plates) assembled in final position, which could also be pre-marked for simplicity. The horizontal components of the frame, the so called top and the bottom plates, are end-nailed to the studs by the nails 7 .
[0039] Referring to FIG. 6 , the window sill 9 is assembled in final position, being the sill 9 a section of one of the two studs 14 , still not cut in FIG. 5 . FIG. 6 shows also the window header 10 assembled in the final position. The frame is lying in a horizontal position, as usual in light-frame construction prior to wall erection.
[0040] FIGS. 7 to 18 show several technically equivalent embodiments, not preferred for various reasons. In these figures the spacers are fastened to the side of the studs, except in FIG. 15 where one of the spacers can be also fastened to the head, as in the preferred embodiment.
[0041] Instead of the spacer made out of a sheet other types could be used, such as wires 20 ( FIGS. 7 and 8 ) fastened to the studs with staples, nails or pins 40 , otherwise narrow belts, strips or straps could be used too. Another technically equivalent spacer is a rigid type 21 with a sliding slot 22 , which allows the fastening means (e.g. staples, nails or screws 41 ) to run in the range of the sliding slot ( FIGS. 9 and 10 ). A variant of this rigid spacer is a spacer 23 with two sliding slots 24 and 25 where the means 41 can run, as shown in FIGS. 11 , 12 and 13 , in positions of progressive unfolding. This variation is useful to reduce the size of the spacers, particularly for small wall frames.
[0042] The FIGS. 14 and 15 show a further variant, respectively in packed configuration for transportation and unfolded. In this case the rigid spacers 26 are not fastened in the factory to the studs. The spacers 26 are cut (for example by laser, plasma or water) to be shaped with progressively increasing width 27 . On the head or, in alternative, on the sides of the studs a groove of variable width 50 is cut into the upper surface of the studs, then the studs are packed and shipped. The components of the frame 1 are placed on a horizontal surface in the construction site, then ( FIG. 15 ) a worker need to fasten the spacer to the stud 11 , driving a nail or a screw 51 throughout the spacer 26 to the first stud 11 . So, the rigid spacer 26 , and the stud 11 will be dragged together during the unfolding and each time the width of the spacer 26 will match with the grooves cut into the studs, in the points 27 , being the groove and the spacer of the same width, a stud will unfold in final position, according to the frame design.
[0043] Instead of cutting a groove and a plate shaped spacer a variant could also be drilled a hole, with diameter progressively higher, throughout all the studs, with a spacer of variable diameter able to match with the holes. This spacer may be rigid, or consisting of a wire with small rigid elements of growing section fastened to it, like a “string of pearls”, with “pearls” of increasing diameter.
[0044] In all cases, all these types of spacers need to be positioned on the studs properly, on the head or on the sides, in order to keep parallel all the studs during the unfolding, as the preferred type illustrated above does. So if the spacers are fastened to the side and not on the head of the studs, it is necessary to provide the same spacers on both sides of the studs.
[0045] In alternative to partially-cut the studs 14 it would be possible to completely cut the studs 14 in the factory, but additional spacers are going to be needed to maintain parallel the cripple studs (the completely cut studs) during the unfolding, because the free end of the cripples could otherwise be free to move uncontrolled during the unfolding operation.
[0046] Another alternative, instead of cut partially the studs 14 , could be pre-assemble completely the window opening (or the door opening) in the factory, complete with sill and header. So we can have one or more sections of studs with the collapsible spacers fastened and one ore more sections completely prefabricated, preferably the sections with openings.
[0047] This is going to be a much bigger frame to transport but could be faster to unfold on site.
[0048] The spacers may be made out of the most disparate materials, as fabrics, plastics, cardboard, metals. The aluminum has been preferred for its mechanical strength, the characteristic of being rustproof, fireproof and not sharp-edged at low thickness, but also to be easily foldable and easy to drill or punched if needed.
[0049] FIG. 16 shows a configuration scheme of the spacers 28 configured differently, fragmented in a series of smaller spacers rather that a continuous one, not preferred but technically equivalent.
[0050] FIG. 18 shows another configuration scheme, equivalent but not preferred, where the spacers 29 are connected to the studs in a parallel configuration, with the first or the last stud connected with a spacer to all the others.
[0051] The operating principle of the system according to the invention is as follows: Every wall frame need to be designed (or drawn) on a CAD system, which can run on PCs, tablets and smartphones. The file is then sent to a small, cost-effective, automated CNC machine inside the manufacturing facility, which very efficiently and without errors, in a weather-protected environment, assemble every packed wall frame ( FIG. 1 ), as the example shown in FIG. 1 to FIG. 6 . The manufacturing process operates as follows:
[0052] Whenever a wall opening occurs in the design, the studs 12 are trimmed (jack studs) and the studs 14 are also cut 8 , but incompletely. Then the trimmed jack studs 12 are fastened to the adjacent full-height studs 13 , called king studs (e.g. by screws, nails, staples, glue)
[0053] Next step (although this could be done at the same time of the above-listed operations) is to fasten the spacers 2 to the stud heads, using, for example, staples 4 .
[0054] The spacers in the preferred embodiment are metal strips and are not going to be part of the final structure of the frame. These spacers 2 are fastened to the heads of all the studs ( 1 , 11 , 12 , 13 and 14 ) so that the portion of the metal strip between a stud and the next one matches with the distance designed between this two studs once the frame is unfolded. The spacer 2 is preferably folded (and pushed) towards the inner part of the frame structure, along the middle 3 of the portion between two studs, so that during storage and transportation the spacers stay protected. The folding and fastening operations are repeated for each stud, on both heads.
[0055] All this can be manufactured on a cost-effective equipment which could also be quite small in alternative to the traditional off-site assembly of the frame, usually not fully automated and made on a huge stud framing table. In fact all the aforementioned operations require to space only two or three studs at a time, even just slightly, cut ( 8 ) the studs, fasten the spacers 2 put the two studs next to each other again, and proceed to the two/three following studs, Also, if required, the flexibility of the spacers 2 allows to fold and push them between one stud and the other avoiding a complete spacing.
[0056] The thickness of the strip 2 could be less then 2/10 mm, so the thickness of the folded strip between the studs, about 4/10 mm, it is irrelevant for the packaging and does not increase the volume during transportation compared to standard lumber, and consequently the transportation cost. The whole operation can be performed with CNC machines, without errors and very quickly, with minimal or no assistance of an operator. The studs of each wall frame are then packed and shipped.
[0057] Once the wall frame of the example arrives on site it can preferably be placed in a horizontal position, the strips 15 are removed, then dragging one of the outer studs 11 , or both external outer studs 11 at the same time if two workers are available, the wall frame is unfolded. In a few seconds all the studs will be at the designed distance automatically, the spacers 2 will unfold completely along the folds 3 during the operation as showed in FIG. 4 . The studs 13 and 12 , fastened together off-site, will be dragged together, being a single part.
[0058] Referring to FIG. 5 the structural horizontal components 6 and 6 ′ (top and bottom plate) are now placed in final position and it is possible to proceed to end nail, by nails 7 , both the two studs 11 to the top and bottom plates 6 and 6 ′, making sure all is squared properly. Automatically the rest of the studs will stay still and squared, greatly speeding up the nailing of the rest of the frame.
[0059] Some of the studs 14 are partially pre-cut. The cuts 8 are deep enough to easily complete the cut but not deep enough to compromise the structural integrity of the studs 14 during transportation, and are intended to be placed on the bottom, from the floor up, during the unfolding process.
[0060] Once the studs are all end nailed to the top and bottom plates 6 and 6 ′ it will be time to cut the studs 14 , so preventing every movement of the members. The cuts 8 provide a rail and a marking to easily complete the cut that can be quickly executed using any low-cost tool, such as a circular saw 11 , with no need to move anything.
[0061] The usual operations of measurement, marking, repositioning, cutting and finally repositioning back in place are no longer necessary with this system.
[0062] The trimmed member 9 in the example ( FIG. 5 ) will become the window sill, as shown assembled in FIG. 6 . The scrap after the cutting is minimal, and could be used for double the sill 9 as some framers do, or used as fire-blocks, between a stud and the other.
[0063] The window header 10 is now nailed in position and the wall frame is completed, ready for the traditional next steps, as sheeting and raising.
[0064] The spacers 2 , which are not structural, once the frame is unfolded could be easily removed, but the operation is not necessary because they do not disturb any of the next steps of the construction. In case they can be easily cut and removed.
[0065] This system is even more advantageous with gable walls, where the studs length is variable and the cuts are inclined.
[0066] The invention eliminates completely both the manual measuring, marking & cutting operations subject to errors usually necessary on-site and the need to use a crane for the installation of prefabricated frames. This system does not increase the cost of transportation. In addition, the installation is so simple that a few hours training for the crew is enough. All this allows to a error-proof, fast and very cost-effective frame construction thanks to a low-cost automatization and the negligible cost of the aluminum strips and staples.
[0067] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments, therefore, are to be considered in all respects illustrative rather than limiting the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.
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The present invention refers to a pre-distancing collapsible system particularly for the elements of a structural frame of a building. An embodiment of the invention comprises at least three components of a structural frame and at least two spacers, not being these spacers structural elements of the frame, fastened to the heads of aforementioned components of the frame, and said spacer being foldable.
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[0001] This application is the U.S. national phase of International Application No. PCT/CN2014/094197 filed on 18 Dec. 2014 which designated the U.S. and claims priority to Chinese Application Nos. CN 201410384106.6 filed on 6 Aug. 2014, the entire contents of each of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention belongs to the field of environmental engineering, and particularly points to an application of the fermentation broth of Potamogeton crispus in the removal of nitrogen in constructed wetlands.
BACKGROUND
[0003] In recent years, the annual water quality assessment of Taihu Lake shows that 85.2% of the monitoring section water quality cannot meet Grade III requirements, most of them are Grade V and poor Grade V. The main exceeded pollutants are ammonia nitrogen, permanganate index, dissolved oxygen, biochemical oxygen demand after 5 days (BOD5), petroleum, total phosphorus and chemical oxygen demand The water quality of the upper stream river inflowing into lake and the lake area continued to deteriorate, directly leading to an increase in the total amount of pollutants in the Taihu Lake. The contents of TP and TN in the Taihu Lake were increasing in recent years due to the increase of inflowing into lake pollutants. Therefore, the key to protect the water environment of Taihu Lake is to intercept the pollutants from the source inflowing into Taihu Lake, and control the total amount of pollutants discharged into the lake area from upper stream river.
[0004] At present, there are nearly 200 urban sewage treatment plants in the Taihu Lake, all of them are executing the Grade 1 (A) discharge standard in “Pollutant Discharge Standards for Urban Sewage Treatment Plants” (GB18918-2002). But the concentration of nitrogen and phosphorus in the Grade 1 (A) discharge standard (TN 15 mg/L, NH 3 —N5 (8) mg/L, TP 0.5 mg/L) still far exceeds the surface water environmental quality standard (surface water Grade V water standard TN 2 mg/L, NH 3 —N 2 mg/L, TP 0.4 (lake 0.2 ) mg/L). Facing the increasingly serious eutrophication of Taihu Lake, if tail water directly be discharged from sewage treatment plant without further treatment, it will have a big impact on the water quality of the rivers channel inflowing into the lake, then it will aggravate the pollution degree of nitrogen and phosphorus in Taihu Lake, threatening the safety of drinking water. At the same time, carrying out the further treatment and reuse of tail water is also a powerful measure to solve the problem of water shortage in Taihu Lake. It has significant environmental, economic and social benefits.
[0005] At present the commonly used water further treatment technologies are mainly physic-chemical method (filtration, adsorption, etc.), biological method (bioreactor, biofilter, constructed wetlands, etc.) and membrane separation method (reverse osmosis, microfiltration, nanofiltration, etc.). The constructed wetlands technology is widely used because of its low investment and maintenance cost, good effect of removing nitrogen and phosphorus, small secondary pollution and both scenery and view effects.
[0006] It was found that the nitrogen was highly nitrified and the carbon source was seriously insufficient in sewage treatment plant tail water. In addition, the carbon source of the water inlet was insufficient in nearly 50% of the urban sewage treatment plant in the Taihu Lake. However, the carbon source is the electron donor in the process of denitrification, which is the key factor for restricting the denitrification. To achieve the further treatment of the tail water of the sewage treatment plant, enough additional carbon source must be added to ensure a certain ratio of carbon and nitrogen, and then the denitrification process can be completed successfully.
[0007] The traditional denitrification carbon sources include glucose, methanol, ethanol and acetic acid, etc. But these carbon sources are expensive, and some of them, such as methanol, ethanol, acetic acid, etc have a certain toxicity and have a potential risk to the environment. In recent years, many researchers domestic and overseas try to find a new carbon source with low toxicity and cost to replace the traditional carbon source.
[0008] A large number of aquatic plants which are rich in cellulose matter are planted in constructed wetlands, and these plants can produce large amounts of volatile fatty acids (VFAs) and other nutrients by anaerobic fermentation, which are excellent potential additional carbon source of denitrification.
[0009] Taking the aquatic plants planted in constructed wetlands as raw materials, the cellulose matter in the plants is converted into volatile fatty acids (VFAs) and other nutrient elements by anaerobic fermentation, used to be the carbon source of denitrification. Results showed that further nitrogen removal of sewage treatment plant tail water is achieved, and the resource utilization of aquatic plants is realized at the same time.
[0010] The previous research results showed that the nitrification and denitrification of microorganisms are important ways of nitrogen cycling in nature. Denitrification is the process that under anaerobic or hypoxic conditions microorganism converts the nitrate nitrogen and nitrite nitrogen into nitrogen and release it into the atmosphere. The main influencing factors of nitrogen removal are dissolved oxygen (DO), pH, temperature, carbon source, etc.
[0011] (1) Dissolved Oxygen (DO): in order to ensure normal denitrification, dissolved oxygen must be kept at 0.5 mg/L or below. This is because the ability of O 2 to accept electrons is stronger than that of NO 2 —N and NO 3 − —N. When both molecular oxygen and nitrate are existed, denitrifying bacteria preferentially carry out aerobic respiration.
[0012] (2) pH: the optimal pH of denitrification is 7-8.
[0013] (3) Temperature: the optimal temperature of denitrification is 15˜30 . Denitrifying bacteria are more sensitive to temperature reduction than nitrifying bacteria. When seasonal cooling occurs, the denitrification process will be inhibited before the nitrification process, at this time additional carbon source is needed in order to improve the denitrification effect. In addition, the temperature has a significant impact on the mircrobial activity, and then affecting the effect of denitrification.
[0014] (4) Carbon source: carbon source is the electron donor in the denitrification process, and it is also the main source of energy for microbial growth and reproduction. The lack of carbon source will directly affect the denitrification. Adding additional carbon source is one of the effective methods to improve denitrification nitrogen removal efficiency. The species and the amount of the additional carbon source will have a significant impact on denitrification efficiency.
[0015] Existing additional carbon sources can be broadly divided into two categories, the traditional carbon sources and the new carbon sources. Traditional carbon sources are mainly liquid state organic matter, including low-molecular organic matter (such as methanol, ethanol and acetic acid, etc.) and carbohydrate matter (such as glucose, sucrose, etc.). The new carbon sources mainly include natural solid organic matter rich in cellulose matter (such as plant stalks, etc.), some degradable artificial materials (such as waste paper, degradable lunch boxes, etc.) and high carbon content of industrial waste water.
[0016] Methanol, ethanol, acetic acid and other low molecular organic matter are easily used by denitrification bacteria, and these materials are considered as ideal additional carbon source. Gersberg et al. (1983) achieved a 95% nitrogen removal efficiency by adding methanol to the constructed wetlands system. The research results of Pochana et al. (1999) showed that the addition of acetic acid as carbon source can greatly improve the progress of simultaneous nitrification and denitrification. Rustige et al. (2007) added acetic acid as the carbon source to treat the landfill leachate in the horizontal stream section of the composite flow constructed wetlands, the results showed that the denitrification rate increased with the increasing of acetic acid concentration, and the nitrate removal rate was up to 98%. The denitrification efficiency of this species carbon source is high, but the cost is expensive and methanol has a certain toxicity and its transportation is inconvenient.
[0017] Carbohydrate matter as an additional carbon source of denitrification, the cost is lower. Zhao Lianfang et al. (2006) treated urban polluted river by constructed wetlands, the results showed that the addition of glucose could effectively improve the removal efficiency of nitrogen, when the wetlands C/N was increased from 2 to 8, TN removal rate was increased from 55% to 89%. She Lihua et al. (2009) added carbon source through specific breather pipe of the composite integrated vertical flow constructed wetlands (IVCW) system to the bottom of wetlands in order to strengthen wetlands denitrification effect. The results showed that glucose was better than carboxymethyl cellulose (CMC) as the additional carbon source, and the optical dosage of glucose was 1.5 g for integrated vertical flow constructed wetlands (IVCW) system with 60 L/d treatment capacity. Under this circumstance, the mass ratio of glucose to nitrate nitrogen was only 4.3, much lower than the ratio that denitrification required. However, when glucose was used as the carbon source, the productivity rate of microbial cells was high, which may lead to clogging of artificial wetlands and other process.
[0018] Liu Gang et al. (2010) believed that denitrification efficiency was restricted by the low-molecular organic matter content in industrial waste water when industrial waste water was used as an additional carbon source, if the low-molecular organic matter content was low, denitrification efficiency would not be significantly improved. At the same time, the dosage of industrial waste water must be controlled to prevent water quality deterioration of water outlet.
[0019] Cellulose carbon sources come from a wide range and the cost is low. At present many scholars have studied the potential implications of waste paper, corn stalks, wheat straw, straw and cattail, reed and other aquatic plant branches or stalks as carbon sources. Wenhui et al. (2011) studied the effect of wheat straw as an additional carbon source on the removal of nitrogen in constructed wetlands. The results showed that when the concentration of water inlet nitrate nitrogen was 30 mg/L, the optimal conditions for removal of nitrate nitrogen were 25 , the reaction time was 10 h, the mass ratio of straw to water was 1:50. Scanning electron microscopy showed that the surface of the reacted wheat straw appeared hollow, from the dense striated structure into a broken filamentous structure, indicating that the biodegradable components of wheat straw surface were largely decomposed by microbes as denitrifying carbon source. Jin Zanfang et al. (2004) studied the nitrogen removal effect of cotton and paper as carbon sources. The results showed that both carbon sources could make the reactor start quickly. At room temperature 25 , the water inlet nitrate nitrogen were 22.6 and 45.2 mg/L and hydraulic retention time were 9.8 and 8.6 h respectively, the removal rates of nitrate nitrogen were 100% and 99.6%, respectively, and no nitrite accumulation in water outlet. Chen Yunfeng et al. (2010) compared the nitrogen removal effect of wheat straw, peanut shells, sweet potato stem, corn cob, Canna litter, degradable meal boxes, polybutylene succinate (PBS) and polyhydroxyalkanoates (PHAs) as carbon sources, and the results showed that wheat straw was more suitable as the additional carbon source of denitrification for the sewage treatment plants tail water. Zhao Lianfang et al. (2009) determined that the reed rods was the more suitable plant carbon source compared to com stover, rice husk, sawdust, according to their organic matter release ability and the potential effect on water quality. When the addition amount was 1.0 kg/m 2 , the removal rate of TN in integrated vertical flow constructed wetlands increased from 60% to 80%. The application of cellulose matter on carbon source of denitrification could not only improve the removal efficiency of nitrogen, but also achieve the purpose of waste utilization. But its shortcoming is that the release of carbon source cannot be effectively controlled, the required hydraulic retention time is long, and the water outlet quality is susceptible to external temperature.
[0020] The urban organic waste water (such as vintage waste water, molasses waste water, starch waste water, etc.) and excess sludge in urban sewage plant contains a large number of easily biodegradable matter. After anaerobic fermentation, it can produce large amounts of short chain volatile fatty acids, such as acetic acid, propionic acid, which can be used by denitrifying microorganisms. Table 1 summarizes the nitrogen removal effects of fermentation broth of several urban organic wastes as denitrification additional carbon source.
[0000]
TABLE 1
Research Status of the Fermentation Broth of Abandoned Biomass as Denitrification Carbon Source
Acid-
producing
Production composition/%
quantity/mgCOD ·
Acetiv
Propionic
Butyric
Denitrification efficiency/
Matrix
L−1
acid
acid
acid
VFA/SCOD
mgNO 3 − —N · (gVSS · h)−1
Excess sludge
92~370
—
—
—
0.1~0.2
2.4
fermentation
Primary sludge
3500~8700
41
36
18
0.69~0.94
2.34
fermentation
Hydrolysis of
100~200
2.9~3.6
molasses
Hydrolysis of
1165
54
23
31
0.72
0.9
starch waste water
Hydrolysis of
—
—
—
—
—
41
primary sludge
Food waste water
9500
25
14
18
0.33
8.2
fermentation
matter
[0021] At present, most of the domestic and foreign scholars studied the nitrogen removal effect by using the anaerobic fermentation acidification products of the excess sludge in urban sewage treatment plant as the additional carbon source. The excess sludge is used as the fermentation substrate, which reduced the amount of sludge and the cost of sludge treatment, and provided high quality carbon source for nitrogen and phosphorus removal in sewage. Tong Juan (2008) used the fermentation broth of the excess sludge obtained under the alkaline condition as the additional carbon source to treat the low COD (Chemical Oxygen Demand) domestic wastewater, and used the actual sewage as the carbon source for comparative study. The results showed that in the SBR system added fermentation broth, the nitrogen and phosphorus removal rates improved a lot, and the removal of COD (Chemical Oxygen Demand), TN and SOP were 93%, 80.9% and 97.2%, respectively. When adding the actual sewage as carbon source, the removal rates of COD, TN and SOP were 85%, 63.5% and 43.9% respectively. Liu Daoguang used surfactant to promote acid production process, and then use the fermentation broth as the carbon source of nitrogen and phosphorus removal system. Results showed that the removal rates of TP, NH 3 —N and TN reached 97%, 95% and 81%, respectively and the VFAs in the fermentation broth was used in the sequences of butyric acid, propionic acid, acetic acid.
[0022] Potamogeton crispuses have strong vital force, wide adaptability, and thus a lot of cultivation in the constructed wetlands. Potamogeton crispuses is rich in cellulose matter. After harvest, Potamogeton crispus may produce a large amount of volatile fatty acids (VFAs) and other nutrients by anaerobic fermentation. It is an excellent potential additional carbon source and can be used as a carbon source supplement for denitrification. The further denitrification treatment of the subsurface flow type constructed wetlands with the sewage plant tail water can be realized, and the resource utilization of the aquatic plants can be realized.
SUMMARY
[0023] The technical problem to be solved by the present invention is to provide an application of fermentation broth of Potamogeton crispus added into the constructed wetlands as the carbon source of denitrification.
[0024] In order to solve the above-mentioned technical problem, the present invention uses the following technical solutions:
[0025] An application of fermentation broth of Potamogeton crispus in the removal of nitrogen in constructed wetlands.
[0026] Wherein, the fermentation broth of Potamogeton crispus is prepared by the following method:
[0027] (1) Preparation of Potamogeton crispuses : collecting, draining off and grinding the Potamogeton crispuses ;
[0028] (2) Preparation of the fermentation broth: placing the Potamogeton crispuses into a fermentation tank, mixing it with domesticated fermented sludge, and then adding water and fermenting the mixture at a constant temperature, removing the residue of Potamogeton crispuses , thereby the fermentation broth of Potamogeton crispus is prepared.
[0029] Wherein, in the step (2), Potamogeton crispuses , activated sludge and water are placed at a ratio of 100 kg:1 L:1 L.
[0030] In the step (2), the domestication method of activated sludge is cultivated and domesticated by the well-known methods in the art., and the nitration microorganism finally turn to be dominant bacterial community by controlling the composition of the domesticated medium and the temperature, pH and time; preferably, using the following method:
[0031] The compositions of the domesticated medium are as follows: glucose 15 g/L, NaNO 3 3.04 g/L, KH 2 PO 4 0.44 g/L, MgSO 4 .7H 2 O 0.96 g/L, CaCl 2 0.72 g/L, NaHCO 3 0.96 g/L, MnCl 2 0.11 g/L.
[0032] Filling 2.5 kg excess sludge of sewage treatment plant after dehydration into the 5 L fermentation tank, adding 4 L domesticated medium, adjusting the pH to 7.4, 28° C. domestication one week, monitoring the pH every day.
[0033] Wherein, in the step (2), the fermentation temperature is 12-30° C. preferable is 20-30° C. the best is 30° C.
[0034] Wherein, the fermentation time is 5-10day, preferable is 7 day.
[0035] Wherein, during the fermentation process, pH is controlled at 7˜8, preferable is 7˜7.5.
[0036] Wherein, waste water is sewage treatment plant tail water, of which nitrogen content is 10-15 mg/L, preferable is 12 mg/L.
[0037] Wherein, adding the fermentation broth of Potamogeton crispus into the tail water of the sewage treatment plant according to the following adding amount: the ratio of COD value of fermentation broth of Potamogeton crispus to the N content of tail water is 8-16, preferable is 9-10; the hydraulic retention time of tail water is 4-8 h, preferable is 6 h.
[0038] Beneficial Effects:
[0039] The present invention has the following significant features and effects:
[0000] 1. The raw material of Potamogeton crispuses is low cost and widely grown in environment, and the preparation method of fermentation broth of Potamogeton crispus is simple and easy.
2. The resource utilization of Potamogeton crispuses solved the problem that it is difficult to dispose harvested disposed Potamogeton crispuses , and alleviated its harm to the environment.
3. It was found that the nitrogen removal efficiency of the subsurface flow style constructed wetland could be improved quickly and effectively by adding the fermentation broth of Potamogeton crispuses as the carbon source to the constructed wetlands, and the nitrogen and phosphorus in the fermentation broth is removed mostly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIG. 1 horizontal subsurface flow constructed wetlands;
[0041] FIG. 2 removal rate of TN in subsurface flow type constructed wetlands;
[0042] FIG. 3 removal rate of NO 3 − —N in subsurface flow type constructed wetlands;
[0043] FIG. 4 removal rate of NO 3 —N in subsurface flow type constructed wetlands;
[0044] FIG. 5 removal rate of TP in subsurface flow type constructed wetlands.
DETAILED DESCRIPTION
[0045] The present invention will be better understood with the following examples. However, it will easier to understand by those skilled in the field. The description is for the purpose of illustrating the invention and should not limit the invention as detailed in the claims.
[0046] The structure of the experimental device used in the examples is shown in FIG. l. The experimental device is a horizontal subsurface flow type constructed wetlands, made of PVC perspex sheet with inner diameter of L×W×H=40 cm×15 cm×30 cm, divided into 3 parts which are water distribution zone, treatment zone and catchment zone. The length of water distribution zone is 5 cm, and the width is 15 cm. It is separated from the treatment zone by the perforated plate. The perforated plate is evenly distributed from the bottom to the top with 4 diameter of 2 cm circular water-passage holes, laying 3 cm grain size gravel in the inside of the zone, preliminary filtering of the inlet water to prevent the blockage of wetlands inside. The length of treatment zone is 30 cm, and the width is 15 cm. The treatment zone is filled 25 cm thick soil mixed with vermiculite (the mixture mass ratio of vermiculite and soil is 1:1, vermiculite grain size is 1 cm), and 6 strains of calamus are planted inside, which are collected from Nanjing University Xianlin campus Teana River. The height of plants is about 50˜60 cm, and the growth condition is well. The length of catchment zone is 5 cm, and the width is 15 cm, which is separated from the treatment zone by a perforated plate, laying 3 cm grain size gravel in the inside of the zone. Three outlet valves are setting at the 0 cm, 10 cm, 25 cm height to adjust the water level, respectively.
[0047] The instruments used in the examples are: Baoding Lange BT-2 type constant current pump, XX type magnetic stirrer, 1.5 L suction filter bottle, 1.25 L Wahaha pure water bottle, plant crusher, water jacked thermostatic incubator, UV-Visible Spectrophotometer UV2450, D-1 Automatic Steam Sterilizer, Electronic Scales, 25 mL glass-ground colorimetric tube with a plug, Quartz Cuvette, Ultrapure water system (Milli-Q, Millipore), 0.45 μm water-based filter membrane.
[0048] Detection methods of water examples are as follows: (1) using peroxide potassium sulfate-ultraviolet spectrophotometry to measure TN; (2) using ultraviolet spectrophotometry to measure NO 3 − —N; (3) using N-(1-naphthyl)-ethylenediamine spectrophotometry to measure NO 3 − —N; (4) using Nessler's reagent spectrophotometry to measure NH 3 —N; (5) using Potassium persulfate digestion-ammonium molybdate coloration method to measure TP: using potassium dichromate method to measure COD Cr ; (6) using Hash HQ30d portable dissolved oxygen instrument to measure DO; (7) using Hash HQ30d portable pH meter to measure pH.
[0049] Before the formal testing, the constructed wetlands system need some time to run. The system was started on 2013 the middle of August. In the first three days, adding a certain amount of activated sludge was added which was domesticated by denitrification medium to carry out microorganism inoculation, NaNO 3 was used as nitrogen source for influent water, and glucose as carbon source. The concentration of nitrate nitrogen in water inlet was 15 mg/L, and the C/N was 8. The outlet water quality was stable after running for a month, and all the four wetland devices were in stable operation status, and the nitrogen removal efficiency under the same condition had no significant difference.
[0050] Water inlet was suctioned from the reservoir into constructed wetlands water distribution zone by using a constant flow pump at a constant rate, and the treated water from the outlet valve of the top catchment zone flowed into the catchment pool. Using NaNO 3 as nitrogen source, the concentration of NO 3 —N in inlet was 12 mg/L, and the fermentation broth of Potamogeton crispus was the carbon source. The ratio of COD to nitrogen in water inlet were 0, 8, 16 and 24 by changing the adding amount of the fermentation broth of Potamogeton crispus , and hydraulic retention time were 2, 4 and 8 h. Continuing water inlet and water outlet for 2 d under each hydraulic retention time, water samples were taken at 8 h intervals, determination of total nitrogen, nitrate nitrogen, ammonia nitrogen, nitrite nitrogen, total phosphorus, COD Cr , pH and DO. The experiment was repeated three times.
Example 1
The Preparation of a Fermented Sludge
[0051] The fermentation sludge used in the experiment was obtained from the excess sludge after dewatering in sewage treatment plant.
[0052] The composition of the acclimation medium was as follows: glucose 15 g/L, NaNO 3 3.04 g/L, KH 2 PO 4 0.44 g/L, MgSO 4 .7H 2 0.96 g/L, CaCl 2 0.72 g/L, NaHCO 3 0.96 g/L, MnCl 2 0.11 g/L. Filling 2.5 kg excess sludge of sewage treatment plant after dehydration into the 5 L fermentation tank, adding 4 L domesticated medium, adjusting the pH to 7.4, 28° C. domestication one week, monitoring the pH every day.
[0053] The fermentation sludge in the following examples was prepared according to the above-mentioned method.
Example 2
The Preparation of Fermentation Broth of Potamogeton Crispus
[0054] Potamogeton crispuses used in the experiment were collected from the Tianlai River in Xianlin campus of Nanjing University. Collecting and draining off the Potamogeton crispuses , taking 1.3 kg, grinding by using a plant crusher, placing into a volume of 5L fermentation tank, adding the domesticated fermentation sludge 350 ml, and 3000 ml of tap water at the same time, adjusting the pH to 7-8. Fermentation tank was placed in a water-jacked thermostatic incubator, anaerobic fermentation at 30° C. for 7 days, filtrating the fermentation broth to remove the Potamogeton crispuses residue, collecting filtrate, preserved and reserve at 4° C.
[0055] The fermentation broth of Potamogeton crispus in the following examples was prepared according to the above-mentioned method.
Example 3
Effect of Adding Fermentation Broth of Potamogeton Crispus on Nitrogen Removal Effect in Constructed Wetlands
[0056] The effects of different ratio of COD to nitrogen in water inlet and different HRT on the water quality of water outlet were shown in Table 2, with the fermentation broth of Potamogeton crispus as the additional carbon source for horizontal subsurface flow style constructed wetlands.
[0057] It can be seen from FIG. 1 and FIG. 2 that under the three kinds of hydraulic retention time. The removal rate of TN and NO 3 − —N were all enhanced with the increasing of ratio of COD to nitrogen in water inlet. when the ratio of COD and nitrogen in water inlet was 0, under 3 different hydraulic retention time the removal rates of TN and NO 3 − —N were 4%˜9% and 4%˜14% respectively, which indicated that denitrification nitrogen removal efficiency was very low; when the ratio of COD and nitrogen in water inlet was 8, the removal rates of TN and NO 3 − —N increased to 37%˜74% and 68%˜87%, respectively. Compared to no Potamogeton crispus fermentation broth added condition, the removal efficiency of nitrogen was significantly improved (p=0.001); when the ratio of COD and nitrogen in water inlet was 16 and 20, the removal rate of TN and NO 3 − —N reached 66%˜90%, 84%˜100% respectively, which indicated that the denitrification occurred in system strongly. The concentration of NO 3 —N in water outlet (HRT=4,8 h) was below the limit of detection, and the NO 2 − —N in water outlet is no accumulation, indicating that the addition of fermentation broth of Potamogeton crispus was enough for denitrifying microorganisms to achieve complete denitrification.
[0058] Under the same ratio of COD to nitrogen and different hydraulic retention time, the removal rates of TN and NO 3 − —N were compared, and it was found that the removal rates of TN and NO 3 − —N were increased with the extension of hydraulic retention time. When the ratio of COD and nitrogen was 16 and HRT were=2, 4, 8 h, the removal rate of TN was 66%, 80%, 90% respectively, and the removal rates of NO 3 − —N were 84%, 100%, 100%. It was revealed that the hydraulic retention time had a significant effect on the removal efficiency of nitrogen in water outlet when the carbon source was sufficient. Appropriate extension of hydraulic retention time would help denitrifying microorganisms remove more nitrogen.
[0059] It can be seen from Table 2 that ratio of COD and nitrogen in water inlet and hydraulic retention time all have a significant effect on NO 2 − —N content in water outlet. When the ratio of COD and nitrogen was 8 and HRT were=2, 4, 8 h, the concentration of NO 2 − —N in water outlet was 4.1, 2.1, 0.35 mg/L respectively. Compared with the concentration of NO 2 − —N in water inlet, the outlet cumulated 205, 105, 17.5 times of NO 2 − —N, respectively. This was because that the carbon source was insufficient and the denitrification process staid at the stage of NO 3 − —N transforming into NO 2 —N, leading to the continuous accumulation of NO 2 − —N in the system. After increasing the ratio of COD and nitrogen in water inlet into 16, the NO 2 − —N content in water outlet decreased significantly and the degree of accumulation decreased greatly. It is also found that NO 2 − —N concentration in water outlet decreased with the extension of hydraulic retention time. When the ratio of COD and nitrogen was 8 and HRT were=2, 4, 8 h, the concentration of NO 2 N in water outlet concentration was 1.3, 0.08, 0.02 mg/L respectively. The results showed that the process of NO 2 − —N transforming into N 2 occurred at 2˜4 h when the carbon source was sufficient.
Example 4
Effect of the Fermentation Broth of Potamogeton Crispus on the Concentration of NH 3 − —N and TP in Water Outlet
[0060] Adding the fermentation broth of Potamogeton crisous as the additional carbon resource of the horizontal subsurface flow type, the concentration of NH 3 —N and TP in water outlet are shown in the Table 2.
[0000]
TABLE 2
Water Quality of Constructed Wetlands Water Outlet
Water
HRT
inlet
TN
NO 3 − —N
NO 2 − —N
NH 3 —N
TP
COD Cr
(h)
COD/N
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
COD consumption /N
2
0
14.55
13.7
0.02
0.17
0.11
8
1.1
8
10.37
4.5
4.1
1.3
0.56
56
3.9
16
6.1
2.3
1.3
2.3
0.87
120
7.0
20
6.2
2.1
1.6
3.6
0.98
212
8.6
4
0
14.45
13.5
0.02
0.12
0.08
8
1.1
8
6.4
2.5
2.1
0.94
0.21
34
5.5
16
3.65
0
0.08
1.8
0.48
83
9.6
20
3.71
0
0.08
2.3
0.55
188
10.3
8
0
13.7
12.2
0.01
0.08
0.07
6
1.3
8
4.2
1.9
0.35
0.73
0.17
32
5.6
16
1.8
0
0.02
1.3
0.33
57
11.5
20
2.1
0
0.02
1.5
0.42
198
9.6
[0061] FIG. 3 and FIG. 4 respectively show the removal efficiency of NH 3 —N and NH 3 —N in horizontal subsurface flow constructed wetlands system. The concentration of NH 3 —N and TP in water outlet all enhanced with the increasing of water inlet COD to nitrogen. This is mainly because that the higher the ratio of COD to nitrogen in the water, the more nitrogen (mainly ammonia nitrogen) and phosphorus were introduced in by adding Potamogeton crispuses . There is no obvious correlation between at the removal rate of NH 3 —N, TP and the ratio of COD and nitrogen in water inlet, but the removal rate of NH 3 —N, TP increase with the extension of hydraulic retention time. The existing studies have shown the three main ways to remove NH 3 —N in the constructed wetlands system: (1) Ammonia nitrogen in the surface of the wetlands enters into the atmosphere by volatilization. (2) Ammonia oxidizing bacteria and ammonia oxidizing archaea transformed ammonia nitrogen into nitrate nitrogen, and then turned to N 2 through denitrification. (3) Plant absorption and matrix adsorption. The removal of phosphorus in the constructed wetlands system depends mainly on soil adsorption. Appropriate extension of hydraulic retention time can make ammonia oxidizing bacteria and ammonia oxidizing archaea have more time to transform into ammonia nitrogen, at the same time it is favor of the soil adsorption of ammonia nitrogen, phosphorus. When the ratio of COD and nitrogen was 16 in water inlet, HRT was 4 h. The concentration of TP in constructed wetlands system was 0.48 mg/L, which is close to the standard of surface water Grade V.
[0062] When the HRT was 4 h, as long as carbon source is sufficient in water inlet, the denitrifying microorganism in the constructed wetlands system can completely remove the NO 3 —N in the water inlet. At the same time the ratio of COD consumption and nitrogen was 9.6 is the most optimum ratio of COD and nitrogen in water inlet for water treatment. And under this circumstance the best ratio of COD and nitrogen was 9.6, the ammonia nitrogen and TP content in water outlet can completely reach the standard of surface water Grade V. In addition, the introduced nitrogen and phosphorus by adding fermentation broth can be removed by the system itself, and there in no influence on the water quality of water outlet.
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It discloses an application of a fermentation broth of Potamogeton crispus in the removal of nitrogen in constructed wetlands. The fermentation broth of Potamogeton crispus is prepared by the following method: collecting, draining off and grinding the Potamogeton crispuses , then, placing the grinded Potamogeton crispuses into a fermentation tank, mixing them with domesticated fermented sludge, and then adding water and fermenting the mixed liquor at a constant temperature, removing the residue of the Potamogeton crispuses , and obtaining the prepared fermentation broth of Potamogeton crispus . The present invention also discloses an application of the fermentation broth of Potamogeton crispus in the removal of nitrogen in constructed wetlands.
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CROSS REFERENCE TO RELATED APPLICATIONS
This invention claims priority to currently pending U.S. patent application Ser. No. 14/166,467 filed on Jan. 28, 2014 and entitled, “Voltage Profile Based Fault Location Identification System and Method of Use”, which claims priority to U.S. Provisional Patent Application No. 61/757,507 filed on Jan. 28, 2013 and entitled, “Voltage Profile Based Fault Identification”.
STATEMENT OF GOVERNMENT INTEREST
This invention was made with Government support under Grant No. EEC0812121 awarded by the National Science Foundation. The Government has certain rights in the invention.
FIELD OF INVENTION
This invention relates to a voltage profile based fault location identification system for use in a power distribution system. The voltage profile based fault location identification system includes power electronic converters and employs a short circuit limiting fault current.
BACKGROUND OF INVENTION
The IEEE interconnection standard recommends that the distributed resources (DRs) of a power distribution system be disconnected from the power distribution system when the voltage level falls below a recommended threshold to ensure that the distributed resources do not inject power onto the main power grid of the power distribution system. The IEEE interconnection standard is additionally based on the fact that as the voltage level of the distribution system drops, the distributed resource's voltage reference from the substation may no longer be available or may no longer be accurate.
Identifying the location of a fault in a traditional power system is a challenging task. Electric power only flows in one direction, i.e. from the substation to the various loads. Therefore, when a severe short circuit fault occurs in a distribution system, there is an associated current rise and accompanying voltage sag near the faulted node which extends to every node that is downstream of the faulted node. The fault protection system of a power distribution system currently known in the art responds to the short circuit fault by isolating the assumed faulted nodes and all the downstream nodes of the actual faulted node.
In a power distribution system containing distributed resources, most fault location technologies known in the art ignore the presence of the distributed resources by assuming either low distributed resource penetration or no power injection from the distributed resources during a fault situation. While there are additional fault location technologies known in the art that do consider the presence of distributed resources, these technologies do not consider a current limited system when a fault situation does occur.
Accordingly, what is needed in the art is a system and method for fault location identification in a power distribution system that addresses the presence of distributed resources and provides a current limited system when a fault occurs.
SUMMARY OF THE INVENTION
The present invention provides a method to ensure that distributed resources remain connected to the circuit to assist in the fault location by continuing to inject current in the distribution system. The system contains a plurality of power electronic based converters which convert local direct current (DC) of the distributed resources (DRs) to the power grid alternating current (AC). These converters also have the ability to limit the current in the system when a fault occurs; hence, protecting the system equipment against high fault currents.
In one embodiment of the present invention, a method of identifying the location of a fault in a power distribution system is provided. In the present invention, the power distribution system includes a plurality of distributed resources, and the method includes, injecting, by one or more of the plurality of distributed resources, a current into the power distribution system, generating a voltage profile resulting from the injection of current by the one or more distributed resources and analyzing the voltage profile to identify the location of the fault in the power distribution system.
In an additional embodiment, the present invention provides a system for locating a fault in a power distribution system. The system includes a power distribution system including a plurality of distributed resources coupled to the power distribution system, one or more of the plurality of distributed resources comprising a controllable voltage source converter configured to inject a current into the power distribution system. The system further includes, a voltage profile generator configured for generating a voltage profile resulting from the injection of current by the one or more distributed resources and an analyzer configured for analyzing the voltage profile to identify the location of the fault in the power distribution system.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the disclosure set forth hereinafter and the scope of the invention will be indicated in the claims.
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 block diagram illustrating a fault location identification system in accordance with an embodiment of the present invention.
FIG. 2 is a voltage profile for a fault at node 2 and node 6 in a traditional distribution system, wherein the system contains no distributed resources or they are disconnected during the fault in accordance with an embodiment of the present invention.
FIG. 3 is a voltage profile for a fault at node 2 and node 6 in a distribution system containing distributed resources in accordance with an embodiment of the present invention.
FIG. 4 is voltage profile for a fault at node 6 in a traditional distribution system and one containing distributed resources in accordance with an embodiment of the present invention.
FIG. 5 is a schematic of a test system 11.9 kV (8 nodes) in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Modern power distribution systems include distributed resources that provide local power generation and are connected to the power distribution system. Such local power generation sources include photovoltaic (PV) systems, wind systems and microturbines. The number and diversity of these local power generation sources is rapidly increasing. As the number of local power sources connected to an existing power distribution system rises, the distribution system fault location methods currently known in the art have become increasingly inadequate. Reasons for the increasing inadequacy of the current fault location methods include unreasonable cost of the system, system complexity (mesh-like topology) and bidirectional power flow in the distribution system that is not addressed by the current fault location methodologies.
The fault location identification system of the present invention takes advantage of the existing topology of the power distribution system. The fault location identification includes controllable voltage source converters (VSCs) to assist in the location of the fault and alters the voltage profile of the system in the presence of a fault condition. Utilizing controllable voltage source converters to locate the fault reduces miss-trips of the circuit breakers that result when relying on the measured voltage when there is no electrical supply in a section of the distribution system as a result of a fault. The incorporation of controllable voltage source converters in the fault location identification system will serve to boost the voltage of the distribution system, locate the fault and provide rapid restoration of the distribution system.
Power distribution system currently known in the art do not employ controllable voltage source converters and the voltage on a feeder associated with the distributed resource is expected to decrease as the distance between the distributed resource and the power distribution system increases. In accordance with the present invention, if the distributed resources in the power distribution system are allowed to inject power, the voltage profile of the system will change as shown in FIG. 2 for the prior art system and FIG. 3 for the fault location identification system of the present invention.
When a severe short circuit fault occurs in a distribution system, there is an associated current rise and accompanying voltage sag near the faulted node which extends to every node that is downstream of the faulted node. The fault protection system of a power distribution system currently known in the art responds to the short circuit fault by isolating the assumed faulted nodes and all the downstream nodes of the actual faulted node. As shown in the graph of FIG. 2 , when a fault occurs in a prior art fault location identification system, the voltage profile resulting from the fault will provides very limited information regarding the location of the fault. For example in the prior art system, when a fault occurs at node 2 100 , in both the 1 MVA 105 and 12 MVA 110 cases, the distributed resources at nodes 2 100 through 8 125 will be disconnected from the power distribution system by the fault protection system of the power distribution system. Similarly, a fault at node 6 130 will result in the distributed resources at nodes 6 130 through 8 125 being isolated from the rest of the system.
In contrast, as shown in the graph of FIG. 3 , the voltage profile resulting from a fault in accordance with the fault location identification system of the present invention identifies the fault at either node 2 200 or node 6 205 . For example, when a fault occurs at node 2 200 , it is seen that the voltage level 210 drops at node 2 200 , but the voltage level at nodes 3 220 through 8 225 is maintained by the use of the controlled voltage source converters at each of the distributed resources associated with each of nodes 3 220 through 8 225 . Additionally, when a fault occurs at node 6 205 , it is seen that the voltage level 215 drops at node 6 205 , but the voltage level at nodes 7 230 through 8 225 is maintained by the use of the controlled voltage source converters at each of the distributed resources associated with each of nodes 7 230 through 8 225 . As such, the voltage profile provided by the fault location identification system of the present invention results from the injection of current from all the distributed resource at each of the nodes in the system using the controllable voltage source converters.
FIG. 4 illustrates the difference in the voltage profiles of a prior art fault location system and the fault location identification system employing multiple distributed resource with controllable voltage source converters achieved by the present invention. As shown, when a fault occurs at node 6 310 in the prior art system, the voltage level drops at nodes 6 310 through 8 315 . In contrast, with the fault location identification system of the present invention, when a fault occurs at node 6 310 , the voltage level at node 7 320 through 8 315 is maintained by the controllable voltage source converters of the distributed resources at these nodes. As such, the voltage profile for a distributed resource system utilizing the fault location identification system of the present invention clearly indicates the fault at node 6 310 in the system of the present invention, whereas the fault is not clearly identified in the prior art system.
FIG. 5 is a schematic illustrating an exemplary embodiment of the present invention that was used to generate the graphs shown in FIGS. 2-4 . The physical distance between two adjacent distributed resource nodes will also determine if the faulty node can be located accurately. To get an accurate voltage profile for a power distribution system, it is necessary to measure the voltage at multiple nodes in the system. However, making measurements at the nodes is difficult in the prior art systems because there are limited nodes at which a voltage measurement can be performed. In contrast, in the fault location identification system of the present invention which includes a plurality of distributed resources and a controllable voltage source converter associated with each of the distributed resources, each controllable voltage source converters can serve as a measurement unit at which voltage measurement can be performed and used to generate an accurate voltage profile. As shown in FIG. 5 , each of the nodes 1 - 8 are positioned at varying distances from the distribution grid. It is known that the voltage level naturally decreases the farther the node is away from the distribution grid. In the present invention, the controllable voltage source converters at each of the nodes are used to inject current into the power distribution system thereby providing the system with a means for measuring the voltage level at each of the nodes. Knowing the distances between the nodes will improve the accuracy of the fault location identification system of the present invention.
The voltage profile of the power distribution system changes when a fault occurs in the system and the location of the observed voltage drop in the voltage profile is closely related to the location of the fault. Furthermore, most distributed resources provide DC voltage. Therefore, in a DC system, controllable voltage source converters can modulate an AC signal on top of the DC signal and that modulated AC signal profile may be used to locate the fault similarly to the AC system.
In an exemplary embodiment, as illustrated with reference to FIG. 1 , the fault location identification system of the present invention includes a power distribution system 400 and a plurality of distributed resources 405 , 410 , 415 , 420 coupled to the power distribution system 400 . One or more of the plurality of distributed resources 405 , 410 , 415 , 420 comprising a controllable voltage source converter 425 , 430 , 435 , 440 configured to inject a current into the power distribution system 400 . The power distribution system 400 further includes, a voltage profile generator 450 configured for generating a voltage profile resulting from the injection of current by the one or more distributed resources 405 , 410 , 415 , 420 and an analyzer 445 configured for analyzing the voltage profile to identify the location of the fault in the power distribution system 400 .
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 that, as a matter of language, might be said to fall therebetween.
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The present invention provides a system to ensure that distributed resources of a power distribution system remain connected to the circuitry of the power distribution system when a fault occurs at a distributed resource node to assist in identifying the location of the fault by continuing to inject current from the distributed resources into the distribution system, wherein at least one of the distributed resources is a microturbine.
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CROSS REFERENCE TO RELATED APPLICATION
This is a division of Ser. No. 182,531 filed Aug. 29, 1980 now U.S. Pat. No. 4,361,298, which was a continuation-in-part of Ser. No. 884,923 filed Mar. 9, 1978, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to pneumatic deicers and more particularly to a pneumatic deicer and the method of making a pneumatic deicer of the type employing a boot of resilient material attached to the leading edge of an airfoil wherein the boot has a plurality of inflatable tubes which are selectively distended as by inflation pressure to break up ice accumulation which tends to form on the surface of the boot. The inflatable tubes are generally disposed in a direction parallel to each other in the spanwise direction of the leading edge of the airfoil. The tubes, however, may be disposed to extend in the direction of the airfoil or in any other angular position. The deicer is vulcanized by steam which also passes through the inflation tubes assuring that the tubular passageway remains open so that the inner peripheral surfaces of such passageway do not adhere to each other. The inflation of the tube is performed through a manifold that extends transversely of and overlies the tubes. In the manufacture of the boot assemblies, various modifications in tube construction have been tried to facilitate the inflating and evacuation process of the tubes since it is desirable to so construct the boot assembly to provide an unencumbered flow of air to and from the tubes. To insure such flow, additional materials, such as flocked liners or fabrics, have been integrated into the tube structure; however, such finally constructed boots would present ripples and objectionable thickness thereby rendering such boot objectionable for aesthetic reasons as well as for aerodynamic reasons.
The present invention provides a simple structure and method of constructing a deicer to provide for the adequate bleeding of the inflation tubes during the deflation cycle, eliminating the need for building in additional separating devices that add to the manufacturing cost and adversely affect aerodynamic conditions of the airfoils. The present invention substantially eliminates the causes of erosion of the skin of the deicers and materially improves the aerodynamics of the airfoils by keeping the airfoils smooth externally.
SUMMARY OF THE INVENTION
The pneumatic deicer and method of the present invention provides a boot which is smooth and of uniform thickness, wherein the inflating tubes are formed using fabric coated with an elastomer of a nonflowing compound on the one side thereby leaving the fabric with uncoated portion on the other side in cooperation with the nonflowing compound on the inside of the tube allowing the bleeding off of the inflation air directly to the manifold or via a channel and the manifold. The cross communication of the tubes with the manifold is maintained easily and in an economic manner.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a plan view of the deicer boot with the inflation tubes being shown in dotted lines;
FIG. 2 is an enlarged section of the deicer boot taken along line 2--2 of FIG. 1 with a portion broken away;
FIG. 3 is an enlarged section of the deicer boot taken along line 3--3 of FIG. 1 with a portion broken away.
DETAILED DESCRIPTION
Referring to the drawings wherein like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a laminated inflatable deicer boot 10 in the condition prior to installation on an airfoil with the leading edge of the airfoil to be covered by the leading edge portion of the boot indicated by the dot-dash line L--L. Trailing edges 11 and 12 of the boot extend toward the rear of the airfoil on the upper and under side thereof. The bottom ply 15 which may be fabric coated with rubber or other resilient rubberlike material extends over a series of longitudinal tubular members or inflation tubes 16 as shown in dotted lines in FIG. 1.
The inflation tubes 16 are made of a nylon or other similar fabric 17 which has a nonflowing, during curing, rubberized compound 18 containing cross-linked natural rubber greater than 1% by weight on one side and with the other side (inward side) being uncoated due to the nonflowing nature of such compound 18 to provide an inner tubular surface that has fabric and the nonflowing compound 18. The fabric 17 of the inflation tubes 16 is tricot knit fabric or woven fabric coated with the rubberized compound 18 in such a manner that the tubes 16 may expand during inflation but are not extensible in the longitudinal direction. A top ply 20 of resilient rubber or rubberlike materials is disposed on top of the inflation tubes 16. A sheet of resilient rubberlike material 21 such as Neoprene covers the top ply 20. Side fill gum 23 is positioned adjacent to the outermost tube 16 between top ply 20 and the bottom ply 15. Fill gum 23A is interposed between the respective tubes 16 and the bottom ply 15 and top ply 20. A variation of such invention contemplates the elimination of the fill gum 23A.
The rubber compound 18 is made nonflowing by mixing with a conventional rubber compound an amount greater than 1% by weight of cross-linked natural rubber. The cross-linked natural rubber found to be particularly desirable in this invention is one sold under the tradename PA 80. PA 80 is a blend of 80% cross-linked natural rubber and 20% unvulcanized natural rubber. In addition to containing greater than 1% by weight of crosslinked natural rubber, the compound 18 may also contain conventional rubbers, preferably natural rubber; fillers such as carbon black and/or silica fillers and the like; activators such as zinc oxide, stearic acid and the like; processing aids such as oils and resins; age resistors; rubber to fabric adhesion promotors such as HRH systems (hexamethylenetetramine-resorcinol-HiSil) or adhesion promotors sold under the tradename Cohedur RL and the like; vulcanizing agents such as sulfur, sulfur donors and accelerators also are present in the rubber compound 18.
An example of a nonflowing compound which would have acceptable performance in this invention is one having the following formulation:
______________________________________INGREDIENT PARTS BY WEIGHT______________________________________Natural Rubber 86PA-80 (80% cross-linked 14natural rubber)Carbon Black 40Resins, oils, antioxidant 7Silica Fillers 18Zinc Oxide 3Stearic Acid 3Vulcanizing Agents 3Adhesion Promotors 6______________________________________
The ingredients of the nonflowing compound may be varied as is well understood by those skilled in the art of rubber compounding. The essential feature that the compound must have is that it must be nonflowing. The nonflowing feature is achieved by using greater than 1% by weight of cross-linked natural rubber.
The nonflowing rubber compound is prepared by mixing the ingredients on standard rubber mixing equipment such as Banbury mixers, mills and the like. The mixing procedures used are conventional and well understood by those skilled in the art.
As shown in FIG. 3, extending transversely across the inflation tubes 16 of the deicer boot 10 is a manifold ply 25 having a plurality of closely spaced elements such as stiff fibers 26 projecting outwardly and downwardly from the fabric to provide interstices and a passageway 40 through which the inflating medium can flow. The respective tubes 16 all have channels 28 (FIG. 2) on their back side of the boot 10 that run the full length of the tube and communicate with the space provided by the interstices of the fibers 26 of manifold ply 25 to provide for the inflation and deflation of the tubes 26. In lieu of such channels 28, a single port may be located directly in the tubes 16 at the juncture with manifold ply 25 to exhaust the pressurized air from the tubes 16 to the manifold. The interstices of the manifold ply 25 communicate with a central bore 29 on frustoconical annular supporting member or air connecting means 30 which is made of resilient rubber other rubberlike materials which may contain a hollow body of steel or other suitable material for the supply of inflating medium from the aircraft supply. Gum plies 32, 33, and reinforcing fabric material 34 encompass the supporting member 30 which supporting member 30 is cemented to the bottom ply 15. The above described plies of resilient rubberized materials are impervious to the inflating medium. Manifold ply 25 may have a central passageway therethrough that communicates with the respective ports or channels in the tubular members 16.
In the manufacture of the deicer boot 10 described above, the various plies, parts, and tubes are assembled and cemented together with tube 16 being compounded to include cross-linked natural rubber greater than 1% by weight, which cross-linked rubber prevents flow during cure. Ordinarily the deicer is cured by steam, having the steam enter the respective tubes during the actual cure to maintain the tubes 16 in a distended condition to prevent adhesion of the inner surfaces. In curing the deicer pad by this method, the steam can penetrate voids or pockets of material that were not properly sealed or cemented and adversely affect the quality of the end product. In the instant invention, the deicer pad in its assembled condition without the air connecting means 30 is covered by a bleeder material such as heavy-duty paper. The paper and deicer are then covered with a suitable cover ply that overlaps both to assure a positive seal around the edges. The cover ply has a small bore in it such that all air can be withdrawn from under the cover. In this instance a vacuum is drawn on the bore to evacuate the air from underneath the cover, with the paper acting as a wick to facilitate the removal of the air. The assembled deicer boot and cover are then subjected to vulcanization heat and vulcanized to provide a unitary structure with the nonflowing rubberized compound 18 assuring that the inner peripheral wall surface of the tubes 16 which have fabric therein retain their form and upon receiving pressurized air will inflate. Upon completion of vulcanization, the cover and paper are removed and a port or bore is cut into the deicer pad to communicate with the central passageway in the manifold 40. The air connecting means 30 is then cemented onto the deicer pad and vulcanized so that the central bore 29 thereof communicates directly with the cut port to the manifold 40.
A modification of the above process is to place a thin mesh nylon fabric onto the bottom ply 15 of the unvulcanized assembled deicer pad (containing the top ply 20, sheet material 21, tubes 16, manifold ply 25, and bottom ply 15) and then cover such pad with a bleeder pad such as a layer of porous paper. The deicer pad, nylon fabric, and paper are then covered completely with a suitable cover that overlaps all edges of the deicer pad and paper. In this condition, the parts as assembled are flat and void of air. However, to assure a complete absence of air, the cover is pierced to provide a port or bore and suitable means are connected to this pierced hole to withdraw all air from the deicer assembly, after which the pierced hole is immediately covered and sealed. The entire deicer assembly and cover are then vulcanized. Thereafter, the cover, paper, and nylon fabric are removed. The nylon fabric gives the bottom surface of the deicer pad a textured fabric finish thus acting as an impression cover or an impression fabric finish cover. The paper facilitates the removal of air and acts as a wick means for the removal of trapped air. The vulcanized deicer pad then has a hole cut into its bottom ply 15 on the manifold section 40 so as to communicate therewith. An air connecting means or valve 30 is then secured and vulcanized to the bottom ply 15 to have its bore 29 register with the hole cut in the ply 15. A further mcdification is to omit evacuation of the air from underneath the cover prior to vulcanization since careful assembling will substantially eliminate trapping of air; and since no steam is introduced into the tubes 16 themselves, the subsequent vulcanization process provides a more economical means for manufacturing quality deicers. The present invention also provides a flat, nonripple surface. When pressurized air is communicated to tubes 16 during deicing process, all tubes will be in full communication with the central passageway in the manifold ply 40 which in turn communicates with the central bore 29 of the air connecting means 30. Such deicer boot may be mounted on any airfoil of an aircraft in a manner old and well-known in the art.
It will be apparent that, although a specific embodiment and certain modifications of the invention have been described in detail, the invention is not limited to the specifically illustrated and described constructions since variations may be made without departing from the principles of the invention.
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A pneumatic deicer and a method for making such deicer having a plurality of inflatable tubes which are capable of being distended by inflation to break up the accumulation of ice. The tubes are constructed with a nonflowing elastomeric compound leaving a passageway therein after vulcanization of the deicer by external heat.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit of: U.S. patent application Ser. No. 10/211,229, filed 16 Jun. 2003; International Application Serial Number PCT/US01/07759, filed 8 Mar. 2001; U.S. Provisional Patent Application Ser. No. 60/187,742, filed 8 Mar. 2000, each of which is incorporated herein by reference in its entirety.
SUMMARY OF THE INVENTION
[0002] The present invention pertains to an apparatus and a method for generating and/or for obtaining a three-dimensional representation from a two-dimensional image and, in particular, to an apparatus and a method for generating a three-dimensional image from a two-dimensional image.
BRIEF DESCRIPTION OF THE FIGURES
[0003] FIG. 1 is a graph showing an example of principal component analysis according to an embodiment herein.
[0004] FIG. 2 is an example of an annotated 2-D image according to an embodiment herein.
DETAILED DESCRIPTION
[0005] The apparatus includes a central processing computer, a network computer, and/or a server computer, and any number of computers, remote computers, client computers and/or any other communication devices, for facilitating communication with the respective central processing computer, network computer and/or server computer. Each of the respective computers and/or communication devices can include any necessary and/or desired hardware, peripheral devices, and/or software, for performing any of the respective processing routines and/or functionally described herein.
[0006] The apparatus and method of the present invention can be utilized to generate three-dimensional images from any type of two-dimensional images and/or from any other images and/or representations of images, digital and/or otherwise. In this regard, the scope of the present invention is not to be construed to be limited by and/or to any specific examples and/or applications which are described herein.
[0007] This document describes a technique that can be used to obtain a 3D representation of the human face from a 2D image. The requirements of such a technique are briefly outlined as data inputs and data outputs. The data input requirements are broadly described as a 2D digital image of a human face, more detailed requirements (such as image resolution, focus etc.) are given in subsequent sections. The data output requirements can be loosely described as faithful 3D representation of a human face incorporating the original 2D image as a texture map. A more rigorous definition of the phrase ‘faithful representation’ is given in subsequent sections in the form of assumed market requirements. For example, a low polygon count low accuracy requirement for the games market or a high polygon count high accuracy requirement for the mug shot market. These requirements impact on all aspects of the algorithm and its application. However, the underlying technique remains unchanged. Many different medical applications have benefited from the use of statistical modeling algorithms, from the location and tracking of the ventricles in the human heart from a sequence of ultrasonic images to 3D modeling of brain sulci. The References Section, ¶¶0030, 0031, 0032, identifies 3 references that describe some of the applications of the apparatus and method described herein. Additional references (and more details) are located at the Wolfson Image Analysis Unit web site which can be found at: www.wiau.man.ac.uk.
Algorithm Overview
[0008] The algorithm is based upon a multivariate mathematical modeling technique called principal component analysis (PCA). PCA provides a compact statistical representation of the variation in an n-dimensional (can't figure out the word) data set.
Principal Component Analysis
[0009] A simple illustration of PCA can be seen in FIG. 1 . The data set consists of many data points, each point is represented by two variables (x and y dimensions). However, the graph demonstrates how each data point can be represented by a single variable and what is termed a basis change. The basis change effectively re-orients the axes so that one axis lies along the line of most variation (in this case the positive diagonal) and the other axes lies along the line of the next greatest variation (in this case the negative diagonal, with zero variation). The resulting effect of this basis change allows each data point to be represented by a single variable describing the distance along the positive diagonal (i.e. the axis of most variation). Thus, a more compact representation is achieved.
[0010] The application of PCA to data representing real world variables (such as the 2D position of eyes in an image of a human face) obtained from a statistically significant training set results in a more compact representation. Additionally, the statistically modeled axes often represent more meaningful modes of variation. Taking the example of the human face, a simplistic illustration can be visualized as the first mode of variation describing the aspect ratio of human faces, whilst the second may describe the size of the mouth etc.
Building a 2D Face Model
[0011] The 2D face model is constructed from an annotated training set of 2D images. An example of an annotated 2D image is given in FIG. 2 .
[0012] Each point in the annotation represents 2 variables (x position and y position) and each annotation contains no points. Thus, a single observation vector containing 2 variables describes the face shape. To construct a statistical model of face shape the training set of observation vectors is first normalized to remove scale and pose. That, is, each face shape is rotated (pose) and scaled with respect to either the mean (average) shape or with respect to the first shape in the training set. Model building then proceeds by constructing the covariance matrix from the training set of normalized observation vectors.
[0013] Eigen analysis is performed on the covariance matrix to extract a set of orthogonal eigen vectors that describe the basis change from 2D face space to a set of principal components. The dimensionality of the matrix of eigen vectors (P) can be significantly reduced by ordering the column eigen vectors in terms of decreasing eigen values. The eigen values are equal to the variance in each orthogonal axis described by the eigen vectors. In real data sets the number of eigen values required to describe 90-95% of the training data set variation can be as small as ten. Thus for an observation vector with 200 elements (100 points) the required number of variables (also known as principal components) to describe a face shape has been reduced by a factor of 20, i.e. a more compact representation of face shape. Additionally, each of the principal components represents a mode of variation that describes a more meaningful variation. (does equation look ok?)
[0000] x=Pb i +m Equation 1
Where,
[0000]
x i =i th observation vector (i.e., the annotation points)
P=orthogonal matrix of eigen vectors
b i =i th reduced dimensionality vector of principal components
m=mean observation vector (i.e., the average face annotation)
[0000] b i =P T ( x i −m ) Equation 2
[0018] Using equation 1, a vector of principal components can be converted into an observation vector and hence a face shape. As matrix P is orthogonal, equation 2 can be used to convert an observation vector into a vector of principal components.
Finding Faces in 2D
[0019] Once a mathematical model representing the human face has been trained using a statistically significant (for example a realistic cross-section, adequately representing the variation of human faces) training set of 2D images of faces, it can be used to find the face in a 2D image. Thus, given a new image of a face (i.e. not in the training set) the relevant parts of the face (e.g. eyes, chin, etc) can be automatically found. To find the face, an iterative search strategy is used. The mean observation vector (m) is used to provide an initial estimate of the location of the face in the 2D image. Subsequently, local searches for relevant features (a feature can simply be an edge on which an annotation point lies) at each annotation point are performed and used to estimate a new position for the face annotation in the image. At each iteration the model is used to best estimate the most realistic position of the face annotation. The best estimate is obtained by calculating the b vector of principal components from the new face annotation (equation 2). The b vector is then used to obtain the best annotation estimate (x) (equation 1). The iterative process continues until the values in the b vector are approximately constant. The model, therefore, constrains the search to be statistically realistic until the face is found.
[0020] The speed of the search strategy can be improved by utilizing a multi-resolution approach. In this case the image is smoothed (gaussian smoothing) and sub sampled by a factor of two, thus producing an image half the size of the original. The sub-sampled image is smoothed and again sub sampled resulting in an image one quarter the size of the original. The smoothing and sub-sampling continues to produced a pyramid of images. The positions of the annotations are adjusted (by factors of two) to produce annotations at each image resolution (level in the pyramid). A PCA model is built at each resolution level. The face is found in a new image as follows. First build the image pyramid from the original image. Then apply the lowest resolution model to the lowest resolution image, i.e. find the face in the low resolution image. The resulting found face position is used as the initial estimate to start the search in the next resolution. This process continues until the face is found at the highest resolution (i.e. the original image).
Converting 2D to 3D
[0021] The construction of a 3D representation of the face can be achieved in two ways, both of which are driven by output requirements. A simple generic 3D representation can be texture mapped from the 2D face image after the face has been found using the technique briefly illustrated above. This may be adequate for some markets (such as the games market, where faithful 3D reconstruction may not be a requirement). The second technique requires building a 3D statistical model of human faces in exactly the same way as the 2D face model but this time using 3D data. For the 3D case, each point is described by 3 variables (x,y,z). In this way the 2D face can be found as above and used as input to the 3D face model, which can then reconstruct the most realistic estimate of the 3D face based on the 2D face. How realistic the resulting 3D model is will depend on the statistical significance in the training sets (2D and 3D) and the parametric representation (for example, representing the lips with 2 lines or 3). Theory suggests that a faithful representation can always be achieved if the training sets contain the variability present in the populace. However, in practice this will have to be quantified via a technique such as leave-one-out testing, as one can never assume that the variability has been adequately captured. Researchers have successfully produced 2D face models that were capable of finding faces in new (unseen) images. These models were built from databases containing approximately 50-100 faces.
Data
[0022] The 2D face image must have a resolution that can faithfully represent facial features. It has been shown that an image from a standard digital camera or an image scanned via a standard flat-bed document scanner provides sufficient resolution to faithfully represent the relevant facial features. It may be possible to reconstruct the face from a low resolution 2D image, however, this remains to be tested.
[0023] The face image must be a front facing image. It is not crucial to position the face in the centre of the image, however, for successful texture mapping the whole of the face must be present in the image. The technique can always provide a best estimate of the position of the facial features, however, the accuracy of their location will be adversely affected by the focus of the image. Badly focused images can lead to incorrect feature location and will result in a blurred texture map.
[0024] The number of 3D faces in the training set is the significant factor affecting the faithful representation of the 3D face. If a relatively low faithful representation is required, the number of 3D faces in the training set may be as low as 30. Again, this remains to be determined. To produce and apply models that are adequate for markets requiring a highly faithful 3D representation, the training sets must be large enough to capture the variability of the human face. In pursuing these markets, bearing in mind the extra resource required to produce the models, the same models can be used for all markets.
[0025] The apparatus and method of the present invention can process financial transactions and/or financial transaction information. Financial transactions can be processed in conjunction with the image processing routine described herein in order to facilitate the utilization of the present invention in a commercial environment.
REFERENCES
[0000]
Cootes et al: “Training models of shape from sets of examples”, Proc: British Machine Vision Conference, Springer-Verlag, 1992 pp 9-18.
Cootes et al: “Active Shape Models—Smart Snakes”, in Proc: British Machine Vision Conference, Springer-Verlag, 1992, pp. 266-275.
Lanitis et al: “A unified approach to coding and interpreting face images”, Proc: ICCV 1995, pp. 368-373.
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In an apparatus and method for generating a three-dimensional representation from a two-dimensional image, a memory device stores information for processing a two-dimensional image and for generating a three-dimensional image from the two-dimensional image, a processing device processes a digital representation of an image by generating a two-dimensional image from the digital representation and by generating a three-dimensional image corresponding to the two-dimensional image, and an output device outputs a three-dimensional image and a digital signal representation of the three-dimensional image.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates in general to electrical meters, and more specifically to watthour meters constructed to prevent unauthorized usage of electrical energy.
2. Description of the Prior Art
Theft of electricity has always been a problem, and the problem has been growing in magnitude due to the increasing cost of electrical energy. The theft of electrical energy may occur through the use of a stolen electric meter, reorienting a meter to either stop the register, or to cause it to run backwards, internal tampering of the meter to affect the registration of usage, and external wiring which by-passes the meter.
Various approaches have been used in the prior art to discourage the different types of electrical service theft. For example, new meter and meter socket combinations have been designed which permit only a special meter to be plugged into a specially designed meter socket, with the special meter being pluggable into the special socket with only one orientation. This approach prevents reorienting a meter to stop or reverse the register, and it reduces theft by swapping the original meter with a stolen meter between meter reading periods. The use of a new meter-meter socket combination, however, may economically be applied only to new installations because of the time and cost of removing a standard meter socket from an existing installation and rewiring the special meter socket in its place.
It would be desirable to be able to discourage meter swapping and/or reorienting of the meter, without the necessity of removing the standard meter socket from an existing installation and replacing it with a non-standard special socket.
SUMMARY OF THE INVENTION
Briefly, the present invention is a new and improved electric meter assembly which utilizes a special plug-in meter and a terminal adaptor for a standard meter socket. The special meter will not operate with a standard meter socket, but the proper terminal adaptor quickly converts a standard meter socket to permit it to only accept the special meter. Further, it permits the special meter to be plugged into the modified meter socket with only one orientation of the meter relative to the meter socket.
In the preferred embodiment of the invention, the special plug-in meter has an unsymmetrical terminal arrangement, wherein one of its blade terminals is laterally displaced from the usual location. An electrically conductive terminal adaptor is plugged into a predetermined jaw terminal of the standard meter socket. The adaptor is self-locking, preventing the removal of the adaptor once it has been plugged into the jaw terminal, it blocks access to the jaw terminal, and it includes an auxiliary jaw terminal for receiving the displaced blade terminal of the meter. Thus, a stolen standard meter will not plug into the modified meter socket due to the blocked jaw terminal, and the special meter will only plug into the modified meter socket with the proper orientation relative thereto. While the invention is particularly suitable for modifying existing meter installations, it may also be used on new meter installations by merely placing the adaptor on the proper meter socket terminal, before or after wiring the standard meter socket into position.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood, and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of exemplary embodiments, taken with the accompanying drawings in which:
FIG. 1 is a perspective view of a socket-type or plug-in electrical meter constructed according to the teachings of the invention;
FIG. 2 is a diagrammatic and schematic view of the meter terminals and the coils connected thereto, when viewing the meter shown in FIG. 1 from the front, in the direction of arrows II--II;
FIG. 3 is an elevational view of a standard meter socket with one of its jaw terminals modified with an adaptor, according to the teachings of the invention;
FIG. 4 is a schematic view of the meter socket shown in FIG. 3, indicating the connection of the line and load conductors to its jaw terminals; FIGS. 5 and 6 are elevational and sectional views, respectively, of a terminal adaptor which may be used to modify a jaw terminal of a standard meter socket; and
FIGS. 7 and 8 are elevational and sectional views, respectively, of still another terminal adaptor which may be used to modify a jaw terminal of a standard meter socket.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and to FIGS. 1 and 2 in particular, there is shown a plug-in meter 10 constructed according to the teachings of the invention. FIG. 1 is a perspective view of the meter 10, and FIG. 2 is a diagrammatic view of the meter terminals shown in FIG. 1, along with a schematic representation of the various coils or windings connected thereto. The meter terminals shown in FIG. 2 are arranged as they would appear when viewing the meter 10 shown in FIG. 1 from the front thereof, i.e., in the direction of arrows II--II.
More specifically, meter 10 is an induction watthour integrating meter which is of the self-contained, detachable or socket-type utilized for billing electrical power supplied by an electrical utility to a customer load. The meter 10 includes a meter movement having an electromagnetic structure which drives an electroconductive disc and associated shaft which drives a meter register. Since the meter movement may be conventional, it is not shown in detail. The coils or windings of the electromagnetic structure are shown schematically in FIG. 2, and will be hereinafter referred to.
The meter movement includes a frame which is carried on a first side of a base assembly 12 to provide a meter chassis assembly which includes four bayonet-type terminal blades 14, 16, 18 and 20, which extend in a sealed relationship through the base assembly 12 to project outwardly from the second side thereof. A cover 22, formed of glass or a suitable transparent plastic, cooperates with the base 12 to provide an enclosure for the meter movement.
As illustrated schematically in FIG. 2, a first electrical circuit is established from line terminal 14 to load terminal 18 via a current coil or winding 23, and a second electrical circuit is established from line terminal 16 to load terminal 20 via a current coil 24. A voltage winding 26 is connected between terminals 14 and 16.
In a conventional meter, the terminals are symmetrically arranged about a central axis or horizontal center line 28 of the meter, which center line is perpendicular to the base 12. Accordingly, the two upper line terminals 14 and 16 are equally spaced laterally from the center axis along the symmetrical terminal axes 29A and 29B. In conventional meters these axes extend vertically. In prior art meters, the two lower load terminals are aligned with the upper line terminals along the parallel axes 29A and 29B. This symmetrical arrangement permits a meter to be disoriented by 180 degrees, and still establish electrical circuits from the electrical utility lines to the customer's load. If the meter is not equipped with a special unidirectional register, the disorientation will either stop the register, or it will cause it to run backwards, depending upon the register type. According to the teachings of the invention, three of the terminals are placed in the conventional locations, while the remaining terminal is displaced laterally from the usual location to provide an unsymmetrical arrangement of the terminals about center line 28.
The terminal of meter 10 which is displaced is preferably a lower terminal, such as terminal 18, as the lower terminals are connected to jaw terminals on the load side of the meter socket, which terminals are "dead" when the meter is removed from the socket. As illustrated most clearly in FIG. 2, terminal 18 is displaced from its usual position, shown in phantom at 30, by a suitable dimension indicated at 32. The value of dimension 32, and the direction of the displacement relative to the usual terminal location on the axis 29B in FIG. 1, will depend upon the specific terminal adaptor used to modify a terminal of the meter socket. The illustrated horizontal displacement of terminal 18 towards terminal 20 is convenient from the standpoint of available space in the meter socket.
FIGS. 3 and 4 illustrate a meter socket 40, modified with an adaptor 42, according to the teachings of the invention. FIG. 3 is an elevational view of meter socket 40, and FIG. 4 is a diagrammatic and schematic view of the socket 40, when viewing the socket 40 from the same side thereof as the FIG. 3 view.
More specifically, socket 40 includes a plurality of jaw terminals 44, 46, 48 and 50 symmetrically arranged about a horizontal center line 52 within an open ended enclosure 54. The symmetrical arrangement of the jaw terminals 44, 46, 48 and 50 is the usual arrangement for receiving the blade contact terminals of the usual watthour meter. The symmetrical terminal axes 55A and 55B are vertically parallel and equally spaced laterally from the axis 52 by the symmetrical horizontal axes 55C and 55D. The terminals 44 and 48 are on the common axis 55A and the terminals 46 and 50 are on the common axis 55B with the axes 55A and 55B being coaligned with the meter axes 29B and 29A, respectively, when the meter 10 is positioned for mounting in the socket enclosure 54. As illustrated schematically in FIG. 4, line jaw terminals 44 and 46 are connected to the electrical power line conductors, via suitable connectors, such as to line conductors 56 and 57, respectively, and load jaw terminals 48 and 50 are connected to load conductors 58 and 59, respectively, via suitable connectors. While a single phase three-wire system is illustrated in the Figures, it is to be understood that a single phase two-wire system may also be used.
The symmetrical arrangement of jaw terminals 44, 46, 48 and 50 is modified to provide the same unsymmetrical arrangement as the blade terminals of meter 10, via the adaptor 42. Adaptor 42 is an electrically conductive member, which may be formed out of the same material as the jaw terminals, such as a high quality resilient copper alloy, either bronze or beryllium. Adaptor 42 includes a first portion 60 which plugs into the conventional jaw terminal in a self-locking manner, which portion also blocks access to the modified jaw terminal. As illustrated in the Figures, with terminal 18 of the meter 10 displaced from the usual location, jaw terminal 48 of the socket 40 would be the terminal which would be modified by the adaptor 42.
Adaptor 42 includes a second portion 62 which functions as an auxiliary jaw terminal. The auxiliary jaw terminal 62 is displaced from the center line of jaw terminal 48 by the dimension 64, which dimension is the same as the dimension 32 shown in FIGS. 1 and 2.
Jaw terminal 48 is a load terminal, being connected to load conductor 58, and as such it will be "dead" when a meter is not plugged into the socket. Thus, adaptor 42 may be quickly and easily snapped into the jaw 48 at the time the special meter 10 is to be installed. Once adaptor 42 is positioned over jaw terminal 48, the meter socket 54 will only accept the special meter 10, and it will accept special meter 10 only in the proper orientation thereof relative to the socket. A standard meter will not fit the modified socket in any orientation because jaw terminal 48 is blocked from receiving a blade terminal. Further, meter 10 cannot be disoriented 180 degrees and mounted in the socket 40, as jaw terminal 48 is blocked.
FIG. 5 is an elevational view of adaptor 42 shown in position over jaw terminal 48, with adaptor 42 being constructed according to an embodiment of the invention. FIG. 6 is a sectional view of adaptor 42 and terminal 48, taken between arrows VI--VI. Portion 60 of adaptor 42 includes an outer U-shaped member 69 having first and second spaced leg portions 70 and 72, a connecting bight 74, and a portion 76 which depends from the inner surface of bight 74. Portion 76 enters the opening in jaw terminal 48, and once in the proper position within the jaw terminal 48 it locks itself, preventing removal thereof. The locking means associated with the depending portion 76 includes locking tabs 80 and 82, best shown in FIG. 6, which are located at the extreme outer ends of portion 76, with these ends flaring in opposite directions away from a center line of the terminal 48 to provide the locking tabs. Any attempt to pull the adaptor 42 from the jaw terminal 48 is defeated by the tabs 80 and 82 which catch on the finger-like resilient portions of the jaw terminal which are spread apart by the locking tabs as portion 76 is forced into the jaw terminal, and then the finger-like members snap back as the tabs 80 and 82 clear the ends of the jaw fingers.
The depending portion 76 also includes side guards 84 and 86 at one open end of the U-shaped member 69, and side guards 88 and 90 at the other open end, which prevent the fingers of jaw terminal 48 from being manually spread apart to clear the locking tabs 80 and 82. As illustrated in FIG. 5, the side guards may be integral, flared portions of the depending portion 76.
The second portion 62 of the adapter 42, which functions as the auxiliary jaw terminal, may be constructed similar to the jaw terminal 48 and brazed or otherwise mechanically and electrically connected to leg portion 72 of the U-shaped member 69.
FIG. 7 is an elevational view of an adaptor 42', disposed over terminal 48, which adaptor is constructed according to another embodiment of the invention. A first portion 60' of adaptor 42' includes a top portion 100 which has a depending portion 102 for insertion into the fingers of the jaw terminal 48, with the lower end of portion 102 having locking tabs 104 and 106 thereon which prevent the adaptor 42' from being removed once it is snapped into position in the jaw terminal. Opposite ends of the top portion 100 include side portions 108 and 110 which function as side guards to close the open ends of terminal 48 and prevent manual spreading of the jaw fingers to clear the locking tabs 104 and 106. The top portion 100 may also include a first leg portion 112 integral therewith which is of sufficient length to be bent into a configuration which includes a bight 114 and a second leg portion 116. A spring-like resilient metallic member 120 is attached to the second leg portion 116 by suitable hardware 122, with the spring-like member 120 being spaced from the leg portion 112 to define an opening 124 for receiving the blade terminal 18 of the meter 10.
In summary, there has been disclosed a new and improved meter assembly which discourages theft of electrical energy by modifying a standard meter socket to accept a special meter having unsymmetrically arranged blade terminals. A stolen electrical meter will not fit the modified standard socket in any orientation, and the special meter will fit the modified socket in only the proper orientation.
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An electrical meter assembly including a plug-in meter and a meter socket, each having terminals. An adaptor modifies a terminal of the meter socket, enabling the modified and unmodified terminals thereof to engage the terminals of the meter in only one orientation of the meter relative to the meter socket.
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BACKGROUND OF THE INVENTION
Most paving machines now-a-days for laying bituminous or asphalt roadways are of the so-called "floating screed" kind. Each employs a tracked or wheeled tractor unit having a pair of rearwardly extending screed pull arms pivoted to its sides, the screed assembly itself being attached to the rear ends of the pull arms. In this type of paver the texture and density of the mat is influenced by the weight of the screed assembly, since it "floats" upon the material beneath it, and by the angular attitude of the underlying screeding surface relative to the roadway, known as the "attack angle" of the screed. For a given paving speed the thicker the mat being laid the greater the attack angle must be in order to achieve a required mat density. Hence the screed assembly in turn must be pivoted relative to the pull arms about a transverse axis so that the attack angle can be adjusted on the run as conditions dictate.
A typical width of the screed assembly of a paver for highway and the like construction is ten feet, approximately the overall width of the paver itself. In order to lay a mat of greater width, and so reduce the number of passes needed, extensible screed assemblies are commonly used. These include a pair of shorter screeds, or "screed extensions" as they are often called, carried by and disposed rearwardly of the main screed, being attached to the latter so that one or both can be slid longitudinally outwards of the main screed and so extend the effective width of the latter up to twofold. The overall width of the mat laid in a single pass is thereby increased and also the efficiency of the paver in terms of time and cost needed to pave a given roadway. But inherent in the use of screed extensions are certain deficiencies which have not been recognized or if recognized have simply been ignored in practice.
These deficiencies arise from the fact that as the width of the screed assembly is increased by the extensions the weight upon the portion or portions of the mat being laid by the extensions as well as the main screed decreases, especially towards the outer ends of the extensions. The result is a mat of uneven or variable texture and density. Another problem results when one screed extension strikes a curb, a manhole cover or the like, a not infrequent or isolated occurrence during some paving conditions. The screed extension is thereby often thrown out of alignment with the main screed, thus altering the effect of the attack angle of the extension on the mat and so the texture of the latter. Accordingly, the chief object of the present invention is an improved extensible screed assembly which eliminates or at least reduces the deficiencies mentioned as well as incorporating other improvements in structure and ease of operation.
SUMMARY OF THE INVENTION
The invention modifies the screed assembly so that the attack angle of each screed extension can be adjusted on the run, if necessary, relative to that of the main screed. Hence, especially when the screed assembly is fully extended, the attack angle of one or both extensions can be increased to compensate for the fact that the weight upon the mat, especially adjacent its lateral edges, is decreased. The texture and density of the overall mat is thus more uniform. In addition, the alignment of each screed extension can be adjusted relative to that of the main screed in order to correct any misalignment resulting from the extension bumping a curb or the like. Other features and advantages of the extensible screed assembly illustrated in the drawing and later described in more detail will be apparent.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic top plan view of a typical bituminous paver having an extensible screed assembly according to the invention, the screed extensions being shown partially extended.
FIG. 2 is a partial rear perspective view of the extensible screed assembly of the invention, the lefthand extension being shown fully extended.
FIG. 3 is a rear perspective view of the lefthand portion of the main screed of FIG. 2 illustrating the slope, attack angle and alignment controls for the lefthand screed extension.
FIG. 4 is a detail view of the slope control for the screed assembly.
FIG. 5 is a detail view illustrating the lefthand control for the attack angle of the entire screed assembly.
FIG. 6 is a perspective view of the lefthand screed extension showing the manner in which it is mounted to the main screed and the manner by which its elevation is controlled relative to the main screed.
FIG. 7 is a detail view taken along the line 7--7 of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1 a typical bituminous paver 10 includes a tractor unit 11 having slat conveyors 12 to carry the mix from the hopper 13 rearwardly to the spreader augers 14. The forward ends of a pair of screed pull arms 15 are journaled at 16 to the sides of the tractor 11 and extend rearwardly, being connected at their rear ends to an extensible screed assembly, generally denoted at 20, disposed transversely across the rear of the tractor 11.
The screed assembly 20 (see FIG. 2) comprises a main screed 21 (see FIGS. 3-5) divided into left and right hand halves but having a common underlying U-shaped screed plate 22 providing an underlying screeding surface 22a. The walls of the screed plate 22 are notched at 23 at its midpoint so that the slope of each half can be adjusted relative to the other in order to vary the crown of the main screed 21. Atop each screed half is an inverted U-shaped floor plate 24 to which the screed plate 22 is attached in conventional manner as by J-bolts 25. Each floor plate 24 carries a pair of upstanding, flanged inner and outer end plates 26 and 27, a front wall plate 28 having a top flange 28a, and an upstanding truss 29 adjacent the inner end plate 26 and tied into the front wall plate 28. Slope control is provided by a pair of oppositely threaded screw shafts 30 between the screed halves which engage threaded blocks 31 journaled between brackets 32 and 33 mounted atop the front wall flanges 28a and the trusses 29. To the midpoints of the screw shafts 30 are fixed a pair of driven sprockets 34. A drive chain 35 passes about the sprockets 34 and up over a smaller drive sprocket 36 journaled on an upstanding bracket plate 37 on the screw shafts 30. A pair of hand cranks 38 drive the sprocket 36, whence rotation of the latter will rotate the screw shafts 30 and thus adjust the crown of the entire screed assembly 20 about its midpoint 23.
The screed assembly 20 is bolted to flanges 40 at the rear ends of the screed pull arms 15. The flanges 40 in turn engage mating flanges 41 at the forward ends of heavy L-shaped pivot brackets 42 (only the left-hand one being shown) passing through the upper outer corners of the screed front wall plates 28 and then down along the inside of the screed outer end plates 27, the lower ends of the brackets 42 being pivoted at 43 to the end plates 27. Attack angle adjustment is provided by threaded blocks 44 (only the left-hand one being shown) journaled between brackets 45 atop the front wall flanges 28a, the blocks 44 receiving screw shafts 46 carried within rearwardly extending, boxed housings 47 secured to bracket plates 48 bolted to the elbows of the pivot brackets 42. The screw shafts 46 are journaled in the rear ends of the housings 47 and fitted with hand cranks 49. Thus rotation of the latter adjusts the attack angle or fore-and-aft inclination of the entire screed assembly 20 by moving the latter about the axis A--A (see FIG. 5) of the two pivots 43.
Each screed extension, generally designated at 50 (only the left-hand one being shown in FIGS. 2 and 6 and described since both are identical in structure and operation), is attached to the main screed 21 through a large box frame 51, fabricated from steel plate, having a lower leg 52 disposed transversely across an outer end of the main screed plate 22, the floor plate 24 being relieved at 53 for that purpose. A shaft 54, fixed to the frame leg 52, extends therethrough transversely of the screed plate 22, the rear end of the shaft 54 being journaled in a split bearing 55 mounted to the screed plate 22. The front end of the shaft 54 is also journaled in a split bearing 56, bolted at 57 to the front wall plate 28, the bolt holes in the latter being enlarged for purposes to be described. From FIG. 3 it will be seen that the top half of the bearing 56 extends upwardly and its mid-portion is provided with a pair of shoulders in the form of ramps. The latter are engaged by a pair of cooperative wedge blocks 58 having tongues which extend through vertical slots 59 in the wall plate 28. The wedge blocks 58 are held to the bearing 56 by slotted clamp plates 60 and bolts 61. To the top of the bearing 56 is bolted a block 62 to which in turn is welded the lower end of a threaded rod 63 which extends up through the front wall flange 28a and is captured there between two nuts 64 (only one being shown). Movement of the box frame 51 about the axis of the shaft 54 is controlled by a screw shaft 65 threaded at its outer end into a pivot block 66 journaled between a pair of bracket plates 67 welded to the top of the frame 51. The other end of the screw shaft 65 is journaled in a bearing 68 attached to the horizontal portion of the truss 29 adjacent which a driven sprocket 69 is fixed to the screw shaft 65. A drive chain 70 is entrained around the sprocket 69 and smaller drive sprocket 71 journaled in a supporting bracket 72 attached to the truss 29, the sprocket 71 being fitted with a hand crank 73. Hence by rotating the crank 73 the frame 51 will be tilted back and forth on the shaft 54 about its axis B--B (see FIG. 3) relative to the main screed 21.
Each box frame 51 is provided with a pair of vertically spaced, horizontal bracket plates 75 extending rearwardly from the frame 51 to which are welded the ends of a pair of laterally spaced vertical steel tubes 76. Each of the latter receives a pair of bearings 77 (only two being shown in FIG. 3) retained within a pair of vertically spaced brackets 78 extending forwardly from a second box frame 79 such that the latter frame can slide up and down on the tubes 76 relative to the frame 51. That movement in turn is controlled by a vertical screw shaft 80 (see FIG. 6) threaded into a pivot block 81 journaled between a pair of bracket plates 82 on the front face of the frame 79. The screw shaft 80 extends upwards between the tubes 76 and is journaled in the upper bracket plate 75, its upper end being fitted with a driven sprocket 83. A drive chain 84 passes around the sprocket 83 and a smaller drive sprocket 85 journalled in a rearwardly extending channel 86 welded to the top of the frame 51, the sprocket 85 being fitted with a hand crank 87. Thus rotation of the latter will move the frame 79 up and down along an axis C--C (see FIG. 3) relative to the frame 51.
From the rear face of the frame 79 extends a pair of laterally spaced vertical brackets 90 (see FIGS. 3 and 6) into which are fitted two pairs of bearings 91, like the bearings 77, which slidably receive a pair of vertically spaced, horizontal steel tubes 92 whose inner ends are joined by a vertical channel member 93. To the lower end of the latter is welded the inner end of a box beam 94 extending out beyond the end of the main screed 21, the outer portion of the beam 94 being offset rearwardly at 95 and welded to the top of the floor plate 96 of the screed extension 50, the latter thus being offset rearwardly of the main screed 21. Beneath the floor plate 96 and attached by J-bolts 97, is the screed plate 98 of the extension 50 having an underlying screeding surface 98a. Welded to the floor plate 96 are a low front wall plate 99 and a flanged outer end plate 100, the outer ends of the tubes 92 being bolted at 101 through the end plate 100 into plugs 102 (only one being shown in FIG. 7) welded in the outer ends of the tubes 92, the latter being received in flanges 103 welded to the inboard face of the end plate 100. The end of the lower tube 92 only is welded in turn to its flange 103 while to the end of the upper tube 92 are welded the arms of a yoke 104 just inboard of the flange 103. The shank of the yoke 104 is captured between two nuts 105 on a vertical bolt 106 secured to a bracket 107 welded to the end plate 100. As the extension 50 is being attached to the upper tube 92 the nuts 105 are rotated one to two turns which imposes a pre-torque load in the direction indicated by the arrow in FIG. 7 on the tube 92, the holes for the upper bolts 101 in the end plate 100 being slotted for that purpose. The rigidity of the entire extension 50 relative to the main screed 21 is thus increased because the twisting force imposed upon the tubes 92 by the mix ahead of the extension 50 during paving is better resisted. Hence the entire extension 50 is supported by the tubes 92 and the beam 94 and slides in and out through the bearings 91 longitudinally of the main screed 21 to retract and extend the width of the screed assembly 20.
Movement of each extension 50 is controlled, as is typical, by a pair of hydraulic rams 108 secured to the main screed 21, its piston rods 109 being bolted at 110 in turn to the extension end wall 100. The forward face of the extension screed plate 98 (as is that of the main screed 21) is provided with a strike-off plate 111, vertical adjustment of which is provided at 112 on the front wall plate 99. Provision is also made at 113 for attaching typical cut-off shoes 114 (see FIG. 2) or screed extenders to the outer ends of the extensions 50. The screed assembly 20 of course includes many other typical items such as burners 115, vibrators 116, telescoping walkways 117, various additional controls 118, etc., all as will be apparent to those of skill in the art, including a pair of movable "handsets" 119 (only one being shown in FIG. 2) for the screed man or men, each of which handsets carries a switch for activating the rams 108 to extend or retract extensions 50, an override switch for its associated auger 14, and a horn button.
As previously noted, rotation of the cranks 38 will adjust the slope of each half of the entire screed assembly 20 in directions transversely of that of the roadway, that is, the angle the screeding surfaces 22a and 98a of one half make with those of the other half, as indicated at "A" in FIG. 3. Likewise, as previously noted, rotation of one or both cranks 49 will adjust the attack angle or fore-and-aft inclination of the entire screed assembly 20 about the axis A--A, that is, the inclination the screeding surfaces 22a and 98a relative to the direction of the roadway, as indicated at "X" and "Y", respectively, in FIGS. 3 and 6. Since each extension 50 is connected to the main screed 21 through the box frame 51, rotation of one or both cranks 73 will adjust the slope, in the foregoing sense, of one or both extensions 50 relative to that of their respective halves of the main screed 21 about the axes B--B parallel to the screeding surfaces 98a. And because each extension 50 is connected to its respective box frame 51 through the box frame 79, rotation of each crank 87 will raise or lower its respective extension 50 in along the axis C--C normal to its screeding surface 98a and thus the elevation of the latter surface relative to the surface 22a of the main screed 21 so that the two surfaces can be made co-planar.
When it becomes desirable, for the reason mentioned, to increase the attack angle of one (or both) extension 50 relative to that of the main screed 21, the bolts 57 of the bearing 56 are loosened and the nuts 64 on the rod 63 adjusted so that the entire bearing 56 is raised, thus tilting the box frame 51 about another axis D--D (see FIG. 3) transversely of the screed pull arms 15 and hence increasing the attack angle or fore-and-aft inclination "Y" of the screed extention 50 relative to the inclination "X" of the main screed 21. This can be accomplished on the run by one of the screed men, after which the bolts 57 are retightened. Should one extension 50 strike an obstacle and disturb its alignment with the main screed 21 such that the longitudinal axis of the extension 50, indicated by the line E--E in FIG. 1, is no longer in a plane parallel to a plane through the longitudinal axis of the main screed 21, indicated by the line F--F in FIG. 1, the bearing bolts 57 and 61 are first loosened. Then the wedge blocks 58 are vertically adjusted in opposite directions on the ramps of the bearing 56, thus moving the latter longitudinally of the main screed plate 22 and so pivoting the entire screed extension 50 about a vertical axis G--G (see FIG. 3) relative to the screed extension surface 98a, whereby the axis E--E of the extension 50 can be shifted to correct the misalignment, after which the bolts 57 and 61 are retightened. In practice it has been found that the bearings 55 and 56 readily accommodate the relatively small misalignments with the shaft 54 caused by vertical and horizontal movements of the bearing 56, which movement is permitted owing to the enlarged holes in the front wall plate 28 for the bolts 57. Other aspects of the structure and operation of the screed assembly 20 will be apparent to those of skill in the art.
Though the invention has been described in terms of a particular embodiment, being the best mode known of carrying out the invention, it is not limited to that embodiment alone. Instead the following claims are to be read as encompassing all adaptations and modifications of the invention falling within its spirit and scope, in which claims the terms "inclination", "slope", "elevation", and "alignment" have the above meanings.
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An extensible screed assembly for a bituminous paver incorporates a pair of screed extensions which are movable laterally outwards of the paver in order to pave roadway widths greater than that of the main screed. The screed extensions feature means by which the attack angle of each extension can be adjusted relative to the attack angle of the main screed and by which the alignment of each extension can also be adjusted relative to that of the main screed.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to equipment used in producing fluid from a well and more particularly concerns tools to enhance the operation of downhole reciprocating pumps.
[0002] U.S. Pat. No. 6,068,052, issued to the present inventor on May 30, 2000, explains the common practice and problems of “tapping” and discloses a no tap tool for downhole reciprocating pumps. That tool eliminates the need for “tapping” in the operation of a downhole pump, reduces the unidirectional application of force to the plunger of a downhole pump and allows the plunger to take the path of least resistance to overcome a “stuck” condition.
[0003] The tool is connectable between the last sucker rod of the sucker rod string and the downhole pump. A cylinder with a closed end and an internal annular seat proximate an open end houses a piston which reciprocates slidably within the cylinder and is free to rotate within the cylinder. The tool components are concentric about the longitudinal axis of the tool, so the tool components are independently free to rotate about the tool axis, allowing the plunger of the pump to rotate to the path of least resistance to achieve its freedom, thereby further reducing the forces exerted on the system components.
[0004] The freedom of the tool components to independently rotate is one of the keys to the success of this “old” tool. However, because of this freedom of the tool components to independently rotate, use of the tool in the string renders the tool and any of the equipment downhole of the tool irretrievable without retrieval of all of the equipment downhole of the tool.
[0005] It is, therefore, an object of this invention to provide a no tap tool which affords the benefits of the “old” tool. To this end, it is also an object of this invention to provide a no tap tool which utilizes independently rotating components. But, it is a further object of this invention to provide a no tap tool which does not prevent retrieval of equipment downhole of the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
[0007] FIG. 1 is a diametric cross section of a preferred embodiment of the no-tap tool;
[0008] FIG. 2 is an elevation view of the upper portion of the piston of the tool of FIG. 1 ;
[0009] FIG. 3 is a cross-sectional view taken along the line 3 - 3 of FIG. 1 ;
[0010] FIG. 4 is a cross-sectional view taken along the line 4 - 4 of FIG. 1 ; and
[0011] FIG. 5 is a cross-sectional view taken along the line 5 - 5 of FIG. 1 .
[0012] While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
SUMMARY OF THE INVENTION
[0013] In accordance with the invention, a tool is provided for connection between the last sucker rod of a sucker rod string and a downhole pump. A circular cylinder has a closed upper end which is externally adapted for connection to the last sucker rod of the sucker rod string. A circular cylindrical piston slides reciprocally and rotates freely within the cylinder. The piston has a lower portion which extends through an open lower end of the cylinder and is adapted for connection to the pump. The closed upper end of the cylinder and the upper face of the piston have a cooperable tongue and groove which prevent relative rotational motion of the piston in the cylinder when the tongue is engaged in the groove. Preferably, the tongue and groove are of rectangular cross section, are diametric in relation to the cylinder and piston and the groove is sufficiently wider than the tongue to facilitate their engagement.
[0014] In a preferred embodiment, the cylinder is concentric about a vertical longitudinal axis and has an internally threaded upper portion, a smooth middle portion and a lower portion of inner diameter less than the inner diameter of the middle portion so as to form an annular seat at a junction of the cylinder middle and lower portions. The piston is a plunger which is concentric about the vertical longitudinal axis and has an externally threaded lower portion adapted to be coupled to the pump, a smooth middle portion and a smooth upper portion with a horizontal end face and an outer diameter greater than an outer diameter of the middle portion so as to form an annular stop at a junction of the plunger middle and upper portions. The plunger upper portion slides reciprocally and rotates within the cylinder middle portion and the stop and seat are cooperable to limit the lowermost travel of the plunger upper portion within the cylinder. A pin concentric about the vertical longitudinal axis has an externally threaded lower portion with a horizontal end face engaged in the internally threaded upper portion of the cylinder, a middle portion of outer diameter greater than an inner diameter of the plunger so as to position the pin end face at the top of the cylinder middle portion when the pin lower portion is fully threaded into the cylinder upper portion and an externally threaded upper portion adapted for engagement with the last sucker rod of the sucker rod string. The pin and plunger end faces are cooperable to limit the uppermost travel of the plunger upper portion within the cylinder with the plunger lower portion extending below the cylinder lower portion. The horizontal end face of the pin has a diametric groove therein and the plunger upper portion horizontal end face has a diametric tongue thereon. The tongue and groove are cooperable to disconnect the tool from the pump in response to rotation of the string to engage and turn the tongue and groove at the uppermost stroke of the plunger.
DETAILED DESCRIPTION
[0015] Turning to FIGS. 1 through 5 , the tool consists of a cylinder 30 , a piston or plunger 50 and a pin 70 , all concentrically aligned on a vertical longitudinal axis 27 .
[0016] In the preferred embodiment shown, the cylinder 30 has an internally threaded upper portion 31 , a smooth middle portion 33 and a lower portion 35 . The lower portion 35 has an inner diameter less than the inner diameter of the middle portion 33 so as to define an internal annular seat 37 at the junction of the middle and lower portions 33 and 35 of the cylinder 30 . At least one aperture 41 is provided through the upper side wall of the middle portion 33 of the cylinder 30 , preferably substantially immediately below the top of the middle portion 33 of the cylinder 30 . At least one aperture 43 is also provided through the lower side wall of the middle portion 33 of the cylinder 30 , preferably substantially immediately above the internal seat 37 . Preferably, four upper apertures 41 and four lower apertures 43 will be substantially equally spaced about the circumference of the cylinder 30 .
[0017] The piston or plunger 50 has a smooth upper portion 51 , a smooth middle portion 53 and an externally threaded lower portion 55 . The outer diameter of the middle portion 53 is less than the outer diameter of the upper portion 51 , thus providing a stop 57 which cooperates with the seat 37 of the cylinder 30 to limit the lowermost travel of the downstroke of the piston 50 within the cylinder 30 . The length of the middle portion 53 of the piston 50 is such that the upper portion 51 of the piston 50 can reciprocate from the top to the bottom of the middle portion 33 of the cylinder 30 with the lower threaded portion 55 of the piston 50 extending below the bottom of the cylinder 30 . Since the components of the cylinder 30 and the components of the piston 50 are all concentric, the piston 50 may be slidably reciprocated along the tool axis 27 and is also free to rotate within the cylinder 30 about the tool axis 27 . As shown, the middle portion 53 of the piston 50 is provided with tooling flats 61 .
[0018] As best seen in FIGS. 1 and 2 , a diametric tongue 63 extends upwardly from the upper face 59 of the piston 50 . The tongue 63 shown is, looking at FIG. 1 , rectangular in cross-section, but is most easily formed by use of a rotating cutter so that the upper face 59 of the piston 50 is, looking at FIG. 2 , arcuate. Other cross-sections and machining methods may be used, however, and the upper face 59 of the piston 50 may be in a horizontal plane. The upper face 65 of the tongue 63 is, preferably, in a horizontal plane, as is hereafter explained.
[0019] The pin 70 has an externally threaded lower portion 71 which engages within the internal threads of the upper portion 31 of the cylinder 30 . the middle portion 73 of the pin 70 has an outer diameter which is greater than the inner diameter of the upper portion 31 of the cylinder 30 so that, when the pin 70 is fully threaded into the cylinder 30 , the middle portion 73 of the pin engages the upper end of the cylinder 30 and sets the horizontal lower face 75 of the pin 70 at the junction of the upper and middle portions 31 and 33 of the cylinder 30 . the upper portion 77 of the pin 70 is externally threaded for engagement with a polish rod coupling at the lowermost end of the sucker rod string. The pin 70 closes the upper end of the cylinder 30 and the lower horizontal face 75 of the pin 70 is cooperable with the upper face 59 of the piston to limit the uppermost travel of the piston 50 within the cylinder 30 . As shown, the middle portion 73 of the pin 70 is provided with tooling flats 81 .
[0020] As best seen in FIGS. 1 and 5 , a diametric groove 83 extends upwardly into the lower horizontal face 75 of the threaded lower portion of the pin 70 . The groove 83 in the pin 70 is wider than the tongue 63 of the piston 50 . The difference should be sufficient to facilitate engagement of the tongue 63 in the groove 83 even if the tongue 63 is slightly flared or debris may have collected in the path of engagement.
[0021] In operation, the tool is mounted between the lowermost sucker rod and the pump. The stroke of the plunger in the pump is set so that the plunger does not strike the pump at the bottom of its stroke. However, during the reciprocation of the sucker rod string, as the cylinder 30 is reciprocated, the upper face 65 of the tongue 63 of the piston 50 strikes the lower face 75 of the pin 70 and the stop 57 of the piston 50 strikes the seat 347 in the cylinder 30 , resulting in cyclical upward and downward impact n the pump plunger without impacting the pump. At the same time, the piston 50 and therefore the plunger which is attached to it, are free to rotate about the tool longitudinal axis 27 , thus allowing the plunger to take the path of least resistance and resulting in minimal force being exerted on the other system components while the plunger is freed from a stuck condition.
[0022] Since the piston 50 is free to rotate in the cylinder 30 , it is possible but relatively uncommon that the piston tongue 63 will align with the groove 83 in the pin 70 during normal operation of the tool. Generally, the upper horizontal face 65 of the tongue 63 will strike the lower horizontal face 75 of the pin 70 . However, even if this rare event should occur, the minimal duration of any penetration of the tongue 63 into the groove 83 will have no substantial effect on the freedom of rotation during normal operation. The tool is presented as seen in FIG. 1 to illustrate the intentional alignment of the tongue 63 and groove 83 so that the tool can be disengaged from the downhole equipment for retrieval of the tool without the equipment. This is accomplished by an intentional rotation of the string and, therefore, the tool pin 70 at the top of the stroke. As the groove 83 rotates it comes into alignment with the tongue 63 and the upward inertia of the tongue 63 causes it to engage in the groove 83 and turn the tool. The opposite rotation of the string can be used as a tool is lowered to engage the tongue 63 and groove 83 and permit connection of the tool to downhole equipment.
[0023] While, in the preferred embodiment, the piston 50 extends through the open lower end of the cylinder 30 , the tool could be inverted and the piston 50 adapted for connection to the sucker rod string and the pin 70 adapted for connection to the pump.
[0024] Thus, it is apparent that there has been provided, in accordance with the invention, a no-tap tool that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.
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A tool which connects the last sucker rod of a sucker rod string to a downhole pump has a circularly cylindrical cylinder and piston so that the piston slides reciprocally and rotates freely within the cylinder. However, the closed upper end of the cylinder and the upper face of the piston have a cooperable tongue and groove which prevent relative rotational motion of the piston in the cylinder when the tongue is engaged in the groove so that the tool can be disconnected from the pump in response to rotation of the string at the uppermost stroke of the plunger to engage and turn the tongue and groove.
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This application is a divisional of U.S. application Ser. No. 08/796,984, filed Feb. 7, 1997, now U.S. Pat. No. 5,893,874.
BACKGROUND OF THE INVENTION
The invention relates to a surgical instrument, particularly to a surgical instrument for use during arthroscopic surgery.
Arthroscopic instruments generally have an actuating assembly attached to a handle with an end effector having at least one movable implement located at the distal end of the actuating assembly. Arthroscopic instruments are known which have an actuating assembly that is removable from a handle. It is also known to make arthroscopic instruments having an end effector that is replaceable as a unit.
SUMMARY OF THE INVENTION
The invention permits individual replacement of the implements of the end effector as opposed to replacement of the end effector as a unit.
In one general aspect of the invention, a medical instrument includes an elongated shaft, a plurality of implements mounted to the shaft, and an actuator coupled to produce relative movement between the implements. At least one of the implements is detachable from the shaft and the actuator and from another one of the implements.
Preferred embodiments may include one or more of the following features.
The actuator includes a distal portion with an inclined slot. One of the implements is detachably coupled to the slot such that movement of the actuator causes the relative movement between the implements. The distal portion of the actuator includes a plurality of inclined slots. Each of the implements is detachably coupled to one of the slots. The implements are scissors mounted to pivot open and closed.
The shaft includes spring arms detachably coupled to the implements. The actuator includes a proximal portion for snap-on releasable attachment of the actuator to a handle.
According to another aspect of the invention, a medical instrument includes a handle, an actuator for controlling an end effector, the actuator including a proximal portion with a tapered end section and a groove located distally of the tapered end section, and a coupler for connecting the actuator to the handle. The coupler includes an opening for receiving the actuator proximal portion and a spring loaded mechanism movable between a first position extending into the opening for engaging the groove and a second position allowing passage of the proximal portion through the opening, the tapered end acting to move the spring loaded mechanism toward the second position during insertion of the proximal portion into the opening.
Preferred embodiments of this aspect of the invention may include one or more of the following features.
A release mechanism is coupled to the spring loaded mechanism for moving the spring loaded mechanism toward the second position to allow removal of the proximal portion from the opening. The release mechanism is a spring loaded pin. The coupler is attached to the handle to rotate with respect to the handle.
According to another aspect of the invention, a medical instrument includes a handle, an actuator, a coupler for connecting the actuator to the handle, and an end effector attached to a actuator.
Preferred embodiments of this aspect of the invention may include one or more of the following features.
A shaft surrounds the actuator. The end effector includes a plurality of implements mounted to the shaft. At least one of the implements is detachable from the shaft and the actuator and from another one of the implements. The shaft includes spring arms detachably coupled to the end effector. A sheath surrounds the shaft.
According to another aspect of the invention, a detachable medical instrument includes an actuator for controlling an end effector. The actuator includes a proximal portion having a tapered end section and a groove located distally of the tapered end section for snap-on detachable coupling of the actuator to a handle. A sheath is detachably coupled to the actuator.
According to another aspect of the invention, a medical instrument includes a coupler mounted to a handle for rotation relative to the handle. The coupler includes an opening for receiving an actuator, a spring loaded mechanism movable between a first position extending into the opening for engaging the actuator and a second position allowing passage of a portion of the actuator through the opening, a release mechanism coupled to the spring loaded mechanism for moving the spring loaded mechanism toward the second position to allow removal of the portion from the opening, and a positioning member which interfaces with the handle to position the coupler in a desired rotated position relative to the handle.
According to another aspect of the invention, an end effector for a medical instrument of the kind that includes an actuating member for actuating the end effector has a pair of implements configured for releasable connection to each other and to the actuating member.
Preferred embodiments of this aspect of the invention may include one or more of the following features.
Each of the pair of implements includes a working portion, a coupler in the form of a coupling pin which is received in a corresponding slot in the actuating member, and a coupler configured for releasably connecting the pair of implements to each other.
The medical instruments of the invention may be used in arthroscopic procedures in which, for example, scissors or graspers are employed. The medical instruments can be adapted to connect to a power source for use in procedures where cauterization capability is desired.
Advantages of the invention include detachable implements which permit individual replacement of dulled blades without the need for any further components to be disposable, thus providing a cost effective disposable system. Additionally, instruments according the invention can be quickly disassembled such that components can be individually cleaned and easily reassembled.
Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a medical instrument;
FIG. 2 is an exploded view of the medical instrument of FIG. 1;
FIGS. 3 and 3A are diagrammatic illustrations of an end effector of the medical instrument of FIG. 1;
FIG. 4 is a cross-sectional view of the distal end of the medical instrument of FIG. 1, shown with an outer tube removed;
FIG. 4A is a diagrammatic illustration of the distal end the medical instrument of FIG. 1, showing an actuator coupled to an end effector;
FIG. 5 is a diagrammatic illustration of the distal end of the medical instrument of FIG. 1, shown with an outer tube removed;
FIG. 6 is a cross-sectional view of a coupler of the medical instrument of FIG. 1, shown with a cover removed;
FIG. 6A is an end view of the coupler, taken along lines 6A--6A in FIG. 6;
FIG. 7 is a diagrammatic illustration of an additional embodiment of a medical instrument;
FIG. 8 is an exploded view of the medical instrument of FIG. 7;
FIGS. 9 and 9A are diagrammatic illustrations of an alternative embodiment of an end effector of the medical instrument of FIG. 1; and
FIGS. 10 and 10A are diagrammatic illustrations of an additional alternative embodiment of an end effector of the medical instrument of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, an arthroscopic instrument 210 includes a handle 212, a coupler 214 with base section 216 and cover 218, and a tube assembly 220 with a detachable end effector 222, e.g., a scissor dissector. Handle 212 has an electrical connector 213 which attaches to a power source (not shown) to permit cauterization of tissue with end effector 222.
End effector 222 includes implements 250, 252, e.g., cutting blades, which become dulled with use. In order to replace one or both dulled implements, implements 250, 252 are individually detachable from each other and from tube assembly 220.
Referring to FIG. 2, end effector 222 is detachably coupled to an actuator 230 and an intermediate shaft 231 of tube assembly 220. Actuator 230 terminates in a distal coupler 241, and shaft 231 terminates in a distal coupling section 235 with spring arms 233, described further below, for detachably coupling end effector 222 to actuator 230 and shaft 231.
An outer sheath 232 of tube assembly 220 is hollow to accommodate the insertion of shaft 231 into sheath 232, and shaft 231 is hollow to accommodate the insertion of actuator 230 into shaft 231. Shaft 231 includes a proximal section 237 with external threads 237a which extend beyond a proximal end 239 of sheath 232 when tube assembly 220 is assembled. A spacer 256 has a distal section 256a with internal threads 257 for threaded engagement with proximal threads 237a of shaft 231 and a proximal, enlarged section 256b. Section 256b has a knurled edge 256c to aid in threading spacer 256 onto shaft 231. Alternatively, instead of spacer 256 being a separate component, spacer 256 can be integral with sheath 232. When instrument 210 is assembled spacer 256 is positioned between base section 216 and cover 218 to prevent axial movement of shaft 231 and sheath 232 when actuator 230 is moved axially.
A distal end 236 of shaft coupling section 235 has an increased outer diameter against which a distal end 234 of sheath 232 abuts when assembled. With tube assembly 220 assembled, a proximal end 248 of actuator 230 extends outside proximal section 237 of shaft 231. Proximal end 248 of actuator 230 includes a tapered portion 252, a groove 249, and a flattened section 261 (there being a corresponding flattened section, not shown, on the opposite side of proximal end 248) for coupling actuator 230 to coupler base section 216, described further below. Groove 249 has a width, e.g., of about 0.045", a diameter, e.g., of about 0.065", and actuator 230 has a diameter, e.g., of about 0.095".
Referring to FIGS. 3 and 3A, implements 250, 252 of end effector 222 include coupling members 251, 253, respectively, having shaft couplers 254, 254a, respectively, through which a pin 259 passes to attach implements 250, 252 to each other. Pin 259 can be integral with one of the implements 250, 252, or not. Implements 250, 252 rotate with respect to each other about pin 259 to open and close. Implements 250, 252 includes cutting edges 255, 255a, respectively, and are arched with surface 257 of implement 250 contacting a corresponding surface (not shown) of implements 252.
Referring to FIGS. 4 and 4A, distal coupler 241 of actuator 230 includes a slot 260 on one face 262 of distal coupler 241 and a second slot 264 located on the opposite face 266 of distal coupler 241. As seen in FIG. 4, slots 260, 264 are inclined to form an "X". An actuator coupling pin 258a (FIG. 3A) of implement 250 is positioned in slot 264 and an actuator coupling pin 258b of implement 252 is positioned in slot 260.
Referring to FIG. 5, spring arms 233 each include a hole 280, only one hole being shown, for receiving a respective coupler 254 of implements 250, 252 to attach the implements to shaft 231.
With shaft 231 holding implements 250, 252 axially stationary during axial, proximal motion of actuator 230 (arrow 270, FIG. 4), actuator coupling pins 258a, 258b slide within slots 264, 260, respectively, while slots 260, 264 move proximally. Due to the inclination of slots 260, 264 relative to the axial direction, moving actuator 230 proximally causes implements 250, 252 to open. During distal motion of actuator 230 (arrow 272, FIG. 4A), actuator coupling pins 258a, 258b slide within slots 260, 264 while slots 260, 264 move distally. Moving actuator 30 distally causes implements 250, 252 to close.
Spring arms 233 are outwardly flexible to permit insertion of end effector 222 into shaft 231. A cap 223 (FIG. 2) can be used to help hold implements 250, 252 together during assembly.
To assemble tube assembly 220, actuator 230 is first placed within shaft 231 with distal coupler 241 extending out of distal end 236 of shaft 231. Actuator coupling pins 258a and 258b of implements 250, 252 are placed in slots 264, 260, respectively. To aid in the placement of coupling pins into slots 264, 260, each pins 258a, 258b is initially positioned in a detent 243 located on distal coupler 241 (see FIG. 2, a corresponding detent, not shown, being located on the opposite side of distal coupler 241). Detents 243 are aligned with slots 264, 260 such that after placement of pins 258a, 258b in detents 243, pushing implements 250, 252 proximally locates pins 258a, 258b in the proximal ends of slots 264, 260.
Actuator 230 is then pulled proximally such that distal coupler 241 is located within shaft 231. Arms 233 of shaft 231 are flexed outward to enable couplers 254, 254a to be aligned with holes 280 in shaft 231. Arms 233 are then released resulting in couplers 254, 254a being located in holes 280. Outer sheath 232 is then slid over shaft 231 and adapter 256 is threaded onto proximal section 237 of shaft 231.
To remove implements 250, 252 from actuator 230 and shaft 231, outer sheath 232 and adapter 256 are removed from shaft 231 and actuator 230 surrounded by shaft 231 is connected to coupler 214, described further below. By holding shaft 231 while rotating coupler 214 (which causes rotation of actuator 230) arms 233 of shaft 231 are flexed outward by distal coupler 241 of actuator 230 causing implements 250, 252 to be released from holes 280 in shaft 231 and removed from actuator 230. The releasable coupling of implements 250, 252 to each other and to actuator 230 and shaft 231 enables one or both implements 250, 252 to be replaced when worn.
Referring to FIG. 6, in which coupler 214 is shown with cover 218 removed, the base section 216 of coupler 214 includes a housing 60 with a through channel 64. A coupling member 66 located in channel 64 has a through bore 68 for receiving proximal end 248 of actuator 230. Channels 70, 72 in coupling member 66 intersect bore 68 and house a pin 74 and spring 76 for loading pin 74. A hole 82 in pin 74 permits passage of actuator 230 through pin 74. Spring 76 biases pin 74 upwardly, as viewed in FIG. 6, such that a wall 80 of hole 82 extends into bore 68 of coupling member 66.
Tapered portion 252 on proximal end 248 helps to guide actuator 230 into bore 68 during insertion of actuator 230 into coupler 214 and acts to push pin 74 downwardly against the force of spring 72 to move wall 80 out of through bore 68. When groove 249 of actuator 230 is aligned with wall 80, pin 74 moves upward due to the force of spring 76, and wall 80 moves into position in groove 249 to lock actuator 230 to base section 216. To remove actuator 230 from coupling member 66, pin 74 is manually depressed against the force of spring 76 to disengage wall 80 from groove 249.
Referring to FIG. 6A, bore 68 has flattened sides 68a, 68b. Actuator 230 is placed in bore 68 with flats 261 aligned with bore flats 68a, 68b. Actuator 230 is thus keyed to bore 68 such that rotation of coupler 214 also causes rotation of actuator 230.
Referring again to FIG. 6, housing 60 includes an externally threaded section 62 for attachment of internal threaded cover 218 over housing 60. With actuator 230 locked into position in housing 60, spacer 256 abuts a distal surface 84 of housing 60. Cover 218 captures spacer 256 against surface 84 when threaded onto housing 60 to prevent axial movement of spacer 256, and thus shaft 231 and sheath 232, during axial movement of actuator 230.
Handle 212 is coupled to actuator 230 and member 66 by a trigger rod 90. A distal end 92 of trigger rod 90 abuts coupling member 66 and includes a distal cut out 93 for receiving actuator 230. A proximal end 94 of trigger rod 90 is coupled to a pivotable trigger 96 of handle 212. Actuation of trigger 96 causes axial movement of trigger rod 90 and thus axial motion of coupling member 66 and actuator 230. Slots 100, 102 in housing 60 provide clearance for movement of pin 74 with coupling member 66.
Handle 212 includes an integral mount 110 for rotatably mounting housing 60 to handle 212. A circumferential groove 112 in housing 60 contains an o-ring 114 providing a seal between housing 60 and mount 110. A second o-ring 116 located in a second circumferential groove 118 in mount 110 also provides a seal between housing 60 and mount 110. A third circumferential groove 120 in mount 110 includes surface detentes 122 spaced around the circumference of groove 120. A dowel pin 124 and a ball plunger 126 extend through housing 60 to groove 120. Dowel pin 124 is press fit into place to couple mount 110 to housing 60 while permitting rotation of housing 60 relative to mount 110. Ball 126a of ball plunger 126 is spring biased to enter detentes 122 as housing 60 is rotated to aid in rotationally positioning housing 60, and thus end effector 222.
In use, cover 218 is placed onto sheath 232 and actuator 230, shaft 231 and end effector 222 are assembled and positioned within sheath 232 to form tube assembly 220 (FIG. 2). Tube assembly 220 is then coupled to base section 216 of coupler 214 by "snapping" proximal end 248 of actuator 230 into place, and cover 218 is threaded onto base section 216 to capture spacer 248.
Instrument 210 can be easily disassembled for cleaning. Tube assembly 220 can be easily removed from base section 216 by removing cover 218, depressing pin 74, and removing proximal end 248 of actuator 230 from base section 216. Tube assembly 220 can then be disassembled to permit cleaning of actuator 230, shaft 231, sheath 232, and end effector 222, and to permit replacement of one or both implements 250, 252.
The coupling mechanism for joining actuator 230 to coupler 214, described above, provides a simple method of attaching and detaching tube assembly 220 and coupler 214. Coupler 214 is not limited to use with tube assembly 220 and can be used with any medical instrument having an actuator with a proximal end 248 for "snap-on" joining to coupler 214.
Referring to FIG. 7, an arthroscopic instrument 10 includes a handle 12, a handle lock 15, a coupler 14 with a base section 16 and a cover 18, identical to coupler 214 described above, and a tube assembly 20 with a distal end effector 22, e.g., a grasper or dissector. End effector 22 may include one or more moveable members 23. Tube assembly 20 is removable from coupler 14 and can be disassembled, described below, to facilitate cleaning of instrument 10.
Referring to FIG. 8, tube assembly 20 includes an actuator 30 terminating in distal end effector 22, and a hollow outer sheath 32 through which actuator 30 is placed (shown in phantom). Actuator 30 includes a rod 40 and a distal tube 42 radially spaced from rod 40 which are both coupled to end effector 22 as described, e.g., in U.S. Pat. No. 4,712,545 to Honkanen. Tube 42 has an internally threaded section 44. Sheath 32 has a proximal section 46 with external threads 46a for attaching actuator 30 to sheath 32 by insertion of section 46 into tube 42 (shown in phantom) and threaded engagement of sections 44 and 46. In an alternative, preferred embodiment, tube 42 is externally threaded at section 44 and sheath 32 is internally threaded at proximal section 46.
With actuator 30 positioned inside and threadedly attached to sheath 32, a proximal end 48 of actuator 30 extends outside a proximal end 50 of sheath 32 (shown in phantom). Proximal end 48 of actuator 30 includes a tapered portion 52 and a groove 49 for coupling actuator 30 to coupler base section 16, as described above. Proximal end 50 of sheath 32 includes a spacer 56 which, when instrument 10 is assembled, is captured between base section 16 and cover 18 to prevent axial movement of sheath 32, and thus tube 42, when actuator 30 is moved axially.
In use, cover 18 is placed onto sheath 32 and actuator 30 is positioned within sheath 32 to form tube assembly 20. The tube assembly 20 is then coupled to base section 16 of coupler 14 by "snapping" proximal end 48 of actuator 30 into base section 16, and cover 18 is threaded onto base section 16.
Tube assembly 20 can be easily removed from base section 16 by removing cover 18, depressing pin 74, and removing proximal end 48 of actuator 30 from base section 16. Tube assembly 20 can then be disassembled by unscrewing sheath 32 from actuator 30 to permit cleaning of actuator 30, sheath 32, and end effector 22.
End effector 22 can be coupled to tube assembly 20 in the manner described above with reference to FIGS. 4-5.
Other embodiments are within the scope of the following claims.
For example, referring to FIGS. 9 and 9A, actuator distal coupler 241 can be used with an end effector 322, e.g., a grasper or cutter, having a fixed implement 350 and a movable implement 352. Implements 350, 352 include coupling members 351, 353, respectively, having shaft couplers 354, 354a. Coupling member 351 of movable implement 352 includes an actuator coupling pin 358 which is positioned in slot 264 of coupler 241 such that movement of actuator 230 causes implement 252 to open and close as described above. Coupling member 353 of fixed implement 350 does not include an actuator coupling pin and has a contoured outer surface 353a having a radius corresponding to the inner radius of shaft 231. Fixed implement 350 is therefore not coupled to actuator 230 and contoured surface 353a insures that implement 350 remains stationary during axial movement of actuator 230 to open and close movable implement 352.
Referring to FIGS. 10 and 10A, alternatively, coupling member 353 of fixed implement 350 has a fixation knob 353b which abuts shaft 231 to insure that implement 350 remains stationary during axial movement of actuator 230 to open and close movable implement 352.
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A medical instrument includes an elongated shaft, a plurality of implements mounted to the shaft, and an actuator coupled to produce relative movement between the implements. At least one of the implements is detachable from the shaft and the actuator and from another one of the implements. The actuator includes a distal portion with an inclined slot. One of the implements is detachably coupled to the slot such that movement of the actuator causes the relative movement between the implements. A coupler including an opening for receiving the actuator is mounted to a handle for rotation relative to the handle.
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BACKGROUND OF THE INVENTION
This invention relates to a power supply arrangement comprising a monitoring circuit for no less than two different-polarity direct voltages connected to a common reference potential, and including a signal transmission element.
Power supply arrangements comprising monitoring circuits are necessary, for example, for protecting the connected users against overvoltages in the case of failure or, in the case of undervoltages avoiding the transfer of faulty data are transferred without such transfer being timely recognised. Consequently, the failure of a direct output voltage, i.e. the deviation from a predetermined set value, is to with certainty be indicated by means of a signal transmission element so that safety measures can be taken. If a failure occurs in a secondary circuit, especially in a clocked power supply arrangement, the direct output voltages are accordingly adjusted or switched off by means of adjusting elements provided in the primary circuit. If electric isolation of the secondary circuit and the control circuit operating, for example, in the primary circuit of a transformer is necessary, a signal transmission element with electrically isolated inputs and outputs, for example, an optocoupler, is used for transmitting the control signals of the monitoring circuit.
In DE-A 37 07 973 there is disclosed a power supply arrangement comprising an overvoltage protection circuit and a signal transmission element. In this arrangement a series connection of a zener diode and a diode is inserted between a reference potential and each direct output voltage which is positive or negative with respect to this reference potential. A signal transmission element, arranged as a light-emitting diode optocoupler is inserted between the zener diode and the diode of either one of the two series connections. If no overvoltages occur, the zener diode will be blocked and the light-emitting diode will not emit. If an overvoltage occurs in a direct output voltage, the zener diode concerned will conduct and power will flow through the light-emitting diode of the signal transmission element. The accuracy of response of the signal transmission element and thus of the overvoltage protective circuit is then determined by the tolerances of a plurality of different modules, i.e. more specifically, by the tolerances of the diode, the zener diode, the signal transmission element and a dropping resistor connected in series thereto and thus has insufficient accuracy of response when more stringent requirements are involved.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a power supply arrangement comprising a monitoring circuit of the type mentioned in the opening paragraph, in which the monitoring circuit has enhanced accuracy of response whereas, on the other hand, the circuitry remains simple.
This object is achieved by means of a power supply arrangement comprising a monitoring circuit of the type mentioned in the opening paragraph, in that a series connection of a zener diode and a resistor is shunted to each direct voltage, with the junction point of each zener diode and resistor being connected to the base of a transistor. A first electrode of each transistor is connected to the signal transmission element and a second electrode to the respective positive or negative pole of the direct voltages.
Other advantageous embodiments are contained in the dependent-claims.
BRIEF DESCRIPTION OF THE DRAWING
In the following the invention will be further explained with reference to the exemplary embodiments shown in the accompanying drawings in which:
FIG. 1 shows a power supply arrangement comprising an overvoltage monitoring circuit for two direct voltages of different polarities;
FIG. 2 shows a power supply arrangement comprising an overvoltage monitoring circuit for two positive and two negative direct voltages; and
FIG. 3 shows a power supply arrangement comprising an undervoltage monitoring circuit for two direct voltages of different polarities.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the exemplary embodiment shown in FIG. 1, a power supply arrangement 1 generates a direct voltage U1+ which is positive with respect to a reference potential OV and a direct voltage U1- which is negative with respect to this reference potential. The positive pole of the direct voltage U1+ is connected to the emitter and through a resistor R1 to the base of a PNP transistor T1. The base of the transistor T1 is connected to the cathode of a zener diode Z1, whose anode is connected to the reference potential OV. The anode of a diode D1 is connected to the reference potential OV and its cathode is connected to the collector of transistor T1. The negative pole of the direct voltage U1- is connected to the emitter and through a resistor R2 to the base of an NPN transistor T2. The base of the transistor T2 is connected to the anode of a zener diode Z2 whose cathode is connected to the reference potential OV. The cathode of a diode D2 is connected to the reference potential OV and its anode is connected to the collector of the transistor T2. Between the collector of the transistor T1 and the collector of the transistor T2 is a signal transmission element consisting of as an optocoupler 2 in series with a dropping resistor R3. A light-emitting diode 21 is arranged such that its cathode is connected to the collector of the transistor T2. The optocoupler 2 is connected to a control arrangement of the power supply arrangement 1 so that the direct voltages U1+, U1- of the power supply arrangement 1 are adjusted back or switched off completely by means of a photocurrent produced in a photodiode 22 when the light-emitting diode 21 is emitting.
If the power supply arrangement has a normal operation, i.e. if with a positive direct voltage U1+ no overvoltage occurs, a current flow will be created through resistor R1 across the reverse biased zener diode Z1. The resistor R1, shunted to the base-emitter path of the transistor T1, is dimensioned such that in an undisturbed condition a voltage drop is produced which is smaller than the base-emitter voltage necessary for conduction of the transistor. The transistor T1 is blocked in this fashion. If an overvoltage occurs in the positive direct voltage U1+, the transistor T1 will become conductive via resistor R1 after the base-emitter voltage of approximately 0.6 Volt necessary for conduction is exceeded. The collector current of the transistor T1 now flows through the dropping resistor R3, the light-emitting diode 21 of the optocoupler 2 and the diode D2 to the reference potential OV. The dropping resistor R3 is dimensioned such that the current flowing through the light-emitting diode 21 is sufficient for light emission and the photocurrent produced by the photodiode 22 adjusts the direct voltage U1+ back so that the current is not too high or, alternatively, switches it off. In an embodiment not shown in the Figure a resistor and/or a capacitor is shunted to the signal transmission element 2 to receive a residual current. In a power supply arrangement controlled by means of the signal pulse width, the reduction of the direct voltage U1+ may be realised, for example, by reducing the pulse width of the control signals.
Alternatively, if the overvoltage occurs in the negative direct voltage U1-, the current will flow from the reference potential through the diode D1, the dropping resistor R3, the light-emitting diode 21 of the optocoupler 2 and through the conducting transistor T2 to the direct voltage U1-. In a practical embodiment of the d.c. overvoltage monitoring circuit the value of the direct voltages U1+, U1- is +/-5 volts. The zener voltage of the zener diodes Z1, Z2 is thus dimensioned at 5.1 volts and the resistance of the resistors R1, R2 at 1 kOhm. The accuracy with which the overvoltage monitoring circuit responds is determined only by the tolerances of the zener diodes Z1, Z2 and the base-emitter paths of the transistors T1, T2 and is thus independent of the collector circuit of the transistors T1, T2 and thus is independent of the tolerances of the dropping resistor R3 as well as that of the signal transmission element 2. Consequently, the overvoltage monitoring circuit is preeminently suitable even with requirements as to enhanced accuracy of response.
In the exemplary embodiment shown in FIG. 2, two more direct voltages U2+, U2- are monitored in addition to the direct voltages U1+, U1- of the exemplary embodiment shown in FIG. 1. For this purpose, the positive pole of the direct voltage U2+ is connected to the emitter and through a resistor R11 to the base of a PNP transistor T11. The base of the transistor T11 is connected to the cathode of a zener diode Z11 whose anode is connected to the reference potential OV. Accordingly, the negative pole of the direct voltage U2- is connected to the emitter and through a resistor R12 to the base of an NPN transistor T12. The base of the transistor T12 is connected to the anode of a zener diode Z12 whose cathode is connected to the reference potential OV. The zener voltages of the zener diodes Z11, Z12 are selected in accordance with the voltage values of the direct voltages U2+, U2-. With the aid of the overvoltage monitoring circuit represented in FIG. 2 each of two direct voltages of different polarities may be monitored and with little additional cost of circuitry.
If in addition to the direct voltages U1+, U1-, U2+, U2- further direct voltages of different polarities are to be monitored, the circuit shown in FIG. 2 merely needs to be extended by an arrangement of a transistor, a resistor and a zener diode, while the signal transmission element 2 is used for all direct voltages. In an embodiment the signal transmission element 2 is arranged as an optocoupler having a thyristor output.
In the exemplary embodiment shown in FIG. 3, a power supply arrangement provides the direct voltage U1+ which is positive with respect to the reference potential OV and the direct voltage U1- which is negative with respect to this reference potential. The positive pole of the direct voltage U1+ is connected to the emitter and through the resistor R1 to the base of the transistor T1. The base of the transistor T1 is connected to the cathode of the zener diode Z1 whose anode is connected to the reference potential OV through a resistor R4. The negative pole of the direct voltage U1- is connected to the emitter and through the resistor R2 to the base of the transistor T2. The base of the transistor T2 is connected to the anode of the zener diode Z2 whose cathode is connected to the reference potential OV through a resistor R5. Between the collector of the transistor T1 and the collector of the transistor T2 the signal transmission element 2 is inserted via a dropping resistor R3. A light-emitting diode 21 is arranged such that its cathode is connected to the collector of the transistor T2. The optocoupler 2 is connected to a control circuit of the power supply arrangement 1 so that, when the light-emitting diode 21 does not emit, the direct voltages U1+, U1- of the power supply arrangement 1 are adjusted accordingly or switched off as a result of the photocurrent that is no longer generated in the photodiode 22.
The resistors R1, R2, R4, R5 and the zener diodes Z1, Z2 are dimensioned such that in normal operation, i.e. when no undervoltage occurs, the transistors T1, T2 are conductive. For this purpose the voltage drop at the resistors R1, R2 is to be larger than the base-emitter voltage of approximately 0.6 Volt necessary for conduction of the transistors T1, T2. The collector current of transistor T1 then flows through the dropping resistor R3 across the light-emitting diode 21 of the optocoupler 2 and the likewise conductive collector-emitter path of the transistor T2 to the negative pole of the direct voltage U1-. The dropping resistor R3 is dimensioned such that the current flowing through the light-emitting diode 21 is sufficient for light emission but, on the other hand, not too much power is dissipated. If an undervoltage occurs in the positive direct voltage U1+, the transistor T1 will be blocked at resistor R1 since the base-emitter voltage value necessary for its conduction is now too low. The total power will then flow to the reference potential OV through resistor R1 and the reverse biased zener diode Z1 and the resistor R4. After the transistor T1 is blocked, current will no longer flow through the light-emitting diode 21 so that there will be no photocurrent passing through the photodiode 22 either and the direct voltage U1+ may, for example, be increased or switched off. In a power supply arrangement controlled by means of signal pulse width, the increase of the direct voltage U1+ may be realised, for example, by increasing the pulse width of the control signals. If, alternatively, the undervoltage occurs at the output having the negative direct voltage U1-, the transistor T2 will be blocked so that in this case too current will no longer flow through the light-emitting diode 21. The total current will then flow from the reference potential OV via the resistor R5 through the reverse biased zener diode Z2 and the resistor R2 to the negative pole of the direct voltage U1-.
The accuracy with which the undervoltage monitoring circuit responds is determined merely by the tolerances of the zener diodes Z1, Z2, resistors R4, R5 and the base-emitter paths of the transistors T1, T2 in the exemplary embodiment shown in FIG. 3, and is therefore independent of the collector circuit of the transistors T1, T2 and thus is independent of the tolerances of the dropping resistor R3 as well as the signal transmission element 2. Therefore, the undervoltage monitoring circuit shown in FIG. 3 is preeminently suitable in the case of requirements as to enhanced accuracy of response.
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Power supply arrangement comprising a direct voltage monitoring circuit. A power supply arrangement comprising a direct voltage monitoring circuit for at least two different-polarity direct voltages connected to a common reference potential, and including a signal transmission element. The monitoring circuit arrangement has an enhanced accuracy of response with limited circuitry and cost. A series connection of a zener diode and a resistor is connected in shunt with each direct voltage. The junction point of each zener diode and resistor is connected to the base of a transistor. A first electrode of each transistor is connected to the signal transmission element and a second electrode.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved dissolved oxygen electrode for measuring a concentration of oxygen in a sample liquid and, more particularly, to a verification system to monitor its operability during use.
2. Description of Related Art
Conventional galvanic cell-type dissolved oxygen electrodes are frequently utilized to measure a concentration of oxygen in various sample liquids. A partial cross-sectional view of such a dissolved oxygen electrode is shown in FIG. 2.
A housing substrate 1 can be made of an insulating material, such as a synthetic resin, that will be inert to the fluids that it will encounter. The housing 1 can be formed into a cylindrical lower half portion having a central annular groove 1b that extends about an axial core portion 1a. The core portion 1a integrally extends from a central portion of the cylindrical lower half portion and is capable of supporting, for example, an annular anode 2 located on its outer circumferential surface. This anode 2 is connected with an appropriate terminal wire 6 that can extend outside of the housing 1 through a lead wire 4 arranged within the housing 1. An additional lead wire 5 is connected to another terminal 7 located outside of the housing 1, and extends to the lower tip of the axial core portion 1a. Cathode 3 can be mounted within a recess in the core portion 1a and connected to the lead wire 5 at this location. The entire lower end of the housing substrate 1 is covered with a diaphragm 8, of a known construction, that is permeable to oxygen. The inner hollow portion is thus formed between the diaphragm 8 and the annular groove 1b of the housing substrate 1. An appropriate electrolyte 9 can be sealed within this hollow portion 1b.
The dissolved oxygen electrode, when immersed in a sample liquid, can have oxygen from the sample liquid transmitted through the diaphragm 8, and subsequently be electrochemically reduced on a surface of the anode 2. This reaction will produce an electric current proportional to the concentration of oxygen in the sample liquid between the anode 2 and the cathode 3 through the electrolyte 9, which can be conveniently measured across the respective terminals 6 and 7 to provide a measurement signal proportional to the concentration of oxygen in the sample liquid.
If, during the use of the dissolved oxygen electrode, the diaphragm 8 becomes damaged, then the electrolyte 9 can either flow out of the housing 1 through the damaged portion of the diaphragm 8, or sample liquid can flow into the inner hollow portion 1b of the housing 1, to correspondingly contaminate the electrolyte 9. As a result, a value of electric current flowing between the anode 2 and the cathode 3 will be affected and will be generally reduced. In a conventional dissolved oxygen electrode, any damage to the diaphragm 8 may not be easily confirmed, so that a problem has frequently occurred in that the concentration of oxygen being measured will become erroneous since the operator may not know that there has been damage to the diaphragm 8. Additionally, the degree of damage to the diaphragm 8 may be progressive, and the resulting accuracy of the reading may also progressively deteriorate without being detected by the technician.
Efforts in the prior art to determine any damage to the diaphragm 8 have usually resulted from an estimate of the reduction of value of the electric current, but this generally required the necessity of specifying a sufficient reduction of the value of the electric current so that it would be observed as being outside of the range of the expected measurement. It may also require a testing procedure wherein the conventional dissolved oxygen electrode can be immersed in a specified sample, such as the atmosphere and a precalibrated saturate dissolved oxygen solution, in order to measure the value of the electric current. This calibration or testing procedure can be troublesome and can require the interruption of the actual measurement cycle of the dissolved oxygen electrode.
An additional problem occurs in that a reduction in the measured electric current can also occur as a result of a simple deterioration in the useful lifetime of both the anode 2 and the cathode 3. It is not always possible to determine if there has been damage to the diaphragm 8 or if the life cycle of the anode 2 and cathode 3 has been simply reduced through normal usage.
Thus, there is a demand in the prior art to provide an easy and economical verification system to determine the reliability of a dissolved oxygen electrode.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a dissolved oxygen electrode that is capable of efficiently and easily detecting any deterioration in its performance that can result from damage to its diaphragm.
A further object of the present invention is to provide a verification system that is relatively simple and easily incorporated into the structure of a dissolved oxygen electrode.
An additional object of the present invention is to provide a verification system that can provide a constant monitoring during the use of the dissolved oxygen electrode in its measurement operation.
In order to achieve the above-described objects, the present invention can be characterized as providing an exterior electrode on the outside of the housing member and second electrode position within an inner hollow portion of the housing member for operative contact with the electrolyte contained within the inner hollow portion 1b.
As a result of such a construction, if there is any damage to the diaphragm, an electrolyte either flows out of the housing through the damaged portion of the diaphragm, and/or sample liquid flows into the inner hollow portion. Then the respective interior and exterior electrodes of the verification system will record a significant change in the electrical resistance between them so that the existence of damage in the diaphragm can be confirmed through measurement of this electrical resistance independent of any deterioration of the oxygen measuring cathode and anode electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings.
FIG. 1 is a partial cross-sectional view showing one preferred embodiment of a dissolved oxygen electrode with the verification system according to the present invention; and
FIG. 2 is a partial cross-sectional view showing a conventional dissolved oxygen electrode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the art to make and use the present invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a relatively economical and easily manufactured dissolved oxygen electrode with a monitoring verification system.
Referring to FIG. 1, a partial cross-sectional view of an improved dissolved oxygen electrode according to the present invention is disclosed. In this preferred embodiment, a galvanic cell-type dissolved oxygen electrode has a housing 1, a measuring anode 2, a measuring cathode 3, and respective lead wires 4 and 5 connected to the anode 2 and cathode 3. The lead wires are also connected to exterior terminals 6 and 7, which can be connected to an appropriate monitor, as known in the art. A diaphragm 8 seals the electrolyte 9 within an interior inner portion 1b of the housing 1. As can be seen, these elements are similar to that of the conventional dissolved oxygen electrode, and similar reference numbers are accordingly utilized.
The housing 1 can be made of an insulating material, for example, a synthetic resin, and generally comprises a cylindrical lower half portion with its lower end open to provide a ring-like hollow with an axial core portion 1a integrally extending or juxtapositioned within the center of the cylindrical lower half portion. The axial core portion 1a is provided with an anode 2 made of, for example, platinum, gold, silver, and the like, which can extend about the outer circumferential surface of the axial core portion 1a. This anode 2 is connected with a terminal 6 outside of the housing 1 through an appropriate lead wire 4 arranged integrally within the housing 1.
The axial core portion 1a is further provided with a cathode 3 made of, for example, lead, zinc, and the like, at a lower end thereof. The cathode 3 is also connected with a terminal 7 exterior to the housing 1 through a lead wire 5, also arranged to extend integrally within the housing 1. A diaphragm 8 that is permeable to oxygen can be made of, for example, Teflon, polyethylene, and the like, as known in this art, and this diaphragm 8 can be sealed about the lower end opening of the housing 1 to form an interior chamber of an inner hollow portion 1b within the housing 1. The diaphragm 8 is sealed to the housing 1 to maintain an electrolyte 9, for example, an aqueous solution of sodium hydroxide, an aqueous solution of potassium chloride, and the like, as known in this art.
The verification system is designed specifically to be relatively economically integrated into the manufacture of a dissolved oxygen electrode. In this regard, a metallic electrode 10 is positioned within the housing 1 separately from the anode 2 so as to extend into the inner hollow portion 1b and to be brought into direct contact with the electrolyte 9. This electrode 10 is connected with a terminal 14, also positioned outside of the housing 1 through a lead wire 12 integrally arranged within the housing 1.
A second metallic electrode 11 can be mounted on an outer circumferential portion so that it is exposed and brought into direct contact with the sample liquid when the dissolved oxygen electrode is immersed in the sample. The metallic electrode 11 is connected with a terminal 15 positioned outside of the housing 1 through a lead wire 13 integrally arranged within the housing 1. The second and third metallic electrodes can be formed from a noble metal such as gold or silver, and also from a corrosive-resistant metal such as SUS (stainless steel).
The operation of the monitoring verification system will be capable of determining any damage to the diaphragm 8 in the dissolved oxygen electrode by responding to a change in the electrolyte, as follows:
An appointed direct current or alternating current voltage can be applied between the terminals 14 and 15 to activate the metallic electrodes 10 and 11 with the dissolved oxygen electrode immersed in a sample solution. A meter can appropriately measure the electrical resistance between the respective metallic electrodes 10 and 11 resulting from the value of the electric current flowing at this time. This value can establish the datum level of an operative and functioning diaphragm 8. If the diaphragm 8 is damaged, for example, by a collision with a foreign substance or an abrasion during transportation or mounting in a sample container to a degree that the electrolyte 9 within the inner hollow portion 1b of the housing 1 will be lost and/or sample liquid will flow into the inner hollow portion lb of the housing. Then the electrical resistance between the metallic electrodes 10 and 11 will markedly change from that datum level.
As can be readily appreciated, this change in electrical resistance can be easily monitored and an appropriate indicator or an alarm (not shown) can be utilized to indicate the operative status of the dissolved oxygen electrode.
As can also be further appreciated, this measurement of the operability of the dissolved oxygen electrode can be carried out simultaneously with an actual measurement of the concentration of oxygen in a sample. Thus, oxygen from a sample fluid can be transmitted through the diaphragm 8 to be electrochemically reduced on a surface of the cathode 3. As a result, electric current proportional to the concentration of oxygen in the sample liquid will flow between the anode 2 and the cathode 3 through the electrolyte 9. An appropriate concentration of oxygen can be determined by the value of electric current between the terminals 6 and 7. Simultaneously, applying an appropriate current to the terminals 14 and 15 will permit a monitoring of any alteration in the resistance which will indicate a significant change in the status of the electrolyte 9 contained within the diaphragm 8.
As can be appreciated, a dissolved oxygen electrode can also include a polarograph-type electrode in addition to the above-described galvanic cell-type electrode. A polarograph-type dissolved oxygen electrode differs from the galvanic cell-type in that the appointed voltage is applied between the anode and the cathode during the time when the concentration of oxygen is measured. It is also possible to use the monitoring verification system in such a polarograph-type dissolved oxygen electrode.
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.
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An improved oxygen sensing electrode assembly is provided with first and second electrodes mounted within a cavity of a housing substrate. An oxygen permeable diaphragm closes the cavity and contains an appropriate electrolyte solution. A third electrode is mounted in the cavity, while a fourth electrode is mounted on the exterior of the housing. The third and fourth electrodes can be activated to monitor the condition of the electrolyte whereby the operability of the electrode assembly can be verified during an oxygen sensing measurement.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT/DE03/01529, filed May 12, 2003, and titled “Metal Article Intended for at Least Partially Coating with a Substance,” which claims priority under 35 U.S.C. §119 to German Application No. DE 102 21 503.0, filed on May 14, 2002, and titled “Metal Article Intended for at Least Partially Coating with a Substance,” the entire contents of each are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a metal article intended for at least partially coating with a substance and to components, and to a method for producing the same.
BACKGROUND
[0003] If metal articles, in particular, connecting, supporting, or conducting components for an electronic component, are to be coated on their macroscopically smooth surfaces with a substance, in particular, plastic, ceramic, or glass, adhesion promoters are electrodeposited on the macroscopically smooth surfaces of the metal articles. Dendrites form and consequently provide an interlocking bond between the metal article and the substance. These electrodeposited adhesion layers form two further boundary layers or phase transitions, i.e., a boundary layer between the smooth unchanged metal surface and the dendritic adhesion layer and a further boundary layer between the dendritic adhesion layer and the substance to be applied.
[0004] In addition, with this preparation of the metal surface, the adhesion layer is applied with the aid of a wet process, and consequently, contaminations by components of the electrolytic bath are unavoidable. Such contaminations can reduce the service life of the adhesion layers, and consequently, reduce the service life of the electronic components.
[0005] Macroscopically smooth surfaces of metal articles are understood to mean surfaces which have at least a polished quality. Metal articles with polished surfaces of this type are used, in particular, in electronic components as connecting, supporting, or conducting components, with further precious metal layers frequently being deposited on the polished surfaces in order to produce bonded connections and soldered connections on them.
[0006] By applying adhesion layers to the macroscopically smooth surface or by roughening the macroscopically smooth surfaces by mechanically or by etching means, these macroscopically smooth surfaces are transformed into rough surfaces that are partially strewn with dendrites of the adhesion promoter, grinding pits, or etching pits, respectively. The macroscopically smooth surface regions that are intended to represent contact terminal areas, bonding fingers, or other components must be protected from roughening with covering processes.
[0007] A metal article intended for at least partial connection to a substance without additional adhesion-promoting materials, to permit mechanical connecting of its surface to a further substance is desirable. At the same time, the macroscopically smooth surface of the metal article is retained. To simplify connecting macroscopically planar surfaces of metallic articles to a substance and to provide mechanically stable phase transitions is desirable.
SUMMARY
[0008] According to the invention, a metal article intended for at least partially coating with a substance, in particular, connecting, supporting, or conducting components for an electronic component, with macroscopically smooth surface portions is provided. In this case, a plurality of open nanopores, which are multiply curved and open out on the surface portion concerned, are provided in one region of at least one surface portion. Microscopically small nanopores of this type promote the mechanical connecting of the metal article to a substance, but the surface portion or the entire surface of the metal article remains macroscopically smooth and planar. Microscopically small is understood to mean dimensions which can only be detected and measured under an electron microscope.
[0009] With such a metal article, desired substances, in particular, glass, ceramic, and plastic, can be anchored in the nanopores. This anchoring takes place three-dimensionally due to the multiple curvature of the nanopores, and consequently, relatively reliable adhesion and positive connection of the substance on the metal article are ensured. In addition, a macroscopically smooth surface is retained in spite of the nanopores. As a result, finishing or coating of the surface portions, i.e., bonding, soldering, and other techniques in which smooth surfaces of a metal article are a precondition, remains possible.
[0010] In a method for producing the nanopores, the metal surface is initially oxidized and subsequently the metal oxide layer created is reduced. As a result, the material in the region of the surface portion with nanopores is relatively identical to the material of the metal article. Furthermore, both the oxidation and the reduction of the metal article can be carried out in dry processes. There is no contamination by foreign substances remaining in the nanopores. This results in the formation of high-purity metallic surfaces, which can be mechanically connected directly to the substance to be applied.
[0011] A reduction of the metal oxide layer may be set to create a metal article for at least partially coating with a substance, which has a buried metal oxide layer. In this case, the metal article has a solid metal core, which has at least one porous macroscopically planar metal layer region in the region of at least one surface portion. In this case, the metal layer region includes the material of the metal core and exhibits multiply curved open nanopores. These nanopores open out at the surface of the metal layer region. A pore-free buried layer of metal oxide is arranged between the metal layer region with nanopores and the solid metal core.
[0012] This three-layer formation includes metal imbued with nanopores, pore-free metal oxide, and a pore-free metal core. The buried layer of metal oxide forms an electrically isolating layer. As a result that, when electrically conducting substances are applied, the electrically conducting substances are electrically isolated from the metal core of the metal article.
[0013] In another embodiment of the invention, the surface portion with nanopores may be arranged alongside a pore-free metal surface. Structures and geometries of this type are possible if the oxidation process and reduction process are restricted to the surface portions of the metal article to be mechanically connected to a substance. Instead of a pore-free metal surface, the surface portion with nanopores may also be surrounded by a pore-free metal oxide area. For this embodiment of the metal article, the entire surface is initially oxidized and is reduced at the surface portions on which nanopores are to be formed. If this reduction is carried out down as far as the metal core, individual islands or surface portions of the metal article, which can be intensively connected to a substance are obtained, while the surrounding areas can shift in a sliding manner with respect to the surrounding substance. As a result, for example, thermal stress can be relieved.
[0014] Furthermore, a surface structure of this type is particularly suitable for producing external contact areas with nanopores and surrounding solder resist areas, which dispenses with the need to apply layers of solder resist and to provide external contact areas that have been improved in their adhering and connecting properties.
[0015] The metal article can improve contact vias of metal. The contact vias lead through glass, ceramic, or plastic. For this purpose, the contact via of metal, i.e., in the form of flat conductors or conduction wires, may have a surface portion with a multiplicity of open nanopores, which are multiply curved and open out on the surface portion concerned, in its region of through-contact. In the case of the contact via, these nanopores are filled with the substance to be connected, such as glass, ceramic, or plastic. As a result, in spite of macroscopically smooth surface regions of the metallic contact via, the substance is interlocked with the substance to be connected.
[0016] In another embodiment of the invention, a contact via as a metal article includes copper or a copper alloy. Copper or copper alloys are, for instance, used in contact vias that are mechanically connected to glass, ceramic, or plastic, since they have a low electrical resistance. However, the coefficient of thermal expansion of copper or copper alloys cannot be adapted at will to the substance. As a result, in further embodiments of the invention, metal articles of chromium/nickel/iron alloys are also used as contact vias, especially because, depending on the composition, i.e., nickel-iron alloys, in particular, can be adapted to different coefficients of expansion of the substances.
[0017] In a further embodiment of the invention, a number of metal articles, such as flat conductor ends, inner flat conductors, or chip islands on which semiconductor chips are arranged, are connected to a plastic package molding compound of an electronic component. For this purpose, the metal articles have macroscopically smooth surface portions, a multiplicity of open nanopores which are multiply curved, open out on the surface portion concerned, and are filled with plastic package molding compound, which is to be mechanically connected to the metal articles being provided in the region of at least one surface portion.
[0018] An electronic component has metallic articles or metal components do not have to be coated with an additional adhesion-promoter layer or adhesion layer. As a result, additional material that could reduce the service life of the component is not introduced into the overall construction. Rather, the metals that are required for the metal articles are used and are connected directly to the plastic package molding compound without any further additions.
[0019] The metal article can also be used in electronic components with a plastic package and a semiconductor chip which has metallic conductor tracks. The semiconductor chip is closed off on its active upper side from external influences by a passivation layer of ceramic. This ceramic layer lies partially on smooth, metallic conductor tracks. The ceramic layer has silicon nitride in particular. In order to anchor this ceramic layer of silicon nitride on the macroscopically smooth surface portions of the conductor tracks, a multiplicity of open nanopores, which are multiply curved and open out on the surface portion of the conductor track, may be provided in the region of at least one of the surface portions. In the case of this embodiment of the invention, the nanopores are filled with ceramic compound and the conductor tracks and the ceramic compound are consequently mechanically connected intimately to one another.
[0020] The metallic article according to the invention can be used for metallic chip islands. These chip islands have macroscopically smooth surface portions to which the semiconductor chip is to be electrically connected. For this purpose, a conductive adhesive is used between the semiconductor chip and the macroscopically smooth surface of the chip island. The mechanical connection between the conductive adhesive and the chip island can be intensified, if a multiplicity of open nanopores, which are multiply curved and open out on the surface portion concerned, are provided. In this way, apart from its electrical connection, the conductive adhesive is then also mechanically connected to the metallic chip island because the conductive adhesive fills the curved nanopores.
[0021] When connecting patterned metal foils as an intermediate layer between two substances that are mechanically connected, for example, ceramic and plastic, which each have a different coefficient of thermal expansion, problems can occur. The substances can become delaminated from the patterned metal foils. Delamination of the substances from the patterned metal foils can be prevented, if the metal foil has on both sides macroscopically smooth surface portions which have in one surface portion a multiplicity of open nanopores which are multiply curved and open out on the surface portion concerned. These nanopores are then respectively filled with the material of one of the substances to be mechanically connected by the metal foil. Consequently, delamination of a laminate of this type, which has different substances with patterned metal foil lying in between, can be prevented.
[0022] The nanopores in a metal article of this type have an average diameter D of 10 nm to 300 nm. The average density of the nanopores on the surface of the metal article is dimensioned such that the macroscopically smooth surface is not disturbed by the nanopores and also not made to bow or collapse. Depending on the metal oxide prepared, the depth of the nanopores lies between 0.1 micrometers and 10 micrometers. If a pore-free buried layer of metal oxide is provided, its thickness d may lie between 0.1 micrometers and 3 micrometers.
[0023] A method for producing a metal article for at least partial mechanical connection to a substance can include, partially oxidizing the metal article, forming a metal oxide layer on a surface portion of the metal article, reducing of the metal oxide layer to a porous structure with open nanopores which are multiply curved and open out from the surface portion. Based on heterogeneous kinetics in the oxide layer reduction, a recreated metal surface with a corresponding nanometer porosity is left behind. This structure is formed as a sponge structure on the surface of the metal article, since the molar volume of the metal oxides after oxidation is generally greater than that of the corresponding metals.
[0024] The dimensions and the number of pores can be freely set by the parameters, i.e., oxidation rate, oxide thickness, reduction rate, and by cyclical oxidizing and reducing and renewed oxidizing and reducing. In this case, the system parameters, such as the oxidation/reduction temperature and the oxidation/reduction time as well as the partial pressure of the oxygen component of the oxidizing atmosphere, in the oxidation step can be varied. Similarly, the partial pressure of the reducing medium in the reduction step can be varied. However, nanopores can only be stably produced on those metals which also form stable oxides, i.e., the oxides do not evaporate. Furthermore, these oxides must be reducible at a temperature below the melting temperature of the metals with a reducing medium such as hydrogen. Consequently, copper and copper alloys as well as nickel/chromium/iron alloys can be used, in particular.
[0025] In an exemplary embodiment of the method, the reduction of the metal oxide layer may not take place completely. As a result, a buried metal oxide layer remains as an intermediate layer on the surface of the metal article. The reduction of the metal oxide layer may also be restricted to certain surface portions, with the result that the surface portion. As a result, the surface portion of metal with metal with nanopores is surrounded by a pore-free metal oxide layer. In order to restrict a reduction of the overall oxide layer to certain surface portions, a protective layer is applied to the areas, which are not to be reduced.
[0026] In a further example of the method, oxidizing occurs in an oxygen-containing dry atmosphere with an oxygen content of 20 to 100% by volume. The oxidation temperature depends on the type of metal article. In a dry oxidation process, very dense, but slowly growing layers are formed. A dry oxidation of this type ensures that the regions later reduced form a coherent metal skeleton, which macroscopically has a smooth surface.
[0027] The oxidation of the metal surface may also be carried out in a wet, oxygen-containing atmosphere. The relative humidity is between 60 and 95% and the oxygen content 20 to 98% by volume. Wet oxidation proceeds more rapidly than dry oxidation, since the water molecules are significantly smaller than the oxygen molecules. Consequently, the diffusion rate of oxygen molecules through oxide layers that have already formed is relatively greater than in dry oxidation. While dry oxidation for a copper article or an article of a copper alloy at temperatures between 300 and 600° C. for 10 to 20 minutes, a lower temperature range between 300 and 500° C. is adequate for wet oxidation. The oxidation process of wet oxidation of copper or copper alloy takes approximately between 5 and 10 minutes.
[0028] With the lower temperature range of the wet oxidation, the oxidation of the metal surfaces of an electronic component can also take place after a semiconductor chip is applied to the chip island and after the wire bonding of the semiconductor chip to the corresponding inner flat conductor ends. For this purpose, the semiconductor chip withstands the thermal loading, but is not contaminated by additional chemicals, as when adhesion layers are applied by electrodeposition. Consequently, following mounting of a semiconductor chip on a flat conductor frame and completion of the electrical connections, the exposed surface portions of the various metal components can be provided with nanopores by oxidation and reduction. As a result that an intensive connection to a plastic package molding compound that is subsequently to be applied can be established.
[0029] The reaction temperature or oxidation temperature in the case of metal articles of chromium/nickel/iron alloys is at temperatures between 500 and 900° C. This means that relatively higher oxidation temperatures are used for metal articles of this type, than with copper alloys. Wires of this type of metal alloys are used, however, for contact vias through, for example, glasses and ceramics, since their coefficient of thermal expansion can be adapted to the coefficients of thermal expansion of glasses and ceramics. Mechanical anchoring with and connection to the glasses and ceramics is no longer a problem.
[0030] In the oxidation, an oxide layer between 0.1 and 10 micrometers thick is grown on the metal article. As already mentioned above, this thickness can be specifically set by the oxidation parameters of temperature and time and by the oxidation atmosphere as well as by the choice of a suitable metal material. Consequently, the depths of the different nanopores can at the same time be defined in advance with this oxide layer thickness.
[0031] In a further example of the method, reduction is in a hydrogen-containing atmosphere. The temperature of the reduction is between 300 and 500° C. for copper oxide layers. In the case of oxide layers based on chromium/nickel/iron alloys, the reduction temperatures are correspondingly higher. Diamine, forming gas, hydrazine, and/or formaldehyde may be used as hydrogen-containing components in the reduction atmosphere. Furthermore, an enlargement and deepening of the nanopores can be achieved by repeated oxidation and reduction.
[0032] Electronic components produced by the method according to the invention can include at least partially oxidizing metallic components of the electronic component to be packaged in a plastic package molding compound. After oxidation, these partially oxidized metallic components are reduced, forming multiply curved nanopores which open out from corresponding reduced surface portions of the components. The material of the package, such as the plastic package molding compound, can penetrate into these open pores and relatively firmly anchor with the mechanical components. As a result, the electronic component has an increased service life.
[0033] For producing an electronic component with a semiconductor chip, the semiconductor chip may be specially prepared by the method according to the invention, in order to apply a passivation layer to the active surface of the semiconductor chip in a moisture-resistant manner. For this purpose, the metallic conductor tracks on the active upper side of the semiconductor chip are at least partially oxidized and these partially oxidized metallic conductor tracks are subsequently reduced, forming multiply curved nanopores. The nanopores open out from correspondingly reduced surface portions of the conductor tracks. Subsequently, the passivation layer of polyimide, silicon carbide, silicon dioxide or silicon nitride is introduced into the open nanopores. As a result, the areas of the semiconductor chip having conductor tracks are protected by these nanopores being filled with the material of the passivation layer. The risk of delamination of the passivation layer from the active upper side of the semiconductor chip for electronic components of this type is reduced.
[0034] The adhesion of polymers on macroscopically smooth metal surfaces is a chemical bond between the metal oxides present on the metal surfaces and a functional group of the organic molecule of the polymer. However, these bonding forces are relatively weak and are based on a van der Waals interaction. consequently, the adhesion on pure and smoothly polished metal surfaces is extremely poor. Great adhesion is achieved, however, by a rough surface structure, which is realized with the aid of electrodeposited adhesion layers. However, adhesion layers of this type introduce impurities and contaminations into the overall microstructure, which can reduce the service life of electronic components, in particular, semiconductor chips.
[0035] The metal article according to the invention has metal surfaces with pores on the nanometer scale. For this purpose, the corresponding metal is first thermally oxidized to an oxide thickness of between 0.1 and 10 micrometers, for instance, between 1 and 5 micrometers. Subsequently, the metal oxide present is thermally reduced in the mixture of nitrogen and hydrogen, such as a forming gas which contains 5% hydrogen. Based on heterogeneous kinetics in the oxide layer reduction, the recreated metal surface with a corresponding nanometer porosity is left behind. This metal structure presents itself as if it were as a sponge structure on the surface of the substrate, because the molar volume of the metal oxides is generally greater than that of the corresponding metals.
[0036] The dimensions and the number of pores can be freely set by the parameters, i.e., oxidation rate, oxide thickness, reduction rate, and by cyclical oxidizing-reducing-oxidizing-reducing. In this case, the system parameters, such as the oxidation/reduction temperature and time as well as the partial pressure of oxygen in the oxidation step and the partial pressure of hydrogen in the reduction step are used to achieve a predetermined oxidation thickness, and consequently a predetermined pore depth of the nanopores. In principle, metals which form stable oxides and oxides which can be reduced below the melting temperature of the metals with hydrogen can be used for this process.
[0037] By this measure, adhesion-promoting surfaces are generated without applying or depositing foreign substances. This eliminates contamination of the substrate with foreign substances, which increases the service life of the components. For components, the possibility of treatment both before the chip bonding and wire bonding and the possibility of generating the adhesion-promoting layer with nanopores after the chip/wire bonding is provided. The chip withstands the thermal treatment required in oxidation and reduction. However, the chip is not exposed to chemicals as in conventionally applied adhesion layers. The structure formed in this way includes exclusively the metal of the metal article. Consequently, there is no further boundary surface between the metal article and the adhesion-promoting structure with nanopores. Although no additional substance in the form of an adhesion layer is introduced into the system when roughening a metal surface by mechanical or etching means either, the macroscopically smooth surface is lost in the process, and no anchoring structures in the form of multiply curved nanopores are formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention is now explained in more detail on the basis of embodiments with reference to the accompanying figures.
[0039] FIG. 1 shows a schematic cross section through part of a metal article,
[0040] FIG. 2 shows a schematic cross section through part of a metal article after oxidation of its surface,
[0041] FIG. 3 shows a schematic cross section through part of a metal article after reduction of the metal oxide to metal with nanopores in the metal microstructure,
[0042] FIG. 4 shows a schematic cross section through part of a metal article mechanically connected to a substance,
[0043] FIGS. 5 to 7 show schematic cross sections through part of a metal article after method steps for producing a metal article with a buried oxide layer,
[0044] FIGS. 8 to 10 show schematic cross sections through part of a metal article after method steps for producing a surface portion with nanopores,
[0045] FIGS. 11 to 13 show schematic cross sections through part of a metal article after method steps for producing a surface portion with nanopores, surrounded by a pore-free metal oxide layer, in a metal matrix, and
[0046] FIGS. 14 to 16 show schematic cross sections through part of a metal article after method steps for producing an isolated surface portion with nanopores in a metal matrix.
DETAILED DESCRIPTION
[0047] FIG. 1 shows a schematic cross section through part of a metal article. This metal article has a macroscopically smooth surface 3 , which forms a still pore-free metal surface 9 .
[0048] FIG. 2 shows a schematic cross section through part of a metal article after oxidation of its surface. This creates a metal oxide layer 12 with a pore-free metal oxide surface 10 , which covers the surface of the illustrated part of the metal article. The thickness V of the metal oxide layer is relatively greater than the depth of the amount of metal of the pore-free metal surface 9 consumed in the oxidation, as is shown in FIG. 1 , since the molar volume of the metal oxide is generally greater than that of the corresponding metal. The oxidation is achieved by the metal article being placed in an oxidation oven with an oxygen content of between 20 and 100% by volume. The article is able to oxidize in air at correspondingly high temperatures.
[0049] The oxidation temperature in the oxidation oven for a metal article of copper or a copper alloy is set between 300 and 600° C. for 5 to 20 minutes. In this case, the higher temperature and the longer time is required for dry oxidation, and the shorter time and the lower temperature can be achieved by wet oxidation. For wet oxidation, the reaction atmosphere is operated with a relative humidity of between 60 and 95% and with temperatures between 300 and 500° C.
[0050] The thickness V of the oxide layer lies between 0.1 and 10 micrometers and can be accurately controlled by setting the oxidation parameters.
[0051] FIG. 3 shows a schematic cross section through part of a metal article after reduction of the metal oxide layer 12 to metal with nanopores in the metal microstructure. The heterogeneous kinetics in this oxidation layer reduction have the effect that the recreated metal surface with a corresponding porosity of nanopores is left behind. In this case, the nanopores are open toward the upper side. The diameter of the nanopores D lies between 10 and 300 nanometers. The limit or depth t of the nanopores is determined by the depth V of the metal oxide layer 12 that is shown in FIG. 2 . Complete reduction of the metal oxide layer 12 shown in FIG. 2 achieves a macroscopically smooth surface 3 of metal with nanopores 5 , which extend as far as the surface and have a depth of t. The reduction itself is carried out in a reducing atmosphere of 300 to 500° C. for the reduction of copper or copper alloys. Hydrogen-containing components are used for the reduction. In this case, forming gas with a 5% oxygen content can be used, or diamine, a compound between nitrogen and hydrogen. Furthermore, it is possible also to use hydrazine or formaldehyde for the hydrogen reduction in a corresponding reduction oven.
[0052] FIG. 4 shows a schematic cross section through part of a metal article connected to a substance. Metal articles of this type are preferably components of an electronic component which has a semiconductor chip. In this case, the metal article 2 represented here illustrates the inner end of a flat conductor of an electronic component and the substance 1 is, in this example of FIG. 4 , a plastic package molding compound, into which the flat conductor and other metallic components of the electronic component, such as bonding wires and chip islands, are embedded. The nanopores 5 in the surface of the metal article 2 achieve the effect of an intimate positive interlocking bond, while retaining a macroscopically smooth surface 3 of the metal article 2 . Furthermore, no chemicals are required to realize this bond.
[0053] Instead of a plastic package molding compound, a silicon nitride, a polyimide layer, or a silicon dioxide layer may be deposited, for example, as the substance 1 on conductor tracks as the metal article 2 of a semiconductor chip, if the surface for receiving the material of a passivation layer by oxidation and reduction of these conductor tracks has prepared in advance.
[0054] FIGS. 5 to 7 show schematic cross sections through part of a metal article 2 after method steps for producing a metal article 2 with a buried metal oxide layer 8 . In the case of this production method, the same procedure as in the FIGS. 1 to 3 is followed, but the reduction is ended earlier than would be required for a complete reduction of the metal oxide layer 12 , as shown in FIG. 6 . This allows the formation of a buried oxide layer 8 , as shown in FIG. 7 , which has an isolating effect and is suitable in particular when conductor tracks of a semiconductor chip are provided with a passivation layer of ceramic or polyimide.
[0055] FIG. 5 again shows a schematic cross section through part of a metal article. This metal article has a macroscopically smooth surface 3 , which forms a pore-free metal surface 9 .
[0056] FIG. 6 again shows a schematic cross section through part of a metal article after oxidation of its surface. In this case, a metal oxide layer 12 which covers a pore-free metal core 6 is created.
[0057] FIG. 7 shows a schematic cross section through the metal article after incomplete reduction of the metal oxide layer 12 shown in FIG. 6 . In this case, three layer regions are formed. Firstly, a metal layer region 7 with nanopores 5 includes the same material as the solid metal core 6 , while the buried metal oxide layer 8 is arranged between the metal core 6 and the metal layer region 7 and has a thickness d. The thickness d can be set by setting the duration and the temperature of the reduction phase.
[0058] FIGS. 8 to 10 show schematic cross sections through part of a metal article after method steps for producing a surface portion with nanopores. FIG. 8 shows a cross section through a pore-free solid metal core 6 , which is covered on its smooth upper side 3 by a mask 13 . As a result, only a surface portion 14 is oxidized.
[0059] FIG. 9 shows the cross section through the metal article after the oxidation and after removal of the mask 13 . In this case, an elevation is created in the surface portion 14 on account of the oxidation and the increase in volume of the metal oxide with respect to the metal core 6 .
[0060] FIG. 10 shows the metal article after reduction of the oxide layer generated in FIG. 9 , the elevation being retained, but the reduced metal structure that is created having nanopores 5 . This surface portion with nanopores 5 is suitable for mechanically connecting the metal article at this location, for example, of an external contact area of a metal structure, to a further material, such as an external contact or solder ball.
[0061] FIGS. 11 to 13 show schematic cross sections through part of a metal article after method steps for producing a surface portion with nanopores, surrounded by a pore-free metal oxide layer, in a metal matrix. FIG. 11 shows a schematic cross section through part of a metal article. This metal article with a metal core 6 has a macroscopically smooth surface 3 , which forms a still pore-free metal surface 9 .
[0062] FIG. 12 shows a schematic cross section through part of a metal article after oxidation of its entire surface. In this case, a metal oxide layer 12 , which covers a pore-free metal core 6 , is created. This metal oxide layer is partially covered by a mask 13 . As a result, only the surface region 14 can be reduced.
[0063] FIG. 13 shows the reduced region which is kept free by the metal mask 13 shown in FIG. 12 . FIG. 13 shows the result of the reduction after the mask 13 has been removed. A metal article prepared in this way has isolating areas in the form of metal oxide areas 12 and surface portions 14 , which are conductive and have nanopores. As a result, a further substance can be mechanically connected to this area. A structure of this type is particularly suitable for applying external contacts in the form of solder balls, since a solder resist layer is automatically realized by the surrounding metal oxide layer 12 . An ideal anchoring of the solder ball with the external contact area is in the region of the nanopores.
[0064] FIGS. 14 to 16 show schematic cross sections through part of a metal article after producing an isolated surface portion with nanopores in a metal matrix. FIG. 14 shows a schematic cross section through part of a metal article. This metal article has a macroscopically smooth surface 3 , which forms a pore-free metal surface 9 .
[0065] FIG. 15 again shows a schematic cross section through part of a metal article after oxidation of its entire surface. In this case, a metal oxide layer 12 , which covers a pore-free metal core 6 , is created. This metal oxide layer is subsequently covered by a mask 13 , which keeps a surface portion 14 free for a reduction.
[0066] FIG. 16 shows a schematic cross section through part of a metal article after the reduction of the surface portion 14 . In this example, the reduction was stopped prematurely. As a result, a metal layer region with nanopores, which is surrounded by a metal oxide layer 12 and is similarly isolated from the solid metal core 6 by a buried metal oxide layer 8 , is created. This structure produces a metal structure in a metal oxide which has the same metal material as the solid metal core 6 .
[0067] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Accordingly, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A metal article intended for at least partially coating with a substance, which includes a metal solder, a plastic, a glass, or a ceramic. The metal article itself may include, in particular, connecting, supporting, or conducting components for an electronic component. The metal article has macroscopically smooth surface portions and a multiplicity of multiply curved nanopores in the region of at least one surface portion.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefits of U.S. provisional application Ser. No. 61/872,997, filed on Sep. 3, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to techniques for brushless DC (BLDC) motor, and particularly to a control circuit for driving the BLDC motor and a method for controlling the speed of the BLDC motor.
[0004] 2. Related Art
[0005] Brushless DC (BLDC) motor are synchronous motors that are powered by a DC electric source via an integrated inverter/switching power supply, which produces an AC electric signal to drive the motor. The BLDC motor and its mechanical parts normally will be resonant to specific frequencies. This resonant phenomenal will cause a reliability problem for the motor and/or generate the acoustic noise. The object of the present invention is to solve this problem.
SUMMARY OF THE INVENTION
[0006] The present invention provides a control circuit for driving a brushless DC (BLDC) motor. The control circuit comprises a microcontroller having a memory, and a drive circuit. The drive circuit is configured to drive the BLDC motor according to a control of the microcontroller. The memory include a RPM table, and the microcontroller sends a duty signal to the drive circuit to change a speed of the motor according to the RPM table.
[0007] From another point of view, the present invention provides a method for controlling a speed of a BLDC motor. The method includes following steps. A control signal is generated according to a RPM table in a memory. The BLDC motor is driven according to the control signal. The control signal is generated by a microcontroller, and the control signal is configured to drive the BLDC motor through a drive circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0009] FIG. 1 shows a block diagram illustrating a control circuit for driving a BLDC motor according to one embodiment of the present invention.
[0010] FIG. 2 shows the angle detection and the PWM operation for a sensorless motor control of the BLDC motor according to one embodiment of the present invention.
[0011] FIG. 3 shows a schematic diagram illustrating a RPM table (RpmTable) stored in the memory according to one embodiment of the present invention.
[0012] FIG. 4 shows a control flow illustrating the microcontroller according to one embodiment of the present invention.
[0013] FIG. 5 shows the waveforms generated by the sine-wave generator according to one embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] FIG. 1 shows a block diagram illustrating a control circuit for driving a BLDC motor 10 according to one embodiment of the present invention. The control circuit includes a three-phase bridge driver 20 , a sequencer circuit 30 , a microcontroller (MCU) 100 , and a pulse width modulation (PWM) circuit 50 . The microcontroller 100 has a memory 110 including a program memory and a data memory. The microcontroller 100 generates a duty signal DUTY (i.e., a control signal) and an angle signal θ A according to a signal H S . The signal H S is related to the BLDC motor's position and speed. The duty signal DUTY and an angle signal θ A are coupled to the PWM circuit 50 for generating a signal SPWM. The signal S PWM is configured to control the three-phase bridge driver 20 through the sequencer circuit 30 for driving the BLDC motor 10 . The three-phase bridge driver 20 receives an input signal V IN to drive the BLDC motor 10 . The PWM circuit 50 , the three-phase bridge driver 20 , and the sequencer circuit 30 form a drive circuit for driving the BLDC motor 10 . The drive circuit is configured to drive the BLDC motor 10 according to the control of the microcontroller 100 . In the embodiment of the present invention, the BLDC motor 10 is a permanent magnet synchronous motor (PMSM).
[0015] FIG. 2 shows the angle detection and the PWM operation for a sensorless motor control of the BLDC motor 10 according to one embodiment of the present invention. The circuit for the angle detection and the PWM operation includes the Clarke transform module 40 , the Park transform module 45 , a sine-wave signal generator 60 , an angle estimation module 80 , and a sum unit 65 . The Clarke transform module 40 is configured to transform a three-axis, two-dimensional coordinate system (referenced to the stator a, b, c) to a two-axis coordinate system. In other words, the Clarke transform module 40 receives phase currents i a , i b , and i c of the motor 10 to generate two-axis orthogonal currents iα, iβ for mapping the motor's phase currents of i a , i b and i c . The Park transform module 45 generates signals I d and I q according to the two-axis orthogonal currents i α and i β . The angle estimation module 80 generates an angle signal θ in accordance with the signal I d . The angle signal θ is further feedback to Park transform module 45 . The sum unit 65 generates another angle signal θ A in accordance with the angle signal θ and an angle-shift signal AS. The angle-shift signal AS is used for adapting to various BLDC motors, and/or for the weak-magnet control. The angle signal θ includes the information of the motor's position and speed.
[0016] The angle signal θ A and the duty signal DUTY are coupled to the sine-wave generator 60 for generating the pulse-width modulation signals and 3-phase motor voltage signals (phase A, phase B and phase C). The 3-phase motor voltage signals (phase A, phase B and phase C) are configured to drive the BLDC motor 10 through the three-phase bridge driver 20 . The sine-wave generator 60 has two inputs including a magnitude input and a phase angle input. The magnitude input is coupled to the duty signal DUTY. The phase angle input is coupled to the angle signal θA.
[0017] FIG. 5 shows the waveforms generated by the sine-wave generator 60 according to one embodiment of the present invention. The amplitude of 3-phase motor voltage signals V A , V B , V C is programmed by the duty signal DUTY. The angle of 3-phase motor voltage signals V A , V B , V C is determined by the angle signal θ A .
[0018] FIG. 3 shows a schematic diagram illustrating a RPM table (RpmTable) stored in the memory 110 according to one embodiment of the present invention. The revolution per minute (RPM) represents the speed of the motor. The logic 1 stored in the RpmTable indicates that the RPM is allowed. The logic 0 stored in the RpmTable indicates that the RPM is inhibited. The microcontroller 100 in FIG. 1 sends the duty signal DUTY to the drive circuit to change the speed of the motor 10 according to the RPM table in FIG. 3 .
[0019] FIG. 4 shows a control flow illustrating the microcontroller 100 according to one embodiment of the present invention. From the start step 200 , in step 210 , the MCU 100 in FIG. 1 checks if the change of the speed of the motor 10 is required. A flag YES represents the change of the speed is required. The flag NO represents the change of the speed is not required. If the flag is YES, then the MCU 100 will set a variable x as 1 and measure the RPM value of the motor 10 for generating a constant K in step 230 . The constant K is calculated by the formula (1).
[0000]
K
=
RPM_n
Duty_n
(
1
)
[0020] The parameter Duty_n is the level of the duty signal DUTY that generates the RPM value of RPM_n.
[0021] After the step 230 , in step 250 , the MCU 100 will estimate the next RPM value of RPM_n+x according to three parameters: (1) the constant K, (2) the variable x, and (3) the next step's level (Duty_n+x) of the duty signal DUTY. The next RPM value of RPM_n+x is calculated by the formula (2).
[0000] (RPM — n+x )= k× (Duty — n+x ) (2)
[0022] According the RPM_n+x, the MCU 100 will check the RPM table (RpmTable) in the memory 110 in step 270 . If the RpmTable shows the RPM_n+x is allowed (logic 1), then the MCU 100 will set the level of the duty signal DUTY as Duty_n+x in step 290 . If the RpmTable shows the RPM_n+x is inhibited (logic 0), then the MCU 100 will set the variable x as x+1 in step 295 , and go to execute the step 250 . Therefore, the motor 10 can be operated without running at the speed of the resonant frequency of the motor 10 .
[0023] Although the present invention and the advantages thereof have been described in detail, it should be understood that various changes, substitutions, and alternations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. That is, the discussion included in this invention is intended to serve as a basic description. It should be understood that the specific discussion may not explicitly describe all embodiments possible; many alternatives are implicit. The generic nature of the invention may not fully explained and may not explicitly show that how each feature or element can actually be representative of a broader function or of a great variety of alternative or equivalent elements. Again, these are implicitly included in this disclosure. Neither the description nor the terminology is intended to limit the scope of the claims.
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A control circuit for driving a motor and a method for controlling a speed of a motor are provided. The control circuit comprises a microcontroller and a drive circuit. The microcontroller has a memory. The drive circuit is configured to drive the BLDC motor according to a control of the microcontroller. The memory include a RPM table, and the microcontroller sends a duty signal to the drive circuit to change a speed of the motor according to the RPM table.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to methods for IP address selection, and more particularly to a software based internet protocol address selection method.
[0003] 2. Discussion of Background Art
[0004] Universal Resource Locater (URL) Domain Name System (DNS) entries are uniquely associated with Internet Protocol (IP) addresses and help route communications traffic between clients and servers within the World Wide Web.
[0005] When a company's servers share a single location, IP address routers simply route all traffic to this single location. However, as more and more companies establish a multi-regional or global presence, mirrored servers hosting such companies' web sites may be geographically distributed over several locations in order to ensure sufficiently short response times to client requests. As a result, Web site managers are confronted with a problem of which server will provide the best possible response time and performance for the client.
[0006] There are several current approaches to this problem. The simplest is to require that the client select a server from a list provided on the company's main Web site. Other approaches use specialized hardware to perform various measurements in order to direct clients to the best Web server. These types of solutions however typically involve the installation of very expensive hardware and require additional layers of IT support. Such hardware can thus be cost prohibitive to some smaller companies. Cisco System's Distributed Director http://www.cisco.com/warp/public/cc/pd/cxsr/dd/tech/dd_wp.htm is an example of one such hardware based solution. Other vendors, such as ArrowPoint and Foundry are also pursuing a variety of hardware based approaches to solve this domain name resolution problem.
[0007] In response to the concerns discussed above, what is needed is a system and method for internet protocol address selection that overcomes the problems of the prior art.
SUMMARY OF THE INVENTION
[0008] The present invention is a method and system for software based internet protocol (IP) address selection. The method includes steps of assigning a single domain name to a set of server IP addresses, receiving a request for the domain name from a client IP address, retrieving a set of IP routes linking the server IP addresses and the client IP address, and selecting an IP route from the set of routes which meets predetermined criteria.
[0009] In other aspects of the invention, the method may transmit an IP address from the set of server IP addresses which corresponds to the selected IP route or retrieve the IP routes from routers using BGP, SNMP (MNB retrieval), or Telnet protocols and store the IP routes in cache and IP routes databases. Alternate embodiments may also select a best IP route between the client and server based on a shortest AS path, a lowest origin type, a lowest MED, a default IP address or a hierarchy of some or all of these criteria. A enhanced address resource record data-structure for supporting the present invention may include domain name, list of corresponding servers and routers, router retrieval parameters, default client/server IP route, and timeout fields.
[0010] The system includes a set of servers, having a single domain name, a client computer, a set of routers, coupled to the servers and the client computer, for storing IP routes between the servers and the client; and a domain name system server, coupled to the routers, for selecting one of the IP routes which meets predetermined criteria.
[0011] The system may also include a cache database, coupled to the domain name system server, for storing previously selected IP routes and an IP routes database, coupled to the domain name system server, for storing all of the IP routes.
[0012] The system and method of the present invention are particularly advantageous over the prior art because of a lower cost and a simpler design associated with implementing IP route selection using the present invention's software instead of hardware. The present invention thus is able to meet the needs of many companies that are unable to afford hardware-based systems.
[0013] These and other aspects of the invention will be recognized by those skilled in the art upon review of the detailed description, drawings, and claims set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a dataflow diagram for software based internet protocol address selection within a Domain Name System (DNS) server;
[0015] [0015]FIG. 2 is a data structure of an enhanced address resource record;
[0016] [0016]FIG. 3 is a dataflow diagram of an initialization process;
[0017] [0017]FIG. 4 is a dataflow diagram of an BGP IP Routes retrieval process within the initialization process;
[0018] [0018]FIG. 5 is a dataflow diagram of an MIB IP Routes retrieval process within the initialization process;
[0019] [0019]FIG. 6 is a dataflow diagram of a Telnet IP Routes retrieval process within the initialization process;
[0020] [0020]FIG. 7 is a dataflow diagram of a best client/server IP Route selection process;
[0021] [0021]FIG. 8 is a dataflow diagram of an MIB IP Routes retrieval subroutine within the best route selection process; and
[0022] [0022]FIG. 9 is a dataflow diagram of an Telnet IP Routes retrieval subroutine within the best route selection process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] [0023]FIG. 1 is a dataflow diagram 100 for software based internet protocol address selection within a Domain Name System (DNS) server 102 . The DNS server 102 is coupled to a network along with a first corporate server 106 router 108 pair, a second corporate server 110 router 112 pair, and a client computer 114 . The corporate servers 106 and 110 both have a same corporate domain name (e.g. corporation@corp.com) but have different Internet Protocol (IP) addresses. The corporate servers 106 and 110 are preferably mirrored and located at different geographic locations. The DNS server 102 contains a modified bind-code for downloading IP route information from the routers 108 , 112 and selecting a best client/server IP route for connecting the client 114 requesting the corporate domain name to one of the corporate servers 106 , 110 . An IP route is defined by at least two IP addresses. Client/server IP routes are defined between the client's 114 IP address and each of the server's 106 , 110 IP addresses. Those skilled in the art recognize that in actual operable systems incorporating the present invention, hundreds, if not thousands of client computers, and tens of servers and routers may be connected to the network 104 . As such, the DNS server 102 will select a best client/server IP route for connecting each client with one of the servers and transmit a server IP address corresponding to the best route to the client 114 .
[0024] [0024]FIG. 2 is a data structure 200 of an enhanced address resource (“A”) record 202 generated by the modified bind-code of the DNS server 102 . The “A” record 202 includes: a domain name 202 field for storing the corporate server's 106 , 110 common domain name; a list of corresponding servers and routers 204 field for identifying servers and routers assigned to the domain name 202 ; a route retrieval parameters 208 field specifying how IP routes are to be downloaded from the routers 108 , 112 , a default best client/server IP address 210 field containing an IP address for the client 114 to use should the selection process for the best client/server IP route be indeterminate; a cache timeouts field 212 ; and an IP routes timeouts field 214 , for respectively keeping cache and IP route information fresh.
[0025] The router retrieval protocol 208 field is set to either Border Gateway Protocol (BGP), Management Information Base (MIB), or Telnet during configuration of the network 104 and the DNS server 102 . One protocol 208 is used for all routers 108 , 112 .
[0026] [0026]FIG. 3 is a dataflow diagram 300 of an initialization process 302 . All steps are effected by software within the DNS server 102 unless otherwise noted. Initialization 302 begins in step 304 where the “A” record 202 is generated using a network bind configuration file 306 and saved in an “A” record database 308 . In step 310 , a cache database 312 , for storing a set of previously selected best client/server IP route entries, is initialized. Caching improves IP route selection speed and efficiency in response to repeated communications from a same client or from a same client network address range. An IP route database 314 , containing all possible client/server IP routes, is initialized in step 316 .
[0027] In step 318 , if a protocol within the router retrieval parameters 208 is set to BGP, a BGP IP route retrieval routine is initiated in step 320 , after which the initialization process 302 ends. The BGP IP route retrieval routine is described with reference to FIG. 4. In step 322 , the IP routes database timeout 214 in the enhanced “A” record 202 is accessed and if the timeout is set to zero, so as to force dynamic route retrieval, the initialization process 302 ends. In step 324 , if the protocol within the router retrieval parameters 208 is set to MIB, a MIB IP route retrieval routine is initiated in step 326 , after which the initialization process 302 ends. The MIB IP route retrieval routine is described with reference to FIG. 5. Otherwise, the protocol within the router retrieval parameters 208 is Telnet, and a Telnet IP route retrieval routine is initiated in step 328 , after which the initialization process 302 ends. The Telnet IP route retrieval routine is described with reference to FIG. 6.
[0028] [0028]FIG. 4 is a dataflow diagram 400 of the BGP IP Route retrieval process 402 within the initialization process 302 . The process 402 begins in step 404 , where BGP specific information is accessed from the router retrieval parameters 208 in the enhanced “A” records 202 stored in the “A” record database 308 . In step 406 , a BGP session is established with the routers 108 , 112 . BGP code is incorporated into the DNS server's 102 software so that the DNS server 102 can directly peer with the routers. Thus the IP routes database 314 can be updated real time. Next, in step 408 , a BGP routing table is downloaded from the routers 108 , 112 . The IP route database 314 is updated, in step 410 . In step 412 , the process 402 waits for a BGP protocol update signal or a termination signal. If, in step 414 , the termination signal is not received, the process 402 returns to step 408 , else the process 402 ends. As discussed with reference to FIG. 1, those skilled in the art will know that the present invention works equally well with many more than just the one client and two servers and routers discussed herein.
[0029] [0029]FIG. 5 is a dataflow diagram 500 of the MIB IP Routes retrieval process 502 within the initialization process 302 . The process 502 begins in step 504 , where MIB specific information is accessed from the router retrieval parameters 208 in the enhanced “A” records 202 stored in the “A” record database 308 . In step 506 , a Simple Network Management Protocol (SNMP) session is established with and routing tables are downloaded from the routers 108 , 112 . The process 502 uses network management protocols to retrieve IP routes from a router's management information base. The IP route database 314 is updated, in step 508 . In step 510 , the process 502 waits for the IP route database timeout to zero or a termination signal. If, in step 512 , the termination signal is not received, the process 502 returns to step 506 , else the process 502 ends.
[0030] [0030]FIG. 6 is a dataflow diagram 600 of the Telnet IP Routes retrieval process 602 within the initialization process 302 . The process 602 begins in step 604 , where Telnet specific information is accessed from the router retrieval parameters 208 in the enhanced “A” records 202 stored in the “A” record database 308 . In step 606 , a Telnet session is established with and routing tables are downloaded from the routers 108 , 112 . The routing table information is updated periodically to keep the IP routes database 314 current. The IP route database 314 is updated, in step 608 . In step 610 , the process 602 waits for the IP route database timeout to zero or a termination signal. If, in step 612 , the termination signal is not received, the process 602 returns to step 606 , else the process 602 ends.
[0031] [0031]FIG. 7 is a dataflow diagram 700 of a best client/server IP Route selection process 702 . The process 702 begins in step 704 where in response to a domain name request from the client 114 , the DNS server 102 checks the cache database 312 for a previously cached best client/server IP route entry between the client 114 and one of the domain name servers 106 , 110 . In step 706 , if the best client/server IP route cache entry exists, the cache timeouts 212 are accessed. In step 708 , if the cache entry has not timed out, the process 702 proceeds to step 710 . In step 710 , the best client/server IP route cache entry is retrieved from the cache database 312 and a server IP address corresponding to the best route is transmitted to the client 114 in step 711 . After step 711 , the process 702 ends. In step 708 , if the best client/server IP route cache entry has timed out, the process proceeds to step 714 . In step 712 , the cache entry is removed from the cache database 312 .
[0032] Next, in step 714 , the IP routes database timeout 214 is accessed. If the IP routes database 314 has a non-zero timeout value, the process proceeds to step 716 where the DNS server 102 retrieves all Client/Server IP Routes from the IP routes database 314 . In step 716 , the DNS server 102 selects a best client/server IP route for the client 114 from all of the client/server IP routes stored in the IP routes database 314 .
[0033] The DNS server 102 sets the best client/server IP route equal to the IP route having a shortest Autonomous System (AS) path. The AS path is a BGP protocol attribute containing a sequence of autonomous system numbers which a route has traversed to reach a destination. If the AS path for all client/server IP routes is equivalent, the DNS server 102 instead selects the client/server IP route with a lowest origin type. Origin type is a BGP protocol attribute indicating an origin of a routing update with respect to an autonomous system that originated it. If the origin type for all client/server IP routes is equivalent, the DNS server 102 instead selects the client/server IP route with a lowest Multi_Exit_Disc (MED). MED is a BGP protocol attribute that describes an external metric of a route. If the MED for all client/server IP routes is equivalent, the DNS server 102 instead selects the default best client/server IP address 210 which is retrieved from the enhanced “A” record 202 . Those skilled in the art recognize that other best IP route selection methods are possible. In step 720 , the DNS server 102 caches the best client/server IP route in the cache database 312 and the process 702 proceeds to step 711 , which has been discussed above.
[0034] In step 714 , if the IP routes database 314 has a zero timeout value, the process proceeds to step 722 . In step 722 , the DNS server 102 accesses the protocol specified within the router retrieval parameters 208 . If the protocol is set to BGP, then the IIP routes database 314 will be updated continuously, and the process proceeds to step 716 . Step 716 is discussed above. Else, the process proceeds to step 724 . In step 724 , the DNS server 102 accesses the protocol specified within the router retrieval parameters 208 . If the protocol is set to MIB, the process proceeds to step 726 . In step 726 , a MIB IP routes retrieval subroutine is executed, as described with reference to FIG. 8. After step 726 , the process proceeds to step 720 discussed above. If the protocol was not set to MIB, the protocol defaults to Telnet and the process 702 proceeds to step 728 . In step 728 , a Telnet IP routes retrieval subroutine is executed, as described with reference to FIG. 9. After step 728 , the process proceeds to step 720 discussed above.
[0035] [0035]FIG. 8 is a dataflow diagram 800 of an MIB IP Routes retrieval subroutine 802 within the best route selection process 702 . The process 802 begins in step 804 , where SNMP (MIB retrieval) information is accessed from the router retrieval parameters 208 . In step 806 , an SNMP session is established with the routers 108 , 112 , and routing tables are downloaded real-time from a MIB database on the routers. A best client/server IP route is selected from all client/server IP routes downloaded within the routing tables in step 808 . The best IP route is selected using the steps discussed with reference to step 718 in FIG. 7, except that the IP routes in the IP routes database 314 are not accessed. After step 808 , the process 802 ends.
[0036] [0036]FIG. 9 is a dataflow diagram 900 of an Telnet IP Routes retrieval subroutine 902 within the best route selection process. The process 902 begins in step 904 , where Telnet information is accessed from the router retrieval parameters 208 . In step 906 , a Telnet session is established with the routers 108 , 112 and routing tables are downloaded real-time using the Telnet protocol. A best client/server IP route is selected from all client/server IP routes downloaded within the routing tables in step 908 . The best IP route is selected using the steps discussed with reference to step 718 in FIG. 7, except that the IP routes in the IP routes database 314 are not accessed. After step 908 , the process 902 ends.
[0037] While one or more embodiments of the present invention have been described, those skilled in the art will recognize that various modifications may be made. Variations upon and modifications to these embodiments are provided by the present invention, which is limited only by the following claims.
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A method and system for software based internet protocol (IP) address selection is disclosed. The method describes steps of assigning a single domain name to a set of server IP addresses, receiving a request for the domain name from a client IP address, retrieving a set of IP routes linking the server IP addresses and the client IP address, and selecting an IP route from the set of routes which meets predetermined criteria.
The system includes a set of servers, having a single domain name, a client computer, a set of routers, coupled to the servers and the client computer, for storing IP routes between the servers and the client; and a domain name system server, coupled to the routers, for selecting one of the IP routes which meets predetermined criteria.
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CROSS REFERENCE TO RELATED APPLICATION
This application, is a continuation application of U.S. application Ser. No. 09/208,322 filed Dec. 9, 1998, now U.S. Pat. No. 6,048,549 which claims the benefit of U.S. Provisional Application No. 60/068,262, filed on Dec 19, 1997, which is incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel powder composition. More particularly, this invention relates to a novel powder composition having improved anti-microbial, cooling and skin soothing properties.
2. Description of the Prior Art
Miliria Rubra, commonly known as “prickly heat”, is a skin condition that results from an obstruction of the sweat gland ducts. More specifically, keratin plugs are formed due to the maceration of the stratum corneum accompanied by the distension of the sweat gland ducts. Prickly heat may be identified by the development of an intensely itchy rash on the skin that is composed of small vesicles, and may also be accompanied by a secondary bacterial infection. Babies often develop prickly heat, in particular during periods of warmer weather.
Several known methods exist for treating prickly heat and the symptoms thereof. One such method is the application of a powder mixture consisting of talc with one or more antibacterial agents such as boric acid, salicylic acid, and chlorphenesin. Disadvantageously, such treatments are inappropriate for use on babies' skin because the antibacterial agents tend to irritate the skin and because of the concern over the toxicity effects that may be associated with the use of such antibacterial agents.
It would be desirable to develop a powder composition that was effective in treating the symptoms of prickly heat, but that was also safe for use on babies' skin.
SUMMARY OF THE INVENTION
In accordance with this invention, there is provided a novel powder composition comprised of, consisting of, and/or consisting essentially of, based upon the weight of the composition, a skin irritation reducing agent comprising 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, scutellaria baicalensis extract, bisabolol, or mixtures thereof.
Another embodiment of the invention is directed to a method for treating prickly heat comprised of, consisting of, and/or consisting essentially of topically applying an effective amount of a powder comprised, consisting of, and/or consisting essentially of a skin irritation reducing agent comprising 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, scutellaria baicalensis extract, bisabolol, or mixtures thereof.
The powders of this invention exhibit one or more beneficial properties. Not only do the powders relieve the symptoms of prickly heat by providing antimicrobial, soothing, and cooling benefits to the skin, but they also do so without the use of harsh antimicrobial agents which tend to irritate sensitive skin.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The main component of the powder composition of the present invention is a skin irritant reducer. Suitable skin irritant reducers include, but are not limited to 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, which is also known as trimethylglycine (betaine), scutellaria baicalensis extract, bisabolol, and mixtures thereof. One suitable mixture includes bisabolol, soybean oil, and chamomile extract and is available from Dragoco, Ltd. under the tradename, “Phytoconcentrol Chamomile.”
1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, which is an amino acid extracted from sugar beets that is commercially available from Cultor Ltd. (Finnsugar Bioproduct) under the tradename, “BETAFIN BPP”, may be used in the powder composition of the present invention in an amount, based upon the total weight of the composition, from about 0.005% to about 50%, preferably from about 0.05% to about 10.0%, and more preferably from about 0.1% to about 5.0%.
Scutellaria baicalensis extract, which is derived from the root of the Scutellaria baicalensis georgi plant and is commercially available from Ichimaru Pharcos Co., Ltd. under the tradename, “Ougon Exatract Powder,” may be used in the powder composition of the present invention in an amount, based upon the total weight of the composition, from about 0.00001% to about 0.10%, preferably from about 0.0001% to about 0.08%, and more preferably from about 0.001% to about 0.05%.
Bisabolol, which is available from Dragoco, Ltd. under the tradename “DRAGOSANTOL,” may be used in the powder composition of the present invention in an amount, based upon the total weight of the composition, from about 0.1% to about 2.0%, preferably from about 0.15% to about 1.5%, and more preferably from about 0.2% to about 0.5%.
Several other components may be present in the powder composition of the present invention such as a base including, but not limited to talc, cornstarch, and mixtures thereof. Talc is preferred. Preferably the base is sterilized via methods well known in the art such as via steam sterilization. before it is combined with the other ingredients of the powder of the present invention. Suitable amounts of talc may range from, based upon the total weight of the powder composition, about 50% to less than about 100%, preferably from about 70% to about 99%, and more preferably from about 80% to about 99%.
Another component that may be present in the powder composition of the present invention is a cooling agent that includes but not is not limited to menthol; eucalyptus oil; peppermint oil; cyclohexanol, 5-methyl-2-(1-methylethenyl)-, available from Takasago International Corporation, Tokyo under the tradename, COOLACT; 6-Isopropyl-9-methyl-1,4-dioxaspiro-(4,5)decane-2-methanol, (I)-menthone glycerol ketal (Menthone Glycerin Acetal) available from Haarmann & Reimer (“H&R”) under the tradename, FRESCOLAT MGA; 5-methyl-2-(1-methyl ethyl)-cyclohexyl-2-hydroxypropionate, I-menthyl lactate, acid/-menthyl ester (Menthyl Lactate) available from H&R under the tradename, FRESCOLAT ML; menthyl pyrrolidone carboxylate (Menthyl PCA) available from Quest International UK Limited under the tradename, QUESTICE, and mixtures thereof. The cooling agent may be used in an amount, based upon the total weight of the powder composition, of from about 0.01% to about 0.50%. Preferably, the menthol may be used in an amount, based upon the total weight of the composition, from about 0.01% to about 0.50%, more preferably from about 0.05% to about 0.30%, and most preferably from about 0.10% to about 0.20% and the eucalyptus oil and peppermint oil, respectively, may be used in an amount, based upon the total weight of the composition, from about 0.01% to about 0.50%, more preferably from about 0.05% to about 0.40%, and most preferably from about 0.20% to about 0.30%. The menthol and the eucalyptus oil provide a fresh, cooling feeling to the user. A mixture of menthol and eucalyptus oil is the preferred coolant.
Another component that may be used in the powder composition of the present invention is an astringent. Suitable astringents include, but are not limited to zinc oxide, glyoxyl diureide available from Sutton Laboratories under the trade name, “ALLANTOIN,“ and mixtures thereof. The astringents may be used in an amount, based upon the total weight of the composition, from about 0.10% to about 10.0%, preferably from about 0.5% to about 5.0%, and more preferably from about 0.5% to about 3.0%. Zinc oxide is preferred due to its mild antiseptic and astringent properties.
Another component of the present invention may be an antimicrobial agent comprised of benzethonium chloride, (-p-Chloro-3, 5-m-xylenol)(“PCMX”)(also known as “chloroxylenol”), and mixtures thereof. The preferred antimicrobial agent is PCMX. In one preferred embodiment, PCMX is used in combination with bisabolol skin irritant reducing agent. The amount of antimicrobial agent used in the composition of the present invention may range from about 0.10% to about 5.0%, preferably from about 0.2% to about 3.0%, and more preferably from about 0.3% to about 1.0%. Chloroxylenol (-p-Chloro-3, 5-m-xylenol), which is commercially available from Nipa Laboratories Ltd. under the tradename, NIPACIDE PX, is preferred for its unique combination of nontoxic antimicrobial and preservative properties.
In addition to the above components for the powder composition, the composition may include other optional components including, but not limited to, anticaking agents, absorbing agents, water-repellent agents, perfumes, vitamins, and mixtures thereof.
Suitable anti-caking agents include, but are not limited to tribasic calcium phosphate, silicon dioxide, kaolin, hydrated aluminum silicate, and mixtures thereof, and suitable absorbing agents include, but are not limited to magnesium carbonate available from Konoshima Chemical Co. Ltd. under the tradename, “MAGNESIUM CARBONATE LIGHT.” Suitable water-repellent agents include, but are not limited to magnesium stearate. The anti-caking agents, absorbing agents and water-repellent agents may be used in an amount, based upon the total weight of the composition, of from about 0.1% to about 15%, and preferably from 0.5% to about 10%.
The perfume may be present in an amount, based upon the total weight of the powder composition, of from about 0.05% to about 1%, and preferably from about 0.1% to about 0.5%.
Suitable vitamins include, but are not limited to vitamin E, D-Panthenol (also known as “Provitamin B5”), and mixtures thereof, and may be present in an amount, based upon the total weight of the powder composition, of from about 0.01% to about 5.0%, and preferably from about 0.05% to about 2%.
The powder composition of the present invention may be made by combining the components in any mixing device well-known in the art, including, but not limited to any type of powder blender, with a ribbon mixer being most preferred. The components are preferably combined under pressure conditions of about 14.7 psi (atmospheric pressure), and a temperature of about 20° C. to about 32° C., and preferably from about 25° C. to about 28° C.
In a preferred embodiment, the desired amounts of menthol, eucalyptus oil, and chloroxylenol are dissolved in the perfume of choice under a temperature of from about 20° C. to about 32° C., and preferably from about 25° C. to about 28° C. in any of the above-mentioned conventional mixers until this first mixture is homogeneous. Alternatively, in another embodiment, the desired amounts of menthol, eucalyptus oil and chloroxylenol may be premixed in a conventional mixer such as a stainless steel bin with a mechanical stirrer under ambient conditions until the first premixed mixture is homogeneous before being dissolved in the perfume. The mixers are preferably made of corrosion resistant material such as glass or stainless steel. Pressure is not critical, although convenient operating pressures may range from about 14 psi to about 15 psi.
In another mixing device, an effective amount of the scutellaria baicalensis extract, zinc oxide, betaine, and, based upon the total weight of the base used in the powder composition of the present invention, from about 5% to about 20%, and preferably from about 7% to about 15% of talc are mixed under temperature conditions of from about 20° C. to about 32° C., and preferably from about 25° C. to about 28° C. in any of the above-mentioned conventional mixers until the resulting second premixed mixture is homogeneous. A ribbon mixer is preferred. Pressure is not critical, although convenient operating pressures may range from about 14 psi to about 15 psi.
The second premixed mixture is mixed with the remaining amount of talc in a conventional mixer under until the resulting third mixture is homogeneous. Temperature and pressure are not critical; however convenient operating temperatures may range from about 20° C. to about 35° C. and operating pressures may range from about 14 psi to about 15 psi. The first premixed mixture is then added, preferably via spraying with a conventional spraying device such as a Mateer-Burt sprayer, into the third mixture and mixed under similar temperature and pressure conditions until the resulting mixture is homogeneous.
The invention illustratively disclosed herein suitably may be practiced in the absence of any component, ingredient, or step which is not specifically disclosed herein. The examples are set forth below to further illustrate the nature of the invention and the manner of carrying it out. However, the invention should not be considered as being limited to the details thereof.
EXAMPLES
Example 1
Preparation of Premix 1
0.15 kg of menthol, 0.25 kg of eucalyptus oil, and 0.1 kg of p-chloro-3,5-m-xylenol available from Nipa Laboratories Ltd. under the tradename, “Nipacide PX” were dissolved in 0.18 kg of perfume available from Givaudan-Roure Ltd. under the tradename, “Parfex 46109” under a temperature of 25 to 30° C. and atmospheric pressure in a steel bin having a mechanical stirrer. The mixture was mixed at a speed of about 25 revolutions/minute for about 10 minutes until the resulting mixture was homogeneous.
Example 2
Preparation of Premix 2
0.005 kg of Scutellaria baicalensis Extract available from Ichimaru Pharcos Co., Ltd. under the tradename, “Ougon Extract Powder,” 0.5 kg. of 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt available from Cultor Ltd. under the tradename, “Betafin BPP,” and about 1 kg of zinc oxide were mixed with 10 kg of talc under ambient conditions in a 37 SC model Mateer-Burt ribbon mixer for about 12 minutes at a speed of about 25 revolutions/minute until the resulting mixture was homogeneous.
Example 3
Preparation of Powder Composition
The product of Example 2 was mixed with 88 kg of talc in a large 37 SC model Mateer-Burt ribbon mixer under ambient conditions for about 10 minutes at a speed of about 25 revolutions/minute to form a homogeneous mixture. After spraying in the product of Example 1 into the homogeneous mixture via a 37 SC model Mateer-Burt sprayer at a volumetric rate of about 0.07 kg/min for a period of about 8 minutes, the resultant mixture is further mixed in the same mixer under ambient conditions at a speed of about 28 revolutions/minute for about 40 minutes until the resulting powder was homogeneous.
Example 4
Consumer Testing of Powder Composition
Samples of the powder produced in Example 3 were given to 28 babies and samples of Johnson's™ Baby Prickly Heat Powder were given to 32 other babies, all of which possessed symptoms of prickly heat rash. The latter does not possess either Scutellaria baicalensis extract or 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, but instead includes about 200 g. of 0.2% Chamomile Oil. About 93% of the participants were classified as having mild to moderate rashes and about 7% of the participants were classified as having more severe rashes.
The parents were instructed to apply the powder to the affected area(s) on their babies after such area(s) were washed and patted dry for a minimum of at least two times a day for 10 consecutive days. After the ten-day period, 96.9% of the rashes on babies who used the Johnson's™ Baby Prickly Heat powder and 92.9% of the rashes on babies who used the powder of Example 3 were improved. More specifically, for babies who used the powder of Example 3, 92.8% of the participants reported that the rashes improved after only 5 days of treatment and further improved/cleared after 10 days of treatment. Similarly, 96.87% of those using the Johnson's™ Baby Prickly Heat powder reported an improvement in the rashes after 5 days of treatment and further improvement/clearing after 10 days of treatment.
This Example shows that the claimed powder composition effectively clears and prevent the symptoms of prickly heat rash. Since many of the participants had rashes over multiple areas of their bodies, this Example shows that the powder compositions were effective in treating the rashes independent of the location or number of body sites affected.
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A novel powder composition comprised of a skin irritation reducing agent comprising 1-Carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt, scutellaria baicalensis extract, bisabolol, or mixtures thereof. Also provided is a method for treating prickly heat comprised of topically applying an effective amount of the powder to a desired area.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to integrated photovoltaic roofing systems, and more specifically to methods and systems for roofing shingles having photovoltaic modules integrated into the shingle.
[0002] At least some known roofing systems with asphalt roofs mount directly on top of the existing shingles. Other known roofing systems replace the roofing tiles with an area that looks like a black or blue area covering a portion of the roof. Such products are often advertised as being photovoltaic cells “integrated” into a shingle roof but the photovoltaic cells are simply surrounded by standard asphalt roofing tiles. However, such roofing systems lack flexibility in design or construction methods to allow the various colors and shapes that are necessary to match the various product lines available in the asphalt roofing market to provide the aesthetic appeal needed for a residential rooftop photovoltaic solar system.
BRIEF DESCRIPTION OF THE INVENTION
[0003] In one embodiment, a photovoltaic roofing system includes a back sheet including a length, L, a width, W, and a thickness, T, the back sheet including an overlap portion extending along length L having a width, W O and an active portion extending along length L having a width, W A . The system also includes a photovoltaic cell formed on a surface of the active portion, the photovoltaic cell including a photovoltaic member electrically responsive to an absorption of photons, a negative electrode coupled to a surface of the photovoltaic member, and a positive electrode coupled to the surface of the photovoltaic member, wherein the thickness T is selected such that thickness T plus a thickness of the photoelectric cell substantially match a thickness of a proximate non-photovoltaic roofing member when the photovoltaic roofing system is installed.
[0004] In another embodiment, a method of assembling a photovoltaic roofing system includes providing a substrate of roofing material including a top surface, a bottom surface and an edge extending therebetween about an outer periphery of the substrate, the substrate includes an overlay portion configured to be covered by at least one of an adjacent photovoltaic roofing system and an adjacent roofing shingle, the substrate further includes an active portion, forming a photovoltaic cell on the top surface of the active portion, the photovoltaic cell including a photovoltaic member electrically responsive to an absorption of photons, a negative electrode coupled to a surface of the photovoltaic member, and a positive electrode coupled to the surface of the photovoltaic member, and electrically coupling the negative electrode and the positive electrode to an electrical plug extending from the edge.
[0005] In yet another embodiment, a photovoltaic roofing system includes a back sheet including a first thickness, the back sheet including an overlap portion, a header portion configured to permit the roofing assembly to be coupled to a roof surface, and an adjacent active portion extending from the overlap portion, the active portion including a plurality of tab portions, a photovoltaic cell formed on a surface of each the tab portions, the photovoltaic cell including a second thickness, the photovoltaic cell further including a photovoltaic member, a negative electrode coupled to a surface of the photovoltaic member, and a positive electrode coupled to the surface of the photovoltaic member, wherein the first thickness plus the second thickness is substantially equal to a thickness of a proximate non-photovoltaic roofing member when the photovoltaic roofing system is installed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a roof including a plurality of exemplary photovoltaic roofing systems in accordance with an embodiment of the present invention; and
[0007] FIG. 2 is an exploded view of an exemplary photovoltaic cell that may be used with photovoltaic roofing systems shown in FIG. 1 ;
[0008] FIG. 3 is a perspective view of the photovoltaic cell shown in FIG. 2 after assembly;
[0009] FIG. 4 is an exploded view of the exemplary photovoltaic roofing system shown in FIG. 1 ;
[0010] FIG. 5 is a perspective view of a photovoltaic roofing system in accordance with an embodiment of the present invention;
[0011] FIG. 6A is an exploded perspective view of the photovoltaic roofing system in accordance with another embodiment of the present invention;
[0012] FIG. 6B is a perspective view of the photovoltaic roofing system in accordance with another embodiment of the present invention; and
[0013] FIG. 7 is an exploded view of an exemplary embodiment of an electrically active shingle tab assembly shown in FIGS. 6A and 6B .
DETAILED DESCRIPTION OF THE INVENTION
[0014] FIG. 1 is a perspective view of a roof 100 including a plurality of exemplary photovoltaic roofing systems 102 in accordance with an embodiment of the present invention. A plurality of non-photovoltaic roofing shingles 104 are mixed in combination with the photovoltaic roofing systems 102 to form roof 100 . In FIG. 1 , photovoltaic roofing systems 102 are shown darker than non-photovoltaic roofing shingles 104 for illustration only. In the exemplary embodiment, photovoltaic roofing systems 102 are colored to match non-photovoltaic roofing shingles 104 . Although non-photovoltaic roofing shingles are described herein as “shingles”, they may be more complex assemblies than typical roofing shingles, for example, non-photovoltaic roofing shingles may include a plurality of components and may lay flat on roof 100 , or may be textured or shaped to a particular feature. Photovoltaic roofing system 102 is configured to match a color, shape, and/or texture of non-photovoltaic roofing shingles 104 such that an aesthetic look is achieved. Additionally, a thickness of photovoltaic roofing systems 102 is selected to substantially match the thickness of non-photovoltaic roofing shingles 104 such that a profile difference between non-photovoltaic roofing shingles 104 and photovoltaic roofing systems 102 is essentially indiscernible.
[0015] FIG. 2 is an exploded view of an exemplary photovoltaic cell 200 that may be used with photovoltaic roofing systems 102 (shown in FIG. 1 ). Photovoltaic cell 200 includes a waffle grid pattern 202 that is exposed to the sun when photovoltaic cell 200 is in operation. A molded wafer of photovoltaic material 204 is positioned on waffle grid pattern 202 . A first side 206 adjacent waffle grid pattern 202 is exposed to the sun during operation through opening 208 formed in waffle grid pattern 202 . A front contact wrap through layer 210 is applied to a second side 212 of photovoltaic material 204 . Front contact wrap through layer 210 is configured to provide a plurality of connection points 214 on second side 212 for connection to electrical bussing that will transmit the output of photovoltaic material 204 external to photovoltaic cell 200 . A back contact bussing 216 is coupled to a cathode portion of photovoltaic material 204 . A back field layer 218 and a dielectric layer 220 are applied over photovoltaic material 204 with openings 222 , 224 that are complementary to front contact wrap through layer 210 and back contact bussing 216 , respectively such that front contact wrap through layer 210 and back contact bussing 216 are exposed through back field layer 218 and dielectric layer 220 . In the exemplary embodiment, back field layer 218 is fabricated from a metal ink, for example, but not limited to, aluminum or copper. A front contact bussing 226 is applied over dielectric layer 220 such that legs 228 of front contact bussing 226 are arranged to cover openings 222 and make connection to photovoltaic material 204 through connection points 214 . In the exemplary embodiment, connection points 214 are coupled to photovoltaic material 204 at cathode sites on photovoltaic material 204 such that front contact bussing is negatively charged during operation and back contact bussing 216 is coupled to photovoltaic material 204 at anode sites such that back contact bussing 216 is positively charged during operation. In an alternative embodiment, the polarity of back contact bussing 216 and front contact bussing 226 may be reversed during operation by coupling them to cathode sites and anode sites respectively. Both bus systems are coupled to a single side of photovoltaic material 204 , and in the exemplary embodiment, it is the side opposite of the side that receives the sunlight to provide the motive force for electron flow in photovoltaic material 204 .
[0016] FIG. 3 is a perspective view of photovoltaic cell 200 (shown in FIG. 2 ) after assembly. Front contact bussing 226 is electrically connected to photovoltaic material 204 through connection points 214 coupled to side 212 of photovoltaic material 204 . Connection points 214 are exposed to front contact bussing 226 through openings 222 in dielectric layer 220 and back field layer 218 . Back contact bussing 216 is electrically connected to photovoltaic material and is exposed through openings 224 in dielectric layer 220 and back field layer 218 . In the exemplary embodiment, both front and back contact bussing 226 , 216 , respectively are electrically coupled to the same side of photovoltaic material 204 .
[0017] FIG. 4 is an exploded view of an exemplary photovoltaic roofing system 102 (shown in FIG. 1 ). Photovoltaic roofing system 102 includes a back sheet 402 comprising for example, a polyvinyl fluoride (PVF) film. An interconnection portion 404 permits a plurality of electrical wires to couple one or more photovoltaic cells to each other or to an electrical plug connection 406 . An encapsulation portion 408 permits the electrical wires and plug connection 406 to be sealed from ambient. In the exemplary embodiment, a header portion 410 is configured to receive one or more fasteners for affixing photovoltaic roofing system 102 to a roof. In the exemplary embodiment, photovoltaic roofing system 102 includes a first ethylene-vinyl acetate (EVA) layer 412 applied to an active portion 414 of back sheet 402 . One or more photovoltaic cells 200 are positioned on EVA layer 412 such that an edge of EVA layer 412 extends beyond an edge of photovoltaic cell 200 on all four sides. A second EVA layer 416 is applied to photovoltaic cell 200 such that the edges of second EVA layer 416 extend beyond the edges of photovoltaic cell 200 and substantially match the edges of first EVA layer 412 . In the exemplary embodiment, the edges of first EVA layer 412 and second EVA layer 416 are sealed to form a hermetic environment within first EVA layer 412 and second EVA layer 416 and surrounding photovoltaic cell 200 . Photovoltaic roofing system 102 includes a protective layer 418 such as solar glass. Production techniques used in the manufacture of photoelectric sensitive material 204 are selected such that the color of photovoltaic roofing system 102 as finally assembled is configured to match a non-photovoltaic roofing shingle or system that is positioned adjacent photovoltaic roofing system 102 .
[0018] FIG. 5 is a perspective view of a photovoltaic roofing system 102 in accordance with an embodiment of the present invention. Photovoltaic roofing system 102 includes back sheet 402 having a length and a width W O . In this embodiment, back sheet 402 includes one or more notches 501 defined by a slit or cutout through back sheet 402 and extending at least partially through a width W A of active portion 414 to divide active portion 414 into a plurality of tabs 503 . In various other embodiments, back sheet 402 does not include notches 501 . Photovoltaic roofing system 102 also includes active portion 414 , and an overlay portion 502 on back sheet 402 . Overlay portion includes interconnection portion 404 , encapsulation portion 408 , header portion 410 , and plug connection 406 . Plug connection 406 extends from an upper edge 504 or lower edge 505 with respect to the pitch of the rrof such that electrical connections are made to other assemblies 200 above or below each assembly 200 . Waffle grid pattern 208 is exposed to the sun on an upper surface of back sheet 402 . Interconnection portion 404 includes a plurality of electrical traces or wires that carry electrical current from photovoltaic material 204 to plug connection 406 .
[0019] FIGS. 6A and 6B are perspective views of photovoltaic roofing system 600 in accordance with another embodiment of the present invention. FIG. 6A is an exploded view with respect to FIG. 6B . Photovoltaic roofing system 102 includes a roofing membrane 602 configured to extend under the entire photovoltaic roofing system 600 assembly and also includes a header portion 604 . In the exemplary embodiment, roofing membrane 602 does not include cutouts for separating shingle tabs. The tab “look” is achieved by spacing a plurality of electrically active shingle tab assemblies 606 with a gap 608 between assemblies 606 and along a roofing membrane edge 610 . Electrically active shingle tab assembly 606 is coupled to roofing membrane 602 such as by using an adhesive to affix tab assembly 606 to roofing membrane 602 . Interconnect wiring 612 connects electrically active shingle tabs 606 together in series with a plug assembly 614 . Interconnect wiring 612 is sandwiched between a stiffener 616 and roofing membrane 602 using an adhesive encapsulant. Stiffener 616 extends above interconnect wiring 612 and is used with header portion 604 as a nailing header for fastening photovoltaic roofing system 600 to a roof. Two rows of nails may be used, similar to standard roofing shingle installations. Plug assembly 614 includes a small wire extending downward from the middle of plug assembly 614 , which connects assembly 606 to the next row down on the roof. Once assembled on the roof, plug assembly 614 is completely covered by the shingle tab from the row above.
[0020] FIG. 7 is an exploded view of an exemplary embodiment of an electrically active shingle tab assembly 606 (shown in FIGS. 6A and 6B ). In the exemplary embodiment, tab assembly 606 includes roofing membrane 602 , a first encapsulant layer 702 fabricated from for example, ethylene-vinyl acetate (EVA). An interconnection portion 704 permits a plurality of electrical wires to couple one or more photovoltaic cells to each other or to an electrical plug connection (not shown). A front contact bussing structure 706 is electrically coupled to interconnection portion 704 . A dielectric layer 708 is applied over front contact bussing structure 706 and a back field layer 710 is applied over dielectric layer 708 . Openings 712 in dielectric layer 708 and back field layer 710 facilitate electrical connection through dielectric layer 708 and back field layer 710 . Back contact bussing 714 and a front contact wrap through layer 716 is exposed to front contact bussing structure 706 through openings 712 . A molded wafer of photovoltaic material 718 is positioned over front contact wrap through layer 716 and an optional waffle grid pattern 720 is applied over photovoltaic material 718 . A first side 722 of waffle grid pattern 720 is exposed to the sun during operation through a plurality of openings 724 formed in waffle grid pattern 720 . A second encapsulant layer 726 fabricated from for example, ethylene-vinyl acetate (EVA) is applied over waffle grid pattern 720 , if used, and sealed to first encapsulant layer 702 to form a hermetic environment therebetween. A protective layer 728 such as solar glass is applied over second encapsulant layer 726 .
[0021] Exemplary embodiments of photovoltaic roofing systems and are described above in detail. The photovoltaic roofing system components illustrated are not limited to the specific embodiments described herein, but rather, components of each photovoltaic roofing system may be utilized independently and separately from other components described herein. For example, the photovoltaic roofing system components described above may also be used in combination with different photovoltaic roofing system components.
[0022] The above-described photovoltaic roofing systems and methods are cost-effective and highly reliable. The method permits maintaining the aesthetic appeal of a shingle type roof using both photovoltaic and non-photovoltaic roofing systems in adjacent position with respect to each other. A thickness of each roofing system is configured to match giving an even profile when viewed by a user. The appearance and profile permits using the above described photovoltaic roofing system with a variety of non-photovoltaic roofing systems with a minimum of obvious aesthetic differences between the two systems. Accordingly, the systems and methods described herein facilitate the operation of photovoltaic roofing systems in a cost-effective and reliable manner.
[0023] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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Methods and systems for photovoltaic roofing systems are provided. The system includes a back sheet including a length, L, a width, W, and a thickness, T, the back sheet including an overlap portion extending along length L having a width, WO and an active portion extending along length L having a width, WA. The system also includes a photovoltaic cell formed on a surface of the active portion, the photovoltaic cell including a photovoltaic member electrically responsive to an absorption of photons, a negative electrode coupled to a surface of the photovoltaic member, and a positive electrode coupled to the surface of the photovoltaic member, wherein the thickness T is selected such that thickness T plus a thickness of the photoelectric cell substantially match a thickness of a proximate non-photovoltaic roofing member when the photovoltaic roofing system is installed.
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FIELD
[0001] The field of the invention generally relates to methods and devices for controlling moveable barrier operators. More particularly, the invention relates to adapting the operation of the barrier to detect and overcome nuisance obstructions.
BACKGROUND
[0002] Barrier movement operators are automated systems which are used to move a barrier with respect to an opening. Examples of the barriers to be moved include garage doors, gates, fire doors and rolling shutters. The primary examples herein involve garage door operators but the principles described and claimed therein relate to all barrier movement operators. A number of barrier movement operators have been sold over the years most of which include a head unit containing a motor connected to a transmission. The transmission, which may include, for example, a belt drive, a chain drive, a screw drive or extendible arm is then coupled to the barrier for opening and closing.
[0003] Such barrier movement operators also typically include a wall control unit, which is connected to send signals to the head unit thereby causing the head unit to open and close the barrier. In addition, these operators often include a receiver unit at the head unit to receive wireless transmissions from a hand-held code transmitter or from a keypad transmitter, which maybe affixed to the outside of the area closed by the barrier or other structure.
[0004] As barrier movement operators open and close the barriers, the barrier may come into contact with an obstruction. Previous systems have allowed the barrier operator systems to determine if an obstruction has been encountered and to either stop or reverse the direction of the travel of the barrier once this determination has been made. For instance, some previous systems measured the force applied to the barrier by the motor. The systems then compared the measured force to an expected value plus a fixed cushion value. If the comparison indicated that the measurement value exceeded the expected value plus the cushion value (together, a threshold value), then the downward barrier movement was reversed. These systems typically determined the force by measuring the barrier speed or current in the motor and then calculated the force using these measurements.
[0005] Secondary obstruction detectors have also been used to detect obstructions in the path of the barrier. For instance, infrared (IR) detectors and barrier edge sensors have been used to determine if an obstruction exists in the path of the barrier. Typically, if the secondary obstruction detector indicated that an obstruction was present, the downward movement of the barrier was halted and then reversed in previous systems.
[0006] As system components age and are subjected to various environmental conditions and the system is not properly maintained, errors in the operation of previous systems may occur. For instance, if force measurements are made, the measured force may exceed the threshold value, but the door may not be encountering a real obstruction. In this case, the downward movement of the door would be reversed even though there was no actual obstruction present in the path of the barrier. For example, a nuisance such as sand or dirt maybe present in the guiding apparatus of the door path. In other examples, the door may have not been lubricated or may have worn parts. In summary, present systems are not capable of adapting their performance over time to determine if a real obstruction exists or whether the barrier reversal was caused by a nuisance or mistake.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a system and method for operating a barrier movement operator between open and closed positions. The system and method determines if an obstruction is truly present in the barrier and stops and potentially reverses the direction of travel if an obstruction is detected. The detection and determination is accomplished by measuring the force applied to the barrier and comparing this measured force to a threshold. After the direction of travel of the barrier is reversed, a request is made to move the barrier downward, the barrier is moved downward, and the force applied to the barrier is compared to a new, higher threshold. The request may be made by pressing and then releasing an actuator device such as a button or switch. The barrier travel direction may be reversed again if the second test indicates that the measured force exceeds the new threshold. If the barrier reaches the end of its path, it is determined that an obstruction did not really exist in the path of the barrier.
[0008] In many of the embodiments, a barrier movement operator moves a barrier between open and closed positions. The operator receives a first request to move the barrier. The force required to move the barrier is measured. Whether an obstruction to barrier movement exists is determined by comparing the measured actual force to a first predetermined force threshold. Responsive to the detection of an obstruction, the direction of travel of the barrier is stopped and potentially reversed. The operation of the barrier movement operator is modified, by permitting the use of a higher force threshold in future measurements and comparisons.
[0009] A second request to move the barrier is then received. The actual force required to move the barrier is measured a second time. An obstruction to barrier movement is detected by comparing the measured actual force with the new, higher force threshold.
[0010] The modification of the force threshold may be reversed upon completion of the barrier movement in response to the second request without detecting an obstruction. Alternatively, the new force threshold may be made permanent.
[0011] In other approaches, a user is allowed a predetermined time to make the second request for the barrier movement. If the request is received within the time period, the system may use a modified, new threshold value in the comparisons performed. If the request is not received within the specified time period, the system may use the old threshold in the comparisons. In still another approach, the system may also test for obstructions using secondary obstruction detectors such as IR sensors and use this information together with the threshold comparison to determine whether an obstruction exists.
[0012] Thus, a method and system to determine obstructions in the path of a barrier is adaptable to environmental and other conditions and changes in system components. In this regard, a new threshold is used to determine whether an actual obstruction exists in the path of the closing barrier or whether an alleged obstruction does not exist and the barrier can be safely closed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of a garage door opening system according to the present invention;
[0014] FIG. 2 is a block diagram of a controller for use in a barrier opening system according to the present invention;
[0015] FIG. 3 a is a flowchart illustrating the operation of the barrier opening system using a temporary threshold according to the present invention;
[0016] FIG. 3 b is a flowchart illustrating the operation of the barrier opening system using a permanent threshold according to the present invention;
[0017] FIG. 4 a is a flowchart illustrating the operation of the barrier opening system using a temporary threshold according to the present invention; and
[0018] FIG. 4 b is a flowchart illustrating the operation of the barrier opening system using a permanent threshold according to the present invention.
[0019] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are typically not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.
DETAILED DESCRIPTION
[0020] For illustrative purposes, the following description refers to a moveable barrier that is a garage door. However, it will be understood by those skilled in the art that the moveable barrier may not only be a garage door but may be any type of barrier such as a fire door, shutter, window, gate. Other examples of barriers are possible.
[0021] Referring now to the drawings and especially to FIG. 1 , a movable barrier operator, which is a garage door operator, is generally shown therein and includes a head unit 12 mounted within a garage 14 . More specifically, the head unit 12 is mounted to the ceiling of the garage 14 and includes a rail 18 extending therefrom with a releasable trolley 20 attached having an arm 22 extending to a multiple paneled garage door 24 positioned for movement along a pair of door rails 26 and 28 . The system includes a hand-held transmitter unit 30 adapted to send signals to an antenna 32 positioned on the head unit 12 as will appear hereinafter. An external control pad 34 is positioned on the outside of the garage having a plurality of buttons thereon and communicates via radio frequency transmission with the antenna 32 of the head unit 12 . An optical emitter 42 is connected via a power and signal line 44 to the head unit. An optical detector 46 is connected via a wire 48 to the head unit 12 . The head unit 12 also includes a receiver unit 102 . The receiver unit 102 receives a wireless signal, which is used to actuate the garage door opener.
[0022] The head unit 12 has the wall control panel 43 connected to it via a wire or line 43 A. The wall control panel 43 includes a decoder, which decodes closures of a lock switch 80 , a learn switch 82 and a command switch 84 in the wall circuit. The wall control panel 43 also includes a light emitting diode 86 connected by a resistor to the line 43 and to ground to indicate that the wall control panel 43 is energized by the head unit 12 . Switch closures are decoded by the decoder, which sends signals along lines 43 A to a control unit 200 coupled via control lines to an electric motor positioned within the head unit 12 . In other embodiments, analog signals may be exchanged between wall control 43 and head unit 12 .
[0023] The wall control panel 43 is placed in a position such that an operator can observe the garage door 24 . In this respect, the control panel 43 may be in a fixed position. However, it may also be moveable as well. The wall control panel 43 may also use a wirelessly coupled connection to the head unit 12 instead of the wire 43 A. As discussed below, control unit 200 of head unit 12 determines the applied force or a value representative of the applied force to the door 24 (both referred to herein as the “measured force”) and compares this to an expected value plus a variable cushion value (together, the threshold value, which is variable). Based upon the results of the comparison, the direction of the door travel may be reversed. A user may then press and release an actuator device, for example, the command switch 84 . The direction of travel of the door 24 is again be reversed and a new threshold can be used and compared to the measured force. The new threshold value may be a higher threshold value than the old threshold. However, in other circumstances, a lower threshold value may be used. The threshold value may be adjusted by altering the cushion value and recalculating the threshold or simply directly altering the threshold.
[0024] In one approach, a time limit is set for the actuator device to be actuated and the threshold is adjusted if the actuator device is actuated within the time limit. Otherwise, the threshold may remain unchanged.
[0025] Based upon the results of comparing the measured force to the new threshold, an obstruction may be detected, the door movement may be halted, and then reversed. Alternatively, the door 24 may travel to the end of its path indicating that an obstruction does not exist. In another approach and as described elsewhere in this specification, a secondary obstruction detector, for instance, sensor 46 , maybe used in conjunction with a force measurement to determine whether an obstruction exists in the path of the door 24 .
[0026] Referring now to FIG. 2 , an example of the control unit 200 is described. The control unit 200 includes a memory 202 and a controller 204 . The controller 204 receives control signals from a current sensor 206 and a speed sensor 208 . The current sensor 206 indicates the amount of electrical current that is present in a motor 212 of a moveable barrier operator. The speed sensor 208 indicates how quickly a door 214 is moving in a downward direction. The controller 204 receives these measurements from the sensors and from these measurements determines a value representing the amount of force being applied to the door 214 .
[0027] As described elsewhere in this specification, the controller 204 compares the measured force to a threshold value. The measured force may be a value representative of force. For instance, it may be a speed of the motor or barrier or it may be the amount of current going to the motor sensed by the sensors. Alternatively, the system may actually calculate a force from these or other measurements. The expected force and threshold values are stored in the memory 202 . As also explained elsewhere in the specification, the door 214 is initially moved in a downward direction. Upon exceeding the threshold value the controller will cause the door to stop and/or reverse its direction. In order to test and possibly clear the second obstruction the user momentarily presses and then releases an actuator 216 (switch 84 ) and the door 214 proceeds again in a downward direction and a new threshold may be used in comparison. If the new threshold value is exceeded, the direction of movement of the barrier is again reversed and it is determined that an obstruction existed in the path of the door 214 . The new threshold may replace the old threshold in the memory 202 or the threshold may revert to the old threshold value.
[0028] A secondary obstruction detector 210 (optical emitter 42 and detector 46 ) may also be used. For example, the secondary detector 210 may be an IR detector, an optical motion detector, an acoustic motion detector, an RF motion detector, or a door edge detector. Other types of secondary obstruction detectors are possible.
[0029] The secondary obstruction detector 210 is used to verify the decision made by operator. In this regard, the controller 204 receives a signal from the secondary obstruction detector 210 . If the detector 210 indicates that an obstruction exists and the operator insists on moving the door in a downward direction, then the old force threshold is used. In another example, the threshold will not be changed to a new threshold unless a secondary obstruction detector is being used and the secondary obstruction detector verifies that an obstruction exists. In this case, the threshold is changed and a verification can be performed indicating that both the secondary obstruction detector and the force comparisons indicate that an obstruction exists.
[0030] Referring now to FIG. 3 a, an example of an approach that adjusts the force threshold is described. At step 302 , the system measures the present force or value representing force being applied. The force or a value representing force may be determined by measuring several different system values. For instance, the system may measure the door speed by watching how fast markers (e.g. slits) move past a point or by measuring current in the motor. The speed or current representation is then used to calculate a value representing the force. At step 304 , the system determines if the present measured force is less than a threshold value. If the answer at step 304 is affirmative, then execution continues at step 303 . If the answer is negative at step 306 , door movement in the downward direction is halted and movement of the door is reversed to an upward direction. At step 303 , the system determines if limits were reached. If the answer is affirmative, execution ends. If the answer is negative, execution continues with step 302 .
[0031] At step 307 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 320 . If the answer is negative, control continues at step 308 .
[0032] At step 308 , the system waits for a control button to be actuated by a user. For example, the button may be a command button. At step 310 , the system determines if the command signal created by the actuation of the button has been received. If the answer is negative, control returns to step 308 . If the answer is affirmative, control continues at step 312 where the threshold is increased to a new value.
[0033] At step 314 , the door is sent downward and the force being applied to the door is measured. At step 316 , the system determines if the present measured force is less than the threshold value. If the answer is affirmative, control continues at step 314 . If the answer is negative, control continues at step 318 where the direction of travel of the door is reversed. At this point, it can be determined that a valid obstruction has been detected. At step 320 , the threshold is returned to the old threshold value.
[0034] Referring now to FIG. 3 b, an example of an approach that adjusts the force threshold and uses the new threshold as a permanent value is described. At step 352 , the system measures the present force or a value representing force being applied. The force or value representing force may be determined by measuring several different system values. For instance, the system may measure the door speed by watching how fast markers (e.g. slits) move past a point or by measuring current in the motor. The speed (or current) is then used to calculate the force. At step 354 , the system determines if the present measured force is less than a threshold value. If the answer at step 354 is affirmative, then execution continues at step 353 . If the answer is negative at step 356 , door movement in the downward direction is halted and movement of the door is reversed to an upward direction. At step 353 , the system determines if limits were reached. If the answer is affirmative, execution ends. If the answer is negative, execution continues with step 352 .
[0035] At step 357 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 370 . If the answer is negative, control continues at step 358 .
[0036] At step 358 , the system waits for a control button to be actuated by a user. For example, the button may be a command button. At step 360 , the system determines if the command signal created by the actuation of the button has been received. If the answer is negative, control returns to step 358 . If the answer is affirmative, control continues at step 362 where the threshold is changed increased to a new temporary value. For instance, the system may increase the threshold value to a new higher value.
[0037] At step 364 , the door is sent downward and the force being applied to the door is measured. At step 366 , the system determines if the present measured force is less than the updated threshold. If the answer is affirmative, control continues at step 364 . If the answer at step 366 is negative, control continues at step 368 where the direction of travel of the door is reversed. At this point, it can be determined that a valid obstruction has been detected. If the answer at step 366 is affirmative, control continues at step 367 .
[0038] At step 367 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 370 . If the answer at step 367 is negative, control continues at step 364 . At step 370 , the threshold is permanently changed to the new threshold value.
[0039] Referring now to FIG. 4a , an example of an approach that adjusts the force threshold is described. At step 402 , the system measures the present force or a value representing force being applied. The force or the value representing force may be determined by measuring several different system values. For instance, the system may measure the door speed by watching how fast markers (e.g. slits) move past a point or by measuring current in the motor. The speed (or current) is then used to calculate the force. At step 404 , the system determines if the present measured force is less than a threshold value. If the answer at step 404 is affirmative, then execution continues at step 403 . At step 403 , the system determines if limits were reached. If the answer is affirmative, execution ends. If the answer is negative, execution continues with step 402 .
[0040] If the answer is negative at step 406 , door movement in the downward direction is halted and movement of the door is reversed to an upward direction. At step 407 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 422 . If the answer is negative, control continues at step 408 .
[0041] At step 408 , a predetermined waiting time is determined. This value maybe set by a user and it may be measured from the initial detection of an obstruction at step 404 . At step 410 , the system determines if the command signal created by the actuation of a command button has been received within the time window set at step 408 . If the answer is negative, control returns to step 414 where the threshold value remains unchanged. If the answer is affirmative, control continues at step 412 where the threshold is changed or increased to a new temporary value. For instance, the system may increase the threshold value to a new higher value.
[0042] At step 416 , the door is sent downward and the force being applied to the door is measured. At step 418 , the system determines if the present measured force is less than the updated threshold (either a higher threshold or original threshold). If the answer is affirmative, control continues at step 416 . If the answer is negative, control continues at step 420 where the direction of travel of the door is reversed. At this point, it can be determined that a valid obstruction has been detected. At step 422 , the threshold is returned to the old threshold value.
[0043] Referring now to FIG. 4 b, an example of an approach that adjusts the force threshold and uses the new threshold as a permanent value is described. At step 452 , the system measures the present force or a value representing force being applied. The force or the value representing force may be determined by measuring several different system values. For instance, the system may measure the door speed by watching how fast markers (e.g. slits) move past a point or by measuring current in the motor. The speed (or current) is then used to calculate the force. At step 454 , the system determines if the present measured force is less than a threshold value. If the answer at step 454 is affirmative, then execution continues at step 453 . If the answer is negative at step 454 , door movement in the downward direction is halted and movement of the door is reversed to an upward direction. At step 453 , the system determines if limits were reached. If the answer is affirmative, execution ends. If the answer is negative, execution continues with step 452 .
[0044] At step 457 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 472 . If the answer is negative, control continues at step 458 .
[0045] At step 458 , a predetermined waiting time is determined. This value maybe set by a user and it may be measured from the initial detection of an obstruction at step 454 . At step 460 , the system determines if the command signal created by the actuation of a command button has been received within the time window set at step 458 . If the answer is negative, control returns to step 464 where the threshold value remains unchanged. If the answer is affirmative, control continues at step 462 where the threshold is changed or increased to a new temporary value. For instance, the system may increase the threshold value to a new higher value.
[0046] At step 466 , the door is sent downward and the force being applied to the door is measured. At step 468 , the system determines if the present measured force is less than the updated threshold (either a higher threshold or original threshold). If the answer at step 468 is negative, control continues at step 470 where the direction of travel of the door is reversed. At this point, it can be determined that a valid obstruction has been detected. If the answer at step 468 is affirmative, control continues at step 469 .
[0047] At step 469 , it is determined whether the door has reached the closed position. If the answer is affirmative, control continues at step 472 . If the answer at step 367 is negative, control continues at step 466 . At step 472 , the threshold is permanently changed to the new threshold value.
[0048] For the approaches described in FIGS. 3-4 , a test may be made for a secondary obstruction detector may be made. If the test for the secondary obstruction detector indicates that the detector exists and is functioning correctly, then a new threshold maybe used as described above in relation to these figures. However, if the test indicates that a secondary obstruction detector is not being used, then no new threshold value is used. In this case, the test can be performed again to determine if an obstruction is still determined to exist. In another example, the secondary obstruction detector protects against human operator errors. If the secondary obstruction operator indicates than an obstruction exists, any forcing down of the door by the operator by pressing the control button will utilize the old threshold value. In other words, the new threshold value will not be used.
[0049] While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.
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A barrier movement operator moves a barrier between open and closed positions. The operator receives a first request to move the barrier. The actual force required to move the barrier is measured. An obstruction to barrier movement is determined by comparing the measured actual force to a first predetermined force threshold. Responsive to the detection of an obstruction, the direction of travel of the barrier is reversed. The operation of the barrier movement operator is modified, by permitting the use of a higher force threshold in future measurements. A second request to move the barrier is received. The actual force required to move the barrier is measured a second time. An obstruction to barrier movement is detected by comparing the measured actual force with the new, higher force threshold.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the suppression of echoes in digital data transmission. In particular, this invention relates to the cancellation of echoes in a two-wire full-duplex data transmission system which has to deal with echoes having propagated through carrier systems in the telephone network.
DESCRIPTION OF THE PRIOR ART
Full-duplex data transmission over the direct-distance dialing (DDD) network has traditionally been achieved by using frequency-division multiplexing (FDM). With this technique, the calling and answering modems use different frequency bands for transmitting data. At high data rates (≧4.8 kb/s), FDM is not feasible because of the limited bandwidth of voice-grade circuits, and echo cancellation is the preferred technique to make efficient use of the available bandwidth. The general use of echo cancellation for achieving full-duplex data transmission over the DDD network is described in S. B. Weinstein in U.S. Pat. No. Re. 31,253, reissued May 24, 1983, and in the IEEE Transactions on Communications (July 1977, pp. 654-666) in a paper entitled "A Passband Data-Driven Echo Canceller for Full-Duplex Transmission on Two-Wire Circuits".
The above mentioned references also describe an echo canceller structure which is proposed for the intended application. In addition, the second reference describes an arrangement which allows the tracking of frequency offset in the "far or talker" echo. This is the echo which has propagated through the switched network, and is thus likely to be corrupted by the channel impairments which are commonly encountered in carrier systems. Frequency offset is the most damaging of these impairments. While propagating through the carrier systems, the far echo experiences several modulation and demodulation operations. As a result, due to clock mismatches in the modulators and demodulators, it can reappear at the input of the echo canceller with a carrier frequency (say 1800.1 Hz) which is slightly different from the carrier frequency of the transmitted signal (say 1800 Hz). Even such a small difference in carrier frequencies interferes with the ability of a conventional echo canceller to cancel the far echo when it has to adapt under "double-taking" (full-duplex) conditions.
Cancellation of a far echo corrupted by frequency offset can be achieved by using the right type of echo canceller structure and a phase-lock loop. One possible arrangement is given in the S. B. Weinstein reference in IEEE Transactions on Communications mentioned previously. Another possible arrangement is described in a European patent application (in French), entitled "Annuleur D'echo Pour Signal D'Echo A Phase Variable", by L. B. Y. Guidoux, (application No. 81200209.3, Mar. 19, 1981).
These two techniques for cancelling an echo corrupted by frequency offset work well in theory. That is, they should perfectly cancel the echo under ideal conditions of implementation. However, they can suffer serious degradation in performance when practical implementation considerations are taken into account. This is because the echo canceller structures used in these schemes cannot readily compensate, in an adaptive fashion, for the unavoidable imperfections in the practical implementation of the in-phase and quadrature filters which have to be used in front of the echo canceller. In view of the foregoing, it is the broad object of the present invention to provide an echo cancellation arrangement for use in full-duplex transmission on 2-wire circuits which allows the cancellation of an echo corrupted by frequency offset, and whose performance is not significantly limited by practical implementation constraints.
SUMMARY OF THE INVENTION
In accordance with the present invention, an echo canceller is described in which the real and imaginary outputs can evolve independently. By removing the coupling heretofore found in cross coupled echo canceller structures known in the art, the echo replica obtained with this echo canceller in conjunction with carrier-phase tracking circuitry can be a more exact duplicate of the real and imaginary components of a received echo-containing signal, despite the fact that these components are derived from the received signal by imperfect in-phase and quadrature phase filters.
In a first embodiment, the echo replica is obtained by applying symbols representing input data to a plurality of subcancellers each of which includes a plurality of adaptive filters. In each subcanceller, the real symbol sequence is applied to first and second adaptive filters, and the imaginary symbol sequence is applied to third and fourth adaptive filters. Each filter is arranged to form a sum of the weighed products of the stored symbol sequence and an ensemble of tap weights or coefficients. The coefficient ensemble is different for each of the filters, and is based upon a recursion using (1) the prior coefficient value, (2) the stored symbol sequence, and (3) a measure of the difference or error between the error replica and the received signal. The outputs of the first and third filters are algebraically combined to form one component (e.g., real) of the echo replica, while the outputs of the second and fourth filters are combined to form the other (e.g., imaginary) component. The subcanceller outputs are sequentially combined with the in-phase and quadrature-phase components of the received signal during each symbol interval.
In a second embodiment, the filters within each subcanceller are implemented by a digital signal processor arranged to (1) store the coefficient ensembles for each filtering operation, (2) store samples of the real and imaginary components of the input signal, (3) compute and sum the products of each coefficient ensemble with the appropriate ones of the stored input signal component samples, and (4) update the coefficient values as set forth above.
Either of the embodiments advantageously includes a phase locked loop for compensating for carrier-phase variations and frequency offset. A compensation term can be included in the echo replica signal components before the error representing the difference between the replica and the received signal is formed. Alternatively, the compensation can be accomplished by modifying the received signal before the error signal representing the aforesaid difference is formed.
BRIEF DESCRIPTION OF THE DRAWING
The features and advantages of the present invention will be better understood by consideration of the following detailed description when read in light of the accompanying drawings in which:
FIG. 1 is a block diagram illustrating the relationship between a local and a remote data set and a transmission channel interconnecting the two;
FIG. 2 is a block diagram of a portion of a data set indicating the relationship of its passband echo canceller to the remaining components and, in particular, one arrangement of a carrier phase and frequency offset compensation circuit;
FIG. 3 is a generalized block diagram of a data set similar to the one shown in FIG. 2 but which incorporates a baseband echo canceller, rather than a passband echo canceller;
FIG. 4 illustrates a series of subcancellers including a cross coupled filter structure well known in the prior art;
FIG. 5 illustrates a series of subcancellers arranged in accordance with the present invention;
FIG. 6 is a diagram of one possible implementation for one of the filters shown in FIG. 5;
FIG. 7 illustrates comparative test results showing the advantageous operation of the present invention in removing energy derived from the remote echo in a signal received by a data set using the present invention;
FIG. 8 is a block diagram of a portion of a data set indicating the relationship of its passband echo canceller to the remaining components and, in particular, another arrangement of a carrier phase and frequency offset compensation circuit; and
FIG. 9 is a detailed circuit diagram of one possible implementation of carrier phase and frequency offset compensation circuits 210 and 810 of FIGS. 2 and 8, respectively.
DETAILED DESCRIPTION
The objectives of the present invention will be understood from an examination of FIG. 1, which shows a typical connection over the switched network. Echoes arise because of impedance mismatches in the hybrid couplers 102, 110, 107 and 114 which make the connections between four-wire and two-wire transmission facilities. For example, consider modem 100. Some of the energy transmitted by transmitter 101 will leak through hybrid 102 and appear as an echo at the input of receiver 103. This echo is called the near echo. Similarly, at the other end of the carrier system 104, some energy will leak through hybrid 107. This signal is looped back through the carrier system and hybrids 110 and 102, and it will also appear as an echo at the input of receiver 103. This echo is called the "talker" or "far" echo.
The purpose of an echo canceller is to generate a replica of these echoes, which is then subtracted from the incoming signal at the input of the receiver. Thus, if such an arrangement is used in modem 100, and assuming ideal echo cancellation, the input to receiver 103 should only consist of the signal transmitted by transmitter 113 of the far modem 111, and some additive noise. In most applications, it is necessary to break the echo canceller into two parts, a near canceller and a far canceller. This is because the characteristics of the channels traversed by these two echoes are generally quite different. For example, the far echo propagates through the carrier system 104 and can therefore be corrupted by the channel impairments commonly encountered in these systems, such as non-linearities, phase jitter and frequency offset. The near echo is not plagued by these types of impairments. However, it can be corrupted by other types of impairments. The objective of the present invention is to provide an arrangement which allows the cancellation of a far echo which has been corrupted by frequency offset. The following discussions will concentrate on the far canceller, and it will be assumed that the near echo has been cancelled by a suitable near canceller.
The possibility of encountering frequency offset in the far echo can be understood by again referring to FIG. 1. After passing through hybrid 110, the signal transmitted by modem 100 is first modulated up to a frequency range suitable for transmission over the carrier system 104. This is done by modulator 105 which uses a modulation frequency f m . At the other end of the connection, demodulator 106 shifts the modulated signal back to baseband by using a demodulation frequency f d . In general, the frequencies f m and f d are very close but not quite equal, so that the frequencies of the signal appearing at the output of demodulator 106 will be slightly offset with respect to the frequencies of the signal at the input of modulator 105. As a matter of illustration, assume that a single sinewave f(t) with frequency f c is transmitted
f(t)=sin (2Hf.sub.c t). (1)
After modulation and demodulation in circuits 105 and 106 this sinewave becomes
f.sub.1 (t)=A.sub.1 sin [2H(f.sub.c +f.sub.m -f.sub.d)t+Φ.sub.1 ], (2)
where A 1 and Φ 1 are some arbitrary gain and phase, respectively. After leaking through hybrid 107 the far echo is again modulated by modulator 108 and demodulated by demodulator 109. Thus, illustratively, the sinewave in (1) after looping through the carrier system 104 becomes at the output of demodulator 109
f.sub.2 (t)=A.sub.2 sin [2H(f.sub.c +f.sub.m -f.sub.d +f.sub.m '-f.sub.d ')t+Φ.sub.2 ], (3)
where A 2 and Φ 2 are again an arbitrary gain and phase, respectively. Usually, the frequencies f m ' and f d ' will again be slightly different. The sinewave in (3) will be offset in frequency with respect to the sinewave in (1) if
Δf=f.sub.m -f.sub.d +f.sub.m '-f.sub.d '≠0. (4)
Such a frequency offset occurs in carrier systems where the clocks of colocated modulators and demodulators (e.g., modulator 105 and demodulator 109) are not synchronized, that is, when f m ≠f d 'and f m '≠f d . Frequency offset in the far echo has been observed in many carrier systems, and thus it has to be dealt with in echo-cancellation based modems.
The effect of frequency offset and other carrier-phase variations on the echo of a high-speed voiceband data signal is now considered. A two-dimensional (in-phase and quadrature) modulated signal generated by modems 100 and 111 in FIG. 1 is generally represented by the expression ##EQU1## where A n =a n +jb n is the discrete-valued multilevel complex symbol to be transmitted, g(t) is a Nyquist pulse, 1/T is the symbol rate, ω c /2H is the carrier frequency, and Re denotes the real part of the quanity inside the brackets. In the usual case where the highest frequency component in g(t) is smaller that the carrier frequency, the complex signal in brackets in equation (5) is an analytic signal z(t), where ##EQU2## and where s(t) is the Hilbert transform of s(t). After passing through an echo channel which introduces linear (delay and amplitude) distortion and carrier-phase variations, the signal in (6) becomes ##EQU3## is now a complex baseband impulse response, and Φ(t) represents the undesirable carrier phase fluctuations. In the case where Φ(t) consists only of a frequency offset Δ f it reduces to
Φ(t)=2HΔft. (9)
The expression in (7) suggests two possible echo-cancellation arrangements which are now discussed. First, while the far echo available on the receiving legs of hybrids 102 and 114 in FIG. 1 is the real part of Z 1 (t) in (7), the complex signal Z 1 (t) can be constructed by passing the far echo through in-phase and quadrature filters. Ideally, the outputs of these filters will have frequency components with the same amplitude but phases which are 90 degrees apart at all frequencies. The complex signal Z 1 (t) which is now available at the outputs of the in-phase and quadrature filters can then be multiplied by the complex quantity e -j Φ(t), where Φ(t) is an estimate of the carrier phase fluctuations introduced by the far echo channel. This estimate is obtained by using an adaptive phase-lock loop. Ideally, if Φ(t)=Φ(t) the complex multiplication removes the carrier phase variations from the far echo and a conventional echo canceller can now be used to cancel this echo.
Alternatively, the carrier-phase compensation circuit can also be incorporated at the output of the echo canceller. Such an arrangement, which is direct mechanization of the expression in (7), was proposed in the second Weinstein reference and is shown in FIG. 3. The complex symbols A n at the output of symbol generator 300 generated in response to data applied on line 350 are passed through a baseband echo canceller 302 with complex impulse response G(t) which is an estimate of the complex baseband response G(t) in equation (7) of the far echo channel. The outputs of canceller 302 are multiplied by e j ω.sbsp.c t in complex modulator 303, where ω c /2H is the carrier frequency of the transmitted signal. The outputs of modulator 303 are then multiplied by e j Φ(t) in carrier phase compensation circuit 304, where Φ(t) is again an estimate of Φ(t), and is obtained by using a phase-lock loop (PLL). The resulting complex signal is an estimate of the complex signal obtained by passing the far echo s 1 (t) on line 351 through in-phase and quadrature filters 308. These two complex signals are subtracted from each other in subtractor 305. The resulting complex error is used to update the PLL in carrier-phase compensation circuit 304. After rotation in error rotator 306 and demodulation in demodulator 307 the complex error is also used to update the tap coefficients of baseband echo canceller 302.
Yet another type of echo cancellation arrangement can be obtained by rewriting equation (7) in the following way: ##EQU4## and R(t) now represents the complex impulse response of a passband filter. The expression in (11) suggests the echo cancellation structure shown in FIG. 2. The complex symbols A n output from symbol generator 200 in response to input data on line 250 are first rotated in symbol rotation circuit 201 by multiplying them by e j ω.sbsp.c nT . The rotated symbols can then be fed to in-phase and quadrature transmitting filters 202 and 222, respectively as proposed by J. J. Werner in U.S. Pat. No. 4,015,222, issued Mar. 29, 1977. The rotated symbols are also fed to a bulk delay line 203 which mimics the round-trip delay of the far echo through the carrier system 104 in FIG. 1. The length of delay line 203 is set at start up. The outputs of bulk delay line 203 are passed through a passband echo canceller 204 with complex impulse response R(t) which is an estimate of R(t) in (11). The outputs of this canceller are then multiplied by e j Φ(t) in carrier phase and frequency offset compensation circuit 210, where Φ(t) is an estimate of Φ(t). A replica of the complex signal Z 1 (t) in (11) is now available at the inputs of subtractors 220 and 221. The purpose of the subcanceller selector switch 206 will be discussed later. The complex error derived at the outputs of subtractors 220 and 221 is used to update the PLL of the carrier phase compensation circuit 210. After rotation in error rotator 212 it is also used to update the tap coefficients of passband echo canceller 204. Finally, either the real or imaginary part of the complex error, or both, are sent to the modem's receiver via lines 251 and 252 for further processing.
The present invention can be used with all three echo cancellation arrangements described previously. The motivation for its use will be discussed with reference to the arrangement shown in FIG. 2. For simplicity of notation, the discussion will assume analog rather than digital samples. However, actual implementations utilize digital signal processing.
Echo canceller 204 of FIG. 2 implements, in an adaptive fashion, an approximation R(t) of the far echo channel's complex passband response R(t) in equation (12b). That is, its output should approximate the quantity ##EQU5## From equation (12b), it can be shown that R(t) is an analytic signal. Therefore it can be written as
R(t)=r(t)+jr(t), (14)
where r(t) is the Hilbert transform of r(t). Defining A n '=a n '+jb n ', the expression in equation (13) can be rewritten as ##EQU6## Using the relation r(t)=-r(t) it is readily shown that the complex signal in equation (15) is also an analytic signal. The expression in equation (15) suggests an echo canceller structure consisting of two adaptive filters whose impulse responses are made to converge to the impulse responses r(t) and r(t). The output of each filter is computed twice, once with the symbols a n ' as inputs and once with the symbols b n ' as inputs. Proper subtraction and addition of the four possible outputs should then yield a good replica of the complex signal in equation (15).
An echo canceller structure which uses two adaptive filters whose outputs are computed twice, with two difference sets of inputs, is called a cross-coupled structure. Such a structure is depicted in circuit 400 of FIG. 4, where a digital implementation is assumed. The two filters 401 and 402 each receive the same two sets of inputs a n ' and b n '. Their outputs are computed twice and combined in the proper fashion in adders 403 and 404 to provide the echo canceller's complex output. In FIG. 4, the structure of circuit 400 is used several times in parallel, as illustrated by circuit 405. The need for doing so is explained later.
Cross-coupled structures of the type described in FIG. 4 were proposed in the Guidoux and Weinstein references. However, I have found experimentally that practical implementations of such cross-coupled structures do not provide a sufficient amount of echo cancellation. The reason for this can be understood from the following discussion, which assumes, for the purpose of explanation, that the echo channel does not introduce carrier-phase distortion, (i.e., Φ(t) in equation (11) is taken to be zero) so that the far echo is simply represented by the real part of F 1 (t) in equation (15). Ideally, the outputs of the in-phase filter 218 and quadrature filter 219 in FIG. 2 should be a Hilbert pair and provide the analytic signal given in equation (15). In practice, it is not possible to implement perfect in-phase and quadrature filters. As a result, the complex signal available after the filters will not be the analytic signal given in equation (15). Rather, it will be a complex signal Z 2 (t) which can be expressed as ##EQU7## where r 1 (t) and r 4 (t), as well as r 2 (t) and r 3 (t) are not exactly equal, and where r 2 (t) and r 3 (t) are not exactly the Hilbert transforms of r 1 (t) and r 4 (t). An echo canceller using a cross-coupled structure tries to synthesize an analytic signal of the type give in equation (15), which can be generated by using only two sets of filters. Thus, it will not be able to make an exact replica of the signal give in equation (16) which requires the use of four different filters. In other words, a cross-coupled structure cannot compensate for the imperfections introduced by non-ideal, practically implemented in-phase and quadrature filters.
An echo canceller structure which can compensate for these imperfections is shown in circuit 510 of FIG. 5. It consists of four sets of adaptive filters 511, 512, 513 and 514, which are adapted independently. After convergence, the impulse responses of these filters will have converged to the impulse responses r 1 (t), r 2 (t), r 3 (t) and r 4 (t) in equation (16). The need for replicating circuit 510 will be discussed later.
The advantage of the new echo canceller structure of FIG. 5 compared to the cross-coupled structure of FIG. 4 is best appreciated with reference to FIG. 7, which shows two sets of traces obtained on a spectrum analyzer. In both sets, the upper trace 701 is the same and represents the power spectrum of the uncancelled echo at the input of subtractor 220 (or 221) in FIG. 2. The lower traces 702 and 703 represent the power of the residual echo after cancellation is performed, when either the cross-coupled structure of FIG. 4 or the new structure of FIG. 5 were used for echo canceller 204, respectively. The same in-phase and quadrature filters 218 and 219 were used in each case, and the two echo cancellers had the same memory span. Notice that the structure of FIG. 5 achieves a much larger amount of cancellation than the cross-coupled structure of FIG. 4. The measured difference in the amount of echo cancellation achieved was over 20 dB.
The digital implementation of the echo cancellation arrangement shown in FIG. 2 is now discussed. In the following discussion, the echo canceller arrangement of the present invention, as shown in FIG. 5, is used to implement the functions of echo canceller 204 of FIG. 2. The stream of data (0's or 1's) to be transmitted is first passed through symbol generator 200, which partitions the bit stream into blocks which are then mapped into symbols A n with real (a n ) and imaginary (b n ) parts. These symbols are rotated in rotation circuit 201 at the rate 1/T at which symbols are generated and fed to digital in-phase and quadrature passband filters 202 and 222. The rotated symbols are also used as inputs to bulk-delay line 203 whose purpose was explained earlier. As an example, if the data rate is 4800 bps and the symbol rate is 2400 bauds, then symbol generator 200 segments the data stream into blocks of two bits (dibits). Each bit of a dibit is mapped into values ±1 to provide the real and imaginary values of a n and b n . These symbols are then rotated in circuit 201 according to equation (12). For example, if the carrier frequency is 1800 Hz, then the rotated complex symbol A n ' is equal to A n (-j) n , where A n =a n +jb n is the non-rotated complex symbol generated by circuit 200.
The outputs of filters 202 and 222 are generated at a sampling rate which is usually larger than the symbol rate 1/T. The sum of the filters' outputs formed in adder circuit 260 is fed to digital-to-analog (D/A) converter 213 whose output is passed through interpolating low-pass filter 214 and then hybrid 215. On the receiving side of hybrid 215, the incoming or received signal is first passed through an antialiasing bandpass filter 216 and then an analog-to-digital (A/D) converter 217. In order to achieve Nyquist cancellation, the sampling rate of converter 217 has to be at least twice the highest frequency of the incoming signal, which is about 3 kHz for voiceband data communications. The advantages of Nyquist cancellation are discussed in the above mentioned Weinstein references. In practice, it is often advantageous to use the same sampling rate 1/T' for A/D converter 217 and the transmitting filters 202 and 222, although this is not necessary. The sampled values from A/D 217 are used as inputs to in-phase and quadrature filters 218 and 219. The outputs of these filters represent a complex signal from which is subtracted a complex replica of the far echo in subtractors 220 and 221.
In the following it will be assumed that the ratio T/T' between the sampling rate 1/T' and the symbol rate 1/T is equal to an integer M. Thus, A/D converter 217 generates M sampled values of signal s 1 (t) in each symbol period T. The sampling times can then be written as nT+mT', and the sampled values of s 1 (t) becomes s 1 (nT+mT'), or, more concisely s 1 (n,m), where m=1, 2, . . . M, and n is the n th symbol period. With these conventions the complex output of in-phase and quadrature filters 218 and 219 is written as Z 2 (n,m) and the complex echo replica at the output of circuit 210 is written as Z c (n,m).
The delayed and rotated symbols a n ' and b n ' at the output of bulk delay line 203 are used as inputs to passband echo canceller 204, which, in accordance with the present invention consists of a parallel arrangement of M "subcancellers", 510, 517 shown in FIG. 5. Each subcanceller receives the same inputs a n ' and b n ', and consists of four different parallel adaptive filters. As an example, subcanceller 511 consists of filters 511, 512, 513 and 514. The outputs of filters 511 and 513 are subtracted in subtractor 515 and the outputs of filters 512 and 514 are added in adder 516. A similar filter arrangement is used for subcanceller 517 and the other subcancellers, not shown in FIG. 5. In the n th symbol period, each subcanceller generates a complex output U n ,m, where m=1, 2, . . . M designates the m th subcanceller.
The subcanceller selector 206 in FIG. 2 selects, in a cyclic fashion, the outputs of the subcancellers shown in FIG. 5. These outputs are selected at the sampling rate 1/T'. Since there are M subcancellers and since the ratio between the symbol period T and the sampling period T' is also M, each subcanceller will provide one output to selector 206 in each symbol period. Thus, for example, the first subcanceller 510 in FIG. 5 will provide an input to selector 206 in the first sampling period T' of a given symbol period T, and the M th subcanceller 517 will provide an input to the selector in the M th (last) sampling period of the same symbol period.
In a first echo cancellation arrangement using the present invention, the outputs U n ,m of selector 206 are the inputs of the carrier phase and frequency offset compensatio circuit 210. The operations performed by this compensation circuit yield the complex output Z c (n,m) defined by the following equation
Z.sub.c(n,m) =U.sub.n,m e.sup.jΦ.sbsp.n,m, (17)
where Φ n ,m is an estimate of the carrier-phase variations and frequency offset. This estimate is provided by a phase-lock loop (PLL) whose updating algorithm is described below.
The complex output Z c (n,m) of the compensation circuit 210 is subtracted from the complex output Z 2 (n,m) of the in-phase and quadrature filters 218 and 219, in substractors 220 and 221. The result of the subtraction is a complex error E n ,m given by
E.sub.n,m =e.sub.n,m +je.sub.n,m =Z.sub.2(n,m) -Z.sub.c(n,m) (18)
which is used to update the phase of the PLL in the phase compensation circuit 210. After rotation in an error rotation circuit 212, the error is also used to update the tap coefficients of the passband echo canceller 204. Complex error rotation is performed in circuit 212 in a manner similar to that used in circuit 201; the result is a rotated error E r (n,m) given by:
E.sub.r(n,m) =E.sub.n,m e.sup.-jΦ.sbsp.n,m (19)
where Φ n ,m is the carrier-phase estimate.
Before describing the updating algorithms used for canceller 204, it is necessary to specify the type of implementation used for the adaptive filters shown in FIG. 5. Transversal filters are preferred, although other types of filters could be used as well. The transversal filter implementation of one of the filters in FIG. 5, filter 511 in this case, is shown in FIG. 6. It consists of a tapped dealy line including a series of delay elements 601 each providing a dely spacing of interval T. In the case of filter 511 (and filter 512), the delayed elements in the delay line are the symbols a n '. (In filters 513 and 514, the entries of the delay line are the symbols b n '.) Individual multipliers 609 shown in FIG. 6 multiply the delayed symbols with the adaptive tap coefficients stored in memory elements 604. However, in a practical implementation, several or all of the tap coefficients will generally time share the same multiplier. The outputs of multipliers 609 are summed in adder 605, and the resulting sum, available on lead 613, is used as the input to adder 515 in FIG. 5.
In FIG. 5, the outputs of filters 512, 513 and 514 are computed in the same fashion as that used in filter 511. Once the outputs of adders 515 and 516 are available, they are used as inputs to subcanceller selector 206 of FIG. 2. Assuming that selector 206 is, at a particular time, configured so that subcanceller 510 has been selected, it will be observed that after carrier-phase compensation in circuit 209 and error computation in subtractors 220 and 221, the signals needed for updating the tap coefficients are available at the output of error rotation circuit 212. The correction terms used to form the tap updates for the m th subcanceller are obtained by using the so-called "least-mean-square" (LMS) algorithm. This algorithm minimizes the mean-squared error (MSE) <E n ,m 2 >, where
<E.sub.n,m.sup.2 >=<e.sub.n,m.sup.2 >+<e.sub.n,m.sup.2 > (20)
in FIG. 2, and where <.> denotes expectation. In practice this algorithm is usually approximated by minimizing the squared error
E.sub.n,m.sup.2 =e.sub.n,m.sup.2 +e.sub.n,m.sup.2, (21)
and using a stochastic-gradient algorithm. The relevant equations for the updating algorithm are obtained by first forming the gradient (partial derivative) of equation (21) with respect to the value of a tap coefficient, say c 1 ,N in FIG. 6. For c 1 ,N, this gradient is found to be equal to -x n ,1 a n-N , where x n ,1 is the real part of E r (n,1) in FIG. 2. The gradient is then multiplied by a scaling factor β, and the result is used to update the value of c 1 ,N in the opposite direction of the gradient. That is, a correction term +β x .sbsb.n,1 a .sbsb.n-N is added to c 1 ,N. Thus, the new value c 1 ,N (n+1) in symbol period (n+1)T of c 1 ,N is related to the old value c 1 ,N (n) in symbol period nT by the equation
c.sub.1,N (n+1)=c.sub.1,N (n)+β.sub.x.sbsb.n,1.sub.a.sbsb.n-N. (22)
One possible circuit useful in implementing equation (22) is shown in FIG. 6. The rotated error (x n ,1) received on line 611 from one output of circuit 212 is first multiplied in multiplier 609 by a scaling factor β stored in a step-size control memory 612. The value of β may assume different values at start up and in steady-state operation of the echo canceller. However, it is generally the same at any given instant of time for all of the filters and all of the subcancellers. Referring in particular to the tap-gain control circuit 604 which provides updating for tap c 1 ,N in FIG. 6 it is seen that multiplier 606 forms the product of the scaled error β x .sbsb.n,1 and the symbol a n-N '. This symbol was previously multiplied with tap coefficient c 1 ,N when the output of the filter was computed. A new value of tap coefficient c 1 ,N is obtained by adding β x .sbsb.n,1 a .sbsb.n-N ' to its previous value in adder 607. This new value then replaces the old value at the output of adder 607. In the next symbol period T, this new value of tap coefficient c 1 ,N stored in relay element 608, will again be updated.
In many current implementations, the preceding sequence of operations performed by tap gain control circuit 604 are executed in a somewhat different way, using a digital signal processor including an arithmetic unit, a read only memory (ROM) for instruction storage, and a random access memory (RAM). The value of tap coefficient c 1 ,N is first fetched from a storage location in the RAM, which serves as a coefficient store. This value is then added to the product β x .sbsb.n,1 a .sbsb.n-N by the arithmetic unit, which is time shared amongst all the tap coefficients. The result of the addition is then stored back in the same RAM storage location. The details of one computer based echo canceller arrangement are shown in U.S. Pat. No. 4,464,545 issued to applicant on Aug. 7, 1984, which is incorporated herein by reference. Other computer architectures well suited for echo canceller implementations are described in the book, "Bit-Slice Design: Controllers and ALUs," Garland STPM Press, by D. E. White.
Before discussing the equations giving the outputs and the updating algorithms of the four filters, the following definitions are needed. The quantities a n ' and b n ' designate column vectors of the real and imaginary symbols a n ' and b n '. Similarly, c m ,1 (n), c m ,2 (n), d m ,1 (n) and d m ,2 (n) designate column vectors representing the tap coefficients of the four filters used in subcanceller m. Formally: ##EQU8## where i=1,2 and m=1,2, . . . ,M. Illustratively, the N+1 entries of vector a n are the symbols resident between delay elements 601 within each filter, at symbol period nT. Similarly, the N+1 entries of vector c 1 ,1 (n) are the values of the tap coefficients stored in tap gain control circuits 604 at symbol period nT. With these notations the complex output of the m th subcanceller in the n th symbol period is given by ##EQU9## where the superscript T denotes a transposed vector (row vector in this case), and the dots . denote the dot product of two vectors. Illustratively, consider the case where m=1 in FIG. 5. The output of filter 511 is obtained by computing the dot product a n ' T ·c 1 ,1 (n) which, from equations (23) and (24), can be expressed as
a.sub.n 'T·c.sub.1,1 (n)=a.sub.n 'c.sub.1,0.sup.1 (n)+a.sub.n-1 'c.sub.1,1.sup.1 (n)+ . . . +a.sub.n-N 'c.sub.1,N.sup.1 (n). (26)
Similarly, the outputs of filters 512, 513 and 514 are obtained by computing the dot products a n ' T ·c 1 ,2 (n), b n ' T ·d 1 ,1 (n) and b n ' T ·d 1 ,2 (n), repectively. The outputs of subtractor 515 and adder 516 are the real (u n ,m ') and imaginary (u n ,m ") parts of Equation (25), respectively, where m is equal to one.
Notice that the real and imaginary parts of the m th subcanceller's complex output U n ,m in Equation (25) are computed by using two different sets of tap coefficients: c m ,1 (n) and d m ,1 (n) for the real part u n ,m ', and c m ,2 (n) and d m ,2 (n) for the imaginary part u n ,m ". By the way of comparison, in the case of the structure in FIG. 4 the same set of coefficients, c m and d m , is used to compute both the real and imaginary parts of the complex output of the m th subcanceller. As a result there is a "coupling" between these two outputs, and they cannot evolve independently of each other. No such coupling exists in the case of the structure of FIG. 5 where u n ,m ' and u n ,m " can assume values which are completely independent of each other. Thus, this structure is capable of synthesizing a larger variety of complex outputs than the structure in FIG. 4, and therefore it will generally provide a superior performance. The stochastic-gradient algorithms for updating the tap coefficients of the m th subcanceller are given by
c.sub.m,1 (n+1)=c.sub.m,1 (n)+2β.sub.a.sbsb.n '.sub.x.sbsb.n,m (27)
c.sub.m,2 (n+1)=c.sub.m,2 (n)+2β.sub.a.sbsb.n '.sub.y.sbsb.n,m (28)
d.sub.m,1 (n+1)=d.sub.m,1 (n)-2β.sub.b.sbsb.n '.sub.x.sbsb.n,m (29)
d.sub.m,2 (n+1)=d.sub.m,2 (n)+2β.sub.b.sbsb.n '.sub.y.sbsb.n,m (30)
where x n ,m and y n ,m are the real and imaginary parts of the rotated error E r (n,m) and are generated by error rotation circuit 212 in FIG. 2 according to the equation
E.sub.r(n,m) =x.sub.n,m +jy.sub.m,n =(e.sub.n,m +je.sub.n,m)e.sup.-jΦ.sbsp.n,m, (31)
and thus
x.sub.n,m =e.sub.n,m cos Φ.sub.n,m +e.sub.n,m sin Φ.sub.n,m and (32)
y.sub.n,m =-e.sub.n,m sin Φ.sub.n,m +e.sub.n,m cos Φ.sub.n,m. (33)
The quantity Φ n ,m in equations (32) and (33) is the carrier phase estimate at time nT+mT'. It is also adapted according to a stochastic-gradient algorithm which is given by
Φ.sub.n+1,m =Φ.sub.n,m -2α[e.sub.n,m z.sub.c(n,m) "-e.sub.n,m z.sub.c(n,m) '], (34)
where α is a scaling factor and z c (n,m) ' and z c (n,m) " are the real and imaginary parts of Z c (n,m), the output of compensation circuit 210 in FIG. 2, respectively. That is:
Z.sub.c(n,m) =z.sub.c(n,m) '+jz.sub.c(n,m) ". (35)
Equation (34) describes a so-called first-order phase-lock loop (PLL). A more powerful, or second-order PLL is obtained in the following fashion. First, let ΔΦ n ,m be the non-scaled correction factor for the phase Φ n ,m in equation (34), that is:
ΔΦ.sub.n,m =e.sub.n,m z.sub.c(n,m) "-e.sub.n,m z.sub.c(n,m) '. (36)
A second-order PLL is then obtained by implementing the following equation: ##EQU10## The third term on the right of equation (37) is a scaled version of a running sum of successive phase correction terms. It can be shown that, in the absence of noise in the phase adjustment algorithm, this quantity can perfectly compensate for the presence of frequency offset in the far echo. Implementation of the first-order PLL in equation (34) will only allow for a partial compensation of the frequency offset in the far echo. If a small degradation in performance is permissible, then equation (37) need not be computed for each subcanceller, and phase updates can be performed once per symbol period by using only one subcanceller. This results in a simplification of implementation of the PLL.
A detailed block diagram of the carrier-phase compensation circuit 210 in FIG. 2 is shown in FIG. 9. The phase increment ΔΦ n ,m given in equation (36) is obtained by first multiplying the real part of E n ,m with the imaginary part of Z c (n,m) in multiplier 900 and the imaginary part of E n ,m with the real and part of Z c (n,m) in multiplier 901, and then subtracting the results in subtractor 902. In many practical applications the multiplications performed by circuits 900 and 901, as well as the other multiplications discussed later, would be time-shared on one single multiplier.
The first-order correction term for updating the carrier-phase estimate (second term on the right in equation (37)), is obtained by multiplying the phase increment ΔΦ n ,m by 2α in circuit 904. The second-order correction term (third term on the right in equation (37)) is implemented with multiplier 903, subtractor 905 and symbol-delay element 906. The first and second-order correction terms are subtracted from each other in subtractor 907, and the result is added, in adder 908, to the present etimate Φ n ,m of the carrier phase. The output of adder 908 is a new estimate Φ n+1 ,m of the carrier phase that will be used in the next symbol period after being delayed in delay element 909.
The carrier-phase estimate Φ n ,m in equation (37) is used as the argument of cosine and sine generators in circuits 910 and 911, respectively. These generators can be implemented by using a ROM look-up technique or by computing power expansions of the sine and cosine functions. The resulting quantities, sin Φ n ,m and cos Φ n ,m, are used twice. First, they are used to rotate the complex output U n ,m of subcanceller selector 206, in FIG. 2, to provide the echo replica Z c (n,m). The rotation is done in circuit 912 which implements the arithmetic operations given in equation (17). Expanding equation (17), one gets:
Z.sub.c(n,m) =U.sub.n,m e.sup.jΦ.sbsp.n,m =u.sub.n,m ' cos Φ.sub.n,m -u.sub.n,m " sin Φ.sub.n,m +j[u.sub.n,m sin Φ.sub.n,m +u.sub.n,m " cos Φ.sub.n,m ], (38)
where u n ,m ' and u n ,m " are the real and imaginary parts of U n ,m, respectively, that is:
U.sub.n,m =u.sub.n,m '+ju.sub.n,m ". (39)
The quantities sin Φ n ,m and cos Φ n ,m are also inputs to error rotator 212, in FIG. 2, which provides the errors for the tap updates of passband echo canceller 204. The error rotation is done in accordance with equation (19) which can be expanded in a manner similar to equation (38).
FIG. 8 shows a second echo cancellation arrangement using the present invention, in which a numbering scheme similar to that of FIG. 2 is used. In FIG. 8, elements which perform functions similar to those of elements in FIG. 2 have a designation of 8xx rather than 2xx. In FIG. 8, carrier-phase and frequency-offset compensation circuit 810 is now located after the output of in-phase and quadrature filters 818 and 819 rather than after the echo canceller's output. The output Z 3 (n,m) of this circuit is obtained from its input Z 2 (n,m) by implementing the following equation:
Z.sub.3(n,m) =Z.sub.2(n,m) e.sup.-jΦ.sbsp.n,m, (40)
where Φ n ,m is an estimate of the carrier-phase variation and frequency offset. The arrangement in FIG. 8 removes the carrier-phase variation and frequency offet from the incoming signal before echo cancellation is performed. As a result there is no need to rotate the complex error E n ,m before updating the echo canceller's tap coefficients, as was done by circuit 212 in FIG. 2. The relevant tap-update algorithms now become:
c.sub.m,1 (n+1)=c.sub.m,1 (n)+2β.sub.a.sbsb.n.sub.e.sbsb.n,m '(41)
c.sub.m,2 (n+1)=c.sub.m,2 (n)+2β.sub.a.sbsb.n.sub.e.sbsb.n,m '(42)
d.sub.m,1 (n+1)=d.sub.m,1 (n)-2β.sub.b.sbsb.n.sub.e.sbsb.n,m '(43)
d.sub.m,2 (n+1)=d.sub.m,2 (n)+2β.sub.b.sbsb.n.sub.e.sbsb.n,m '(44)
where e n ,m and e n ,m are the in-phase and quadrature errors, respectively.
The estimate Φ n ,m of the carrier variation and frequency offset is now updated according to the equation ##EQU11## where
ΔΦ.sub.n,m =e.sub.n,m z.sub.3(n,m) "-e.sub.n,m z.sub.3(n,m) ". (46)
In equation (46) z 3 (n,m) ' and z 3 (n,m) " represent the real and imaginary parts of Z 3 (n,m), that is
Z.sub.3(n,m) =z.sub.3(n,m) '+jz.sub.3(n,m) ". (47)
The block diagram for carrier-phase compensation circuit 810 is the same as the one shown in FIG. 9 except for the following modifications: U n ,m is replaced by Z 2 (n,m) ; Z c (n,m) is replaced by Z 3 (n,m) ; e j Φ.sbsp.n,m in circuit 912 is replaced by e -j Φ.sbsp.n,m.
Various modifications and adaptations of the present invention will be apparent to those skilled in the art. For this reason, it is intended that the present invention be limited only by the appended claims. For example, it is to be understood that the use of subcancellers such as shown in FIGS. 4 and 5 are not mandatory and that a single echo replica can be computed in each symbol interval. A data set which incorporates such an arrangement is shown in FIG. 7 of the paper entitled "A New Digital Echo Canceller for Two-Wire Full-Duplex Data Transmission," IEEE Trans. on Communications, September 1976, by K. H. Mueller.
It is also to be clearly understood that carrier-phase and frequency-offset compensation circuits 210 and 810 in FIGS. 2 and 8, respectively, need not be incorporated in a data set otherwise arranged in accordance with the instant invention if there is no need to compensate for carrier phase variations and frequency offset. Such might be the case, for example, in data sets intended for use only on the U.S. network. In this event, error rotation circuit 212 would also be unnecessary.
An alternative arrangement may also be considered in which symbol rotation circuit 201 and 801 of FIGS. 2 and 8, respectively and in-phase and quadrature phase filters 202 and 222 of FIG. 2 and 802 and 822 of FIG. 8 are replaced by lowpass filters and sine and cosine modulators to yield the more conventional QAM modulation structure as shown, for example, in FIG. 1 of the paper entitled "On the Selection of a Two-Dimensional Signal Constellation in the Presence of Phase Jitter and Gaussian Noise," Bell System Technical Journal, July-August, 1973, by G. J. Foschini et al. In this event, the symbol rotation circuit would nevertheless be used at the input or output of bulk delay line 203 or 803, as appropiate.
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Apparatus and a technique for echo cancellation is described in which the real and imaginary parts of an echo replica signal can evolve independently of each other. By removing the coupling heretofore found in cross coupled echo canceller structures, the echo replica obtained in conjunction with carrier-phase tracking circuitry can be a more exact duplicate of the real and imaginary components of a received echo containing signal. The echo canceller may include a plurality of subcancellers, each including at least four adaptive filters. Alternatively the filters within each subcanceller can be implemented by a suitably programmed digital signal processor.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to a color change paint and varnish remover. More specifically, the present invention provides for a paint removal formulation having a color change feature to indicate when the stripping action of the formulation has substantially ceased and is ready for removal. The formulation comprises: at least one penetrant, at least one carrier and at least one colorant whereby the formulation is applied to the target area and as the surface of the formulation dries, the colorant migrates away from the dehydrating surface leaving a finely divided carrier that emits white light. This color change indicates that the stripping action of the formulation has ceased and is ready for the scraping and removal step.
2. Description of the Related Art
The term “paint and varnish remover” as used herein refers to chemical compositions which can strip or remove all types of coatings, such as, paints, lacquers, enamels, varnishes, shellac, polyurethane, epoxies, and other coatings used on substrates such as metal and wood.
Methylene chloride paint strippers have long been the standard for stripper performance. Although effective in stripping action, high volatility shortens the working time for paint and varnish removal, often requiring more than one application when used on thicker accumulations of paint. In addition, the environmental concerns and the potential carcinogenic effects based on lab tests on mice and rats, has led to ever increasing regulations concerning its use.
Other solvents, such as toluene, xylene, methanol, acetone, ethanol in addition to being flammable, are themselves or in various combinations also highly volatile, requiring multiple applications when thick accumulations of paint are to be removed, and therefore suffer because their work life is insufficient to permit complete penetration of the paint layers before drying out.
The use of safer solvents to replace methylene chloride and flammable paint and varnish removers, is well documented in previous patents. N-methyl-2-pyrrolidone (NMP) has long been employed as the main active ingredient in various paint stripper compositions that offer safer alternatives to methylene chloride and flammable solvent compositions. (NMP) costs over four times as much as methylene chloride, and as much as ten times as much as common flammable alternatives, and various attempts have been made by adding less costly components to (NMP) mixtures, while still maintaining removal properties. U.S. Pat. Nos. 4,120,180; 4,749,510; 5,006,279; and 5,015,410 all refer to various combinations of (NMP) and various aromatic hydrocarbons and other additives to maintain removal efficiency and lower overall costs. Unfortunately, such aromatic hydrocarbons are under increasing regulatory pressures as hazardous air pollutants, and their insolubility in water makes them more difficult to remove from the surface by water washing. Furthermore, these aromatic (NMP) blends, using recommended thickeners, primarily of the cellulosic type, suffer from poor sag resistance, especially when sheared by rapid brushing action or spraying. This leads to insufficient thickness of paint and varnish remover to penetrate effectively, before drying out. U.S. Pat. Nos. 4,666,626 and 4,732,695 refer to paint and varnish removers based on oxy hexyl acetate/cyclohexanone compositions, and benzyl alcohol, aromatic hydrocarbon/(NMP) compositions, respectively, which rely on cellulosic thickeners that sag or drip pulling the paint and varnish remover away from the paint surface so that direct contact is lost. The loss of contact destroys penetrability before drying out.
U.S. Pat. Nos. 5,098,591; 5,124,062; 5,167,853; and 5,298,184 refer to paint and varnish removers based on combinations of (NMP) and various citrus terpene solvents. These compositions also contain cellulosic type thickeners, as well as organoclay thickening agents to aid in sag resistance and to control flow. U.S. Pat. No. 5,035,829 utilizes primarily (NMP), acids and alkylene glycol ethers, and relies on cellulosic thickeners, and is used to remove over spray from spray booths. U.S. Pat. Nos. 5,049,300; 5,098,592, and 5,154,848, disclose compositions containing (NMP) and or (BLO) gamma-butyrolactone, and ethyl 3-ethoxyproprionate (EEP) using cellulosic type thickeners to provide thickening and sag resistance.
Thus, there remains a need in the art to provide an effective paint and varnish stripper which has better sag resistance, especially on vertical surfaces, while maintaining stripping effectiveness, along with the lower toxicities, volatilities, and environmental benefits that are outlined in various patents, while avoiding the use of methylene chloride, toluene, methyl ethyl ketone, acetone, methanol or other highly volatile and/or flammable components.
Most traditional strippers containing methylene chloride or other volatile and flammable chemicals such as methanol methyl ethyl ketones, acetone or toluene, and strip paint quickly, but will remove only 1 or 2 layers per application.
In the color change formulations, the natural color of the components fades to off-white when the stripping action has substantially ceased. The addition of a coloring agent, such as a dye or a pigment, to the compositions in the range of up to 2%, will intensify the color change (i.e. a medium green to off-white or a pale green) to signal better to the applicator that removal should begin. In addition, with the advent of modern day safer stripper formulations, the resulting stripping actions tend to be much slower than paint and varnish removers based on methylene chloride, and other volatile, flammable solvents or combinations thereof, so that it is difficult to determine when the striping action is finished.
Furthermore, it is well known in the art, that modern day paints, based on latexes, because of their tendency to buckle, swell and blister cause difficulties in maintaining contact with the layers of paint to be stripped. The stripping agent is pulled away from the surface by the buckled and blistered paint. Often this results in the paint stripper and loosened top layers of paint to drop from the sub-layer of paint producing a loss of direct contact with the paint stripper. The loss of direct contact requires additional application of paint stripper. Thus, there remains a need in the art to provide an effective paint and varnish remover which has better sag resistance, very low odor, a signaling device to indicate the completion of paint stripper action, and an effective way to prevent the excessive bubbling, blistering and swelling that can lead to the types of problems described herein.
Furthermore, despite the present of surfactants and other wetting agents, soaps and the like, it has been proven through experimentation that many of the compositions and formulas fail to loosen the paint layers sufficiently if dried to the point where little or no liquid is present. Therefore, there remains a need in the art for a paint and varnish remover that is removable at any stage wet or dry, even when the remover has totally dried.
It is advantageous if these improvements in the state of the art also has lower volatilities and, environmental benefits that are outlined in various other patents referenced, while avoiding the use of methylene chloride, toluene, methyl ethyl ketone, acetone, methanol, ethanol or other highly volatile and/or flammable components.
The color change feature of the present invention signals the completion of the paint strippers action and indicates the time at which the paint stripper is ready to be removed along with the softened paint layers. The paint and varnish stripper of the present invention is biodegradable, non-flammable, odor free and easily cleaned up with water. It contains no methylene chloride or caustic. It truly clings to vertical surfaces. It removes most varieties of paints and varnishes, which are oil or water-based including latexes, stains, alkyds, and polyurethane. It can be applied on a multitude of interior and exterior surfaces including wood, brick, plaster, metal, marble, masonry, concrete and fiberglass. It also strips significantly more paint than traditional paint strippers.
SUMMARY OF THE INVENTION
In one embodiment, the present invention relates to a paint removal formulation having a color change feature to indicate when the stripping action of the formulation has ceased and is ready for removal; the formulation comprises: at least one penetrant, at least one carrier and at least one colorant whereby the formulation is applied to the target area and there is a color change to indicate that the stripping action of the formulation has ceased and is ready for the removal step.
In another embodiment, the penetrant is selected from a group consisting of NMP, benzyl alcohol, ethyl lactate, dimethyl adipate, dimethyl glutarate, diethyl adipate, diethyl glutarate, ethyl benzoate, dimethyl succinate, diethyl succinate, dimethyl phthalate, diethyl phthalate, dimethyl terphthalate, diethyl terphthalate, ethylene bis(lactate), dimethyl sulfoxide, soy solvents, D-limonene and mixtures thereof.
In still another embodiment, the carrier is selected from a group consisting of polysaccharides, starch, cellulose, polydextran, chitosan, chitin, limestone, metal oxides, aluminum silicates, hydrated aluminates, sodium magnesium silicates, barium sulphates, ferroxides, magnesium aluminum silicates and mixtures thereof. In yet another embodiment, the colorant is selected from a group consisting of dye, pigments and mixtures thereof. In a further embodiment, the penetrant is selected from a group consisting of methylene chloride, toluene, methyl ethyl ketone, acetone, methanol, xylenes, mineral spirits, hi-flash naphtha and mixtures thereof. In still yet another embodiment, the formulation further comprises water.
In still yet another embodiment, the colorant migrates away from a surface of the formulation as the surface of the formulation dries. In another embodiment, the carrier partially dehydrates and emits white light as the surface of the formulation dries.
In a further embodiment, the formulation comprises from about 5 to about 55% by weight of the penetrant, from about 2 to about 50% by weight of the carrier, from about 0.01 to about 0.10% by weight of the colorant and from about 15 to about 50% by weight of the water.
In another embodiment, the formulation further comprises at least one thickening agents, said thickening agents being selected from a group consisting of Fullers earth, clay, attapulgite, montmorillonite, magnasol, klucel H, hydroxyethyl cellulose, hydroxypropyl cellulose, methocel and mixtures thereof. In still another embodiment, the formulation further comprises at least one wetting agent, said wetting agent being selected from a group consisting of propylene glycol, butylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentamethylene glycol, neopentyl glycol, diethylene glycol monomethyl ether, monomethyl ethers of triethylene glycol, tetraethylene glycol, pentaerythritol, dipentaerythritol, neopentyl glycol and mixtures thereof.
In yet another embodiment, the formulation further comprises at least one activator, the activator being selected from a group consisting of formic acid, acetic acid, glycolic acid, hydroxyacetic acid, chloroacetic acid, fluoroacetic acid, oxalic acid, lactic acid and mixtures thereof.
In still yet another embodiment, the present invention provides for a colored paint removal product that becomes a paler color of the product after it has been applied to the target area, has softened the paint and is ready for removal. In a further embodiment, the product comprises: at least one penetrant, at least one carrier, and at least one colorant whereby the product, when applied to the target area, changes color as the surface of product dries, the carrier partially dehydrates emitting white light and the colorant migrates away from the dehydrating surface. In one embodiment, the colored product becomes white to indicate that the stripping action of the product has ceased and is ready for scraping or removal step. More particularly, the product changes color by a whitening process whereby the colorant migrates away from the dehydrating surface leaving the finely divided carrier to emit white light. In another embodiment, the colored product becomes paler than its original color to indicate that the stripping action of the product has ceased and is ready for the removal step.
In another embodiment, the method of manufacturing a paint removal composition that changes color to indicate that the stripping action of the composition has substantially ceased and is ready for the scraping or removal step, comprises admixing at least one penetrant, at least one carrier, and at least one colorant whereby the composition is applied to the target area and as the surface of the composition dries, the carrier partially dehydrates emitting white light as the colorant migrates away from the dehydrating surface. Hence, there is a color change to indicate that the stripping action of the product has substantially ceased and paint or varnish is ready for removal. For purposes of this invention and this embodiment, the term substantially can mean from about 50 to about 95% of the stripping action of the composition has occurred and the user may begin scraping and removing the paint layers from the medium. For purposes of this invention, the terms “scraping” and “removal” may mean the same thing. In another embodiment, the term “scraping” may mean the back and forth motion by the user utilizing a stripping or scraping tool. In a further embodiment, the term “removal” may mean the overall process of removing the paint with the paint removal composition.
In still another embodiment, the method further comprises admixing water. In yet another embodiment, the formulation comprises from about 5 to about 50% by weight of the penetrant, from about 2 to about 50% by weight of the carrier, from about 0.01 to about 0.1% by weight of the colorant and from about 15 to about 50% by weight of the water.
In still yet another embodiment, the method further comprises admixing at least one thickening agents, the thickening agents being selected from a group consisting of Fullers earth, clay, attapulgite, montmorillonite, magnasol, klucel H, hydroxyethyl cellulose, hydroxypropyl cellulose, methocel and mixtures thereof.
In another embodiment, the method further comprises admixing at least one wetting agent, the wetting agent being selected from a group consisting of propylene glycol, butylene glycol, ethylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentamethylene glycol, diethylene glycol monomethyl ether, monomethyl ethers of triethylene glycol, tetraethylene glycol, pentaerythritol, dipentaerythritol, neopentyl glycol and mixtures thereof.
In yet another embodiment, the method further comprises admixing at least one activator, the activator being selected from a group consisting of formic acid, acetic acid, glycolic acid, hydroxyacetic acid, chloroacetic acid, fluoroacetic acid, oxalic acid, lactic acid and mixtures thereof.
In still another embodiment, the method of manufacturing a paint removal composition that changes color to indicate that a stripping action of the composition has substantially ceased and is ready for a scraping step, the method comprises admixing at least one penetrant, at least one carrier, and at least one colorant whereby the composition is applied to the target area and there is a color change to indicate that the stripping action of the composition has substantially ceased and is ready for scraping and removal, the penetrant is selected from a group consisting of NMP, benzyl alcohol, ethyl lactate, diethyl adipate, diethyl glutarate, ethyl benzoate, dimethyl succinate, diethyl succinate, dimethyl phthalate, diethyl phthalate, dimethyl terphthalate, diethyl terphthalate, ethylene bis(lactate), dimethyl sulfoxide, soy solvents, D-limonene and mixtures thereof, and the carrier is selected from a group consisting of polysaccharides, starch, cellulose, polydextran, chitosan, chitin, limestone, metal oxides, aluminum silicates, hydrated aluminates, sodium magnesium silicates, barium sulphates, ferroxides, magnesium aluminum silicates and mixtures thereof.
In a further embodiment, the penetrant of the formulation of the present invention has an inherent color and the color from the carrier is instrumental in the color change. In still a further embodiment, the formulation comprises another component, not a colorant, that has an inherent color and the color from this component is instrumental in the color change. In another further embodiment, a color changing paint and varnish removal product is provided and the product comprises at least one penetrant and at least one carrier, and the color of the product derived from the color of the penetrant changes when the stripping action of the product has substantially ceased and the paint or varnish is ready for removal. In another embodiment, the penetrant is the colorant.
In still a further embodiment, the carrier of the present invention and the composition's viscosity may add additional benefits and results including but not limited to safe short-term human skin contact with the product or composition. In yet a further embodiment, the carrier may also function to mask the odor of other ingredients in the formulation thereby allowing for an odor free or odorless composition. In still yet a further embodiment, the present invention provides for better sag resistance and an effective way to prevent the excessive bubbling, blistering and swelling associated with problems relating to modern day paints, in particular, latex paints.
DETAILED DESCRIPTION OF THE INVENTION
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 that may be embodied in various forms. Therefore, specific 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 employ the present invention in various ways.
The specific examples below will enable the invention to be better understood. However, they are given merely by way of guidance and do not imply any limitation.
EXAMPLE 1
One embodiment of the paint and varnish remover of the present invention marketed under the trademark “READY STRIPS® PLUS” was tested to determine if it would indicate a color change when the remover was finished working and was ready for the stripping step. In addition, the stripping steps were conducted at different time intervals to evaluate further the number of layers of paint removed at such time intervals. The time intervals included times prior to color change, at color change and after color change.
Test Sample:
A pine plank measuring 9 3/16 inches wide by 72 3/16 inches long by 0.748 (¾) inch thick painted with twelve (12) coats of paint of varying colors was the test sample. Each paint coat was visible from one end of the plank by successive receding starting points of four (4) inch spacing for each paint coat. Prior to applying the first paint coat, the pine plank had been sealed with a varnish sanding sealer and sanded with sandpaper.
Paint Materials:
The paints used were as follows in the identified sequence of application: 1.) Black latex flat enamel; 2.) White hi-gloss, interior/exterior alkyd spray enamel; 3.) Wildflower Blue latex satin enamel; 4.) Claret Wine latex satin enamel; 5.) Taupe latex satin enamel; 6.) Hunter Green interior/exterior alkyd spray enamel; 7.) Cinnamon latex satin enamel; 8.) White hi-gloss latex enamel; 9.) Banner Red hi-gloss, interior/exterior alkyd spray enamel; 10.) Black latex flat enamel; 11.) Yellow hi-gloss, interior/exterior alkyd spray enamel; and 12.) Wildflower Blue latex satin enamel.
Instruments:
The average film thickness per paint coat was ascertained by measuring the pine plank with a vernier micrometer following the sanding step and following the dried twelve (12) coats of paint. The paint scrapers used were a triangular drag scraper with a stainless steel blade measuring 6.2 cm (2.44 inches) per edge and a “five-in-one” flat blade paint scraper with a stainless steel blade measuring 5.8 cm (2.283 inches). The applicators for applying the paint strippers were two-inch wide paint brushes.
Paint Application Procedure:
The pine board (plank) was first coated with a varnish sanding sealer and allowed to dry overnight [about sixteen (16) hours]. The board was sanded with 220 grain sandpaper to provide a smooth sealed wood surface. The paint coatings were applied with successive receding starting points at four (4) inch spacings so that each paint coat remained visible and traceable. The order of the paint coat deposition was black, white, blue, claret wine, taupe, hunter green, cinnamon, white, banner red, black, yellow, and blue. After the application of each paint coat, the paint was allowed to dry for four (4) hours. The first two (2) hours of drying was at ambient temperature which varied from 81° F. to 92° F. during the ambient drying step for the twelve (12) paint coats. The last two (2) hours, the drying was carried out under a hot air stream that varied in temperature between 105° F. to 122° F. After the third, the sixth, and the ninth paint coats, the entire drying was at ambient temperature overnight (14-16 hours). The overnight temperatures varied between 78° F. to 90° F. Following the final paint coat, the painted plank was left to cure for one hundred seventeen (117) hours under conditions of controlled temperature and humidity. The controlled curing environment was a temperature of 70° F. and humidity of 40-45%.
The dry film thickness of the twelve coats (12) of paint measured, with the vernier micrometer, 0.5 mm or 19.685 mil. The average dry paint coat thickness calculates to be 1.64 mil.
Ready Strip Application Procedure:
The READY STRIP® PLUS was applied to the top paint coat (blue) covering the eleven (11) paint coats beneath it. Both paint strippers were applied to cover a rectangular section of the painted plank that measured approximately 9½ inches by 3¼ inches with a thickness sufficient to mask the top paint color (blue). As initially applied, the READY STRIP PLUS had a medium green color. The Plus paint stripper turned color as the active ingredients penetrated the twelve (12) paint coats. The READY STRIP® PLUS changed color from medium green to a pale green after twenty-four (24) hours.
The test results of Example 1 is set forth in Table 1 below:
TABLE 1
Elapsed
Time,
Paint Coats
Stripper
Time
Hours
Removed
READY STRIP ® PLUS
5 15 pm (Aug. 9, 2005)
4
4
READY STRIP ® PLUS
9 15 pm (Aug. 9, 2005)
8
7
READY STRIP ® PLUS
1 15 pm (Aug. 10, 2005)
24
12
READY STRIP ® PLUS
1 15 pm (Aug. 12, 2005)
72
12 b
b The READY STRIP ® PLUS had dried to a hard layer. Water was layered over the dried paint stripper and allowed to soak into the stripper for about ten (10) minutes. The hydrated paint stripper was able to be penetrated with the drag scraper and twelve paint coats came off easily.
The stripping action was tested prior to full color change (partial color change) at the 4 th and 8 th hour of testing and only four (4) and seven (7) layers of paint, respectively were removed. The full color change (medium green to pale green) occurred at the 24 th hour and all twelve (12) layers of paint were removed. In addition, the 72 nd hour was also tested and the color remained changed, and all twelve (12) layers were removed.
EXAMPLE 2
Another embodiment of the paint and varnish remover of the present invention marketed under the trademark “READY STRIP® PRO” was tested to determine if it would indicate a color change when the remover was finished working and was ready for the stripping step. Again, the stripping steps were conducted at different time intervals to further evaluate the number of layers of paint removed at such time intervals. The time intervals included times prior to color change, at color change and after color change.
Test Sample:
A pine plank measuring 9 3/16 inches wide by 72 3/16 inches long by 0.748 (¾) inch thick painted with twelve (12) coats of paint of varying colors was the test sample. Each paint coat was visible from one end of the plank by successive receding starting points of four (4) inch spacing for each paint coat. Prior to applying the first paint coat, the pine plank had been sealed with a varnish sanding sealer and sanded with sandpaper.
Paint Materials:
The paints used were as follows in the identified sequence of application: 1.) Black latex flat enamel; 2.) White hi-gloss, interior/exterior alkyd spray enamel; 3.) Wildflower Blue latex satin enamel; 4.) Claret Wine latex satin enamel; 5.) Taupe latex satin enamel; 6.) Hunter Green interior/exterior alkyd spray enamel; 7.) Cinnamon latex satin enamel; 8.) White hi-gloss latex enamel; 9.) Banner Red hi-gloss, interior/exterior alkyd spray enamel; 10.) Black latex flat enamel; 11.) Yellow hi-gloss, interior/exterior alkyd spray enamel; and 12.) Wildflower Blue latex satin enamel.
Instruments:
The average film thickness per paint coat was ascertained by measuring the pine plank with a vernier micrometer following the sanding step and following the dried twelve (12) coats of paint. The paint scrapers used were a triangular drag scraper with a stainless steel blade measuring 6.2 cm (2.44 inches) per edge and a “five-in-one” flat blade paint scraper with a stainless steel blade measuring 5.8 cm (2.283 inches). The applicators for applying the paint strippers were two-inch wide paint brushes.
Paint Application Procedure:
The pine board (plank) was first coated with a varnish sanding sealer and allowed to dry overnight [about sixteen (16) hours]. The board was sanded with 220 grain sandpaper to provide a smooth sealed wood surface. The paint coatings were applied with successive receding starting points at four (4) inch spacings so that each paint coat remained visible and traceable. The order of the paint coat deposition was black, white, blue, claret wine, taupe, hunter green, cinnamon, white, banner red, black, yellow, and blue. After the application of each paint coat, the paint was allowed to dry for four (4) hours. The first two (2) hours of drying was at ambient temperature which varied from 81° F. to 92° F. during the ambient drying step for the twelve (12) paint coats. The last two (2) hours, the drying was carried out under a hot air stream that varied in temperature between 105° F. to 122° F. After the third, the sixth, and the ninth paint coats, the entire drying was at ambient temperature overnight (14-16 hours). The overnight temperatures varied between 78° F. to 90° F. Following the final paint coat, the painted plank was left to cure for one hundred seventeen (117) hours under conditions of controlled temperature and humidity. The controlled curing environment was a temperature of 70° F. and humidity of 40-45%.
The dry film thickness of the twelve coats (12) of paint measured, with the vernier micrometer, 0.5 mm or 19.685 mil. The average dry paint coat thickness calculates to be 1.64 mil.
Ready Strip Application Procedure:
The READY STRIP® PRO was applied to the top paint coat (blue) covering the eleven (11) paint coats beneath it. The Pro paint stripper was applied to cover a rectangular section of the painted plank that measured approximately 9½ inches by 3¼ inches with a thickness sufficient to mask the top paint color (blue). As initially applied, the READY STRIP® PRO had a medium brown color. The Pro paint strippers turned color as the active ingredients penetrated the twelve (12) paint coats. The READY STRIP® PRO substantially turned color from a medium brown to a very light tan at the eight (8) hour mark and fully turned color from medium brown to off-white after twenty-four (24) hours.
The test results of Example 2 is set forth in Table 2 below:
TABLE 2
Elapsed
Time,
Paint Coats
Stripper
Time
Hours
Removed
READY STRIP ® PRO
5 15 pm (Aug. 9, 2005)
4
4
READY STRIP ® PRO
9 15 pm (Aug. 9, 2005)
8
12
READY STRIP ® PRO
1 15 pm (Aug. 10, 2005)
24
12
READY STRIP ® PRO
1 15 pm (Aug. 12, 2005)
72
12 a
a The READY STRIP ® PRO had crusted over but was sufficiently pliable so that the drag scraper was able to cut through the crust and remove the twelve (12) paint coats.
The stripping action was tested prior to full color change (partial color change) at the 4 th hour of testing and four (4) layers of paint were removed. A substantial color change (brown to light tan) occurred at the 8 th hour of testing and all twelve (12) layers of paint were removed. The full color change (brown to off-white) occurred at the 24 th hour and all twelve (12) layers of paint were removed. In addition, the 72 nd hour was also tested and the color remained changed, and all twelve (12) layers were removed.
Therefore, while the embodiments of the present invention disclosed herein are presently considered to be preferred, various changes and modifications can be made without departing from the spirit and scope of the invention. The scope of the invention is indicated in the appended claims, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.
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A color change paint and varnish removal formulation is provided. The formulation comprises: at least one penetrant, at least one carrier and at least one colorant whereby the formulation is applied to the target area and as the surface of the formulation dries, the carrier partially dehydrates emitting white light as the colorant migrates away from the dehydrating surface and there is a color change to indicate that the stripping action of the formulation has ceased and is ready for the scraping and removal step.
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RELATED APPLICATION DATA
[0001] This application claims priority of U.S. Provisional Application No. 60/738,546 filed on Nov. 21, 2005, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to medical markers and, more particularly, to a medical marker that utilizes a luminescence agent to emit a trackable signal.
BACKGROUND OF THE INVENTION
[0003] Active markers (e.g., LED markers) emit a trackable signal without the need for an external light source. Typically, such markers obtain power, for example, from an external power source via a cable connection or via an internal battery pack. Thus, instruments which are fitted with such active markers either have a cable attached thereto or are supplied with energy by batteries or power packs.
[0004] Cables can be problematic, as they tend to obstruct the work area and/or make it difficult to handle the markers and/or instrument. Batteries or power packs, on the other hand, can be heavy and/or difficult to sterilize. Further, active LED markers have the disadvantage of a narrow emitting angle.
[0005] Passive markers, such as are known for example from DE 196 39 615 A1, solve the handling and sterilization problems associated with active markers. However, manufacturing such passive markers can be relatively complicated, as a reflective covering generally is formed over such markers. Further, a significant amount of manual labor is involved in creating such markers.
SUMMARY OF THE INVENTION
[0006] The present invention provides a medical marker that includes a marker body which can be positionally detected by a medical localization or tracking system. The marker body includes a luminescence agent which can be illuminated without an electrical energy supply coupled to the agent and/or body. In other words, self-illuminating and/or cold-illuminating agents are utilized that enable the marker to illuminate from the material itself, without an energy supply provided by cable or batteries. Thus, costly manufacture of reflective coatings for the markers is not required. Further, the markers have good luminisity (e.g., good recognizability for the respective marker means), and sterilization of the markers is relatively easy compared to prior art active markers. Another advantage is that the infrared (IR) irradiation, which typically is included in a camera system for detecting passive markers, can be omitted. IR radiation generally requires significant power, generates heat, and occasionally can disrupt other operating apparatus, such as video recorder remote controls, operating table remote controls or finger pulsometers.
[0007] The term “luminescence” in the present context substantially means that the marker body can illuminate solely from the material or materials used, without needing an external energy supply (cable or connected batteries/power packs). The luminescence agent can be one which luminesces according to at least one of the following processes: chemoluminescence (a chemical reaction provides the energy to elevate electrons into higher energy states); photoluminescence (electrons are moved to the higher energy state by optical stimulation (irradiation)); electroluminescence (the emission of light is caused by applying an electric field); and/or radioluminescence (shooting particles into a suitable material in order to generate luminescence, for example electrons, alpha-particles).
[0008] In the following, the present description will deal mainly with the use of chemoluminescence. However, it is within the scope of the present invention to use other types of luminescence. For example, it is perfectly conceivable to irradiate the markers before use in a medical procedure with suitable amounts of light, to then position markers on instruments or treatment means and to use them over the period of time in which they re-emit the light energy (as for example the luminous numbers on a clock). Such marker may be used either as passive marker or as active marker, for example, within the scope of surgically navigating instruments and treatment means.
[0009] Chemoluminescence, as mentioned above, is a luminescence (e.g., the emission of light in the visible range or also the emission of ultraviolet or infrared light) associated with a chemical reaction. In chemoluminescence, the temperature is significantly below the incandescent temperature of the substances involved and, therefore, is called “cold light”. This latter property makes chemoluminescence very suitable for medical applications, as it does not generate any disruptive, excess heat that has to be dissipated.
[0010] In chemoluminescence, electrical energy is converted into electronic or, more rarely, oscillation energy. This presupposes that said energy is released at once, i.e., not in numerous stages. Chemoluminescence occurs in numerous chemical processes in which high-energy, unstable intermediate stages are created and immediately decompose again. Although the reaction mechanism of many chemoluminescence reactions has not yet been conclusively explained, the principle of forming high-energy tetracyclic systems (dioxetanes) has in many cases been confirmed by experiments. Reacting oxygen (O 2 ), peroxides (R 2 O 2 ), hyperoxides (O 2 —) or hydroperoxides (RO 2 H) with luminophores often creates dioxetanes, such as 1,2-dioxitanes or 1,2-dioxetes, which in turn decompose into two carbonyl compounds, wherein one of these is created in an electronically excited singlet or triplet state. The fragment in the electronically excited state can return to its ground state by emitting the energy in the form of photons. While the molecules in the excited singlet state quickly return to their ground state by emitting the characteristic fluorescent light, the excited triplet molecules are longer-lived. The phosphorescent light thus created in a substantially smaller yield barely contributes to a “usable” chemoluminescence.
[0011] One example of chemoluminescence is the so-called “luminol reaction”, an example of an oxidation process in which the reaction energy is emitted not as heat but solely as light energy. The reaction is based on the oxidative release of nitrogen from phthalic acid hydrazide (luminol) by the action of alkali hydrogen peroxide. This reaction is catalysed by red prussiate of potash (hexacyanoferrate (III)). The luminescence can be triggered not only by hydrogen peroxide but also by ozone. In an alkali hydrogen peroxide solution, luminol shows a weak but sustained chemoluminescence, the intensity of which is strengthened by certain catalysts (potassium hexacyanoferrate (III), haemin), simultaneously reducing the decay time.
[0012] Chemoluminescence is also known from light sticks (snap light sticks), in which a glass ampoule contains hydrogen peroxide which is used as the oxidant for the reaction which illuminates the stick. When the breaking point in the ampoule is broken, the hydrogen peroxide is released into a solution containing oxalic phthalate ester. When this oxalic phthalate ester is oxidized to form phenol and carbon dioxide, the intermediate stage 1,2-dioxetane-3,4-dione is formed. This intermediate stage reacts with a dye molecule in the light stick, typically a diphenyl anthracene, and the dye molecule is electronically excited. In this excited state, it emits a photon and so generates its luminescence.
[0013] The chemoluminescences described above or similar chemoluminescences can thus be used in a marker, wherein the luminescence agent includes of a number of substances that are illuminated by being mixed, wherein the mixing itself can be separately triggered by a suitable triggering agent. On the other hand, there exists the possibility of using markers which comprise a fastening by which they can be attached to instruments or treatment means. In this case, the mixing of the substances could be triggered by activating or fixing the fastening. In this case, or also in cases in which mixing is triggered separately, the marker body can form a container for a first substance, in which another container is arranged that includes a second substance. The mixing of the substances then, for example, can be triggered by breaking the inner container. If the fastening described above is used, then fixing the marker can open a container including a first substance, which is situated within a space including a second substance.
[0014] For navigation and tracking systems, it is often advantageous for them to operate in the infrared range, such that disruptions from visible light can be minimized or eliminated. The luminescence agent can be a luminescence agent that emits in the infrared range. Furthermore, the luminescence agent can be an agent which solely or at least partially and preferably not glaringly emits in the range of visible light. The marker means can comprise an indicator which shows when the luminosity of the luminescence agent decreases or ebbs. The indicator can be the illuminating portion emitting in the range of visible light of a luminescence agent which otherwise emits in the infrared range. In other words, a marker body can be provided that includes a luminescence agent, wherein the luminescence agent can illuminate in the infrared range and also (to a minor extent) in the visible range across a limited wavelength. Wavelengths for IR light, for example, are 700 to 900 nm, especially 850 to 890 nm; visible light can be below 700 nm in wavelength. Chemoluminescent emitters which can emit in the infrared range, for example, would be CH3Se (750 to 825 nm in wavelength), IF (450 to 800 nm) and SF2 (550 to 875 nm). On the basis of the small portion of visible light, however, it would be possible to determine when the luminosity of the marker decreases or ebbs, and it could be replaced with a new marker.
[0015] The marker can comprise one or more marker bodies or a number of groups of marker bodies, wherein the luminescence agent of each marker may illuminate in a different color. In this example, the marker bodies or groups of marker bodies can be provided on and/or attached to an instrument or treatment means, color-coded and characteristic of the respective instrument or treatment means, wherein an instrument and/or treatment means can comprise marker bodies or groups of marker bodies in the same color or in different colors.
[0016] The marker body can form an insert which can be inserted into a receptacle of an instrument or treatment means, wherein translucent openings for the light emitted by the marker body are provided in or on the receptacle. Rod-shaped luminescent illuminating agents already available, for example, can be used for rod-shaped instruments. The translucent openings, which are inexpensive and simple to manufacture, can serve as the marker itself.
[0017] The invention is explained below in more detail on the basis of embodiments. It can comprise any of the features described here, individually and in any combination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The forgoing and other embodiments of the invention are hereinafter discussed with reference to the drawings.
[0019] FIG. 1 illustrates an exemplary luminescence marker in accordance with the invention, before being fastened to a surgical instrument.
[0020] FIG. 2 illustrates the marker of FIG. 1 fastened to an exemplary instrument.
[0021] FIG. 3 illustrates an exemplary luminescence rod marker which can be inserted into an object, such as an instrument body.
DETAILED DESCRIPTION
[0022] FIGS. 1 and 2 illustrate an exemplary marker fastening system for attaching an exemplary marker 10 to a surgical instrument 20 . The marker 10 can be formed in a spherical shape and includes a casing which is permeable to light and/or diffusely permeable to light. A spherical part 17 of the casing connects to a connecting piece 15 , which in turn connects to a membrane 11 . The parts 11 , and 17 together form an enclosed space. The connecting piece 15 connects the casing to a first fastening part of a socket 13 , said first fastening part including an inner thread which extends in a central inner through-bore. Furthermore, a capsule 14 made of a breakable material is also fixed over the membrane 11 .
[0023] While a first liquid 12 is situated in the spherical casing 17 , the capsule 14 carries a second liquid 16 . The two liquids are substances which, when mixed together, generate a chemoluminescence and preferably emit mainly in the infrared range (around 860 to 890 nm). In addition, this radiation also can include a small portion of visible light. The substances described above, or any substances which those having ordinary skill in the art would regard as suitable, can be used.
[0024] A second fastening part, which in the present example is in the form of a protruding pin 21 , includes an outer thread and is situated on a side of the surgical instrument 20 , of which only a part of the handle can be seen. A breaking device is schematically indicated as a rounded tip 23 on an upper part of the pin 21 .
[0025] FIG. 2 illustrates what happens when the first fastening part 13 of the marker 10 is attached (e.g., via threads) onto the second fastening part (i.e., pin 21 ). Once screwed on, the tip 23 protrudes beyond the upper edge of the socket 13 and extends the membrane 11 without damaging it. Through the membrane, the tip 23 destroys the breakable material of the capsule 14 such that the second liquid 16 can escape from the capsule 14 and mix with the first liquid 12 in the spherical marker. The escape of the liquid is indicated by the arrows 25 and 27 in FIG. 2 . Mixing the liquids creates the luminescence, and the marker 10 can thus be used as a localization aid for the instrument 20 for the entire duration of luminescence. When the luminosity decreases or ebbs, the user sees this in the decrease and/or ebb of the visible light portion, and the marker can be exchanged by unscrewing it and replacing it with another. Because the membrane 11 is not destroyed when the ampoule 14 is broken, no liquid escapes from the inner space of the marker; the system remains “clean” and the markers can be provided as pre-sterilised disposable items.
[0026] FIG. 3 shows an exemplary instrument handle 30 which includes transit holes 32 , 34 , 36 at different points. The handle 30 is formed hollow elongated member, as can be seen from the partial cut-away shown at the receptacle 35 .
[0027] A luminescent rod 40 can be inserted into the receptacle 35 . The luminescent rod 40 in turn includes an enclosed inner space containing a first substance and a breakable ampoule 42 containing a second substance. An activating device is schematically indicated by the reference sign 44 , using which the facing end of the ampoule 42 can be broken and the mixing of the substances and the luminescence can therefore be triggered.
[0028] Using the activating device 44 , the mixing of the two liquids in the luminescent rod 40 can be triggered before it is inserted, and the rod 40 then can be inserted into the receptacle 35 of the handle 30 from behind. The rod 40 then shines by its luminescence through the translucent openings (holes) 32 , 34 and 36 and, thus, provides a sort of marker array and/or group of markers including three openings which can be detected by a tracking system. Here, too, there is scope for individualizations. Each instrument can include characteristically arranged translucent openings, thereby enabling a tracking and/or navigation system to recognize and track the instrument. In this way, an identifiable surgical instrument including a marker array can be manufactured in a very simple way using a luminescent rod which is already commercially available.
[0029] Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
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A medical marker trackable by a medical navigation system includes a marker body and a luminescence agent within the marker body. The luminescence agent is operative to emit light without an electrical power supply coupled to the luminescence agent.
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[0001] The current invention is directed to a method for the determination of immunoglobulin encoding nucleic acid, i.e. RNA and DNA, and primers for PCR determination of immunoglobulin encoding nucleic acid.
BACKGROUND OF THE INVENTION
[0002] In current biotechnological processes genetically engineered microorganism are employed in order to provide therapeutical polypeptides in high yield. The Chinese hamster ovary (CHO) cell line is widely used for the production of recombinant polypeptides, especially therapeutic immunoglobulins. This cell line is capable of providing secondary modifications and most importantly the CHO cell line is capable of secreting the recombinantly produced polypeptide to the culture medium facilitating down stream process operations (Jiang, Z., et al., Biotechnol. Prog. 22 (2006) 313-138; Yee, J. C., et al., Biotechnol. Bioeng. 102 (2009) 246-263). In order to increase the productivity of recombinant cell lines parameters like the parental cell line, the cultivation medium, or the cultivation conditions have to be optimized (Yee, J. C., et al., Biotechnol. Bioeng. 102 (2009) 246-263).
[0003] Based on the analysis of position, structure and copy number of integrated heterologous nucleic acids in the genome of the recombinant cell line indicators for the decision about the recombinant cell lines properties shall be established (Wurm, F. M., Ann. N. Y. Acad. Sci. 782 (1996) 70-78). The nucleic acid encoding the heterologous polypeptide is integrated into the genome of the recombinant cell line as deoxyribonucleic acid (DNA), which is transcribed into ribonucleic acid (RNA) during the transcription process. The RNA is in turn the template for protein biosynthesis in the translation process. Due to the importance of the RNA for gene expression, analysis of this nucleic acid gains importance (Seth, G., et al., Biotechnol Bioeng. 97 (2007) 933-951).
[0004] In WO 2008/094871 a method for the selection of high producing cell lines is reported. A study of monoclonal antibody-producing CHO cell lines is reported by Chusainow, J., et al. (Biotechnol. Bioeng. 102 (2009) 1182-1196). Barnes, L. M., et al. (Biotechnol. Bioeng. 85 (2004) 115-121) report molecular definition of predictive indicators of stable protein expression in recombinant NSO myeloma cells.
SUMMARY OF THE INVENTION
[0005] One aspect of the current invention is a method for the determination of the amount of mRNA encoding an immunoglobulin light chain and/or an immunoglobulin heavy chain of the IgG1 or IgG4 subclass with a polymerase chain reaction and absolute quantitation, by
a) performing a polymerase chain reaction for the immunoglobulin light chain with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33 with the dye FAM in a TaqMan hydrolysis probe format, and/or b) performing a polymerase chain reaction for the immunoglobulin heavy chain with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40 with the dye Cy5 in a TaqMan hydrolysis probe format, and c) performing absolute quantitation with an efficiency of 2.0.
[0009] Further aspects of the current invention are a first kit comprising the nucleic acids of SEQ ID NO: 23, SEQ ID NO: 24 and SEQ ID NO: 33 and a second kit comprising the nucleic acids of SEQ ID NO: 19, SEQ ID NO: 21 and SEQ ID NO: 40. Another aspect is the use of the nucleic acids of SEQ ID NO: 23, 24, and 33 or of SEQ ID NO: 19, 21, and 40 in a polymerase chain reaction.
[0010] Another aspect of the current invention is a method for determining the productivity of a cell expressing a heterologous polypeptide comprising the following steps in the following order:
determining the amount of mRNA encoding said heterologous polypeptide in a cell of known productivity, determining the amount of mRNA encoding said heterologous polypeptide in a cell of unknown productivity, calculating the ratio of the determined amount of mRNA encoding said heterologous polypeptide in said cell of unknown productivity to said cell of known productivity, multiplying the productivity of said cell of known productivity with said calculated ratio and thereby determining the productivity of a cell expressing a heterologous polypeptide.
[0015] In one embodiment said heterologous polypeptide is an immunoglobulin, or immunoglobulin fragment, or immunoglobulin conjugate. In still a further embodiment said determining of said amount of mRNA is via a polymerase chain reaction (PCR). In one embodiment the determining the amount of mRNA is by a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33 with the dye FAM in a TaqMan hydrolysis probe format and/or by a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40 with the dye Cy5 in a TaqMan hydrolysis probe format. In a further embodiment said amount of mRNA encoding said heterologous immunoglobulin is the average of the amount of mRNA encoding the light chain of said heterologous immunoglobulin and the amount of mRNA encoding the heavy chain of said heterologous immunoglobulin. In another embodiment said productivity is the specific production rate in pg/cell/day. In another embodiment said polymerase chain reaction is a multiplex polymerase chain reaction.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In the current invention it has been found that the copy number of an immunoglobulin encoding nucleic acid (DNA) and the amount of transcript generated there from (RNA) can be used to determine the productivity of a recombinant CHO cell line expressing a heterologous immunoglobulin. Also has been found that the amount of mRNA encoding a heterologous polypeptide is a measure for the specific productivity of such a cell.
[0017] The invention comprises a method for determining the productivity of a cell expressing an immunoglobulin comprising
a) performing a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33, and/or performing a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40 and thereby determining the amount of mRNA encoding the immunoglobulin in a cell of known productivity, b) performing a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33, and/or performing a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40 and thereby determining the amount of mRNA encoding the immunoglobulin in a cell of unknown productivity, c) calculating the ratio of the determined amount of mRNA encoding the immunoglobulin of the cell of unknown productivity to the cell of known productivity, d) multiplying the productivity of the cell of known productivity with the calculated ratio and thereby determining the productivity of a cell expressing an immunoglobulin.
[0022] Methods and techniques known to a person skilled in the art, which are useful for carrying out the current invention, are described e.g. in Ausubel, F. M., ed., Current Protocols in Molecular Biology, Volumes I to III (1997), Wiley and Sons; Sambrook, et al., Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989).
[0023] The term “amino acid” as used within this application denotes the group of carboxy α-amino acids, which directly or in form of a precursor can be encoded by a nucleic acid. The individual amino acids are encoded by nucleic acids consisting of three nucleotides, so called codons or base-triplets. Each amino acid is encoded by at least one codon. The encoding of the same amino acid by different codons is known as “degeneration of the genetic code”. The term “amino acid” as used within this application denotes the naturally occurring carboxy α-amino acids and is comprising alanine (three letter code: ala, one letter code: A), arginine (arg, R), asparagine (asn, N), aspartic acid (asp, D), cysteine (cys, C), glutamine (gln, Q), glutamic acid (glu, E), glycine (gly, G), histidine (his, H), isoleucine (ile, I), leucine (leu, L), lysine (lys, K), methionine (met, M), phenylalanine (phe, F), proline (pro, P), serine (ser, S), threonine (thr, T), tryptophan (trp, W), tyrosine (tyr, Y), and valine (val, V).
[0024] A “nucleic acid” or a “nucleic acid sequence”, which terms are used interchangeably within this application, refers to a polymeric molecule consisting of individual nucleotides (also called bases) A, C, G and T (or U in RNA), for example to DNA, RNA, or modifications thereof. This polynucleotide molecule can be a naturally occurring polynucleotide molecule or a synthetic polynucleotide molecule or a combination of one or more naturally occurring polynucleotide molecules with one or more synthetic polynucleotide molecules. Also encompassed by this definition are naturally occurring polynucleotide molecules in which one or more nucleotides are changed (e.g. by mutagenesis), deleted, or added. A nucleic acid can either be isolated, or integrated in another nucleic acid, e.g. in an expression cassette, a plasmid, or the chromosome of a cell.
[0025] To a person skilled in the art procedures and methods are well known to convert an amino acid sequence, e.g. of a polypeptide, into a corresponding nucleic acid sequence encoding this amino acid sequence. Therefore, a nucleic acid is characterized by its nucleic acid sequence consisting of individual nucleotides and likewise by the amino acid sequence of a polypeptide encoded thereby.
[0026] A “polypeptide” is a polymer consisting of amino acids joined by peptide bonds, whether produced naturally or synthetically. Polypeptides of less than about 20 amino acid residues may be referred to as “peptides”, whereas molecules consisting of two or more polypeptides or comprising one polypeptide of more than 100 amino acid residues may be referred to as “proteins”. A polypeptide may also comprise non-amino acid components, such as carbohydrate groups, metal ions, or carboxylic acid esters. The non-amino acid components may be added by the cell, in which the polypeptide is expressed, and may vary with the type of cell. Polypeptides are defined herein in terms of their amino acid backbone structure or the nucleic acid encoding the same. Additions such as carbohydrate groups are generally not specified, but may be present nonetheless.
[0027] The term “immunoglobulin” encompasses the various forms of immunoglobulin structures including complete immunoglobulins and immunoglobulin conjugates. The immunoglobulin employed in the current invention is in one embodiment a human antibody, or a humanized antibody, or a chimeric antibody, or a T cell antigen depleted antibody (see e.g. WO 98/33523, WO 98/52976, and WO 00/34317). Genetic engineering of immunoglobulins is e.g. described in Morrison, S. L., et al., Proc. Natl. Acad. Sci. USA 81 (1984) 6851-6855; U.S. Pat. No. 5,202,238 and U.S. Pat. No. 5,204,244; Riechmann, L., et al., Nature 332 (1988) 323-327; Neuberger, M. S., et al., Nature 314 (1985) 268-270; Lonberg, N., Nat. Biotechnol. 23 (2005) 1117-1125. Immunoglobulins may exist in a variety of formats, including, for example, Fv, Fab, and F(ab) 2 as well as single chains (scFv) or diabodies (e.g. Huston, J. S., et al., Proc. Natl. Acad. Sci. USA 85 (1988) 5879-5883; Bird, R. E., et al., Science 242 (1988) 423-426; in general, Hood et al., Immunology, Benjamin N.Y., 2nd edition (1984); and Hunkapiller, T. and Hood, L., Nature 323 (1986) 15-16).
[0028] The term “complete immunoglobulin” denotes an immunoglobulin which comprises two so called light chains and two so called heavy chains. Each of the heavy and light chains of a complete immunoglobulin contains a variable domain (variable region) (generally the amino terminal portion of the polypeptide chain) comprising binding regions that are able to interact with an antigen. Each of the heavy and light chains of a complete immunoglobulin comprises a constant region (generally the carboxyl terminal portion). The constant region of the heavy chain mediates the binding of the antibody i) to cells bearing a Fc gamma receptor (FcγR), such as phagocytic cells, or ii) to cells bearing the neonatal Fc receptor (FcRn) also known as Brambell receptor. It also mediates the binding to some factors including factors of the classical complement system such as component (C1q). The variable domain of an immunoglobulin's light and heavy chain in turn comprises different segments, i.e. four framework regions (FR) and three hypervariable regions (CDR).
[0029] The term “immunoglobulin conjugate” denotes a polypeptide comprising at least one domain of an immunoglobulin heavy or light chain conjugated via a peptide bond to a further polypeptide. The further polypeptide is a non-immunoglobulin peptide, such as a hormone, or growth receptor, or antifusogenic peptide, or complement factor, or the like. Exemplary immunoglobulin conjugates are reported in WO 2007/045463.
[0030] The term “heterologous immunoglobulin” denotes an immunoglobulin which is not naturally produced by a mammalian cell or the host cell. The immunoglobulin produced according to a method of the invention is produced by recombinant means. Such methods are widely known in the state of the art and comprise protein expression in eukaryotic cells with subsequent recovery and isolation of the heterologous immunoglobulin, and usually purification to a pharmaceutically acceptable purity. For the production, i.e. expression, of an immunoglobulin a nucleic acid encoding the light chain and a nucleic acid encoding the heavy chain are inserted each into an expression cassette by standard methods. Nucleic acids encoding immunoglobulin light and heavy chains are readily isolated and sequenced using conventional procedures. Hybridoma cells can serve as a source of such nucleic acids. The expression cassettes may be inserted into a(n) expression plasmid(s), which is (are) then transfected into host cells, which do not otherwise produce immunoglobulins. Expression is performed in appropriate prokaryotic or eukaryotic host cells and the immunoglobulin is recovered from the cells after lysis or from the culture supernatant.
[0031] An “isolated polypeptide” is a polypeptide that is essentially free from contaminating cellular components, such as carbohydrate, lipid, or other proteinaceous impurities associated with the polypeptide in nature. Typically, a preparation of isolated polypeptide contains the polypeptide in a highly purified form, i.e. at least about 80% pure, at least about 90% pure, at least about 95% pure, greater than 95% pure, or greater than 99% pure. One way to show that a particular protein preparation contains an isolated polypeptide is by the appearance of a single band following sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of the protein preparation and Coomassie Brilliant Blue staining of the gel. However, the term “isolated” does not exclude the presence of the same polypeptide in alternative physical forms, such as dimers or alternatively glycosylated or derivatized forms.
[0032] “Heterologous DNA” or “heterologous polypeptide” refers to a DNA molecule or a polypeptide, or a population of DNA molecules or a population of polypeptides, that do not exist naturally within a given host cell. DNA molecules heterologous to a particular host cell may contain DNA derived from the host cell species (i.e. endogenous DNA) so long as that host DNA is combined with non-host DNA (i.e. exogenous DNA). For example, a DNA molecule containing a non-host DNA segment encoding a polypeptide operably linked to a host DNA segment comprising a promoter is considered to be a heterologous DNA molecule. Conversely, a heterologous DNA molecule can comprise an endogenous structural gene operably linked with an exogenous promoter. A peptide or polypeptide encoded by a non-host DNA molecule is a “heterologous” peptide or polypeptide.
[0033] The term “cell” or “host cell” refers to a cell into which a nucleic acid, e.g. encoding a heterologous polypeptide, can be or is transfected. The term “cell” includes both prokaryotic cells, which are used for propagation of plasmids, and eukaryotic cells, which are used for the expression of a nucleic acid and production of the encoded polypeptide. In one embodiment, the eukaryotic cells are mammalian cells. In another embodiment the mammalian cell is a CHO cell, preferably a CHO K1 cell (ATCC CCL-61 or DSM ACC 110), or a CHO DG44 cell (also known as CHO-DHFR[-], DSM ACC 126), or a CHO XL99 cell, a CHO-T cell (see e.g. Morgan, D., et al., Biochemistry 26 (1987) 2959-2963), or a CHO-S cell, or a Super-CHO cell (Pak, S. C. O., et al., Cytotechnology. 22 (1996) 139-146). If these cells are not adapted to growth in serum-free medium or in suspension an adaptation prior to the use in the current method is to be performed. As used herein, the expression “cell” includes the subject cell and its progeny. Thus, the words “transformant” and “transformed cell” include the primary subject cell and cultures derived there from without regard for the number of transfers or subcultivations. It is also understood that all progeny may not be precisely identical in DNA content, due to deliberate or inadvertent mutations. Variant progeny that have the same function or biological activity as screened for in the originally transformed cell are included.
[0034] The term “expression” as used herein refers to transcription and translation processes occurring within a cell. The level of transcription of a nucleic acid sequence of interest in a cell can be determined on the basis of the amount of corresponding mRNA that is present in the cell. For example, mRNA transcribed from a sequence of interest can be quantitated by RT-PCR or by Northern hybridization (see Sambrook, et al., 1989, supra). Polypeptides encoded by a nucleic acid of interest can be quantitated by various methods, e.g. by ELISA, by assaying for the biological activity of the polypeptide, or by employing assays that are independent of such activity, such as Western blotting or radioimmunoassay, using immunoglobulins that recognize and bind to the polypeptide (see Sambrook, et al., 1989, supra).
[0035] Expression of a gene is performed either as transient or as permanent expression. The polypeptide of interest is in general a secreted polypeptide and therefore contains an N-terminal extension (also known as the signal sequence) which is necessary for the transport/secretion of the polypeptide through the cell wall into the extracellular medium. In general, the signal sequence can be derived from any gene encoding a secreted polypeptide. If a heterologous signal sequence is used, it preferably is one that is recognized and processed (i.e. cleaved by a signal peptidase) by the host cell. For secretion in yeast for example the native signal sequence of a heterologous gene to be expressed may be substituted by a homologous yeast signal sequence derived from a secreted gene, such as the yeast invertase signal sequence, alpha-factor leader (including Saccharomyces, Kluyveromyces, Pichia, and Hansenula α-factor leaders, the second described in U.S. Pat. No. 5,010,182), acid phosphatase signal sequence, or the C. albicans glucoamylase signal sequence (see EP 0 362 179). In mammalian cell expression the native signal sequence of the protein of interest is satisfactory, although other mammalian signal sequences may be suitable, such as signal sequences from secreted polypeptides of the same or related species, e.g. for immunoglobulins from human or murine origin, as well as viral secretory signal sequences, for example, the herpes simplex glycoprotein D signal sequence. The DNA fragment encoding for such a presegment is ligated in frame, i.e. operably linked, to the DNA fragment encoding a polypeptide of interest.
[0036] The transfection of e.g. a CHO cell according to the method according to the invention is performed as sequential steps of transfection and selection. CHO cells suitable in the method according to the invention are e.g. a CHO K1 cell, or a CHO DG44 cell, or a CHO XL99 cell, or a CHO DXB11 cell, or a CHO DP12 cell, or a super-CHO cell. Within the scope of the present invention, transfected cells may be obtained with substantially any kind of transfection method known in the art. For example, the nucleic acid may be introduced into the cells by means of electroporation or microinjection. Alternatively, lipofection reagents such as FuGENE 6 (Roche Diagnostics GmbH, Germany), X-tremeGENE (Roche Diagnostics GmbH, Germany), LipofectAmine (Invitrogen Corp., USA), and nucleotransfection (AMAXA Corp.) may be used. Still alternatively, the nucleic acid may be introduced into the cell by appropriate viral vector systems based on retroviruses, lentiviruses, adenoviruses, or adeno-associated viruses (Singer, O., Proc. Natl. Acad. Sci. USA 101 (2004) 5313-5314).
[0037] Usually, gene expression profiling on the DNA or RNA level is monitored on routine basis by a multi-step procedure. First, the respective cellular sample is removed from the culture vessel. In case of adherent cells harvesting may be supported by trypsination (treatment with a Trypsin-EDTA solution) in order to detach the adherent cells from the solid support. Secondly, the collected cells are pelleted and subjected to cell lysis. As a third step it is usually required to at least partially purify the total RNA, mRNA or DNA that is present in the sample (e.g. see EP 0 389 063). Afterwards, if required, a first strand cDNA synthesis step is performed with an RNA dependent DNA polymerase such as AMV or MoMULV Reverse Transcriptase (Roche Applied Science, Germany).
[0038] Subsequently, the amount DNA or of generated cDNA is quantified either by means of quantitative PCR (Sanger, G. and Goldstein, C., Biochemica 3 (2001) 15-17) or alternatively by means of amplification and subsequent hybridization onto a DNA microarray (Kawasaki, E. S., Ann. N.Y. Acad. Sci. 1020 (2004) 92-100). In case of polymerase chain reaction (PCR), a one step RT-PCR may be performed, characterized in that the first strand cDNA synthesis and subsequent amplification are catalyzed by the same Polymerase such as T.th Polymerase (Roche Applied Science Cat. No. 11 480 014, Germany).
[0039] In one embodiment the gene expression analysis is based on real time PCR. Such a monitoring in real time is characterized in that the progress of amplification of the nucleic acid in the PCR reaction is monitored and quantitated in real time. Different detection formats are known in the art. The below mentioned detection formats have been proven to be useful for PCR and thus provide an easy and straight forward possibility for gene expression analysis:
[0040] a) TaqMan Hydrolysis probe format:
[0041] A single-stranded hybridization probe is labeled with two components. When the first component is excited with light of a suitable wavelength, the absorbed energy is transferred to the second component, the so-called quencher, according to the principle of fluorescence resonance energy transfer. During the annealing step of the PCR reaction, the hybridization probe binds to the target DNA and is degraded by the 5′-3′ exonuclease activity of the Taq Polymerase during the subsequent elongation phase. As a result the excited fluorescent component and the quencher are spatially separated from one another and thus a fluorescence emission of the first component can be measured. TaqMan probe assays are reported in detail in U.S. Pat. No. 5,210,015, U.S. Pat. No. 5,538,848, and U.S. Pat. No. 5,487,972. TaqMan hybridization probes and reagent mixtures are reported in U.S. Pat. No. 5,804,375.
[0042] b) Molecular Beacons:
[0043] These hybridization probes are labeled with a fluorescent component and a quencher, the labels preferably being located at both ends of the probe. As a result of the secondary structure of the probe, both components are in spatial vicinity in solution. After hybridization to the target nucleic acids both components are separated from one another such that after excitation with light of a suitable wavelength the fluorescence emission of the first component can be measured (U.S. Pat. No. 5,118,801).
[0044] c) FRET hybridization probes:
[0045] The FRET hybridization probe test format is especially useful for all kinds of homogenous hybridization assays (Matthews, J. A. and Kricka, L. J., Anal. Biochem. 169 (1988) 1-25). It is characterized by two single-stranded hybridization probes which are used simultaneously and which are complementary to adjacent sites of the same strand of the amplified target nucleic acid. Both probes are labeled with different fluorescent components. When excited with light of a suitable wavelength, a first component transfers the absorbed energy to the second component according to the principle of fluorescence resonance energy transfer (FRET) such that a fluorescence emission of the second component can be measured when both hybridization probes bind to adjacent positions of the target molecule to be detected. Alternatively to monitoring the increase in fluorescence of the FRET acceptor component, it is also possible to monitor fluorescence decrease of the FRET donor component as a quantitative measurement of a hybridization event.
[0046] In particular, the FRET hybridization probe format may be used in real time PCR, in order to detect the amplified target DNA. Among all detection formats known in the art of real time PCR, the FRET-Hybridization Probe format has been proven to be highly sensitive, exact and reliable (see WO 97/46707; WO 97/46712; WO 97/46714). As an alternative to two FRET hybridization probes, it is also possible to use a fluorescent-labeled primer and only one labeled oligonucleotide probe (Bernard, P. S., et al., Anal. Biochem. 255 (1998) 101-107). In this regard, it may be chosen arbitrarily, whether the primer is labeled with the FRET donor or the FRET acceptor compound.
[0047] d) SYBR® Green format:
[0048] It is also within the scope of the invention that if real time PCR is performed in the presence of an additive that in case the amplification product is detected using a double stranded nucleic acid binding moiety. For example, the respective amplification product can also be detected according to the invention by a fluorescent DNA binding dye, which emits a corresponding fluorescence signal upon interaction with the double-stranded nucleic acid after excitation with light of a suitable wavelength. The dyes SYBR® Green I and SYBR® Gold (Molecular Probes, USA) have proven to be particularly suitable for this application. Intercalating dyes can alternatively be used. However, for this format, in order to discriminate the different amplification products, it is necessary to perform a respective melting curve analysis (U.S. Pat. No. 6,174,670).
[0049] e) Multiplex format:
[0050] The simultaneous determination of different nucleic acids in one reaction vessel is termed multiplex real time PCR. Generally for the determination of each nucleic acid a fluorescence dye not interfering or having only a small overlap with the other employed dyes is required.
[0051] The PCR primers used in the current invention and which are also aspects of the invention were designed with the software eprimer3 according to the following parameters:
specific binding to the sequence to be amplified, no or unlikely primer dimer formation, length between 18 and 25 nucleotides, G/C content of approximately 50%, melting temperature of approximately 60° C., amplicon of 500 basepairs or less, in one embodiment between 100 and 250 base pairs, preferably the primers should bind to neighboring exons and the PCR product should span at least one intron to enable discrimination between amplification of genomic DNA and cDNA.
[0059] The nucleic acids complementary to the designed primers are located within the constant regions of immunoglobulins heavy and light chains identical in IgG1 and IgG4 type immunoglobulins.
[0060] The probes used in the method are also an aspect of the current invention and were designed with the software eprimer3 according to the following parameters:
melting temperature of approximately 70° C., no G at the 5′ end, no or unlikely dimer formation with primers or other probes, preferably the probes intended to be used for RT PCR should bind to two different adjacent exons to enable discrimination between amplification of genomic DNA and cDNA.
[0065] In one embodiment the nucleic acids complementary to the designed probes are located within the constant regions of immunoglobulins heavy and light chains identical in IgG1 and IgG4 type immunoglobulins. The probes were labeled in order to allow for a multiplex RT-PCR reaction as follows:
light chain: fluorescent dye FAM, excitation at 465 nm, detection at 510 nm, reference gene: Yakima Yellow dye, excitation at 533 nm, detection at 580 nm, heavy chain: fluorescent dye IRD 700 or Cy5, excitation at 618 nm, detection at 660 nm.
[0069] The primers and probes listed in Table 1 were designed and are each individually and as combination an aspect of the current invention.
[0000]
TABLE 1
Primers and probes.
x-
Tm
SEQ ID
#
Primer/probe sequence (5′-3′)
mer
[° C.]
NO:
37
CAGGAGAGTGTCACAGAGC
19
58.8
13
38
CTCTTTGTGACGGGCGAG
18
58.2
14
62
CTCCCTCAGCAGCGTGGTG
19
63.1
15
63
GCTCACGTCCACCACCAC
18
60.5
16
64
GCATTATGCACCTCCACGC
19
58.8
17
65
GCGGCTTTGTCTTGGCATTAT
21
57.9
18
66
GCGTCCTCACCGTCCTGC
18
62.8
19
67
CAAGTGCAAGGTCTCCAACAAAG
23
60.6
20
68
CCATTGCTCTCCCACTCCAC
21
61.4
21
131
CTGTTGTGTGCCTGCTGAAT
20
58
22
132
GACTTCGCAGGCGTAGACTT
20
60
23
133
TCACAGAGCAGGACAGCAAG
20
60
24
134
TGCTTTGCTCAGCGTCAG
18
56
25
139
CTGGAACTGCCTCTGTTGTG
20
60
26
145
TGACGCTGAGCAAAGCAGAC
20
60
27
146
CAGGCCCTGATGGGTGAC
18
61
28
147
(FAM)-ACGAGAAACACAAAGTCTACGCCTGCGA-(TAMRA)
28
70
29
148
CAAAGGCACAGTCAAGGCTGAGAA
24
65
30
149
TGGTGAAGACGCCAGTAGATTCCA
24
65
31
165
(FAM)-CCTCCAATCGGGTAACTCCCAGGA-(BHQ1)
24
69
32
166
(FAM)-AGCACCTACAGCCTCAGCAGCACC-(BHQ1)
24
70
33
167
(IRD700)-ATCACAAGCCCAGCAACACCAAGG-(BHQ3)
24
67
34
168
(IRD700)-ATCTCCAAAGCCAAAGGGCAGCC-(BHQ3)
23
66
35
169
ATTGTGGAAGGACTCATGACC
21
59
36
170
GATGCAGGGATGATGTTCTG
20
58
37
171
(Yakima Yellow)-CCTCCGGAAAGCTGTGGCGT-(BHQ1)
20
65
38
172
(Yakima Yellow)-CCATCACTGCCACCCAGAAGACTG-(BHQ1)
24
69
39
173
(Cy5)-ATCTCCAAAGCCAAAGGGCAGCC-(BHQ3)
23
66
40
174
(Yakima Yellow)-AGATCCCGCCAACATCAAATGGG-(BHQ1)
23
65
41
175
(Yakima Yellow)-AACATCAAATGGGGTGATGCTGGC-(BHQ1)
24
65
42
176
(HEX)-AACATCAAATGGGGTGATGCTGGC-(BHQ1)
24
65
43
[0070] The location of the primers and probes in the immunoglobulin constant region is shown in FIGS. 1 to 4 .
[0071] In the following the current invention is exemplified based on three cell lines producing an immunoglobulin specifically binding to the amyloid β-A4 peptide (anti-Aβ antibody), whereby the first cell line is transfected once, the second cell line is transfected two times, and the third cell line is transfected three times with a plasmid containing a nucleic acid encoding the immunoglobulin.
[0072] The gene expression of the heavy and light immunoglobulin chain was determined with RT-PCR by quantitation of the heavy and light chain mRNAs in the constant region encoding part using the dye SYBR® Green I and TaqMan probes. The determination is in one embodiment performed with total cell RNA.
[0073] The determination of the mRNA amount of the light antibody chain of the three cell lines was independently performed five times each with three different mRNA amounts of 250 ng, 50 ng, and 10 ng and the dye SYBR® Green I. The result of one representative experiment obtained with the primer combination #131 and #132 is listed based on the mRNA amount of the single transfected cell line 8C8, which was set to 100% relative amount in Table 2. It can be seen, that the twice transfected cell line 4F5 has approximately 40% more mRNA encoding immunoglobulin light chain than the single transfected cell line, and that the thrice transfected cell line 20F2 has approximately 70% more mRNA encoding the immunoglobulin light chain.
[0000]
TABLE 2
Exemplary results with primer combination #131 and #132.
amount of mRNA
cell line 4F5
in the sample
% relative to cell line
cell line 20F2
[ng]
8C8 ± σ
% relative to cell line 8C8 ± σ
250
140.44 ± 8.36
178.18 ± 5.34
50
143.06 ± 17.51
160.03 ± 20.18
10
145.40 ± 25.79
166.63 ± 34.76
relative average
142.97 ± 2.48
168.28 ± 9.19
value
[0074] The above performed determination method is specific as only a single product is obtained as confirmed by agarose gel electrophoresis and shown in FIG. 5 .
[0075] For the determination of the mRNA amount of the light antibody chain of the three cell lines with TaqMan hydrolysis probes at first the combination of primers and probe useful in this aspect of the invention had to be determined. The combinations listed in the Table 3 were tested.
[0000]
TABLE 3
Tested TaqMan format nucleic acid.
primer #
forward
reverse
TaqMan probe #
139
134
165, 166
139
132
165, 166
139
146
147, 165, 166
139
38
147, 165, 166
145
146
147
145
38
165
131
134
165, 166
131
132
165, 166
131
146
147, 165, 166
131
38
147, 165, 166
37
134
166
37
132
166
37
146
147, 166
37
38
166
133
134
166
133
132
166
133
146
147, 166
133
38
166
[0076] The PCR products obtained with the different primer-probe-combinations as listed above show (e.g. FIG. 6 ) that the combinations primers #133 and #132 with probe #166 as well as the combination primers #133 and #38 with probe #166 resulted in PCR products with a high specific product yield and low by-product formation. Thus, the primer-probe-combinations #133, #132, and #166 as well as the primer-probe-combination #133, #38, #166 itself are specific aspects of the current invention as well as the use of these primer-probe-combinations. In one embodiment is the primer-probe-combination #133, #132, and #166. This combination is preferred as it shows a better PCR efficiency, i.e. a steeper increase of the amplification curve as denoted in FIG. 7 .
[0077] The determination of the mRNA amount of the light antibody chain of the three cell lines was independently performed four times each with three different mRNA amounts of 250 ng, 50 ng, and 10 ng. The result of one representative experiment obtained with the primer combination #133/#132 and the probe #166 is listed based on the mRNA amount of the single transfected cell line, which was set to 100% relative amount in Table 4. It can be seen, that the cell line 4F5 has approximately 77% more mRNA encoding immunoglobulin light chain than the single transfected cell line, and that the cell line 20F2 has approximately 114% more mRNA encoding the immunoglobulin light chain.
[0000]
TABLE 4
Exemplary results with primer-probe-combination #133/#132/#166.
amount of mRNA
cell line 4F5
in the sample
% relative to cell line
cell line 20F2
[ng]
8C8 ± σ
% relative to cell line 8C8 ± σ
250
171.51 ± 16.83
211.4 ± 15.40
50
183.08 ± 9.22
213.61 ± 5.32
10
177.15 ± 7.14
219.62 ± 8.85
relative average
177.25 ± 5.78
214.88 ± 4.25
value
[0078] The above performed determination method is specific as only a single product is obtained as confirmed by agarose gel electrophoresis.
[0079] For the determination of the mRNA amount of the heavy antibody chain the primers #62 and #65 and the dye SYBR® Green I were used. These primers bind to two different exons (CH1- and CH2 region, respectively), which are separated by one intron, the hinge-exon and a second intron.
[0080] The determination of the mRNA amount of the heavy antibody chain of the three cell lines was independently performed three times each with three different mRNA amounts of 250 ng, 50 ng, and 10 ng. The above performed determination method is specific as only a single product is obtained as confirmed by agarose gel electrophoresis and shown in FIG. 8 .
[0081] The result of one representative experiment obtained with the primer combination #62/#65 is listed based on the mRNA amount of the single transfected cell line, which was set to 100% relative amount in Table 5. It can be seen, that the cell line 4F5 has approximately 60% more mRNA encoding immunoglobulin light chain than the single transfected cell line, and that the cell line 20F2 has approximately 140% more mRNA encoding the immunoglobulin light chain.
[0000]
TABLE 5
Exemplary results with primer combination #62/#65.
amount of mRNA
cell line 4F5
in the sample
% relative to cell line
cell line 20F2
[ng]
8C8 ± σ
% relative to cell line 8C8 ± σ
250
129.83 ± 17.01
174.11 ± 21.34
50
173.71 ± 25.04
120.58 ± 32.31
10
172.91 ± 15.75
235.11 ± 32.11
relative average
158.82 ± 25.10
242.84 ± 57.30
value
[0082] For the determination of the mRNA amount of the heavy antibody chain of the three cell lines with TaqMan hydrolysis probes at first the combination of primers and probe useful in this aspect of the invention had to be determined. The combinations of primers #62, #65, #66, #68, #67, #62, #63 and the TaqMan probes #167 and #168 were tested. The probes contained at the 5′ end the dye IRD700. The PCR products obtained with the different primer-probe-combinations as listed above show (e.g. FIG. 9 ) that the combinations primers #66 and #68 with probe #168 as well as the combination primers #67 and #68 with probe #168 resulted in PCR products with a high specific product yield and low by-product formation. For increase in the fluorescence intensity the fluorescence dye of probe #168 was changed to Cy5. This new probe was denoted as probe #173. Thus, the primer-probe-combinations #66, #68, and #168 or #173 as well as the primer-probe-combination #67, #68, and #168 or #173 itself are specific aspects of the current invention as well as the use of these primer-probe-combinations in the method according to the invention. In one embodiment is the primer-probe-combination #66, #68, and #173. This combination is preferred as it shows a better PCR efficiency, i.e. a steeper increase of the amplification curve.
[0083] The determination of the mRNA amount of the heavy antibody chain of the three cell lines was independently performed four times each with three different mRNA amounts of 250 ng, 50 ng, and 10 ng. The result of one representative experiment obtained with the primer combination #66/#68 and the probe #173 are listed based on the mRNA amount of the single transfected cell line, which was set to 100% relative amount in Table 6. It can be seen, that the cell line 4F5 has approximately 88% more mRNA encoding immunoglobulin heavy chain than the single transfected cell line, and that the cell line 20F2 has approximately 126% more mRNA encoding the immunoglobulin light chain.
[0000]
TABLE 6
Exemplary results with primer-probe-combination #66/#68/#173.
amount of mRNA
cell line 4F5
in the sample
% relative to cell line
cell line 20F2
[ng]
8C8 ± σ
% relative to cell line 8C8 ± σ
250
187.47 ± 12.01
222.94 ± 19.57
50
190.97 ± 3.74
218.86 ± 11.20
10
185.75 ± 6.97
234.84 ± 9.06
relative average
188.06 ± 2.66
225.55 ± 8.30
value
[0084] The above performed determination method is specific as only a single product is obtained as confirmed by agarose gel electrophoresis.
[0085] In order to normalize the results obtained in order to eliminate intraday and interlab variations a correlation to a housekeeping gene can be used. It has been found that the gene encoding the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) can be used for this purpose. Thus, one aspect of the current invention is the primer-probe-combination #169/#170 and #171 and the use of said combination in a TaqMan probe PCR format for the determination of GAPDH mRNA.
[0086] In a multiplex PCR reaction a simultaneous amplification and detection of an mRNA encoding an immunoglobulin heavy chain, an mRNA encoding an immunoglobulin light chain, and an mRNA encoding GAPDH was performed. For the single determination the primer-probe-combinations #132/#133/#166 (light chain, FAM dye), #66/#68/#173 (heavy chain, Cy5 dye), and #169/#170/#171 (GAPDH, Yakima Yellow dye) were used. The combination for the GAPDH gene was not useful in a multiplex PCR reaction. But it has been found that the primer-probe-combination #148/#149/#174 is useful in a multiplex PCR determination of GAPDH mRNA. Thus, one aspect of the current invention is the primer-probe-combination #148/#149 and #174 and the use thereof in a multiplex PCR reaction.
[0087] After the multiplex PCR employing the primer-probe-combinations #132/#133/#166 (for light chain amplification and detection, FAM dye), #66/#68/#173 (for heavy chain amplification and detection, Cy5 dye), and #148/#149/#174 (for GAPDH amplification and detection, Yakima Yellow dye) the PCR products were separated on a 2% agarose gel. The detected bands correlated to the expected fragments of 101 by (light chain), 197 by (GAPDH), 244 by (heavy chain) (see FIG. 10 ).
[0088] The efficiency of the real-time PCR reactions was determined based on a dilution series (200 ng, 100 ng, 50 ng, 25 ng, 12.5 ng, 6.25 ng, 3.125 ng) determined as quadruplicates and is given in Table 7.
[0000]
TABLE 7
Efficiency.
exper-
Light chain
GAPDH
Heavy chain
iment
8C8
4F5
20F2
8C8
4F5
20F2
8C8
4F5
20F2
1
1.905
1.884
1.951
1.94
1.983
2.069
1.949
1.997
1.992
2
1.971
1.936
1.936
2.064
2.067
2.085
2.043
2.027
2.037
3
1.924
1.945
1.936
1.989
2.097
2.041
1.963
1.905
1.991
ø
1.933
1.92
1.94
2.00
2.05
2.07
1.99
1.98
2.01
σ
0.034
0.033
0.009
0.062
0.059
0.022
0.051
0.064
0.026
[0089] Thus, an efficiency of 2 for the calculation can be used.
[0090] In the multiplex PCR the following amounts for the mRNA encoding the immunoglobulin light chain and the immunoglobulin heavy chain in cell lines 4F5 and 20F2 compared to the cell line 8C8, which is set to 100%, were found.
[0000]
TABLE 8
Exemplary multiplex PCR results.
Light chain
Heavy chain
ex-
4F5
20F2
4F5
20F2
peri-
% of
% of
% of
% of
ment
8C8
Dev.
8C8
Dev.
8C8
Dev.
8C8
Dev.
1
172.61
4.96
212.04
10.96
167.9
12.82
241.17
9.24
2
164.19
7.59
179.56
11.96
161.07
7.64
207.46
13.75
3
172.62
17.64
199.23
13.27
155.34
15.98
214.21
22.38
ø
169.81
4.86
196.94
16.36
161.44
6.29
220.95
17.84
[0091] It has now been found that the specific production rate (SPR) of a cell correlates well with the amount of mRNA encoding the produced heterologous polypeptide.
[0092] This was found for simplex PCR reactions (Table 9) as well as for multiplex PCR reactions (table 10).
[0000]
TABLE 9
Exemplary simplex PCR reaction results.
SPR
LC
HC
% Rel-
% Rel-
% Rel-
cell
ative
Factor 1
ative
Factor 2
ative
Factor 3
8C8
100
1
100
1
100
1
4F5
185
1.85
171.51
1.71
188.06
1.88
20F2
166
1.66
211.4
2.11
225.55
2.26
[0000]
TABLE 10
Exemplary multiplex PCR reaction results.
SPR
Light chain
Heavy chain
% Rel-
% Rel-
% Rel-
cell
ative
Factor 1
ative
Factor 2
ative
Factor 3
8C8
100
1
100
1
100
1
4F5
185
1.85
169.81
1.7
161.44
1.61
20F2
166
1.66
196.94
1.97
220.95
2.21
[0093] It has now been found that a factor can be calculated based on the amount of mRNA determined via PCR of a cell with unknown SPR and a cell with known SPR of a heterologous polypeptide which allows for the calculation of the unknown SPR.
[0000]
TABLE 11
Factor determination.
SPR
Factor 1/0.5 * (Factor 2 + 3)
cell
% Relative
Simplex PCR
Multiplex PCR
8C8
100
—
—
4F5
185
1.0
1.1
20F2
166
0.8
0.8
[0094] Thus, one aspect of the current invention is a method for determining the productivity of a cell expressing a heterologous polypeptide comprising the steps of
determining the amount of mRNA encoding the heterologous polypeptide in a cell of known productivity, determining the amount of mRNA encoding the heterologous polypeptide in a cell of unknown productivity, calculating the ratio of the determined amount of mRNA encoding the heterologous polypeptide of the cell of unknown productivity to the cell of known productivity, multiplying the productivity of said cell of known productivity with said calculated ratio and thereby determining the productivity of a cell expressing a heterologous polypeptide.
[0099] In one embodiment the heterologous polypeptide is an immunoglobulin or an immunoglobulin fragment or an immunoglobulin conjugate. In one embodiment the heterologous immunoglobulin is a multimeric heterologous immunoglobulin. In another embodiment the amount of mRNA encoding the heterologous polypeptide is the sum of the amounts of mRNA encoding all subunits of said heterologous polypeptide divided by the number of subunits. In one embodiment the productivity is the specific production rate in pg/cell/day. In one embodiment the amount of mRNA encoding the heterologous immunoglobulin is the average of the amount of mRNA encoding the light chain of the heterologous immunoglobulin and the amount of mRNA encoding the heavy chain of the heterologous immunoglobulin. In one embodiment the determining of the amount of mRNA is via a polymerase chain reaction (PCR). In one embodiment the PCR is a multiplex PCR. In another embodiment the PCR is a reverse transcription PCR (RT-PCR). In one embodiment the calculated ratio is multiplied by a factor of 0.925.
[0100] For example, the specific production rate of a parent cell is 100 pg/cell/day. Via multiplex PCR of the mRNA of a cell of unknown productivity the amount of mRNA encoding the immunoglobulin light chain was determined to be 169% and the amount of mRNA encoding the immunoglobulin heavy chain was determined to be 161% of the amount of mRNA of the parent cell. The average of said mRNA amounts is 165% or 1.65 times the amount of mRNA of the parent cell. Thus, the SPR of the parent cell of 100 pg/cell/day is multiplied by 1.65, thereby obtaining a SPR of 165 pg/cell/day. The SPR of the unknown cell was determined to be 165 pg/cell/day.
[0101] The term “about” as used within this application denotes a deviation of +/−10% of the indicated value. Thus, the term “about 1.65” denotes the range of from 1.49 to 1.82.
[0102] Depending on the amino acid sequence of the constant region of their heavy chains, antibodies are divided in the classes: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses, such as IgG1, IgG2, IgG3, and IgG4, IgA1 and IgA2. The heavy chain constant regions that correspond to the different classes of antibodies are called α, δ, ε, γ, and μ. respectively. The light chain constant regions which can be found in all five antibody classes are called κ (kappa) and λ (lambda).
[0103] Due to the different gene copy numbers encoding the heterologous immunoglobulin integrated into the genome the amount of mRNA transcribed from these genes is also different. Thus, a further aspect of the current invention is a method for the determination of the amount of mRNA or DNA with relative quantitation for mRNA or absolute quantitation for DNA comprising
a) providing a sample, b) performing a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33, and/or c) performing a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40, and d) quantitating with an efficiency of 2.0.
[0108] It has furthermore been found that the specific productivity of the different cell lines correlates well with the mRNA amount. It has also been found that the mRNA encoding the heavy chain of the immunoglobulin accounts for 30% of the immunoglobulin encoding mRNA and that the mRNA encoding the light chain of the immunoglobulin accounts for 70% of the immunoglobulin encoding mRNA.
[0109] A further aspect of the invention is a method for the selection of an immunoglobulin producing cell comprising
a) providing a cell, b) isolating the RNA of said cell, c) performing with the isolated RNA a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33, d) performing with the isolated RNA a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40, e) selecting a cell as an immunoglobulin producing cell if in step c) and d) a polymerase chain reaction product is obtained.
[0115] In one embodiment the provided cell has been transfected with a nucleic acid encoding an immunoglobulin. In another embodiment the provided cell is a cell not endogenously producing an immunoglobulin. In one embodiment the cell is a plurality of cells.
[0116] Another aspect of the invention is a method for the production of an immunoglobulin comprising
a) providing a plurality of cells, b) isolating the RNA of each of said cells, c) performing with the isolated RNA a polymerase chain reaction with the primers of SEQ ID NO: 23 and 24 and the probe of SEQ ID NO: 33, d) performing with the isolated RNA a polymerase chain reaction with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40, e) selecting a cell based on the amount of polymerase chain reaction product formed in step c) and d), f) cultivating the selected cell, g) recovering the immunoglobulin from the cell or the culture medium and thereby producing an immunoglobulin.
[0124] In one embodiment the cell is selected which has the highest amount of polymerase chain reaction product in step d).
[0125] A further aspect of the current invention is a method for the simultaneous determination of IgG1 and IgG4 heavy and light chains in a high throughput manner.
[0126] In one embodiment of the current invention is the heterologous polypeptide an anti-Abeta antibody.
[0127] In one embodiment of the before presented methods according to the invention the polymerase chain reaction is a TaqMan hydrolysis probe format. In another embodiment said light chain primers are labeled with the dye FAM and the heavy chain primers are labeled with the dye Cy5. In one embodiment the primers of SEQ ID NO: 23 and 24 are for the immunoglobulin light chain and the primers of SEQ ID NO: 19 and 20 are for the immunoglobulin heavy chain. In one embodiment steps c) and d) in addition comprises measuring the amplification of the nucleic acid in real time to determine the amplified amount of the nucleic acid.
[0128] The following examples, sequence listing and figures are provided to aid the understanding of the present invention, the true scope of which is set forth in the appended claims. It is understood that modifications can be made in the procedures set forth without departing from the spirit of the invention.
DESCRIPTION OF THE FIGURES
[0129] FIG. 1 Location and direction of primers and probes in the light chain constant region (human IgG kappa chain; SEQ ID NO: 44).
[0130] FIG. 2 Location and direction of primers and probes in the heavy chain constant region 1 (human IgG heavy chain CH1; SEQ ID NO: 45).
[0131] FIG. 3 Location and direction of primers and probes in the heavy chain constant region 2 (human IgG heavy chain CH2; SEQ ID NO: 46).
[0132] FIG. 4 Location and direction of primers and probes in the heavy chain constant region 3 (human IgG heavy chain CH3; SEQ ID NO: 47).
[0133] FIG. 5 Agarose gel separation of light chain PCR reaction with the primer combination #131 and #132 and SYBR® GREEN I.
[0134] FIG. 6 Agarose gel separation of an 8 μl sample of a 45 cycle PCR reaction; samples: MW: base-pair marker; 1: 139/134-165; 2: 139/134-166; 3: 139/132-165; 4: 139/132-166; 5: 139/146-165; 6: 139/146-166; 7: 139/38-147; 8: 139/38-165; 9: 139/38-166; 10: 139/146-147; 11: 131/38-166; 12: 131/38-147; 13: 37/134-166; 14: 37/132-166; 15: 37/146-166; 16: 37/146-147; 17: 145/146-147; 18: 145/38-147; 19: 131/134-165; 20: 131/134-166; 21: 131/132-165; 22: 131/132-166; 23: 131/146-166; 24: 131/146-165; 25: 131/146-147; 26: 131/38-165; 27: 37/38-166; 28: 133/134-166; 29: 133/132-166; 30: 133/146-166; 31: 133/146-147; 32: 133/38-166.
[0135] FIG. 7 Amplification curves of PCR reactions with the primer-probe-combinations #133, #132, and #166, or #133/#38, and #160, respectively.
[0136] FIG. 8 Agarose gel separation of heavy chain PCR reaction with the primers #62 and #65 and the dye SYBR® Green I; bpm =base pare standard marker; 1: empty reference; 2: 8C8; 3: 4F5; 4: 20F2.
[0137] FIG. 9 Agarose gel separation of an 8 μl sample of a 45 cycle PCR reaction; samples: MW: base-pair marker; 1: empty reference; 2: 62/65-167; 3: 66/68-168; 4: 67/68-168.
[0138] FIG. 10 Agarose gel of the PCR products of a multiplex PCR employing the primer-probe-combinations #132/#133/#166 (for light chain amplification and detection, FAM dye), #66/#68/#173 (for heavy chain amplification and detection, Cy5 dye), and #148/#149/#174 (for GAPDH amplification and detection, Yakima Yellow dye). The detected bands correlated to the expected fragments of 101 by (light chain), 197 by (GAPDH), and 244 by (heavy chain).
EXAMPLES
[0139] Materials & Methods
[0140] General information regarding the nucleotide sequences of human immunoglobulins light and heavy chains is given in: Kabat, E. A., et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, Md. (1991). Amino acids of antibody chains are numbered according to EU numbering (Edelman, G. M., et al., Proc. Natl. Acad. Sci. USA 63 (1969) 78-85; Kabat, E. A., et al., Sequences of Proteins of Immunological Interest, 5th ed., Public Health Service, National Institutes of Health, Bethesda, Md. (1991)).
[0141] Recombinant DNA Techniques:
[0142] Standard methods were used to manipulate DNA as described in Sambrook, J., et al., Molecular cloning: A laboratory manual; Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989. The molecular biological reagents were used according to the manufacturer's instructions.
[0143] Gene Synthesis:
[0144] Desired gene segments were prepared from oligonucleotides made by chemical synthesis. The 100-600 by long gene segments, which are flanked by singular restriction endonuclease cleavage sites, were assembled by annealing and ligation of oligonucleotides including PCR amplification and subsequently cloned into the pCR2.1-TOPO-TA cloning vector (Invitrogen Corp., USA) via A-overhangs or pPCR-Script Amp SK(+) cloning vector (Stratagene Corp., USA). The DNA sequence of the subcloned gene fragments were confirmed by DNA sequencing.
[0145] DNA Oligonucleotide Synthesis:
[0146] Unlabeled primers and probes, which were labeled with fluorescent dyes and quenchers, were generated by chemical synthesis.
[0147] Protein Determination:
[0148] Protein concentration was determined by determining the optical density (OD) at 280 nm, using the molar extinction coefficient calculated on the basis of the amino acid sequence.
[0149] DNA and RNA Determination:
[0150] DNA and RNA concentration was determined by measuring the optical density at 260 nm assuming that an optical density of 1 corresponds to 50 μg/ml double stranded DNA or 40 μg/ml RNA.
[0151] Cell Number Determination:
[0152] The cell number was determined in a CASY® TT model. Prior to cell number determination the cells were individualized by treatment with trypsin at 37° C. for 10 minutes. Trypsination was terminated by the addition of fetal calf serum (FCS).
[0153] Immunoglobulin Titer Determination:
[0154] Immunoglobulin titers were determined either by anti-human Fc ELISA or by Protein A chromatography using the autologous purified antibody as a reference.
[0155] SDS-PAGE
[0156] LDS sample buffer, fourfold concentrate (4×): 4 g glycerol, 0.682 g TRIS-Base, 0.666 g TRIS-hydrochloride, 0.8 g LDS (lithium dodecyl sulfate), 0.006 g EDTA (ethylene diamin tetra acid), 0.75 ml of a 1% by weight (w/w) solution of Serva Blue G250 in water, 0.75 ml of a 1% by weight (w/w) solution of phenol red, add water to make a total volume of 10 ml.
[0157] The culture broth containing the secreted immunoglobulin was centrifuged to remove cells and cell debris. An aliquot of the clarified supernatant was admixed with ¼ volumes (v/v) of 4×LDS sample buffer and 1/10 volume (v/v) of 0.5 M 1,4-dithiotreitol (DTT). Then the samples were incubated for 10 min. at 70° C. and protein separated by SDS-PAGE. The NuPAGE® Pre-Cast gel system (Invitrogen Corp., USA) was used according to the manufacturer's instruction. In particular, 10% NuPAGE® Novex® Bis-TRIS Pre-Cast gels (pH 6.4) and a NuPAGE® MOPS running buffer was used.
[0158] Western Blot
[0159] Transfer buffer: 39 mM glycine, 48 mM TRIS-hydrochloride, 0.04% (w/w) SDS, and 20% (v/v) methanol.
[0160] After SDS-PAGE the separated immunoglobulin chains were transferred electrophoretically to a nitrocellulose filter membrane (pore size: 0.45 μm) according to the “Semidry-Blotting-Method” of Burnette (Burnette, W. N., Anal. Biochem. 112 (1981) 195-203).
[0161] RNA-Isolation
[0162] RNA has been isolated with the RNeasy® mini-Kit from Qiagen (Hilden, Germany) according to the manufacturer's manual. DNA contamination was eliminated by the addition of DNAse. The RNA was isolated from 1×10 7 cells sampled at the third day of cultivation.
[0163] DNA-Isolation
[0164] Genomic DNA was isolated with the Blood & Cell Culture DNA Midi Kit from Qiagen (Hilden, Germany) according to the manufacturer's manual from 1×10 7 cells at the fourth day of cultivation.
[0165] Real Time PCR or Real Time RT-PCR
[0166] For the real-time PCR or real-time RT-PCR the dyes SYBR® Green I and TaqMan-probes have been used. The reaction mixtures were after preparation and prior to amplification placed on ice in the dark. The determination and analysis was performed with the LightCycler® 2.0-System and LightCycler® software 4.1 or with the LightCycler® II 480-System and LightCycler® software 1.5 (all Roche Diagnostics GmbH, Mannheim, Germany).
Example 1
[0167] Expression Vector for Expressing an Anti-Aβ Antibody
[0168] An example antibody with which the methods according to the invention can be exemplified is an antibody against the amyloid β-A4 peptide (anti-Aβ antibody). Such an antibody and the corresponding nucleic acid sequences are, for example, reported in WO 2003/070760 or US 2005/0169925 or in SEQ ID NO: 1 to 12.
[0169] Three anti-Aβ antibody expressing Chinese hamster ovary (CHO) cell lines were generated by three successive complete transfections and selection campaigns as reported in WO 2009/046978.
[0170] A genomic human κ-light chain constant region gene segment (C-kappa, C L ) was added to the light chain variable region of the anti-Aβ antibody, while a human γ1-heavy chain constant region gene segment (C H1 -Hinge-C H2 -C H3 ) was added to the heavy chain variable region of the anti-Aβ antibody. The complete κ-light and γ1-heavy chain antibody genes were then joined with a human cytomegalovirus (HCMV) promoter at the 5′-end and a human immunoglobulin polyadenylation signal sequence at the 3′-end.
[0171] For expression and production of the anti-Aβ antibody the light and heavy chain expression cassettes were placed on a single expression vector (heavy chain upstream of light chain in clockwise orientation). Three identical expression vectors were generated differing only in the selectable marker gene included, in particular, in the gene conferring resistance to the selection agent neomycin, hygromycin, or puromycin.
[0172] The preadapted parent host cells were propagated in suspension in synthetic, animal component-free ProCHO4-complete medium under standard humidified conditions (95%, 37° C., and 5% CO 2 ). On regular intervals depending on the cell density the cells were splitted into fresh medium. The cells were harvested by centrifugation in the exponential growth phase, washed once in sterile phosphate buffered saline (PBS) and resuspended in sterile PBS.
[0173] Prior to transfection the anti-Aβ antibody expressing plasmids were linearized within the β-lactamase gene ( E. coli ampicillin resistance marker gene) using the restriction endonuclease enzyme PvuI or AviII. The cleaved DNA was precipitated with ethanol, dried under vacuum, and dissolved in sterile PBS.
[0174] In general, for transfection, the CHO cells were electroporated with 20-50 μg linearized plasmid DNA per approximately 10 7 cells in PBS at room temperature. The electroporations were performed with a Gene Pulser XCell electroporation device (Bio-Rad Laboratories) in a 2 mm gap cuvette, using a square wave protocol with a single 180 V pulse. After transfection, the cells were plated out in ProCHO4-complete medium in 96-well culture plates. After 24 h of growth a solution containing one or more selection agents were added (ProCHO4-complete selection medium; G418: 400 μg/ml; hygromycin: 600 μg/ml; puromycin: 8 μg/ml). Once a week the ProCHO4-complete selection medium was replaced. The antibody concentration of the anti-Aβ antibody was analyzed with an ELISA assay specific for human IgG1 in the culture supernatants.
[0175] For selection of anti-Aβ antibody producing cell lines the productivity was tested in ProCHO4-complete selection medium after propagation in 6-well culture plates, T-flasks and/or Erlenmeyer shake flasks using an anti-human IgG1 ELISA and/or analytic Protein A HPLC.
[0176] For the first transfection and selection step a plasmid containing a gene conferring resistance to the selection agent neomycin has been used. The plasmid has been transfected with electroporation into parent cell line adapted to growth in ProCHO4-complete medium. The transfected cells were cultivated in ProCHO4-complete medium supplemented with up to 700 μg/ml G418 in 96 well plates. The antibody concentration in the culture supernatants was evaluated by an anti-human IgG1 ELISA. Approximately 1000 clones have been tested and the selected of them were further cultivated in 24-well plates, 6-well plates and subsequently in shaker flasks. The growth and productivity of approximately 20 clones was assessed in static and suspension cultures by anti-human IgG1 ELISA and/or analytic protein A HPLC. The best clone (best clone does not denote the most productive clone it denotes the clone with the best properties for the further steps) was subcloned by limited dilution in ProCHO4-conditioned medium supplemented with 700 μg/ml G418. The selected clone was named 8C8.
[0177] For the second transfection and selection step a plasmid containing a gene conferring resistance to the selection agent hygromycin has been used. The plasmid has been transfected with electroporation into cell line cultivated in ProCHO4-complete medium supplemented with 700 μg/ml G418. The transfected cells were expanded for about two to three weeks in ProCHO4-conditioned medium supplemented with 200 μg/ml G418 and 300 μg/ml hygromycin (ProCHO4-double selection medium). Single antibody secreting cells were identified and deposited on the basis of their fluorescence intensity after staining with a Protein A Alexa Fluor conjugate by FACS analysis. The deposited cells were cultivated in ProCHO4-double selection medium in 96 well plates. The antibody concentration in the culture supernatants was evaluated by an anti-human IgG1 ELISA. Approximately 500 clones have been tested and the selected of them were further cultivated in 24-well plates, 6-well plates and subsequently in shaker flasks. The growth and productivity of approximately 14 clones was assessed in static and suspension cultures by anti-human IgG1 ELISA and/or analytic Protein A HPLC. The selected clone was named 4F5.
[0178] For the third transfection and selection step a plasmid containing a gene conferring resistance to the selection agent puromycin has been used. The plasmid has been transfected with electroporation into cell line cultivated in ProCHO4-double selection medium. The transfected cells were expanded for about two to three weeks in ProCHO4-triple selection medium (ProCHO4-conditioned medium supplemented with 200 μg/ml G418 and 300 μg/ml hygromycin and 4 μg/ml puromycin). Single antibody secreting cells were identified and deposited on the basis of their fluorescence intensity after staining with a Protein A Alexa Fluor conjugate by FACS analysis. The deposited cells were cultivated in ProCHO4-triple selection medium in 96 well plates. The antibody concentration in the culture supernatants was evaluated by an anti-human IgG1 ELISA. Approximately 500 clones have been tested and the selected of them were further cultivated in 24-well plates, 6-well plates and subsequently in shaker flasks. The growth and productivity of approximately 10 clones was assessed in static and suspension cultures by anti-human IgG1 ELISA and/or analytic protein A HPLC. The selected clone was named 20F2.
[0179] Clone Characteristics:
[0180] As can be seen from the following table the doubling time and cell density after three days of cultivation were comparable when the basic cell line CHO-K1 (wild-type) and the selected clones are compared.
[0000]
TABLE 12
Clone characteristics.
Doubling
Starting cell
Cell density at
Viability at
time
density
day 3
day 3
Clone
[h]
[10 6 cells/ml]
[10 6 cells/ml]
[%]
CHO-K1
22-23
3
18-20
97-98
(wild-type)
8C8
26-28
3
12-15
96-98
4F5
22-24
3
24-27
96-97
20F2
24-26
2
23-26
97-98
Example 2
[0181] Real-Time RT-PCR with SYBR® Green I
[0182] For the RT-PCR with SYBR® Green I the LightCycler® 2.0 system was employed (Roche Diagnostics GmbH, Mannheim, Germany). From the RNA of cell lines 8C8, 4F5 and 20F2 each a dilution series with decreasing RNA concentration was prepared and analyzed. The RNA amount in all samples was supplemented with wild-type-RNA in a way that the total RNA amount, i.e. the sum of wild-type-RNA and sample-RNA, was the same in all samples.
[0183] After sample preparation 5 μl of the sample was mixed with 15 μl of a RT-PCR-SG solution. The RT-PCR-SG solution comprises:
5 μl PCR grade water 1.3 μl 50 nM Mn(OAc) 2 7.5 μl SYBR® Green I Pre-Mix 0.6 μl forward primer (10 pmol/μl) 0.6 μl reverse primer (10 pmol/μl).
[0189] From each sample three different RNA amounts were analyzed (250 ng, 50 ng, and 10 ng). The PCR conditions were as shown in Table 13.
[0000]
TABLE 13
PCR conditions.
Ramp
deter-
Cycle
T
t
Rate
mina-
Program
Phase
number
[° C.]
[min:s]
[° C./s]
tion
Reverse
1
61
20:00
20
—
Transcription
Denaturation
1
95
02:00
20
—
Real-Time
Denaturation
45
95
00:10
20
—
PCR
Annealing
vari-
00:20
20
—
able
Elongation
72
00:20
2
—
Detection
82
00:00
20
single
Melting
Denaturation
1
95
00:05
20
—
curve
Annealing
60
00:15
20
—
Melting
91
00:00
0.1
contin-
uous
cooling
1
37
00:01
2.2
—
[0190] The fluorescence was determined at 530 nm.
[0191] Analogously the LightCycler® II 480 system was employed in the RT-PCR. The PCR conditions were as shown in Table 14.
[0000]
TABLE 14
PCR conditions.
Ramp
deter-
cycle
T
t
Rate
mina-
Program
phase
number
[° C.]
[min:s]
[° C./s]
tion
Reverse
1
61
20:00
4.4
—
Transcription
Denaturation
1
95
05:00
4.4
—
Real-Time
Denaturation
45
95
00:10
4.4
—
PCR
Annealing
vari-
00:20
2.2
—
able
Elongation
72
00:20
4.4
—
Detection
82
00:00
4.4
single
melting
Denaturation
1
95
00:05
4.4
—
curve
Annealing
60
01:00
2.2
—
Melting
91
00:00
0.11
contin-
uous
cooling
1
37
00:01
2.2
—
Example 3
[0192] Real-time RT-PCR with TaqMan hydrolysis Probes
[0193] For the RT-PCR with TaqMan hydrolysis probes the LightCycler® II 480 system was employed (Roche Diagnostics GmbH, Mannheim, Germany). The PCR samples were prepared by using the LightCycler® 480 RNA Master Hydrolysis Probes Kit (Roche Diagnostics GmbH, Mannheim, Germany).
[0194] After sample preparation 5 μl of the sample was mixed with 15 μl of a RT-PCR-HS solution. The RT-PCR-HS solution comprises:
3.8 μl PCR grade water 1.3 μl 3.25 nM Mn(OAc) 2 7.4 μl LightCycler® Pre-Mix 1.0 μl forward primer (10 pmol/μl) 1.0 μl reverse primer (10 pmol/μl) 0.5 μl TaqMan hydrolysis probe (10 pmol/μl).
[0201] The PCR conditions were as shown in Table 15.
[0000]
TABLE 15
PCR conditions.
Ramp
deter-
cycle
T
t
Rate
mina-
Program
phase
number
[° C.]
[min:s]
[° C./s]
tion
Reverse
1
61
20:00
4.4
—
Transcription
Denaturation
1
95
02:00
4.4
—
Real-Time
Denaturation
45
95
00:10
4.4
—
PCR
Annealing
60
00:05
2.2
—
Elongation
72
00:01
4.4
single
cooling
1
37
00:01
2.2
—
Example 4
[0202] Real-time Multiplex RT-PCR with TaqMan Hydrolysis Probes
[0203] For the multiplex RT-PCR two or three, respectively, TaqMan hydrolysis probes have been combined. After sample preparation 5 μl of the sample was mixed with 15 μl of a RT-PCR-M_HS solution.
[0000]
TABLE 16
Components of the RT-PCR-M_HS solution.
volume for
component
two probes [μl]
three probes [μl
PCR grade water
1.3
1.3
Mn(OAc) 2 , 3.25 mM
1.3
1.3
LightCycler ® Pre-Mix
7.4
7.4
Primer forward 1, 10 pmol/μl
1
0.75
Primer reverse 1, 10 pmol/μl
1
0.75
TaqMan probe 1, 10 pmol/μl
0.5
0.5
Primer forward 2, 10 pmol/μl
1
0.75
Primer reverse 2, 10 pmol/μl
1
0.75
TaqMan probe 2, 10 pmol/μl
0.5
0.5
Primer forward 3, 10 pmol/μl
—
0.75
Primer reverse 3, 10 pmol/μl
—
0.75
TaqMan probe 3, 10 pmol/μl
—
0.5
total
15
15
[0204] The results of the multiplex RT-PCR have been corrected with a color compensation program generated for the employed TaqMan probes.
Example 5
[0205] Real-time PCR
[0206] For the real-time PCR the LightCycler® II 480 system employing SYBR® Green I and TaqMan probes have been used. Each sample was determined in the sample-DNA dilutions 50 ng, 25 ng, 10 ng, 5 ng, and 2.5 ng as quadruplicate. For the real-time PCR 15 μl of the corresponding PCR solution was placed in the well of a 96-well microtiter plate followed by 5 μl of the sample-DNA. The plate was sealed with a LightCycler® 480 sealing foil (Roche Diagnostics GmbH, Mannheim, Germany) and centrifuged at 1,500×g for 2 minutes. Afterwards the plate was mounted into the LightCycler® 480 system. The determination and analysis of the data was done with the LightCycler® 480 software version 1.5.
[0207] The copy number was determined by absolute quantitation with the first transfection plasmid of Example 1 as external standard in linearized form.
[0208] SYBR® Green I
[0209] For the real-time PCR the LightCycler® FastStart Master PLUS SYBR Green I Kit (Roche Diagnostics GmbH, Mannheim, Germany) was employed. The reaction mixture was composed of:
9 μl PCR grade water 4 μl SYBR® Green I Pre-Mix 1 μl forward primer (10 pmol/μl) 1 μl reverse primer (10 pmol/μl).
[0214] The employed PCR conditions were as shown in Table 17.
[0000]
TABLE 17
PCR conditions.
Ramp
deter-
cycle
T
t
Rate
mina
Program
phase
number
[° C.]
[min:s]
[° C./s]
tion
Denaturation
1
95
10:00
4.4
—
Real-Time
Denaturation
45
95
00:10
4.4
—
PCR
Annealing
60
00:10
2.2
—
Elongation
72
00:10
4.4
Detection
86
00:01
4.4
single
cooling
1
37
00:01
2.2
—
[0215] TaqMan Hydrolysis Probe
[0216] For the RT-PCR the LightCycler® 480 Probes Master Kit (Roche Diagnostics GmbH, Mannheim, Germany) was used. The reaction mixture was composed of:
2.5 μl PCR grade water 10 μl LightCycler® Pre-Mix 1 μl forward primer (10 pmol/μl) 1 μl reverse primer (10 pmol/μl) 0.5 μl TaqMan hydrolysis probe (10 pmol/μl).
[0222] The employed PCR conditions were as shown in Table 18.
[0000]
TABLE 18
PCR conditions.
Ramp
Deter-
Cycle
T
t
Rate
mina-
Program
Phase
number
[° C.]
[min:s]
[° C./s]
tion
Denaturation
1
95
10:00
4.4
—
Real-Time
Denaturation
45
95
00:10
4.4
—
PCR
Annealing
60
00:05
2.2
—
Elongation
72
00:01
4.4
single
cooling
1
37
00:01
2.2
—
[0223] Absolute Quantitation
[0224] In the absolute quantitation the amount of a nucleic acid sequence is determined in terms of copy number of said sequence. The standard or reference function was determined by analysis of five solutions with known concentrations of the first plasmid used in example 1. The reference function provided for a linear relationship between the Cp value and the copy number of a nucleic acid and allowed for the determination of an unknown copy number in a sample.
[0225] The dilutions of the standard samples contained 2.5×10 7 to 2.5×10 2 copies of the plasmid. The calculation of the copy number (Nk) of the linearized plasmid of the standard function was done according to the following equations (1) to (4) (see e.g. Jiang, Z., et al., Biotechnol. Prog. 22 (2006) 313-318):
[0000]
M
Plasmid
=
bp
Plasmid
×
M
bp
=
14
,
0333
bp
·
660
g
mol
-
1
=
9
,
261
,
780
g
mol
-
1
(
1
)
c
Plasmid
=
92.92
ng
µ
l
-
1
(
after
linearization
)
(
2
)
N
A
=
6.022
×
10
23
mol
-
1
(
Avogardo
'
s
number
)
(
3
)
N
K
=
c
Plasmid
·
N
A
M
Plasmid
=
6.0416
×
10
9
copies
µ
l
-
1
(
4
)
|
It is reported herein a method for the determination of the amount of immunoglobulin-encoding mRNA comprising: a) providing a sample, b) performing a polymerase chain reaction for amplifying the light chain with the primers of SEQ ID NO: and 24 and the probe of SEQ ID NO: 33, and/or c) performing a polymerase chain reaction for amplifying the heavy chain with the primers of SEQ ID NO: 19 and 21 and the probe of SEQ ID NO: 40, and d) quantitating with an efficiency of 2.0. The primers with SEQ ID NOs 23 and 24 bind at positions CL 247-266 and CL166-185, respectively, and the probe with SEQ ID NO: 33 binds at 189-212 in human IgG koppa chain. The primer with SEQ ID NO: 19 binds at CH region 2 position 220-237 and the primer with SEQ ID NO: 21 binds at CH region 3 position 114-133. Finally the probe with SEQ ID NO: 40 binds from position 315 in CH2 to position 7 in CH3.
| 2
|
RELATED APPLICATIONS
[0001] The present application claims the benefit of co-pending U.S. patent application Ser. No. 09/836,787, filed on Apr. 17, 2001, now abandoned, the specification of which is hereby incorporated in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention refers to a charged internal combustion engine.
[0004] 2. Description of the Related Art
[0005] Internal combustion engines with turbochargers, as commonly known, use the energy contained in the exhaust and convert it into mechanical energy in an exhaust turbine to power a turbo compressor, which increases the pressure of the air supplied to the internal combustion engine. To accomplish this, turbocharging can occur in one or more steps.
[0006] In DE 198 37 978 A1, a two step turbocharging is disclosed, where at least two turbines are attached in the exhaust section, each of which power a turbo compressor. The exhaust turbines are connected in series as high and low pressure level. First, the exhaust flows through the high pressure turbine and then through the low pressure turbine. The charge air is first compressed by the low pressure compressor and then by the high pressure compressor and, in certain cases after cooling by passing through a heat exchanger, is supplied to the fresh gas side of the internal combustion engine. As the RPM of the internal combustion engine is increased, compression is increasingly shifted towards a single stage which occurs exclusively in the low pressure compressor. In comparison to one-step compression, charging is already possible at low engine speeds with such a two-step charging process, but the turbine operation, and therefore indirectly the compressor operation, is limited by the energy contained in the exhaust. That means that the unburned gas conducted into the internal combustion engine can only be compressed a little, especially with lower speeds. Without boost the internal combustion engine creates weak torque, which leads to poor acceleration when used in a motor vehicle.
SUMMARY OF THE INVENTION
[0007] The invention is concerned with the task of improving an internal combustion engine of the type disclosed in the precharacterizing portion of claim 1, so that it can generate high torque even at low RPM, and thus making stationary torque available more rapidly at partial load. In doing so, a high charge pressure should build up early on, which can match the requirements of the internal combustion engine.
[0008] Based on the invention, this task is solved by connecting a supplemental compressor, which has a drive which is independent from the working medium cycle of the internal combustion engine, arranged in parallel or in series with the turbocharger.
[0009] In an especially beneficial embodiment, the supplemental compressor is driven by an electric motor, and the supplemental compressor is connected with the turbocharger in series. The supplemental compressor is beneficially arranged upstream of the turbocharger, in front of the turbocharger in the direction of flow.
[0010] In a further developed embodiment, a closing or switching means is located between the supplemental compressor and the compressor of the turbocharger. Working with an electronic control device for the electric motor and the closing or switching means and power electronics required to support the electric motor, the supplemental compressor supplements the turbocharger in operational conditions in which the power taken from the exhaust flow is not sufficient or not present.
[0011] In a beneficial execution, the supplemental compressor and the compressor of the turbocharger are matched to each other in such a manner, that a comparably wide characteristic diagram or power curve results. The compression ratio of the supplemental compressor and the compression ratio of the turbocharger compressor are multiplied at each operating point.
[0012] In a further developed execution, the electric motor is regulated based on the boost pressure output of the turbocharger in relation to the prescribed boost pressure curve, so that the supplemental compressor is switched off when the required boost pressure is reached by the turbocharger. However, a predetermined excess or reserve of the boost pressure may be maintained in unsteady operating phases.
[0013] In a special execution, the supplemental compressor and the turbocharger take in air via different intake sections, where the closing-switching means guarantees that the air which is pre-compressed by the supplemental compressor can only flow in the direction of the turbocharger, or when the supplemental compressor of the turbocharger is turned off, cannot conduct air through the supplemental compressor any more. In an advantageous execution of the invention, a charge cooler or heat exchanger is provided between the turbocharger and the internal combustion engine. This decreases the thermal stress of the components on the one hand, and on the other decreases the specific volume of the compressed air which had experienced heating during compression in the supplemental compressor and turbocharger, thus resulting in an increase in specific volume. By cooling and densifying the air, the charged mass of the combustion engine is increased, which results in a considerable increase in power.
[0014] Because the power of the supplemental compressor can be operated independently from the internal combustion engine, a further advantage of the invention is that the supplemental compressor also functions as a secondary air pump to conduct the air in the catalytic converter to increase the conversation rate of the catalytic converter in a cold condition.
[0015] Through an appropriate design of the turbine, a decrease in the exhaust gas counterpressure is made possible. The execution of the invention is obviously possible with various structural shapes of turbochargers (turbochargers with waste gate or flap or also a charger with variable turbine geometry). The use of multi-stage turbochargers is as conceivable as the use of several supplemental compressors, where the connection could occur not only in series but also in parallel. Several heat exchangers could also be used beneficially. If needed, the supplemental compressor and the turbocharger can intake from the same intake section. A possible bypass with a switch means makes it possible to detour the exhaust gas side of the turbocharger. In order to reduce the amount of nitrogen oxide emission through the exhausts coming from the internal combustion engine, an exhaust gas recirculation system (EGR) can be used, which draws in an amount of exhaust gas from a engine exhaust conduit to a point upstream from the turbine of the turbocharger, and conducts it into an engine intake conduit (DE 41 20 055 A1).
[0016] In an especially beneficial execution of the invention, the supplemental compressor can be incorporated in an assembly of the internal combustion engine. In doing so it is possible to either incorporate only the supplemental compressor into the assembly or also additional components or aggregates, such as the switching and/or closing means in front of and behind the supplemental compressor, if necessary, required throttle means or even the drive for the supplemental compressor. When putting the supplemental compressor in the intake pipe assembly, it is beneficial to integrate the supplemental compressor in the intake pipe or to build it onto the intake pipe. In a further developed execution, the spiral guide-around the compressor wheel can be directly formed on the intake pipe. When mounting the supplemental compressor drive at the intake pipe (or at the internal combustion engine or the body), it is beneficial to provide a vibration decoupling fastener in order to mitigate the vibration loads of the internal combustion engine's stimulus.
[0017] In another beneficial execution of the invention, the cylinder head assembly contains the supplemental compressor. For this, the supplemental compressor can be integrated or mounted in the cylinder head or in the cylinder head cover. Formation of the spiral guide around the compressor wheel is possible directly on the cylinder head. When mounting the supplemental compressor drive at the cylinder head, vibration decoupling is beneficially executed.
[0018] Other beneficial executions of the invention provide for integration or building on the supplemental compressor in/at the air filter casing or also in/at the exhaust train. Here also, in a further developed execution, the spiral guide around the compressor wheel is formed directly at the air filter casing or in the exhaust train, and the supplemental compressor drive is mounted with vibration decoupling. In a further developed execution of the invention, when arranging the components in the exhaust, these are thermally decoupled, i.e. connecting using a flange with minimal heat conducting capabilities or shielding using a heat shield to minimize the temperature stress on the components.
[0019] It is beneficial to connect the heat produced by the drive using a coolant circuit corresponding with the supplemental compressor drive to cool the supplemental compressor drive when necessary.
[0020] In an especially beneficial execution of the invention, the switching/closing/or throttle means located in front of or behind the supplemental compressor could also be integrated or built into the following components: intake pipe/cylinder head cover/air filter casing/exhaust train. In a further developed execution—if the supplemental compressor is used as a secondary air pump—the secondary air conduit can also be integrated into or mounted into the mentioned components. The same is possible for the exhaust gas recirculation conduit and the engine ventilation. In the same way, it is possible to integrate the on board diagnostic (OBD) monitor and the sensors in the same assemblies. The turbocharger compressor can also be integrated or build into the components in an especially preferred execution.
[0021] A very compact and cost-effective construction is achieved with the mentioned executions where the supplemental compressor is integrated in the assemblies of the internal combustion engine, so that, for example, when used in motor vehicles, the supplemental compressor barely requires additional space compared to the conventional internal combustion engines. Because especially short pipes (air, gas and coolant pipes) are used with these integral constructions, waste and leak risks are minimized.
[0022] In an especially beneficial execution, the invention includes control of the supplemental compressor. In a first execution, this control is integrated into the internal combustion engine's control. In a further developed form of the invention, the electronic control of the supplemental compressor is separate from the internal combustion engine's control, where especially advantageous parameters of the engine performance conditions represent an input quantity of the control electronics.
[0023] In another beneficial execution of the invention, the internal combustion engine's control is split into partial or subcomponent systems, wherein the control of the supplemental compressor is connected to the entire system as a partial system. The individual partial systems communicate with each other using a bus system (CAN-Bus). Benefits of this subdivision are the simple monitoring and programming of the partial system.
[0024] In an especially beneficial execution of the invention, the vehicle's entire system is split into partial systems (system islands). The control of the supplemental compressor is incorporated in such a partial system; the partial systems communicate with each other using a bus system (CAN-Bus). An advantage of this execution is the possibility to match the individual systems with each other optimally, so that the primary goal is optimally adjusting the fuel consumption for the power output as currently or instantaneously necessary for the internal combustion engine. Additional advantages are the simple monitoring and programming of the partial systems and the possibility to add additional components of control without great effort.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Preferred executions of the invention are explained in references to the attached drawings. They show in:
[0026] [0026]FIG. 1 a schematic representation of an internal combustion engine with one-step turbocharging and an supplemental compressor powered by an electric motor in a first execution based on the invention.
[0027] [0027]FIG. 2 a schematic of an internal combustion engine with simple turbocharging and supplemental compressor with secondary air channels, turbine bypass and exhaust return.
[0028] [0028]FIG. 3 a schematic of an internal combustion engine with simple turbocharging and supplemental compressor with secondary air channels, turbine bypass and exhaust return, with the supplemental compressor integrated into the intake pipe assembly.
[0029] [0029]FIG. 4 a schematic of an internal combustion engine with simple turbocharging and supplemental compressor with secondary air channels, turbine bypass and exhaust return, with the supplemental compressor integrated into the cylinder head assembly.
[0030] [0030]FIG. 5 a schematic of an internal combustion engine with simple turbocharging and supplemental compressor with secondary air channels, turbine bypass and exhaust return, with the supplemental compressor integrated into the air filter casing assembly.
[0031] [0031]FIG. 6 a schematic of an internal combustion engine with simple turbocharging and supplemental compressor with secondary air channels, turbine bypass and exhaust return, with the supplemental compressor integrated into the exhaust train assembly.
[0032] [0032]FIG. 7 a schematic of a control for the supplemental compressor integrated into the engine control.
[0033] [0033]FIG. 8 a schematic of a control for the supplemental compressor separate from the engine control.
[0034] [0034]FIG. 9 a schematic of an engine control split into partial systems, including the control of the supplemental compressor as a partial system.
[0035] [0035]FIG. 10 a schematic of a vehicle entire system split into partial systems, including the control of the supplemental compressor as a partial system.
DETAILED DESCRIPTION OF THE INVENTION
[0036] [0036]FIG. 1 shows an internal combustion engine 1 , which on the fresh gas side 2 is connected to the compressor of a turbocharger 3 and a supplemental compressor 4 . The supplemental compressor 4 is connected to the turbocharger compressor 3 in series, and arranged, in the flow direction, in front of the turbocharger compressor 3 . The supplemental compressor 4 is powered by an electric motor 5 . The turbine 7 of the turbocharger is connected to the internal combustion engine 1 on the exhaust side 6 . A closing or switching means 8 is arranged between the supplemental compressor 4 and the turbocharger compressor 3 . Using the switch means 8 , the turbocharger compressor 3 can draw from its own intake area 9 as well as from the supplemental compressor 4 . The supplemental compressor 4 draws from the intake area 10 . If necessary, two air mass measurers or meters as well as two filters are provided.
[0037] [0037]FIG. 2 shows an internal combustion engine with simple turbocharging and an electrically powered supplemental compressor, where the main design corresponds with FIG. 1. A closing means 11 is arranged in flow direction behind the supplemental compressor 4 , parallel to the closing or switching means 8 , with which the mass flow in the secondary air channels 12 can be controlled. A charge cooler 13 is arranged in flow direction behind the turbocharger compressor 3 , which cools the fresh compressed gas before entry into the internal combustion engine 1 . Operation without turbocharging is possible with a bypass 14 , which diverts exhaust gas to the exhaust side of the turbine 7 of the turbocharger. The switching means 15 controls the mass flow, which is conducted on the fresh gas side using the exhaust return 16 .
[0038] [0038]FIG. 3 shows an internal combustion engine with all components from FIG. 2. In this execution, the intake pipe assembly 18 includes the intake pipe 17 , a throttle valve 19 and a supplemental compressor 4 , arranged sequentially going in the upstream direction. In addition, drive 5 of the supplemental compressor 4 and the switching or throttling means 20 are arranged in front of and behind the supplemental compressor 4 in the intake pipe assembly 18 . Supplemental compressor 4 and turbocharger compressor 3 draw raw air from the same intake area 9 , in which the air mass meter 21 and air filter 22 are connected.
[0039] [0039]FIG. 4 shows the schematic of an internal combustion engine in which the cylinder head assembly 23 includes the supplemental compressor 4 , its drive 5 and the closing or switching means. Integrating the supplemental compressor 4 and mounting the drive 5 in the or at the cylinder head cover 1 . 1 is beneficial.
[0040] [0040]FIG. 5 shows the schematic of an internal combustion engine, in which the air filter casing assembly 24 incorporates the supplemental compressor, its drive 5 , the closing or switching means 20 which are arranged in front of the supplemental compressor 4 in flow direction, the air mass measurer 21 and the air filter 22 .
[0041] [0041]FIG. 6 shows the schematic of an internal combustion engine, in which the exhaust train assembly 25 incorporates the supplemental compressor 4 , its drive 5 , compressor 3 and turbine 7 of the turbocharger, the charge cooler 13 and the closing or switching means 20 .
[0042] [0042]FIG. 7 shows the schematic of an internal combustion engine, in which the control 40 of the supplemental compressor is integrated into the engine control 41 .
[0043] [0043]FIG. 8 shows an internal combustion engine with a control 40 of the supplemental compressor which is separately executed from the engine control 41 , where the parameters of the engine operational condition are input quality of the control electronics of the supplemental compressor.
[0044] [0044]FIG. 9 shows the schematic of an engine control split into partial systems, where, for example, the partial system of control 40 of the supplemental compressor, the control of the partial system 42 of the intake pipe, of the partial system 43 of the injection and the partial system 44 of the air filter are represented. Additional partial systems are indicated. The partial systems communicate with each other using the bus system 45 (CAN-bus).
[0045] [0045]FIG. 10 shows the schematic of a vehicle entire system split into partial systems, where, for example the partial system 40 of the control of the supplemental compressor, the partial system 46 (drive train), the partial system 47 (ABS), the partial system 48 (chassis), the partial system 49 (passenger compartment) and the partial system 50 for heating are represented. The partial systems communicate with each other using the bus system 45 (CAN-bus).
REFERENCE NUMBER LIST
[0046] [0046] 1 internal combustion engine
[0047] [0047] 2 fresh gas side
[0048] [0048] 3 turbocharger compressor
[0049] [0049] 4 supplemental compressor
[0050] [0050] 5 electric motor
[0051] [0051] 6 exhaust gas side
[0052] [0052] 7 turbine
[0053] [0053] 8 switch means
[0054] [0054] 9 intake area
[0055] [0055] 10 intake area
[0056] [0056] 11 closing means
[0057] [0057] 12 secondary air channels
[0058] [0058] 13 charge cooler
[0059] [0059] 14 bypass
[0060] [0060] 15 adjusting means
[0061] [0061] 16 exhaust return
[0062] [0062] 17 intake pipe
[0063] [0063] 18 intake pipe assembly
[0064] [0064] 19 throttle valve
[0065] [0065] 20 switching means
[0066] [0066] 21 air mass measurer
[0067] [0067] 22 air filter
[0068] [0068] 23 cylinder head assembly
[0069] [0069] 24 air filter casing assembly
[0070] [0070] 25 exhaust train assembly
[0071] [0071] 40 controller
[0072] [0072] 41 engine control
[0073] [0073] 42 partial system for the intake pipe
[0074] [0074] 43 partial system for the injection
[0075] [0075] 44 partial system for the air filter
[0076] [0076] 45 bus system
[0077] [0077] 46 partial system for the drive train
[0078] [0078] 47 ABS
[0079] [0079] 48 partial system for the chassis
[0080] [0080] 49 partial system for the passenger compartment partial system for the heating
|
The invention concerns a charged internal combustion engine ( 1 ) with at least one stage of charging by a turbocharger ( 3 ).
The invention is characterized by the fact that at least one supplemental compressor ( 4 ) is connected parallel to or in series with the turbocharger, where the supplemental compressor ( 4 ) has a drive independent form the working medium cycle of the internal combustion engine.
| 5
|
FIELD OF INVENTION
This invention pertains to a horizontal augers which are intended to be mounted on skidsteer tractors and other vehicles for boring beneath, streets, sidewalks, conduits and other impediments that make direct vertical trenching not feasible, when cables, piping and the like are to be laid beneath the impediment.
BACKGROUND OF THE INVENTION
Ofttimes it is necessary to lay pipe or wires beneath a driveway, sidewalk or the like. Typically such is necessary when sprinkler systems, outdoor lighting, or other utility improvements such as security systems or street lights or traffic lights are to be installed at locations where the sidewalks and/or the streets are already in place. Direct trenching would require that a street's traffic flow be interrupted during the pipe or cable laying. Or, in the case of a home, the homeowner does not want the expense of having to re-lay his concrete driveway after the pipes or wiring in question are laid in place.
Today, for these types of situations, a trench is dug on both sides of the impediment, such as a driveway, and then a connection is made between the two trenches. This can be carried out by hand digging beneath the impediment, using picks and shovels; or by directing a stream of high pressure water at the dirt or rock beneath the impediment. Both of these procedures are time consuming and do involve a certain amount of difficulty. In the case of the water, there is always the problem of drainage for or pump removal of the accumulated water not to mention the possibility the erosion of the surrounding substrate adjacent the bore which could result in a cave in of the street or sidewalk which is being bored under.
There is a need therefore, for a safe, sure, easy to achieve, low cost method of boring or tunnelling beneath impediments of the nature recited above. Such an apparatus is provided by the invention of this application.
It is an object therefore to provide an auger that can be readily attached to a skidsteer tractor (SST) for horizontal boring and which operatively controlled by the hydraulic system of the SST.
It is another object to provide an auger that can be quickly attached and detached to the mounting foot of an SST.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the appended claims.
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.
SUMMARY OF THE INVENTION
An apparatus adapted for horizontal boring mountable to the mount shoe of a skidsteer tractor, which apparatus can be lowered into a trench to drill beneath a sidewalk, street, culvert or the like. The apparatus includes a main body and a motor housing, which holds the motor, hydraulic coupler and bearing, pivotally mounted thereto. The center of gravity of the auger used therewith acts to retain the drive shaft of the apparatus in a generally horizontal position.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front perspective view of the auger of this invention, shown mounted on a Bobcat™ skidsteer tractor.
FIG. 2 is a perspective view of a second embodiment of the apparatus of this invention.
FIG. 3 is a rear perspective view of the mounting portion of the apparatus of this invention.
FIG. 4 is a rear perspective view showing the apparatus of this invention.
FIG. 5 is a front perspective view of the apparatus of this invention.
FIG. 6 is a closeup perspective view of another portion of this invention.
FIG. 7 shows the accessory mounting foot of a skidsteer tractor which is used to engage the apparatus of this invention for operation by such a tractor.
FIG. 8 is a cutaway view showing the pivotal mounting of the motor housing relative to the main body.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, the auger device 10 of this invention is shown mounted on a tractor of the skidsteer variety. As is known, a skidsteer tractor has no turnable wheels. Turns are negotiated by locking up the left or right front and rear wheels such that the unlocked side's front and rear wheels can continue to move forward, the result being the ability to make a full right turn on a minimum turning radius. While the apparatus of this invention will be shown in the drawings and discussed as being intended primarily for usage on such skidsteer tractors, for instance those sold under the Bobcat trademark among others, the use of the inventive apparatus for standard steerable tractors is of course contemplated, as is the mounting of this apparatus on other prime movers, such as compactors.
Apparatus 10 includes a main housing 11, having a pair of spaced sidewalls, 12, 14, each of which is generally triangular shape. The rear surface of each of these side walls may be generally vertical with the front edge depending outwardly from the top edge. A front wall 15 is disposed preferably flush with the front edge of the two side walls 12, 14, per FIGS. 1 and 5.
A trapezoidally shaped cutout 28, (see FIG. 6) which deletes an entire section of the bottom of the front wall 15 and part of the bottom area of the two side walls, extends rearwardly from the front edge of the two side walls to the two trapezoidal segments, i.e. 17 on the near side and 18 on the far side of the side walls, for the purpose of nestingly receiving the motor housing 20. The description of the motor housing 20 which has mounted thereon at least one, and preferably two upstanding flanges with a pin receiving bore therein for disposition within the opening in the underside of the main housing will be recited infra.
Main housing 11 also includes an elongated U-shaped retainer 16 which is mounted at about the midpoint of the front wall 15 to retain the hydraulic lines used to operate the apparatus and which are shown in FIG. 5.
In FIG. 4 there is seen the adapter plate 50 for the engagement of the particular tractor to this apparatus 10. The adapter plate 50 is welded to and becomes an integral part of the apparatus. Reference is made to the discussion of FIG. 3 for the adapter plate for a J.I. Case skidsteer tractor. Whereas in the variant of the apparatus discussed with respect to FIG. 2, the adapter plate for a Bobcat is depicted.
Returning now to FIG. 4, the adapter 50 which as indicated is integrally attached to and forms a part of apparatus 10 includes a generally rectangular main portion 51, to which is attached top plate section 27 which constitutes the top wall of this device and is seen to be disposed spaced down from the upper edge of the generally rectangular main portion 51 of the adapter 50 and from the top edge of two spaced sidewalls 52' of said adapter 50. At the bottom of main portion 51 is a rearwardly integral lip 52 having a pair of spaced slots 53 therein. Main portion 51 is seen to have an obverse side--FIG. 4--that faces the accessory shoe of the tractor and a reverse side--FIG. 5--which is welded or otherwise attached to the two side walls 12, 14 of this device. Preferably main portion 51 extends beyond sidewalls 12, 14. See FIG. 5.
Rear edges 12', 14' of side walls 12, 14 respectively of apparatus 10 extend from the bottom wall or plate 29 of apparatus 10 up toward the midpoint of the elevation of the apparatus. A small reinforcing plate 30, also extends upwardly from the bottom plate 29 superposed upon a portion of rear edges 12' and 14'.
FIG. 7 shows the accessory quick release mounting means of a skidsteer tractor which is used to engage the apparatus of this invention for operation by such a tractor. While this device forms no part of this invention, a brief discussion of same is necessary for understanding the operation of the instant apparatus. Suffice it to say at this point that accessory shoe 103 of the skid steer tractor 100 will be described below in detail and is shown in FIG. 1 engaging the instant apparatus via opening 30'. This opening is located between the top wall 27 and the lower lip 52 of the adapter plate 50, upper edge of the rear edges 12', 14' of side walls 12 and 14. In FIG. 6, the motor housing 20 is seen to be disposed within cutout 28 previously mentioned. This motor housing 20 includes a top wall 21, which has oil bore 42 therein which bores leads to and communicate with bearing 31 for the lubrication thereof. Motor housing 20 also includes a rear wall 22, which is disposed downwardly and forwardly from top wall 21 at the rear thereof. Bottom wall 23 extends from said rear wall 22 forwardly and generally parallel to top wall 21 and spaced therefrom. Front wall 26, includes a central opening 26' per FIG. 5, said opening being for the passage of the drive shaft not seen, is disposed parallel to both of said top and bottom walls 21, 23 and therebetween, while the wall itself is disposed normal to said top and bottom walls, 21, 23. Front wall 26 may be welded or otherwise secured to said top and bottom walls. Preferably the top wall 21, the rear wall 22 and bottom wall 23 are integral as one piece. A reinforcing gusset 46 is welded or otherwise secured to top wall 21 of the motor housing preferably at a location between the connections for hydraulic lines 35, 36. This gusset serves not only to add strength to the unit, but as an antiflexing stop should the motor unit attempt to counter-rotate.
Bearing unit, 31, such as one made by Helland and designated a model 400 OVERHUNG LOAD ADAPTOR or equal is bolted to the front wall 26 by bolts 26", such as 1/2" bolts, and motor 32 is conventionally mounted to the inner surface of bottom wall 23 within the motor area 33. Conventional hydraulic couplers 34 are disposed between said motor 32 and said bearing 31 with suitable inputs, not seen, for receiving the two hydraulic lines 35, 36, which are connected through bores 42 in the top wall 21 to said couplers 34 via standard quick disconnect couplings 35' and 36' per FIG. 6. The other end of lines 35, 36 are connected to the power take off of the tractor. Obviously other conventional mount means are also contemplated.
The reader's attention is also called to the plurality of spaced bar rests or feet 24 disposed on the underside of bottom wall 23 to prevent damage thereto. These rests 24, are best seen in FIG. 6.
A power coupler, 37 seen in FIGS. 1, 4, 5, and 6 is conventionally secured via a key way to said bearing for and is welded to the drive shaft of the bearing. An auger 38 such as those made by Pengo among others such as the one shown in FIGS. 1 and 4 includes a cutter portion 39 and a shaft 40. Shaft 40 is received by power coupler 37 and retainer in place by set screws 37' which enter into threaded bores in said shaft 40, said threaded bores not being visible due to their small size. The coupling of the power coupler 37 to the drive shaft is deemed to be conventional in the art.
Reference should now be made to FIG. 3 and FIG. 8 which depicts the interior of apparatus 10. As is seen, top wall 21 includes a pair of spaced plates 45 mounted thereon, with the spacing such that they fit within the confines of the side walls of the apparatus. Each flange 45 is connected by a normally disposed tubular member 48, disposed within a suitable bore of each flange, but not through the two side walls. Pin 19 discussed below, permits the rotation of the tubular member 48.
FIG. 8 is a diagrammatic elevational view also showing the pivot flanges 45 that are mounted as by welding, to the top wall 21 of the motor housing 20. These members are retained by pivot pin 19 which extends through the two side walls, 12, 14 of the main body housing 11, per FIG. 8 and through the tubular member 48. The tubular member is connected thereto by cotter pin 47 (also seen in FIG. 3) which is disposed in aligned bores within each of pin 19 and tubular member 48.
The discussion turns now to FIGS. 4 and 7 which depict the mode of attachment of the apparatuses of this invention to tractor 100. Tractor 100 includes a pair of hydraulic cylinders 101, only one of which is seen in FIG. 7, from which is extending piston rod 102, which is seen to be connected to the accessory mounting shoe 103. Again only one of the spaced pair of mounting shoes is visible in each of FIGS. 4 and 7. Mounting shoe 103 comprises a pair of spaced side walls, 104; a top wall 105 overlying the two spaced sidewalls 104; a front wall 106, which extends upwardly beyond the upper edge of the two side walls; a piston connector 107 conventionally mounted within the confines of mount shoe 103, and a forwardly tilted lip 109, angled upwardly from the top wall 105 and extending slightly beyond front wall 106. Tractor 100 also includes a connecting arm 110 to couple the two mounting shoes 103 for simultaneous operation as well a pair of pivotally mounted relative to the mounting shoe fixed arms, 108. These are used for positioning the apparatus 10 relative to the work site. Mounting shoes of the nature just described are well known in the art and form no part of this invention.
Suffice to say that top mounting plate 27 of apparatus 10 does not extend all the way forward on its underside to the front wall 15, (FIG. 5), even though it may fit flush with said front wall on its upper surface, such that angled lip 109 can fit behind the top wall to lock in the mount shoe to apparatus 10. The balance of the mount shoe is sized to be received within opening 30', just above rear wall 13 of the apparatus. Further detail need not be recited as this is indeed a conventional mounting mode for accessories for tractors such as tractor 100.
In FIG. 2, a variant of the apparatus 10 is seen. Here apparatus 150 is seen to differ in two ways. Firstly, is the exclusion of a gusset plate similar to gusset plate 46 which was added as noted previously to reinforce the interface between the main body and the motor housing and to serve as a forward stop to prevent excess tipping forward of the main body relative to the motor housing.
The second difference seen here is that the adapter plate 50 is replaced by adapter plate 80. The present adapter plate includes a generally rectangular main portion 81, the spaced down angled rearwardly and downwardly top wall 82, welded thereto, and rearwardly directed integral bottom lip 83 extending from said rectangular portion 81. Lip 83 includes a single slot 84 in the middle thereof. Adapter 80 is sized to fit and mate with the mounting shoe of a Bobcat skidsteer tractor. It should also be understood that the gusset can be included in the embodiment of FIG. 1 as well in that there is no correlation or connection between the model for use with a Bobcat tractor with respect to the inclusion or exclusion of the gusset 151. Hereto, the adapter plate 80 is an integral part of apparatus 150.
OPERATION
After apparatus 10 has been physically mounted upon mount shoe 103, the two hydraulic lines 35, 36 are attached via their quick disconnects to the hydraulic couplers 34. An auger 38 is tightened into place in the power coupler, at which time the device is ready for use. The fixed arms 108 are raised to lift apparatus 10 off the ground for ease of travel. The tractor 100 is then positioned where the desired boring operation is to take place. It is also seen that variations of the basic apparatus can be configured for utilization with various brands of tractors.
Skilled artisans can easily bore horizontally with the apparatus of this invention, using the apparatus designed for mounting on their particular type of tractor.
Since further changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not as limiting.
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An apparatus is provided that is mountable upon preferably a skidsteer tractor, through a forklift truck or similar wheeled vehicle could be employed. The apparatus can be lowered into a trench on one side of a street or sidewalk and used to bore axially beneath the street or sidewalk to a trench on the other side of the street or sidewalk. Operation of the apparatus, which uses conventional commercial augers is controlled from the hydraulic couplings situated in the skidsteer tractor.
The apparatus includes a main housing which includes a means for receiving the accessory shoe of a prime mover for physical attachment thereto; and a motor housing with a motor, hydraulic coupler and bearing disposed therein, which motor housing is pivotally mounted to the main body.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 10/536,003, filed May 20, 2005, which is a §371 of PCT/SE2004/000194 filed Feb. 16, 2004.
TECHNICAL FIELD
[0002] The present invention generally relates to the field of cleaning gas turbine engines, and more specifically a method and apparatus for cleaning a turbofan gas turbine engine installed in an aircraft.
BACKGROUND
[0003] A gas turbine installed as an aircraft engine comprises a compressor compressing ambient air, a combustor burning fuel together with the compressed air and a turbine for powering the compressor. The expanding combustion gases drive the turbine and also result in thrust used for propelling the air craft.
[0004] Gas turbines engines consume large quantities of air. Air contains foreign particles in form of aerosols which enters the gas turbine compressor with the air stream. The majority of the foreign particles will follow the gas path and exit the engine with the exhaust gases. However, there are particles with properties of sticking on to components in the compressor's gas path. Stationary gas turbines like gas turbines used in power generation can be equipped with filter for filtering the air to the compressor. However, gas turbines installed in aircrafts are not equipped with filters because it would create a substantial fall in pressure and are thereby more exposed to air contaminants. Typical contaminants found in the aerodrome environment are pollen, insects, engine exhaust, leaking engine oil, hydrocarbons coming from industrial activities, salt coming from nearby sea, chemicals coming from aircraft de-icing and airport ground material such as dust.
[0005] Preferably engine components such as compressor blades and vanes should be polished and shiny. However, after a period of operation a coating of foreign particles builds up. This is also known as compressor fouling. Compressor fouling results in a change in the properties of the boundary layer air stream of the components. The deposits result in an increase of the component surface roughness. As air flows over the component surface the increase of surface roughness results in a thickening of the boundary layer air stream. The thickening of the boundary layer air stream has negative effects on the compressor aerodynamics. At the blade trailing edge the air stream forms a wake. The wake is a vortex type of turbulence with a negative impact on the air flow. The thicker the boundary layer the stronger the turbulence in the wake. The wake turbulence together with the thicker boundary layer has the consequence of a reduced mass flow through the engine. The reduced mass flow is the most profound effect of compressor fouling. Further, the thicker boundary layer and the stronger wake turbulence formed at the blade trailing edge result in a reduced compression pressure gain which in turn results in the engine operating at a reduced pressure ratio. Anyone skilled in the art of heat engine working cycles understands that a reduced pressure ratio result in a lower thermodynamic efficiency of the engine. The reduction in pressure gain is the second most remarkable effect from compressor fouling. The compressor fouling not only reduces the mass flow and pressure gain but also reduces the compressor isentropic efficiency. Reduced compressor efficiency means that the compressor requires more power for compressing the same amount of air. The reduced mass flow, pressure ratio and isentropic efficiency reduce the engine thrust capability. The power for driving the compressor is taken from the turbine via the shaft. With the turbine requiring more power to drive the compressor there will be less thrust for propulsion. For the air craft pilot this means he must throttle for more power as to compensate for the lost thrust. Throttling for more power means the consumption of fuel increases and thereby increasing operating costs.
[0006] Compressor fouling also has a negative effect to the environment. With the increase of fuel consumption follows an increase of emissions of green house gas such as carbon dioxide. Typically combustion of 1 kg of aviation fuel results in formation of 3.1 kg carbon dioxide.
[0007] The loss in performance caused by compressor fouling also reduces the durability of the engine. As more fuel has to be fired for acquiring a required thrust, follows an increase in the temperature in the engine combustor chamber. When the pilot throttles for take-off on the runway the temperature in the combustion chamber is very high. The temperature is not too far from the limit of what the material can stand. Controlling this temperature is a key issue in engine performance monitoring. The temperature is measured with a sensor in the hot gas path section downstream of the combustor outlet. This is known as exhaust gas temperature (EGT) and is carefully monitored. Both exposure time and temperature are logged. During the lifetime of the engine the EGT log is frequently reviewed. At a certain point of the EGT record it is required that the engine will have to be taken out of service for an overhaul.
[0008] High combustor temperature has a negative effect to the environment. With the increase of combustor temperature follows an increase of NOx formation. NOx formation depends to a large extent on the design of the burner. However, any incremental temperature to a given burner results in an incremental increase in NOx.
[0009] Hence, compressor fouling has significant negative effects to aero engine performance such as increased fuel consumption, reduced engine life, increased emissions of carbon dioxide and NOx.
[0010] Jet engines can have a number of different designs but the above-mentioned problems arises in all of them. Typical small engines are the turbojet, turboshaft and turboprop engines. Other variants of these engines are the two compressor turbojet and the boosted turboshaft engine. Among the larger engines there are the mixed flow turbofan and the unmixed flow turbofan which both can be designed as one, two or three shaft machines. The working principles of these engines will not be described here.
[0011] The turbofan engine is designed for providing a high thrust for aircraft operating at subsonic velocities. It has therefore found a wide use as engines for commercial passenger aircrafts. The turbofan engine comprises of a fan and a core engine. The fan is driven by the power from the core engine. The core engine is a gas turbine engine designed such that power for driving the fan is taken from a core engine shaft. The fan is installed upstream of the engine compressor. The fan consists of one rotor disc with rotor blades and alternatively a set of stator vanes downstream if the rotor. Prime air enters the fan. A discussed above, the fan is subject to fouling by insects, pollen as well as residue from bird impact, etc. The fan fouling may be removed by washing using cold or hot water only. This cleaning washing process is relatively easy to perform.
[0012] Downstream of the fan is the core engine compressor. Significant for the compressor is that it compresses the air to high pressure ratios. With the compression work follows a temperature rise. The temperature rise in a high pressure compressor may be as high as 500 degree Celsius. We find that the compressor is subject to different kind of fouling compared to the fan. The high temperature results in particles more easily being “baked” to the surface and will be more difficult to remove. Analyses show that fouling found in core engine compressors are typically hydrocarbons, residues from anti-icing fluids, salt etc. This fouling is more difficult to remove. It may at some time be accomplished by washing with cold or hot water only. Else the use of chemicals will have to be practiced.
[0013] A number of cleaning or washing techniques have been developed during the years. In principle, aero engine washing can be practiced by taking a garden hose and spraying water into the engine inlet. This method has however a limited success due to the simple nature of the process. An alternative method is by hand scrubbing the compressor blades and vanes with a brush and liquid. This method has limited success as it does not enable cleaning of the interior blades of the compressor. Moreover, it is time-consuming. U.S. Pat. No. 6,394,108 to Butler discloses a thin flexible hose which one end is inserted from the compressor inlet towards the compressor outlet in between the compressor blades. At the inserted end of the hose there is a nozzle. The hose is slowly retracted out of the compressor while liquid is being pumped into the hose and sprayed through the nozzle. The patent discloses how washing is accomplished. However the washing efficiency is limited by the compressor rotor not being able to rotate during washing. U.S. Pat. No. 4,059,123 to Bartos discloses a mobile cart for turbine washing. However, the patent does not disclose how the cleaning process is accomplished. U.S. Pat. No. 4,834,912 to Hodgens II et al. discloses a cleaning composition for chemically dislodging deposits of a gas turbine engine. The patent illustrates the injection of the liquid into a fighter jet aircraft engine. However, no information is provided about the washing process. U.S. Pat. No. 5,868,860 to Asplund discloses the use of a manifold for aero engines with inlet guide vanes and another manifold for engines without inlet guide vanes. Further the patent discloses the use of high liquid pressure as means of providing a high liquid velocity, which will enhance the cleaning efficiency. However, the patent does not address the specific issues related to fouling and washing of turbofan aero engines.
[0014] The arrangement described hereinafter with reference to FIG. 1 is further regarded as common knowledge in this field. A cross section view of a single shaft turbojet engine is shown in FIG. 1 . Arrows show the mass flow through the engine. Engine 1 is built around a rotor shaft 17 which at its front end is connected a compressor 12 and at its rear end a turbine 14 . In front of the compressor 12 is a cone 104 arranged to split the airflow. The cone 104 is not rotating. The compressor has an inlet 18 and an outlet 19 . Fuel is burnt in a combustor 13 where the hot exhaust gases drives turbine 14 .
[0015] A washing device consist of a manifold 102 in form of a tube which in one end is connected to a nozzle 15 and the other end connected to a coupling 103 . Hose 101 is at one end connected to coupling 103 while the other end is connected to a pump (not shown). Manifold 102 is resting upon cone 104 and is thereby held in a firm position during the cleaning procedure. The pump pumps a washing liquid to nozzle 15 where it atomizes and forms a spray 16 . The orifice geometry of nozzle 15 defines the spray shape. The spray can form many shapes such as circular, elliptical or rectangular depending on its design. For example, a circular spray has a circular distribution of droplets characterized by the spray having the shaped of a cone. An elliptical spray is characterised by one of the ellipses axis is longer than the other. A rectangular spray is somewhat similar to the elliptical spray but with comers according to the definition of a rectangle. A square spray is somewhat similar to the circular spray in that the two geometry axes are of equal length but the square shaped spray has comers according to the definition of a square.
[0016] Liquid is atomized prior to entering the compressor for enhanced penetration into the compressor. Once inside the compressor the droplets collide with gas path components such as rotor blades and stator vanes. The impingement of the droplets results in wetting surface and establishing of a liquid film. The deposited particles on the gas path components are released by mechanical and chemical act of the liquid. Liquid penetration into the compressor is further enhanced by allowing the rotor shaft to rotate during washing. This is done by letting the engine's starter motor turn the rotor whereby air is driven through the engine carrying the liquid from the compressor inlet towards the outlet. The cleaning effect is further enhanced by the rotation of the rotor as the wetting of the blades creates a liquid film which will be subject to motion forces such as centrifugal forces during washing.
[0017] What is said about the cleaning of the compressor will also have effect on cleaning of the whole gas turbine engine. As the cleaning liquid enters the engine compressor and the rotor is rotating the washing fluid will enter the combustion chamber and further through the turbine section and thereby cleaning the whole engine.
[0018] However, this method is not efficient for a turbofan turbine engine for a number of reasons. Firstly, because the fouling of different components of a turbofan engines may have significantly different properties regarding, for example, the stickiness, it will require different methods for the removal as discussed above. Secondly, since the fan and its cone for splitting the airflow is rotating, the cone cannot be used for holding the manifold. Possible, the manifold can be mounted on a stand or a frame placed upstream of the fan but this arrangement would not provide an efficient cleaning of the engine since the main part of the cleaning liquid emanated from the nozzles would impinge at the suction side of the blades of the fan.
SUMMARY
[0019] Thus, an object of the present invention is to provide a device and a method for removing the different types of fouling found on the fan and in the core engine compressor of turbofan engine and thereby reduce the negative effects of the fouling effects to aero engine performance such as increased fuel consumption, reduced engine life, increased emissions of carbon dioxide and NOx.
[0020] It is further an object of the present invention to provide an apparatus and a method that are able to clean the fan and the core engine compressor in one washing operation.
[0021] These and other objects are achieved according to the present invention by providing a method and an apparatus having the features defined in the independent claims. Preferred embodiments are defined in the dependent claims.
[0022] For the purposes of clarity, the terms “radial direction” and “axial direction” refer to a direction radially from the centreline of the engine and a direction along the centreline of the engine, respectively.
[0023] In the context of the present invention, the term “tangential angle” relates to an angle tangential viewed from the centreline of the engine.
[0024] According to a first aspect of the present invention, there is provided a device for cleaning a gas turbine engine, which engine includes at least one engine shaft, a rotatably arranged fan comprising a plurality of fan blades mounted on a hub and extending substantially in a radial direction, each having a pressure side and a suction side, and a core engine including a compressor unit and turbines for driving the compressor unit and the fan, comprising a plurality of nozzles arranged to atomize a cleaning liquid in the air stream in an air inlet of the engine up-stream of the fan. The device according to the first aspect of the present invention comprises a first nozzle arranged at a first position relative a centre line of the engine such that the cleaning liquid emanated from the first nozzle impinges the surfaces of the blades substantially on the pressure side; a second nozzle arranged at a second position relative the centre line of the engine such that the cleaning liquid emanated from the second nozzle impinges the surfaces of the blades substantially on the suction side; and a third nozzle arranged at a third position relative the centre line of the engine such that the cleaning liquid emanated from the third nozzle passes substantially between the blades and enters an inlet of the core engine.
[0025] According to a second aspect of the present invention, there is provided a method for cleaning a gas turbine engine, which engine includes at least one engine shaft, a rotatably arranged fan comprising a plurality of fan blades mounted on a hub and extending substantially in a radial direction, each having a pressure side and a suction side, and a core engine including a compressor unit and turbines for driving the compressor unit and the fan, comprising the step of atomizing cleaning liquid in the air stream in an air inlet of the engine up-stream of the fan by means of a plurality of nozzles.
[0026] The method according to the second aspect of the present invention further comprises the steps of: applying cleaning liquid emanated from a first nozzle substantially on the pressure side; applying cleaning liquid emanated from a second nozzle substantially on the suction side; and directing cleaning liquid emanated from a third nozzle such that the cleaning liquid passes substantially between the blades and enters an inlet of the core engine.
[0027] Thus, the present invention is based on the insight that the properties of the fouling of different components of the engine have different properties and therefore require different approaches for the cleaning. As an example, the fouling of the core compressor is has different properties compared to the fouling of the blades of the fan, for example, due to the higher temperature of the compressors. The high temperature results in particles more easily being “baked” to the surface and will be more difficult to remove. Analyses show that fouling found in core engine compressors are typically hydrocarbons, residues from anti-icing fluids, salt etc. This fouling is therefore more difficult to remove than the fouling of the blades of the fan.
[0028] This solution provides several advantages over the existing solutions. One advantage is that the cleaning of the parts of the engine subjected for fouling is adapted to the certain properties of the fouling of each part. Accordingly, the cleaning of the different components of the fan and the core engine can be individually adapted. This entails a more efficient and time-saving cleaning of the engine compared to the known methods, which utilize an uniform cleaning process. Thereby, costs can be saved compared to the known methods because the consumption of fuel can be reduced.
[0029] Another advantage is that both the suction side as well as the pressure side of the blades of the fan can be reached by the cleaning liquid. Thereby, the cleaning of the fan is more complete and efficient compared to the known methods as they do not allow cleaning of the pressure side.
[0030] A further advantage is that the cleaning device according to the present invention can be used a variety of different types of turbine engines including turbo-fan gas turbine engine having one, two, three, or more shafts, and in which the fan and the cone for splitting the airflow is rotating.
[0031] An additional advantage is that the durability of the engine can be increased since a more efficient fouling removal entails that the combustor temperature can be lowered. This has also a favorable effect on the environment due to a decrease of NOx formation.
[0032] According preferred embodiments of the present invention, the first nozzle and the second nozzle are arranged so that the cleaning liquid emanating from the first nozzle and the second nozzle, respectively, form a spray which, at impinge against a blade of the fan, has a width, along an axis substantially parallel with the radial extension of the blades of the fan, substantially equal to the length of a leading edge of the blade. Thereby, the spray will provide liquid to the blade on its entire length from tip to hub and the efficiency of the cleaning or washing of the pressure side and the suction side, respectively, of the blades of the fan are increased.
[0033] According to embodiments of the present invention, the third nozzle is arranged so that the cleaning liquid emanating from the third nozzle forms a spray which, at the inlet, has a width, along an axis substantially parallel with the radial extension of the blades of the fan, substantially equal to the distance between the splitter and the point on the hub.
[0034] Further objects and advantages of the present invention will be discussed below by means of exemplifying embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Preferred embodiments of the invention will now be described in greater detail with reference to the accompanying drawings, in which
[0036] FIG. 1 shows the cross section of an aero gas turbine engine.
[0037] FIG. 2 shows the cross section of a turbo-fan gas turbine engine.
[0038] FIG. 3 shows the cross section of a turbo-fan gas turbine engine and the preferred embodiment of the invention with two nozzles for cleaning of the engine fan and one nozzle for cleaning the core engine.
[0039] FIG. 4 shows details of the installation of nozzles.
[0040] FIG. 5 shows the nozzle installation for cleaning of the fan blade pressure side.
[0041] FIG. 6 . shows the nozzle installation for cleaning of the fan blade suction side.
[0042] FIG. 7 . shows the nozzle installation for cleaning of the core engine.
DETAILED DESCRIPTION
[0043] With reference now to FIG. 2 , a two shaft unmixed turbofan aero engine will be described. The two shaft unmixed turbofan engine is one of several possible designs of a turbofan engine. This invention is not limited to the embodiment of this description and its figures as it is evident that the invention can be applied to other variants of turbofan engine designs such as the mixed turbofan engine or turbofan engines with one, three or more shafts. Characteristic for the turbofan engine on which the invention is suitable for practice is that the fan and its cone for splitting the airflow is rotating.
[0044] Engine 2 in FIG. 2 comprises of a fan unit 202 and a core engine unit 203 . The engine is built around a rotor shaft 24 which at its front end is connected to a fan 25 and at the rear end turbine 26 . Turbine 26 drives fan 25 . A second shaft 29 is in form of a coaxial to first shaft 24 . Shaft 29 is connected at its front end to compressor 27 and rear end to turbine 28 . Turbine 28 drives compressor 27 . Arrows show the air flow through the engine. Both fan unit 202 and core engine unit 203 provides thrust for propelling an aircraft.
[0045] Engine 2 has an inlet 20 where inlet air enters the engine. The inlet air flow is driven by fan 25 . One portion of the inlet air exits at outlet 21 . The remaining portion of the inlet air enters into the core engine at inlet 23 . The air to the core engine is then compressed by compressor 27 . The compressed air together with fuel (not shown) is combusted in combustor 201 resulting in pressurized hot combustion gases. The pressurized hot combustion gases expands towards core engine outlet 22 . The expansion of the hot combustion gases is done in two stages. In a first stage the combustion gases expands to an intermediate pressure while driving turbine 28 . In a second stage the hot combustion gases expands towards ambient pressure while driving turbine 26 . The combustion gases exits the engine at outlet 22 at high velocity providing thrust. The gas from outlet 22 together with air from outlet 21 together make up the engine thrust.
[0046] FIG. 3 shows a cross section of the two shaft unmixed turbofan aero engine 2 . Similar parts are shown with the same reference numbers as FIG. 2 . FIG. 3 is an example only where the illustrated principals apply to other aero gas turbine engines designs such as the mixed turbofan engine or turbofan engines with one, three or more shafts.
[0047] Turbojet engine fans are designed with set of blades installed on the fan hub and pointing outward in basically radial direction. Each blade has a pressure side and a suction side defined by the direction of rotation of the fan. A compressor washing device consist of three nozzles types for spraying a cleaning fluid each one with a dedicated purpose. One nozzle type serves the purpose of providing a cleaning fluid for cleaning the pressure side of the fan. Another type nozzle serves the purpose of providing a cleaning fluid for cleaning the suction side of the fan. Yet another nozzle type serves the purpose of providing a cleaning fluid for cleaning the core engine. The nozzles are positioned upstream of fan 25 . The nozzles have different spray characteristics and liquid capacities.
[0048] A washing device for washing fan 25 consist of a stiff manifold 37 in form of a conduit which in one end is connected to nozzles 31 and 35 . Nozzles 31 and 35 are firmed by the stiff manifold 37 . The other end of manifold 37 is connected to coupling (not shown) which is further connected to a hose (not shown) which is further connected to a pump (not shown). The cleaning liquid in conduit 37 may consist of water or water with chemicals. The liquids temperature may be as provided from the liquid source or may be heated in a heater (not shown). The pump pumps the washing liquid to nozzle 31 and 35 . Liquid exiting the nozzle atomizes and forms a spray 32 and 36 respectively. Sprays 32 and 36 are directed towards fan 25 .
[0049] The liquid pressure in conduit 37 is in the range 35-220 bar. This high pressure results in a high liquid velocity through the nozzle. Liquid velocity is in the range 50-180 m/s. The liquid velocity gives the droplets sufficient inertia to allow the droplets to travel to the fan from the nozzle tip. Arriving at the fan, the droplet velocity is significantly higher than the rotation velocity of the fan, thereby enabling washing of either the pressure side of the fan or the suction side of the fan as further described below. The droplets collide with the fan and will wet the fan surface. Contaminants will be released by chemical act of the chemicals or the water. During the cleaning process fan 25 is allowed to rotate by the help of the engine starter motor or by other means. The rotation serves several purposes. First, the rotation result in an air flow through the fan enhancing the travel of the spray towards the fan. The air flow thereby increases the collision velocity on the fan surface. A higher collision velocity improves the cleaning efficiency. Second, the rotation of the fan enables wetting of the entire fan area by use of only one nozzle as the spray coverage extends from the fan hub to the fan tip. Third, the fan rotation enhances the removal of released contaminants as the air flow will shear off liquid from the fan blade surface. Fourth, the fan rotation enhances the removal of released contaminants as centrifugal forces will shear off liquid from the fan blade surface.
[0050] A washing device for washing the core engine consist of a stiff manifold 38 in form of a conduit which in one end is connected to nozzles 33 . Nozzle 33 is firmed by the stiff manifold 38 . The other end of manifold 38 is connected to coupling (not shown) which is further connected to a hose (not shown) which is further connected to a pump (not shown). The cleaning liquid in conduit 38 may consist of water or water with chemicals. The liquids temperature may be as provided from the liquid source or may be heated in a heater (not shown). The pump pumps a washing liquid to nozzle 33 . Liquid exiting the nozzle atomizes and forms a spray 34 . Spray 34 is directed towards fan 25 . The liquid pressure in conduit 38 is in the range 35-220 bar. This high pressure results in a high liquid velocity through the nozzle orifice. Liquid velocity is in the range 50-180 m/s. The liquid velocity gives the droplets sufficient inertia to allow the droplets to travel from the nozzle tip through the fan (in between the blades) to inlet 23 . Arriving at inlet 23 , the liquid enters the compressor.
[0051] Inside the compressor the droplets collide with compressor components such as blades and vanes. Contaminants will be released by chemical act of the chemicals or the water. During the cleaning process compressor 27 is allowed to rotate by the help of the engine starter motor or by other means. The rotation serves several purposes. First, the rotation result in an air flow through the compressor enhancing the travel of the droplets towards the compressor exit. The air flow thereby increases the collision velocity on the compressor surface. A higher collision velocity improves the cleaning efficiency. Second, the fan rotation enhances the removal of released contaminants as the air flow will shear off liquid from the fan blade surface. Third, the compressor rotation enhances the removal of released contaminants as centrifugal forces will shear off liquid from the compressor rotor blade surface.
[0052] The orifice geometry of nozzle 31 , 35 and 33 defines the spray shape. The shape of the spray has a significant importance to washing result. The spray can be made to form many shapes such as circular, elliptical or rectangular. This is accomplished by an appropriate design and machining operations of the nozzle orifice. The circular spray has a circular distribution of droplets characterized as a conical spray. The elliptical spray is similar to the conical spray however characterized by one of the circle axis is longer than the other. It can be defined that the elliptical spray has a width-wise distribution and a thickness-wise distribution of droplets where the width-wise direction corresponds to the long axis of the ellipse and the thickness-wise direction corresponds to the short axis of the ellipse. It is also possible by appropriate design and machining operations of the nozzle orifice to create a rectangular spray. The rectangular spray shape has a width-wise and thickness-wise distribution similar as to the elliptical spray. The circular spray has equal width-wise and thickness-wise distribution. The square spray has equal width-wise and thickness-wise distribution.
[0053] FIG. 4 shows a cross section portion of the un-mixed turbofan engine. FIG. 4 shows details of the nozzle installation and orientation relative to engine centreline 400 . Similar parts are shown with the same reference numbers as in FIG. 2 and FIG. 3 . A fan 25 has a blade 40 with a leading edge 41 and a trailing edge 42 . Blade 40 has a tip 43 and a boss 44 at the hub of fan 25 . According to the design of the un-mixed turbofan engine, air flow 20 will after passing fan 25 be split into two flows. One portion of air flow 20 exits the fan section of the engine at outlet 21 . The other portion of the air flow enters the core engine section at inlet 23 for providing air to the core engine. The air stream is split into the two streams by splitter 45 . The opening of inlet 23 is limited by on one side splitter 45 and on the opposite side a point 46 on the hub.
[0054] According to the invention the washing system consist of three types of nozzles, each dedicated for a specific task. The first nozzle type serves the purpose of washing the pressure side of the fan blade. The first nozzle type has an elliptic or rectangular spray shape. The second nozzle type serves the purpose of washing the suction side of the fan blade. The second nozzle type has an elliptic or rectangular spray shape. The third nozzle serves the purpose of washing the core engine. The third nozzle type has an elliptic or rectangular spray shape. A washing unit according to the invention is made up of one or a multiple of each of the three nozzle types.
[0055] FIG. 4 shows the first nozzle type, nozzle 31 , and it's with-wise projection. Nozzle 31 serves the purpose of providing washing liquid for washing the pressure side of blade 40 . The leading edge 41 of blade 40 has a length equal to the distance between tip 43 and boss 44 . Nozzle 31 is positioned in axial direction at a point preferably more than 100 mm, and more preferably more than 500 mm and less than 1000 mm, upstream of the fan leading edge 41 . The nozzle 31 is positioned in a radial direction at a point less than the fan diameter and greater than the fan hub diameter. Nozzle 31 is directed towards fan 25 . Nozzle 31 atomizes a washing liquid forming a spray 32 . Nozzle 31 provides an elliptic or rectangular spray pattern. The nozzle is oriented so that the width-wise axis of the spray pattern is parallel with leading edge 41 of blade 40 . At one side of the spray pattern the width-wise distribution is limited by streamline 75 . On the opposite side of the spray pattern the width-wise distribution is limited by streamline 76 . From the nozzle's orifice point the width-wise measure of spray 32 at leading edge 41 will be equal to the length of leading edge 41 . The spray will thereby provide liquid to the blade on its entire length from tip to hub.
[0056] FIG. 5 shows nozzle 31 as seen from a projection from the rotor periphery towards the shaft centre. In FIG. 5 nozzle 31 is seen in its thickness-wise projection. Nozzle 31 serves the purpose of providing washing liquid for washing the pressure side of blade 40 . Fan 25 consists of a multiple of fan blades mounted on the fan hub and extending basically in radial direction. The view shows the typical blade pitch relative to the engine centreline 400 . The fan rotates in the direction indicated by arrow. Blade 40 has a leading edge 41 and a trailing edge 42 . Blade 40 has a pressure side 53 and a suction side 54 . Nozzle 31 is positioned at a point upstream of fan 25 . Nozzle 31 atomizes a washing liquid forming a spray 32 . Nozzle 31 is directed towards fan 25 . FIG. 5 shows the nozzle tangential angle X relative to the engine centreline 400 . The tangential angle X is preferably more than 40 degrees, and more preferably more than 60 degrees and less than 80 degrees, relatively to the engine centreline 400 . Nozzle 31 forms an elliptic or rectangular spray pattern. Nozzle 31 is oriented around the nozzle axis so that the thickness-wise axis of the spray pattern is limited on one side of the spray pattern by streamline 51 and on the opposite side of the spray pattern by streamline 52 .
[0057] Returning to FIG. 4 , this figure show the second nozzle type, nozzle 35 , and it's with-wise projection. Nozzle 35 has the objectives of providing washing liquid for washing the suction side of blade 40 . Blade 40 has a tip 43 and a boss 44 . The leading edge 41 of blade 40 has a length equal to the distance between tip 43 and boss 44 . Nozzle 35 is positioned in an axial direction at a point preferably more than 100 mm, more preferably more than 500 mm and less than 1000 mm, upstream of the fan leading edge. The nozzle 35 is positioned in radial direction at a point less than the fan diameter and greater than the fan hub diameter. Nozzle 35 is directed towards fan 25 . Nozzle 35 atomizes a washing liquid forming a spray 36 . Nozzle 35 provides an elliptic or rectangular spray pattern. The nozzle is oriented so that the width-wise axis of the spray pattern is parallel with leading edge 41 of blade 40 . At one side of the spray pattern the width-wise distribution is limited by streamline 75 . On the opposite side of the spray pattern the width-wise distribution is limited by streamline 76 . From the nozzle's orifice point the width-wise measure of spray 36 at leading edge 41 will be equal to the length of leading edge 41 . The spray will thereby provide liquid to the blade on its entire length from tip to hub.
[0058] FIG. 6 shows nozzle 35 as seen from a projection from the rotor periphery towards the shaft centre. In FIG. 6 nozzle 35 is seen in its thickness-wise projection. Nozzle 35 serves the purpose of providing washing liquid for washing the suction side of blade 40 . Fan 25 consists of numerous of fan blades mounted on the fan hub and extending basically in radial direction. The view shows the typical blade pitch relative to the engine centreline 400 . The fan rotates in the direction indicated by arrow. Blade 40 has a leading edge 41 and a trailing edge 42 . Blade 40 has a pressure side 53 and a suction side 54 . Nozzle 35 is installed at a point upstream of fan 25 . FIG. 6 shows the nozzle tangential angle Z relative to the engine centre line 400 . The tangential angel is preferably more than 20 degrees and less than −20 degrees, and more preferably zero degrees, relatively the engine centre line 400 . Nozzle 35 atomizes a washing liquid forming a spray 36 . Nozzle 35 is directed towards fan 25 . Nozzle 35 forms an elliptic or rectangular spray pattern. Nozzle 35 is oriented around the nozzle axis so that the thickness-wise axis of the spray pattern is limited on one side of the spray pattern by streamline 61 and on the opposite side of the spray pattern by streamline 62 .
[0059] Returning to FIG. 4 , this figure shows the third nozzle type; nozzle 33 , and it's with-wise projection. Nozzle 33 , has the objectives of providing washing liquid for washing of the core engine. Nozzle 33 is positioned in axial direction at a point preferably more than 100 mm, and more preferably more than 500 mm and less than 1000 mm, upstream of the fan leading edge. Nozzle 33 is positioned in radial direction at a point less than half the fan diameter and greater than the fan hub diameter. Nozzle 33 is oriented as to allow the liquid to penetrate through the fan in between the blades. Nozzle 33 atomizes a washing liquid forming a spray 34 . Nozzle 33 forms an elliptic or rectangular spray pattern. The nozzle is oriented so that the width-wise axis of the spray pattern is parallel with leading edge 41 of blade 40 . At one side of the spray pattern the width-wise distribution is limited by streamline 47 . On the opposite side of the spray pattern the width-wise distribution is limited by streamline 48 . The air inlet to the core engine has an opening corresponding to the distance between splitter 45 and point 46 . The width-wise measure of spray 34 at the inlet opening to the core engine will correspond to the distance between splitter 45 and point 46 . Spray 34 thereby provides liquid for entering inlet 23 .
[0060] FIG. 7 shows details of a typical installation of nozzle 33 as seen from a projection from the rotor periphery towards the shaft centre. In FIG. 7 nozzle 33 is seen in its thickness-wise projection. Fan 25 consists of numerous of fan blades mounted on the fan hub and extending basically in radial direction. The view shows a typical blade pitch relative to the engine centreline 400 . The fan rotates in the direction indicated by arrow. Blade 40 has a leading edge 41 and a trailing edge 42 . The third nozzle type, nozzle 33 , has the purpose of providing washing liquid for washing the core engine. Nozzle 33 is positioned at a point upstream of fan 25 . FIG. 7 shows the nozzle tangential angle Y relative the engine centre line 400 . The tangential angle Y is preferably more than 20 degrees, and more preferably more than 25 degrees and less than 30 degrees relative to the engine centre line 400 . Nozzle 33 atomizes a washing liquid forming a spray 34 . The spray from nozzle 33 is directed as to allow the liquid to penetrate through the fan, in between the blades, in direction from leading edge 41 towards trailing edge 42 . Nozzle 33 forms an elliptic or rectangular spray pattern. Nozzle 33 is oriented around the nozzles axis so that the thickness-wise axis of the spray pattern is limited on one side of the spray pattern by streamline 71 and on the opposite side of the spray pattern by streamline 72 . Nozzle 33 is oriented relative to the shaft centreline 400 as to enable liquid to pass in between the fan blades. Liquid penetrating through the fan will enter into core engine at inlet 23 .
[0061] Although specific embodiments have been shown and described herein for purposes of illustration and exemplification, it is understood by those of ordinary skill in the art that the specific embodiments shown and described may be substituted for a wide variety of alternative and/or equivalent implementations without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Consequently, the present invention is defined by the wordings of the appended claims and equivalents thereof.
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Device for cleaning a gas turbine engine, and in particular an engine of turbofan type. The present invention further relates to a method for cleaning such an engine. The device comprises a plurality of nozzles arranged to atomize cleaning liquid in the air stream in an air inlet of the engine up-stream of a fan of the engine. According to the invention, a first nozzle is arranged at a position such that the cleaning liquid emanating from the first nozzle impinges the surfaces of the blades substantially on the pressure side; a second nozzle is arrange at a position such that the cleaning liquid emanating from the second nozzle impinges the surfaces of the blades substantially on the suction side; and a third nozzle is arranged at a position such that the cleaning liquid emanating from the third nozzle passes substantially between the blades and enters an inlet of the core engine. Thereby, the different types of fouling found on the fan and in the core engine compressor of turbofan engine can be removed in an efficient manner.
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FIELD OF THE INVENTION
[0001] The present invention relates to a device for starting an internal combustion engine.
BACKGROUND OF THE INVENTION
[0002] Many internal combustion engines are not provided with a starter motor and must instead be started by an external force. Often, a rope or handle must be manually used to turn over the engine in order to start it.
[0003] However, this suffers from a number of disadvantages. Firstly, the action of manually starting an internal combustion engine can require a substantial force which a user, for example, an elderly person, may be unable to supply. It may also be necessary to repeat the exercise of turning the engine over several times before the engine starts. This is exacerbated under certain conditions, such as cold weather, where an even greater force is needed to start the engine. Another situation where problems arise is when an engine has been stored without fuel. Although known engines can include means to prime the engine with fuel before starting, the engine may still be difficult to start. Also, even when a person is able to turn over the engine, there remain the danger of injury caused by kick-back from the motor.
[0004] There have been proposed a number of devices for assisting in the starting of internal combustion engines. Some of these relate to the use of an electric drill to turn over the engine. However, none of these proposed methods or devices is believed to overcome all of the existing problems in order to provide a convenient and easy way to start an internal combustion engine.
[0005] There exists therefore a need for an improved apparatus for starting an internal combustion engine.
SUMMARY OF THE INVENTION
[0006] According to the present invention there is provided a device for starting an internal combustion engine comprising a first clutch member attachable to the engine, and a second clutch member attachable to a portable drive means, wherein the first and second clutch members are engageable so that the drive means transmit force through the clutch members so as to turn and start the engine, and wherein, once the engine starts, the first and second clutch members automatically disengage from each other and wherein at least one of the first and second clutch members retracts.
[0007] Preferably, at least one of the first and second clutch members comprise resilient biasing means against retraction.
[0008] Conveniently, at least one of the first and second clutch members is resiliently biased by a spring.
[0009] Advantageously, the second clutch means is suitable for attachment to a portable drill.
[0010] Preferably, the first clutch member is suitable for attachment to a lawnmower engine.
[0011] Conveniently, the first clutch member is retractable.
[0012] Advantageously, the second clutch member is retractable.
[0013] Preferably, the retractable clutch member remains retracted when the clutch members disengage.
[0014] Conveniently, one of the clutch members is slidably mounted on a shaft.
[0015] Advantageously, the clutch member is prevented from rotating about the shaft.
[0016] Preferably, the first and second clutch members comprise a dog clutch.
[0017] According to another aspect of the present invention, there is provided a lawnmower comprising a first clutch member attached to an internal combustion engine wherein the first clutch member may engage with a second clutch member attached to a portable drive means so that the drive means transmit force through the clutch members so as to turn and start the engine, and wherein, once the engine starts, the first and second clutch members automatically disengage from each other and wherein at least one of the first and second clutch members retracts.
[0018] The invention will now be described, by way of example, with reference to the accompanying drawings in which:
[0019] FIG. 1 is a side view of a lawnmower and a starting device of the invention;
[0020] FIG. 2 is a side view of part of the starting device of the invention;
[0021] FIG. 3 is a side view of a lawnmower and a starting device of the invention engaged with a lawnmower engine before the engine has started;
[0022] FIG. 4 is a view corresponding to FIG. 3 after the engine has started;
[0023] FIG. 5 is a side view of a lawnmower and an alternative embodiment of the device of the invention; and
[0024] FIG. 6 is a perspective view of part of an alternative embodiment of the clutch members of the invention.
[0025] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as described by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] A lawnmower is shown generally at 10 and is of conventional construction. It comprises a main body 12 , four wheels 14 , a handle 16 and an engine indicated generally at 18 .
[0027] A first clutch member 20 is attached to the flywheel of the engine 18 . The first clutch member 20 comprises a substantially circular disc with an upstanding annular wall. The annular wall defines a series of asymmetric notches. There is also provided an electric drill 22 in the chuck of which is mounted a starting device indicated generally at 24 . The construction of the first and second clutch members can be more easily understood with reference to FIG. 2 . The starting device 24 comprises a shaft 28 extending from the drill bit of the drill 22 . Fixed on the shaft 28 is located a substantially circular disc 30 . The disc 30 supports a coil spring 32 extending away from the drill 22 . Towards the end of the shaft 28 there is mounted a second clutch member 26 . The second clutch member 26 is of similar configuration to the first clutch member 20 and has complementary asymmetric notches.
[0028] A notch of the first clutch member 20 as attached to a lawnmower will now be described. A first wall is directed substantially perpendicularly to the axis between the first clutch member and the lawnmower and thus defines the distal edge of the notch. A second wall is directed towards the lawnmower substantially parallel with the axis between the first clutch member and the lawnmower. A third wall, of shorter length than the first wall, is directed substantially parallel with the first wall, defining the proximal edge of the notch. A fourth wall is directed away from the lawnmower towards the distal end of the clutch member at an angle away from the first wall. The notch thus tapers away from a smaller width at the proximal edge to a greater width at the distal edge. This pattern is repeated around the annular wall of the first clutch member to define a regular series of notches. The second clutch member is provided with a corresponding complementary set of notches which mesh together with the notches in the first clutch member.
[0029] The second clutch member 26 is slidably mounted upon the shaft 28 but is prevented by rotation about the shaft 28 . The spring 32 biases the second clutch member 26 towards the end of the shaft 28 but allows the second clutch member 26 to move some distance towards the disc 30 .
[0030] As shown in FIG. 3 , in use, the drill 22 and apparatus 24 are aligned with the first clutch member 20 and the second clutch member 26 is brought into contact with the first clutch member 20 . The complementary asymmetric notches of the first and second clutch members 20 and 26 mate together. The notches are shaped so as to allow the drill 22 to efficiently transmit drive through to the engine 18 . Thus, once the first and second clutch members are engaged and the drill 22 is switched on, the engine 18 is forced to turn over, as will be explained below.
[0031] FIG. 5 shows a further embodiment of the invention with the positions of the first and second clutch members 20 ′ and 26 ′ being reversed with respect to the embodiment shown in FIG. 1 . In this embodiment, the first clutch member 20 ′ is attached to the drill 22 . The starting arrangement 24 ′ is attached to the engine 18 . Once the first and second clutch members 20 ′ and 26 ′ are engaged and the drill 22 is turned on, the engine 18 is turned over as explained above. Again, if the engine turns the second clutch member 26 ′ faster than the first clutch member 20 ′, they will automatically disengage, with the second clutch member 26 ′ being forced down towards the engine 18 .
[0032] Once the engine 18 starts, the drill 22 and apparatus 24 may be pulled away from the clutch member 20 . However, if the engine 18 forces the first clutch member 20 to turn at a rate faster than that of the second clutch member 26 , the asymmetric shape of the notches in the first and second clutch members forces them apart. The second clutch member 26 would be thrown away from the engine 18 towards the drill 22 to reach the situation shown in FIG. 4 . Thus, the distance between the drill 22 and the second clutch member 26 has decreased. In other words, the second clutch member 26 has retracted. The axial shock of this movement is absorbed by the spring 32 , reducing the force passed to the user of the drill 22 . After retraction, the second clutch member 26 would be pushed back away from the drill 22 by the spring 32 . The drill 22 and attached arrangement 24 can then be safely withdrawn away from the engine 18 .
[0033] In an alternative embodiment, there is provided a catch on the shaft 28 which allows the second clutch member 26 to travel towards the disc 30 to reach the position shown in FIG. 4 , but prevents the return of member 26 towards the terminus of the shaft 28 . Thus, in this embodiment, if the second clutch member 26 is thrown from the first clutch member 20 the shock is absorbed by the spring 32 and second clutch member is safely retained by the catch away from the engine 18 . In other words, the second clutch member 26 undergoes retraction without immediately moving back away from the drill 22 . The user may return the second clutch member 26 to its initial position by releasing the catch. Thus any injury or shock caused by the kick-back from the motor 18 to the user of the drill 22 is prevented.
[0034] FIG. 5 shows a further embodiment of the invention with the positions of the first and second clutch members 20 ′ and 26 ′ being reversed with respect to the embodiment shown in FIG. 1 . In this embodiment, the first clutch member 20 ′ is attached to the drill 22 . The starting arrangement 24 ′ is attached to the engine 18 . Once the first and second clutch members 20 ′ and 26 ′ are engaged and the drill 22 is turned on, the engine 18 is turned over as explained above. Again, if the engine turns the second clutch member 26 ′ faster than the first clutch member 20 ′, they will automatically disengage, with the second clutch member 26 ′ being forced down towards the engine 18 . In this embodiment, the first clutch member 20 undergoes retraction towards the engine 18 . In an alternative embodiment, means may be provided to prevent the immediate return of the retracted clutch member to its initial position.
[0035] It is to be appreciated that numerous forms and configuration of the first and second clutch members could be used which allow them to automatically disengage once the engine has started.
[0036] FIG. 6 shows an alternative arrangement of a first clutch member 40 , comprising a diametrically extending bar, and a second clutch member 42 , comprising an annular wall defining two asymmetric notches. If the first clutch member 40 is brought into contact with the second clutch member 42 and is turned in one direction, drive may be transmitted as described above. If the first clutch member is turned in the other direction, the members automatically disengage from each other.
[0037] Although the invention has been described in relation to the starting of a lawnmower, it is to be appreciated that it is also applicable to other engines. For example, the invention also applies to chainsaws, strimmers, outboard engines, generators, compressors and other such devices.
[0038] The above specification provides a complete description of the invention. Since many embodiments of the invention can be made to work without departing from the spirit and scope of the invention, the invention resides in the appended claims.
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A device for starting an internal combustion engine comprising a first clutch member attachable to the engine, and a second clutch member attachable to a portable drive means, wherein the first and second clutch members are engageable so that the drive means transmit force through the clutch members so as to turn and start the engine, and wherein, once the engine starts, the first and second clutch members automatically disengage from each other and wherein at least one of the first and second clutch members retracts. Preferably at least one of the first and second clutch members comprises resilient biassing means against retraction. A preferred embodiment relates to a lawnmower comprising such a device.
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TECHNICAL FIELD
The present invention relates generally to a ultraportable multi-purpose support to maintain in an elevated and ergonomic position a laptop/notebook/ultrabook computer, a tablet computer, a tablet plugged into a keyboard, a smartphone and/or paper documents. In addition, the support can be used on any surface, even irregular, especially on the knees.
BACKGROUND
A large amount of support-like products do exist whose stated goal is to allow the user to work comfortably, even in the absence of a table, for example during traveling, in an armchair, on a bed, . . . . Many of these solutions, however, are limited to stationary applications, e.g. in the office or at home, because they are not portable at all or too heavy or cumbersome to be easily carried away.
Among these solutions, a lot of them however can be considered portable in the sense that the user can carry them away with him.
However, these known solutions usually have one or more disadvantages in practice, respectively, an advantage is obtained at the expense of other desired features. Thus, a disadvantage of portable support with folding feet is, for example, that they often require different settings at different places to find a position at least partially ergonomic. If ergonomics was the criterion of choice, the use of the support is often limited to certain situations, such as either sitting or lying down. Contrariwise, if lightness was the main criterion of development, stability, strength and/or flexibility are often lacking. The user comfort is also often sacrificed in order to offer an aesthetic solution.
In view of the existing solutions, it is clear that there is a need for a support type of products, but the great difficulty seems to reside in the apparent incompatibility requirements, respectively, in the apparent contradiction of the effects of the necessary measures to fulfill them.
BRIEF SUMMARY
The invention provides a support device that is easily transportable and therefore relatively lightweight and compact for transport and allows a comfortable and ergonomic utilization even on uneven surfaces, such as on the knees in particular. The invention should therefore allow the user to work with a laptop/notebook/ultrabook computer, a tablet computer and/or a smartphone, in an raised and ergonomic position, anywhere: in a plane, a train, a car, on a chair, a coach, a bed, . . . .
In order to solve the problem mentioned above, the present invention provides a multifunction support, including at least two feet attached by means of hinges allowing rotation of said feet, a locking system of the hinges allowing to maintain the feet into at least two different angular positions, one of said positions corresponding to a folded position for transport or storage and another angular position corresponding to a said unfolded position for support utilization. The support is characterized in that it further comprises at least two straps, each of the straps being attached to the two opposed feet at a location of the foot distant from the hinges.
A first major advantage of the presence of straps according to the invention is that they allow to lay the support on all kinds of surfaces, even irregular, such as on the knees (thighs), on a thick bed quilt, etc. . . . When the user crosses his legs, even while the support rests on his knees, the straps fit perfectly. The adaptation is automatic and instantaneous, there is no need for adjustments when changing the position. A second advantage is the great stability achieved even on irregular and convex surfaces. A third plus is that the straps offer a perfect load distribution, which is a particularly important criterion for comfort, especially when the support is laying on a body part, such as on the knee(s). Fourth, the straps offer a useful and necessary working height, especially when using the knee(s). A fifth benefit, despite the apparent inconsistency with the benefits above, the straps contribute to the compactness and lightness of the product, because they can be made of a thin material, lightweight and durable. Sixth, the use of straps (for example instead of strings with an enlarged central portion for example) ensures they unbend automatically during the unfolding of the support and thus avoid having to check and adjust their position or orientation when laying the support on the knee(s). Finally, the presence of straps does not impede to use the support on a rigid and flat surface like a table. Such an elevated use is although useful when the table is low or when the user is standing at the table, for example during a presentation.
In the context of the present invention, the term <<strap>> is to be understood in its usual and primary meaning, i.e. a <<wide and flat ribbon or belt (leather, fabric, cloth, silk, plastic, fiberglass or other durable material)>>. In fact, a <<strap>> as used herein is a strip with an essentially constant width (i.e. the width does not vary by more than 10%) over the length of the strap and this width may vary between 1 and 15 cm, preferably between 2 and 10 cm, more preferably between 2.5 and 7.5 cm, for example about 3, 4 or 5 cm. The thickness is generally between 0.1 and 5 mm, preferably between 0.3 and 3 mm. In general, the ratio between the width and the thickness of the strap is at least 10, preferably at least 30 and the ratio is preferably between 10 and 500, more preferred between 30 and 200. It therefore does not have an approximately circular section, such as a string, a rope, a wire or cable. It neither has a substantially circular section in some areas, nor is it an assembly of flat portion(s) and circular section portion(s).
Ideally, the portion of the strap between the fixations on the two opposite feet (portion of the straps resting on the knees) has a length equal or slightly greater than the distance between the fixations on the two opposite feet to which the strap is attached when the support is in the unfolded position (distance between the base of the feet in utilization), for example 0.5 to 10% longer. In other words, the portion of the strap resting on the knees (or other surface) is not tight. This allows the strap to take on the shape of the contact surface and distribute the load. The length of the straps can also be adjustable, for example by means of adjustment buckles, magnets, retractors, Velcro-type fasteners . . . .
As described in more detail below, the support feet can be attached directly to each other by hinges or indirectly through a plate. In the latter case the feet are attached laterally on each opposite side of a plate. It should be noted that the term “plate” is to be understood broadly in the sense that it can represent in its simplest example a rectangular shape, but can also be a laptop/notebook/ultrabook computer, a tablet computer, a keyboard or a frame, as presented more fully below.
In order to avoid that the straps protrude or cause discomfort in a folded position (for transport), it may be advantageous or desirable to foresee one of the following solutions (non-exhaustive list):
An elastic area within the strap (optionally with a maximum extension limit): longer strap under load (in use), but shorter in folded position A strap retractor: the strap automatically retracts during folding of the feet, and unrolls automatically at the opening Fold the strap on itself (strap sufficiently flexible and/or strap with hinges). Depending on the geometry of the support, the straps may be twisted when folding the feet (but unbend automatically when opening, as explained above). This may be acceptable and will not be a major concern. It is however possible to place orthogonal or oblique hinges at specific locations of the strap to facilitate the withdrawal or folding of the straps between the feet and the plate or between the feet, so that the straps are perfectly parallel to the feet and/or plate in the folded position. For a similar result, the strap can be made of flexible parts and slightly less flexible parts. During the folding of the feet, the less flexible zones will stay flat and force the folding to take place at the flexible zones and allow the strap to follow the feet during their rotation. The folding of the straps can also be improved by connecting one or more locations of the strap with a spring-like or elastic material to a fixed element, such as an area close to the hinge between the plate and the feet. During the folding of a foot, the elastic is going to pull on the specific location of the strap to bring the strap in a predetermined position. To attach the straps to the feet, the use of articulated fasteners (free to rotate) avoids the problem of torsion of the straps explained in the previous section. Indeed, the straps can then be substantially perpendicular to the feet in utilization and parallel to the feet (and plate) when folded. Attachment of the strap on both sides of the plate or feet, for example with a Velcro-type fastener or magnet, which can serve as a locking system for holding the support in a folded position (for storage or transport).
In general, the straps have identical top and bottom surfaces. However, if desired, one surface of the straps (or both) may be provided with a non-slip surface or a non-slip coating to further increase the stability of the support during use. The lower surface of the strap (for example in contact with the knees) or a portion of this contact surface can optionally be coated with a soft material (for example foam-type) to further increase the comfort of the support. Preferably, the lower surface of the strap (to be placed on the knees) is provided with a non-slip coating and the opposite surface is smooth or slippery. Indeed, the fact that the top is smooth or slippery is particularly advantageous because it makes the folding of the straps easier: less friction between the strap and the plate allows a natural and automatic centering of the straps in the center of the plate when the feet fold and thus promotes a good and flat storage of the straps.
To further increase stability, the straps are preferably as far as possible from each other, but by ensuring that the greatest distance between two adjacent straps (width of straps included) is not greater than the length of a thigh, i.e. generally about 35 to 40 cm, so that the rear strap doesn't fall off the knees. In general, two straps do not only offer an excellent stability, but allow the strap to take on the shape of the underlying contact surface. However, if desired, a larger number of straps may be provided, for example 3 or 4.
The straps are generally attached to the bottom (or near the bottom) of the feet (foot base, foot part opposite to the hinge between the foot and the plate), in a removable manner or not. In principle, they can be attached by any suitable means. For example, they can be riveted to the feet, or attached with specific fixations (freely rotating or not). They may also be attached for example through an opening or slot in the bottom of the foot (by passing the end of the strap through the slot), or by sewing, gluing, stapling, riveting or by means of magnets or fasteners such as clips. A combination of different means is also possible, for example on both of the two ends of each strap.
In a preferred embodiment, there may be three or four openings or fixation systems (at different distances from the user side to the opposite side, optionally at different heights of the feet) and only use two straps attaching them as needed to selected openings or fixation systems, which offer the best suited position to the physiology of the user or the specific use conditions. Alternatively or in addition, there may be longer openings with a system that allows to position the strap on one side of the opening or on the other side. In the case of use of fasteners other than slots, such as metal or plastic fasteners, these may be adjustable in position, or redundant in different positions so that the user can select the fasteners to which the straps are secured.
In particular (but not exclusively), one or more additional straps (or longer straps) may be provided to allow surrounding the thighs and securing the support to the thighs for example (to one thigh if applicable). This is useful for example when the support is used with a tablet computer (e.g. iPad® or e-reader) where the pressure on the touch-screen tends to tilt the whole, or when the support is used in the field of video games where sudden movements are made on a joystick, buttons, a wheel or other accessory sets.
The material used for the straps can be any material or combination of suitable materials known by the professional. It should be noted that in the context of the present invention, a strap can be set to a flat rectangular section of fibers (woven, braided, etc. . . . ), but can also be made of solid material. In this case, the materials used are polyamides such as Nylon® or Aramid®, Dyneema® (UHMW polyethylene), polypropylene, polyester, coated glass fibers, any types of plastics, etc. . . . .
In the context of the present invention, the multifunction support can basically take two forms or configurations, one folded for transport or storage and the other unfolded for use. In the “transport position” or “storage position” or more simply “folded position” feet are folded in/on/under the plate by rotation around the hinges and possibly secured in this position by a locking system. The angle of the feet when folded is about 0° (0°±5°) to each other or relative to the plane of the plate if applicable. The feet are then in substantially parallel planes and, when applicable, parallel to the plane of the plate. (If other accessories are included in the support, they can optionally also have a folded position for transport or storage, see below.) In “use position” or “unfolded position” feet are unfolded, i.e. oriented at an angle different from the folded position.
With the utilization of a “plate”, the angle of the feet when unfolded varies between 60° and 130° relative to the plane of the plate, for example at an angle of about 90 to 105° (again, if other accessories are included in the carrier, they can optionally also have an unfolded position or state of use). In a preferred embodiment, the angle of the feet relative to the plate is selectable from a value of about 0° for transport in the folded position and a value between 60 and 130°, preferably between 90° and 110°, more preferably approximately 90° in the unfolded utilization position.
In a preferred embodiment, an additional hinge in the feet may be provided in a plane orthogonal to the plane of the hinge between the foot and the plate. It allows to rotate the feet along the axis of the thighs, which reduces the length of the foot and therefore their weight and gives more stability to the whole, moving the center of gravity towards the center of the plate. One extra advantage is that the maximum working height for a defined plate size is higher, as feet can't ideally protrude the plate in the folded position. The higher the working height is, the longer the feet are and the more benefits this extra articulation brings. To increase the work height, it is also possible to use telescopic feet or feet with an extra hinge for folding on itself.
Without the use of a plate, when the feet are directly tied together in their upper part, the unfolded angle (angle between the feet themselves) can vary between 15° and 75°. In a preferred embodiment, the unfolded angle is selectable between a value of about 0° in the folded position for transport and a value between 15 and 75°, preferably about 30° in the unfolded position for utilization.
In general, indications of angles, dimensions and other numerical values in this document are, unless stated otherwise, approximate values and may therefore vary in practice up to ±10% of the specified value.
The dimensions of the support may vary within useful limits, depending on the intended use and user requirements. In general, if the support includes a plate, it is expected to lay paper documents and allow hand writing. The dimensions of the plate are therefore preferably (but not necessarily) such that it can support most of an A4 document. In practice, the width of the plate (and therefore in principle of the support) will vary between 15 and 70 cm, preferably between 20 and 45 cm and the depth of the plate between 15 and 50 cm, preferably between 15 and 40 cm. It should be noted that for very narrow supports (15 to 25 cm), the use on both knees is possible if the distance between the feet (at the straps level) is sufficient (>30-35 cm). This can be achieved by an unfolded angle of the feet above 90°, for example between 90 and 120°. Furthermore, a narrow support may (also) be used with an unfolded angle of about 90°, but then the user holds the support on one knee at a time.
For supports with larger plate, it is possible to foresee one (or more) hinge(s) through the plate, for example a central hinge (longitudinal or transverse), so as to further reduce the dimensions of the support in the folded position for transport. With two hinges, it is possible to create a space between both parts of the plate in folded position, which can then enfold a tablet computer, a laptop/notebook/ultrabook computer or a smartphone. The support then serves as a case and protects the device during transport or storage.
The shape of the contour of the support plate can vary: square angles, rounded, etc. . . . A rounded wavelike cut may optionally be made at the center of the lower side of the support (the side facing the user). This will allow to reduce the distance between the support and the user, which may be useful for a “bellied user”. Indeed, for an overweight person or a person with short legs, the top strap may slip beyond the knees. Bringing the support closer is favorable in this case.
Along the lower side of such a plate, adjustable removable or fixed stops will prevent the computer, book or documents from slipping off the support. For the same reason, a coating or non-slip layer (material, varnish, paint, . . . ) can be applied on the upper surface of the plate (or at specific locations).
The plate, in its broadest sense, can be a keyboard. A computer keyboard may also advantageously be included in/on the plate. The keys are preferably not protruding the surface of the plate, such as documents or a computer can be deposited on the support without touching (or damaging) the keyboard. The keys can be mechanical or sensitive. Part or the entire surface of the plate may be sensitive (capacitive touch sensing) or optical (virtual keyboard by holographic light projection). A support with integrated keyboard is useful for computers without keyboard as tablet computers (e.g. iPad®), for smartphones or for television (smart tv). Connecting the keyboard to the computer or other electronic devices, such as smartphone or smart tv, can be wired (e.g. via USB or specific connectors relative to brands and models), but can also be performed wirelessly, for example by Bluetooth®, WiFi, etc. Even a laptop computer with keyboard can be used on a support with integrated keyboard because the rubber feet of the computer are usually located outside the area of the integrated keyboard. The keys of the keyboard may optionally be backlit.
In fact, despite the possible presence of the keyboard, documents can be placed on the support. To write on documents that are flexible or thin (A4 paper sheets for example), it may be advantageous to use a document case or a plastic or rubber sheet between the document and plate/keyboard. This plastic or rubber sheet can be provided with each carrier and easily stored in the bag of the laptop or iPad®. To prevent slippage of the computer, books or documents, the material of this sheet can be anti-slipping or its upper surface can be covered with a non-slip coating (varnish, paint, . . . ).
A further variant to obtain a perfectly flat surface for writing would be to fix the keyboard inside a cut-out in the plate, and for instance be rotated 180° along its central axis or be removed, turned over and re-inserted, so that the keyboard is oriented downward (under the plate) if not needed or for transport.
In some preferred embodiments, the plate includes (in addition) a fastening system for a tablet computer, smartphone, laptop/notebook/Ultrabook® or screen and optionally specific connectors to brands and models used to connect the keyboard of the support, its built-in battery, its touchpad, its numpad and/or a separate power supply.
In such a case, the plate may comprise a groove or a rail (optionally adjustable in rotation), and optionally additional fixations to secure the computer in an inclined plane relative to the plate, optionally adjustable in rotation. Specific connectors to the brands and models of the devices can be present at the bottom of the groove or rail, allowing the link to the numpad, keyboard, touchpad or integrated battery.
Such a fastening system may be provided to allow positioning and holding a portable computer (e.g. tablet type, like iPad®) and/or a smart phone (“smartphone”, e.g. iPhone®) not in the plane of the plate as described below, but at a certain angle relative to the plate (possibly selectable angles), the device being placed in either landscape position or portrait position. The holding should be strong enough so that the user can push on the touch screen in a convenient and comfortable way. Among other possibilities, a suitable system comprises a groove or rail (which may be magnetic) for the lower side of the device and another system to further hold the back face, the upper side or the sides of the device. Holding the lower side may not be enough. By moving the assembly (support and electronic device(s)), there may be a risk for the device(s) to slip off. There are several ways to strengthen the holding of these accessories on the support. Here are some examples:
An elastic or cord or rigid rod (optionally with adjustable length) with two fixations at both ends, one end being attached to the support and the other end to the device (preferably on the upper area). This holding system can also be used for a specific application: using a tablet type computer with its keyboard (like the iPad® with keyboard or Asus Transformer® or HP Envy® or Clamcase®) deposited or secured on the plate or frame. An articulated piece type gusset clipping on the back of the computer or phone or in a shell case holding this device. This gusset can be part of the plate and, thanks to a hinge, will be in the plane of the plate (folded position) or tilted to clip and hold the device (working position). Several gussets can be foreseen for positioning multiple devices at the same time on the support. This will allow to develop and use specific applications on multiple devices (e.g. transferring data from one device to another, managing a smart tv with a smartphone and a tablet simultaneously, . . . ).
In other embodiments, the fastening system for an (ultra)portable computer (e.g. a tablet type computer) allows its fixation in the plane of the plate. It is preferably formed by specific cut-outs in the plate and fasteners or snap-fitting to secure the device in the plane of the plate itself. It is also possible to have a small angle between the device and the plate when the device is plugged to an accessory. For example, tablet cases like the iPad Smartcover® maintain the iPad® at an angle when the case is folded in use position. The plate of the support then contains a fixation system (e.g. a groove, optionally with magnets) for the case and a fixation system (e.g. a groove, optionally with magnets) for the bottom of the device. It is also possible to attach the device directly to the feet, instead of the plate.
In a further embodiment of this type, the plate can be formed simply by an intermediate fastener adapted to secure such a device. Thus, the fastener can be made for example in the form of a frame or a shell (case, cover) comprising fasteners adapted to the model or type of device. Such a “plate” is then reduced to one frame to which are fixed the feet as described here. An advantage of this reduction of the plate to a frame is that it brings a weight reduction of the support. It should be noted that according to the context in the present invention, the term “plate” in this case may designate the frame or shell (case or cover) and may include the computer (tablet, laptop, smartphone, . . . ). In general, the plate can integrate other functions as described with more details in this document.
Alternatively, or in addition, the support may include a numeric keypad (numpad). Preferably it will be a carrier part which, after rotation (180° relative to the transport position), will be outside of the plate. In a preferred embodiment, a button on the hinge between the foot and the plate (see below) will unlock the numpad. For example, the foot turns by 90° and the keypad turns by 90° or 180° (90° to stay in alignment with the foot in use position and not be used, and 180° to become an extension of the plate and be used). In a preferred embodiment, this carrier part will hold a smartphone that will act—among other diversified possible applications—as the numeric keypad (via a wired or wireless connection). The fixation of the smartphone to the carrier can be magnetic or mechanical.
A keypad or numpad can be useful with or without a keyboard integrated in the plate of the support. With keyboard, the keyboard and the keypad can be connected to a tablet computer, smart TV, smartphone, etc. . . . Without integrated keyboard, the keypad can be connected (via USB, Bluetooth®, WiFi, etc.) to a laptop/notebook, ultrabook that does not have a numeric keypad. Thanks to a power supply (battery or solar cell) and a calculator display, the numeric keypad can be used as a standalone calculator. This can be useful if the user works on “paper” documents and there is a need for a calculator. If the support includes a power supply, the keypad keys can optionally be backlit.
Whether for use with a television, a computer, touch screen computer (tablet), a games console or a smartphone, a pointing device can be useful. It can be a separate device such as mouse or integrated such a trackball, joystick, touchpad, steering wheel, etc. . . . . When the device significantly protrudes the plane of the plate, for example a joystick, it may be designed in a retractable manner (adjustable in rotation) or removable (attached by clipping, screwing, magnets, . . . ). It will not hinder an important feature of the invention, which in this case is the fact that it can be folded flat for an easy transport.
The support has at least two folding feet. The function of these feet is on one hand to offer an ergonomic working height, thanks to the straps (where applicable). The screen of the electronic device placed on the support will be indeed much higher, in the optimum vision zone of the user (so no need to lower the head, for example towards the direction of the knees).
The feet (and other elements of the support) may have any shape or form. Only the features described in this document are important. Cutouts or recesses within the support elements allow a weight reduction.
There is no limit concerning the materials of the various elements of the support. Obviously the weight is a practical and commercial factor. Aluminum and its alloys, all plastic-type materials, leather, composites (including sandwich panel), carbon or carbon fibers, glass or Plexiglas are the materials of choice. Sections or profiles of the elements of the support (plate, feet, . . . ) shown in the figures are essentially rectangular. An effective way to reduce the weight of these elements is to use thin sheets (in a lightweight material such as aluminum or plastic) whose rigidity is provided by specific reinforcement shapes (ribs, flanges, gussets).
In a preferred embodiment, the feet are designed to offer an angle of inclination of the plate towards the user, when they are in the unfolded position. The angle of the plate with a greater height at the back offers an ideal position relative to the user, especially to write, type on the keyboard or press the touch screen of the tablet. This inclination towards the user can be achieved by designing the feet so that their height is lower on the user side than on the opposite side (distant from the user). The difference in height is preferably chosen so as to obtain an angle of inclination of the plate between 2 and 70°, preferably between 10 and 30° relative to the plane formed by the lowest points of the feet (unfolded, use position), respectively relative to the horizontal when it is mounted in a use position on a flat horizontal surface.
When the feet are used without plate, i.e. when they are attached directly to each other, for example for supporting a tablet computer on one thigh, the angle of inclination between the base of the feet and the display is set to be between 20 and 90°, preferably between 45 and 65°.
In case of a support with plate, the height of the feet at the highest point measures ideally at most half the width of the plate (plate, computer, touch pad, keyboard). In this way, the thickness of the whole support in the folded position is minimal. For a higher working height of more than half the width of the plate, feet will have to superimpose (overlap) in folded position. The height of the feet at the highest point can then reach up the whole width of the plate.
A further advantage of some variants of the support is that the inclination of the plate on uneven surfaces can also be adjusted for example by the fixation position and/or the length of the straps (see above).
The hinges allow folding the feet under (or above or inside) the plate to set the support in transport position and unfolding the feet for support utilization. Optionally, according to the type of construction of the feet and/or the plate, hinges can be integrated during molding, or they are independent pieces attached to the feet and/or the plate (screws, rivets, clips, glue, etc. . . . ).
In a further embodiment, when the support feet are directly attached to each other (without plate), both feet have a geometry for housing and holding a tablet computer (iPad®, e-reader) or a smartphone (iPhone® type), or an intermediate part between the feet and the device (shell, case or cover types). In particular, a “case” or “cover” containing the tablet and/or smartphone can turn into a support. One of the edges of the periphery of the case can act as a hinge. After opening, the two sides or faces of the case form an angle and serve as feet.
In a further embodiment, when the support feet are directly attached (without plate), folding lines can be integrated into the feet. Once the support (case) is open, folding the feet along these lines will bring up an inclined surface. This surface allows to clip, attach, maintain and optionally tilt a tablet computer or smartphone, thanks to magnets, Velcro® type scratches or other mechanical fasteners. To enhance the stability of the support, one strap (or both) may be longer to allow surrounding the thigh. This may even allow the user to get into ‘standing’ position without risking dropping the support (and device attached), which provides a degree of freedom worth for the user. An optional non-slip coating on the straps will prevent slippage of the support along the thigh. In addition, the straps may possibly be used as a lock to hold the support in the closed position (for storage or transport). A closure system other than the straps can be optionally added: Velcro® type scratch, zip along (part of) the periphery of the feet, button and eyelet, pressure, magnets, etc. . . . . In one specific case, when the support is intended to be used on a flat surface (such as a desk or table), the straps are removable or even optional.
The combination of the two previous points is the special case of a support convertible into a case (or box). In other words, a tablet or smartphone case (cover) is convertible into a support, thanks to one edge serving as a hinge between the two sides acting as feet. Fold lines on the feet can generate an inclined surface to lodge, clip, attach, maintain and possibly tilt the tablet or smartphone.
In another embodiment, when the support feet are directly attached to each other (without plate), in addition to the folding system described above, the feet can integrate a system allowing both of the following features: maintain the tablet or smartphone on the generated inclined surface, and hold the feet relative to each other in a predetermined angle. Openings or holes on each foot are superposed when the support is in the open position. It is possible to fit into that opening a piece that will block the feet and optionally attach the tablet computer or smartphone (or their case). Magnets placed on the feet and tablet (or smartphone) car also act as a holding and blocking system: the electronic device will be secured on the generated surface with magnets but in the same time will block the rotation of the feet and maintain them at a predefined opening angle (both feet attached to the electronic device also thanks to magnets).
In another embodiment, a foot or two feet can incorporate the same opening used to fix a tablet or smartphone on the inclined surface generated by folding, but located so that the tablet or smartphone can be attached when stored inside the support (or case if applicable).
In another embodiment, when the support feet are directly attached to each other (without plate), both feet are not identical: the geometry for holding the electronic device is slightly offset to give a side angle to the left or right. As the support is positioned on one thigh only, the screen is not perfectly aligned towards the eyes. The tilt angle given by the geometry difference between the feet orients the screen in the viewing axis of the user. An additional option is to choose which of the two feet will be left or right (during manufacturing or in use by rotation around the top axis) to allow placement of the support on the left or right thigh according to the wishes of the user or whether he is right or left handed.
Rubber feet located at the corner areas allow to put the stand on a table or desk without scratching. Rubber being a non-slip material, it also provides stability.
Various devices may be added to hold pens, pencils, highlighters, gum, cup holder, etc. These devices can be foreseen on the plate itself or on the feet. Spring or magnetic clips will also allow to hold paper documents on the plate.
Batteries can be integrated into the side hinges, in or under the plate or feet allowing to connect (Bluetooth®, Wi-Fi®, . . . ) the keyboard and the iPad® iPhone® or other electronic accessory used, to power the calculator keypad, and/or to extend the battery life of the electronic accessory used (iPad®, iPhone®, . . . ). In this case the support preferably comprises one or more (types of) connectors to connect one or more external electronic accessories.
Solar cells can be integrated to the plate to ensure the connection (Bluetooth®, Wi-Fi®, . . . ) between the keyboard and the electronic accessory used (iPad®, iPhone®, . . . ) to power the calculator keypad and/or to extend the battery life of the electronic accessory used (iPad®, iPhone®, . . . ) or to recharge the integrated battery.
Some embodiments of the support are designed to form a cavity or housing in the folded position in order to store the electronic accessory(ies) and can thus serve as a case or bag or protection for transportation.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and characteristics of the invention will emerge from the detailed description of some advantageous embodiments described below, as illustration, with reference to the accompanying drawings. These show:
FIG. 1 : shows general three-dimensional views of some embodiments of the support,
FIGS. 2 a -2 f : show detailed three-dimensional views of some embodiments of the support,
FIG. 3 : shows three-dimensional views of various supports for a tablet computer and/or screen, and/or smartphone,
FIGS. 4 a -4 i : show three-dimensional views of closures or withdrawal of the support: the “plate”, feet, straps, keypad, as well as various options to store an iPad® and/or iPhone® between the feet and the platform or between the two halves of the plate,
FIG. 5 : shows two three-dimensional detailed views of other embodiments of the support showing the folding of the straps during the closing of the feet,
FIGS. 6 and 7 : show three-dimensional views and sectional views of hinges,
FIGS. 8 a -8 c : shows three-dimensional views of a type B′ support serving as inclined support (for a tablet, smartphone or other electronic device) and as storage case to transport the same device,
FIGS. 9 a -9 k : shows a series of photos of a type B′ support explaining its opening or closing along the folding lines, as well as the system of overlapping the holes in the feet to secure a tablet, smartphone or any other electronic device,
FIG. 10 : shows a variant of the type B′ support from FIGS. 8 a -8 c with an instantaneous magnetic docking system for an iPad® to the support B′, which allows to orient the iPad® in a portrait or landscape mode,
FIG. 11 : shows other views of the type B′ support from FIGS. 8 a - 8 c,
FIG. 12 : relates to an alternative of the type A support in different views, and
FIG. 13 : provides various views of an alternative of the type A support from FIG. 12 .
DETAILED DESCRIPTION
FIG. 1 shows some models of multifunction support A, B, C, D and E.
For the support A, the plate 1 is a simple rectangular plate and is attached by the hinges (or joints) 3 to the feet 2 . The feet 2 are held in the unfolded position of 90° relative to the plate (position of use) by the locking system 5 of the hinges 3 , in this case in the form of articulated “gusset” 5 . 1 with a coupling system to the feet 2 . The support A includes two straps 4 attached to the feet 2 through (some of the) slots 4 . 1 . In this example, the straps 4 have essentially the same length as the width of the plate 1 . The height of the feet 2 is different between the front and back of the support A so as to obtain an angle of inclination of the plate.
The support B is specifically designed to hold a tablet computer (e.g. iPad®). There is no plate in this case, the feet being connected directly to each other by an upper hinge, which can be maintained in open position by the locking device 5 of the hinge 3 . The support B has two straps 4 attached to the feet 2 , allowing to the whole support to lay on one thigh. The portion of the straps 4 resting on the thigh is here longer than the distance between the two fasteners to the feet 2 to match the contour of the thigh and distribute the load. A version shown has even longer straps 4 . 2 around the thigh and attached with a Velcro®-type adhesive, enhancing the stability of the support for a safe use of the electronic device.
The support C comprises four feet 2 directly attached to the frame of a laptop computer 1 (thus acting as the plate 1 ) at the hinges 3 . The feet 2 are held in the unfolded position at 90° relative to the plate (position of use) by the locking device 5 inside the hinges 3 , which in this case may be either in the hinge of the foot 2 or in the part of the hinge belonging to the frame of the computer. This locking system 5 can unlock the rotation of the feet and block them at certain predetermined positions, in particular at 0° and 90°. The support C includes two straps 4 attached to the feet 2 , allowing to lay the support on two thighs. The portion of the straps 4 . 5 resting on the thigh has here a longer length than the distance between the fasteners on the feet 2 , to match the shape of the thighs and distribute the load.
The support D comprises four feet 2 directly attached to the frame of a tablet computer (i.e. iPad®) (thus acting as the plate 1 ) or to the case (shell) clipped on the back of the tablet. The feet 2 are held in the unfolded position at 90° relative to the plate (position of use) by the locking device 5 inside the hinges 3 , which in this case may be either in the hinge of the foot 2 or in the part of the hinge belonging to the frame of the tablet or its case. This locking system 5 can unlock the rotation of the feet and block them at certain predetermined positions, in particular at 0° and 90°. The support D includes two straps 4 attached to the feet 2 , allowing to lay the support on two thighs. In this example the straps 4 are essentially of the same length as the width of the iPad® 1 .
The support E comprises four feet 2 directly attached to a keyboard (acting the plate 1 ) at the hinges 3 . The feet 2 are held in the unfolded position at 90° relative to the plate (position of use) by the locking device 5 inside the hinges 3 , which in this case may be either in the hinge of the foot 2 or in the part of the hinge belonging to the keyboard. This locking system 5 can unlock the rotation of the feet and block them at certain predetermined positions, in particular at 0° and 90°. The support E includes two straps 4 attached to the feet 2 , allowing to lay the support on two thighs. The portion of the straps 4 . 5 resting on the thigh has here a longer length than the distance between the fasteners on the feet 2 , to match the shape of the thighs and distribute the load.
FIGS. 2 a -2 f are detailed representations of embodiments of a multifunction support A and B with several advantageous options. The plate 1 of the support A is essentially in a plane and attached by the hinges 3 to the feet 2 . The feet 2 are held in the unfolded position at 90° relative to the plate (position of use) by the locking device 5 . Three locking systems are represented: FIG. 2 a shows the locking system type articulated gusset 5 . 1 . FIGS. 2 b , 2 c and 2 e show a blocking system 5 . 2 integrated inside the hinges 3 . Indeed, in this case, the locking system 5 . 2 includes a push button at the front of each side of the plate 1 which unlocks the rotation of the feet and blocks them at certain predetermined positions, including 0° and 90°. The same locking system 5 . 2 can also be used to block the position of a keypad 6 in certain positions, in particular at 0°, 90° and 180°. FIG. 2 d shows a locking system of a pin-type 5 . 3 . Fixations attached to the feet 2 are inserted into cut-outs in an articulated strip 5 . 3 linked to the plate. Magnets or other fixations can be used to maintain the strip in contact with the feet 2 and to ensure the function of blocking the feet in use position. There may be two strips with a similar blocking system on both sides of the plate. In the folded storage position, these strips rotate to come into contact with the upper face of the plate 1 .
The supports A and B shown also include two straps 4 attached to the feet 2 . FIGS. 2 a and 2 d show the straps 4 which have essentially the same length as the distance between the fixations of the straps to the feet, while FIGS. 2 b , 2 c , 2 e and 2 f show the straps that are slightly longer than the distance between these fixations. This provides comfort by distributing the load on the thighs. The height of feet 2 is different between the front and the back so as to obtain an angle of inclination of the plate. Ribs on the feet 2 . 1 and under the plate 1 . 1 provide more rigidity and strength. To avoid scratching the surfaces on which would lay the support, non-slip rubbers 13 are added under the feet 2 . Along the lower side of the plate, adjustable removable or fixed stops will prevent the computer, book or documents from slipping off the support. The support B of FIG. 2 f is designed to be placed on one thigh.
FIG. 2 also shows the following elements: a keyboard 7 integrated into the plate 1 , a keypad 6 , a pointing device 9 (such as a touchpad or trackball or joystick), a holding system to maintain a tablet or smartphone (e.g. in the form of a rail or similar), optional clips 11 can be used to temporarily attach objects to support (e.g. a cup holder, papers, pens or pencils), end stops 10 may be used to prevent objects from slipping off the plate 1 . To get a support as thin as possible in the folded position, the elements out of the plane of the plate can be retractable or removable. For example, the joystick can be clipped to the plate 1 .
FIG. 3 shows two drawings of the support A and two drawings of the support B where several systems to maintain a tablet computer (iPad® type) and/or a smartphone (iPhone® type) are highlighted. One (or more) groove(s) or rail(s) or cut-out(s) 8 . 1 allow to clip the iPad® and/or iPhone® and maintain them, not in the plane of the plate but at a certain inclination angle relative to the plate, the display being fixed in either landscape or portrait positions. This rail can optionally be adjustable in rotation thanks to an additional hinge. The holding should be firm enough so that the user can push on the touch screen in a convenient and comfortable way. Among other possibilities, a suitable system comprises a groove or rail (which may be magnetic) for the lower side of the device and another system to further hold the back face, the upper side or the sides of the device. Holding the lower side may not be enough. By moving the assembly (support and electronic device(s)), there may be a risk for the device(s) to loosen and to slip off. There are several ways to strengthen the holding of these accessories on the support. Here are three examples:
The second drawing of the FIG. 3 shows an elastic or cord or rigid rod 8 . 3 (optionally with adjustable length) with fixations at both ends, one end being attached to the plate 1 (support A) or to a foot (support B) and the other end to the device (preferably in the upper area). The first drawing of the FIG. 3 shows an articulated piece 8 . 2 (gusset type) clipped on the back of the computer or phone or in a shell case holding this device. This gusset can be part of the plate and, thanks to a hinge, will be in the plane of the plate (folded position) or tilted to clip and hold the device (working position). Several gussets can be foreseen for positioning multiple devices at the same time on the support. The last two drawings of FIG. 3 show the support B without plate (with and without iPad®). The contour of the feet contains a profile 8 . 1 for clipping the tablet (iPad®). To avoid scratching or damaging the device, a flexible material (e.g. foam or rubber) can be applied on the edges of the profile. A holding device 8 . 3 (cord, rod or elastic with fixations at both ends) to reinforce the anchoring of the device to the support.
FIGS. 4 a -4 i show two different supports in folded position for storage or transport, and their folding mechanism.
FIG. 4 a shows a support A folded with a multitude of accessories described above, all in the plane of the plate or a parallel plane. The thickness of the whole support in the folded position is thin, even when an electronic accessory such as an iPad® 14 is stored inside, and can take easily place in a computer bag (laptop, notebook, ultrabook, tablet, e-reader, . . . ).
FIG. 4 b shows the same media where an additional articulation 1 . 2 through the center of the plate. This allows an additional fold and halve surface clutter. The thickness of the whole folded support is then twice larger. With this additional articulation, the surface in folded position is then similar to the surface of a tablet computer and the support can be transported in smaller bags specific to tablet computers. The bottom figure shows that the support can act as cover or case for storing e.g. an iPad® 14 and/or a smartphone 15 .
FIG. 4 c shows a simplified support A, where the length of the feet 2 is greater than half the width of the plate 1 . In the folded position, the feet are overlapping and superimpose. This provides a working height (the highest point of the support) greater than half the width of the plate, this height being then able to reach the total width of the plate.
FIG. 4 d shows a support with a double hinge 1 . 3 in the plate for housing an iPad® 14 between the two halves of the plate.
FIG. 4 e shows that a support B can easily be stored with the electronic device.
FIG. 4 f shows a case where the feet are directly attached to the frame of the computer or to a shell or case clipped on the computer (laptop, notebook, ultrabook, tablet, e-reader, . . . ).
FIGS. 4 g and 4 h show variants wherein the straps 4 . 4 are easily stored thanks to a folding mechanism of the straps with parts 4 . 3 acting as hinges.
FIG. 4 i shows the storage or housing of, for example, an iPad® 14 and an iPhone® 15 between the feet 2 and the plate 1 .
FIG. 5 shows a support where the feet are directly attached to a tablet computer. The bottom figure shows an additional hinge 2 . 2 in the feet designed in a plane orthogonal to the plane of the hinge. It allows to rotate the feet along the axis of the thighs, which reduces the length of the feet and therefore their weight and gives more stability to the whole moving the center of gravity towards the center of the plate. One extra advantage is that the maximum working height for a defined plate size is higher, as feet can't ideally protrude the plate in the folded position. The higher the working height is, the longer the feet are and the more benefits this extra articulation brings. To increase the working height, it is also possible to use telescopic feet or feet with an extra hinge for folding on itself.
FIG. 6 shows the longitudinal section A-A in the hinge 3 , explaining the principle of locking and unlocking of the two feet 2 and keypad 6 relative to the plate 1 . The first drawing helps understanding where the cut is made. The feet 2 , the plate 1 and the keypad 6 are all ending in a tubular shape. These tubes are aligned and are traversed by a spindle or pin 5 . 2 . 1 , acting as a hinge 3 and as a locking/unlocking system 5 . The end of the spindle at the front side of the support A is formed by a cylindrical surface acting as a push button. Keys (eight short 5 . 2 . 2 and four long 5 . 2 . 3 ) are placed on both sides of the axis 5 . 2 . 1 . These pins are inserted and guided in cross shaped pieces 5 . 2 . 5 , which are locked in rotation by a lug 5 . 2 . 8 : female part on all the pieces 1 , 2 and 6 , and male part on the cross shaped pieces 5 . 2 . 5 . The second drawing shows the cut in the rest position (without pressure on the button of the spindle 5 . 2 . 1 ). The keys 5 . 2 . 2 and 5 . 2 . 3 are in front of cross shaped pieces 5 . 2 . 5 and the spindle 5 . 2 . 1 is blocked against rotation: the feet 2 and the keypad 6 can't rotate relative to the plate 1 . The third picture shows the cut in the actuated position when the user presses the button on the spindle 5 . 2 . 1 . The short eight keys 5 . 2 . 2 move out of the cross shaped pieces 5 . 2 . 5 and the spindle is then released in rotation: the feet 2 and the keypad 6 can rotate relative to the plate 1 . The user then chooses the angle of the feet 2 (in this example 0 or 90° relative to the plate) and the angle of the keypad 6 (0, 90 or 180°). Indeed, the short keys 5 . 2 . 2 find back one of the openings in the cross shaped piece for every multiples of 90°. By then releasing the pressure on the button, the spindle 5 . 2 . 1 returns and the short keys 5 . 2 . 2 take back their position inside the cross shaped pieces 5 . 2 . 5 , and thus block again the hinge 3 . The interest of the long keys is to always keep the blocking of the spindle relative to the plate. There is only an interest to articulate the feet 2 and the keypad 6 . If the spindle rotates relative to the plate, it would be more difficult to re-align the spindle to lock the hinge 3 . As the keys 5 . 2 . 3 are longer, they do not leave cross shaped pieces attached to the plate and thus keep the spindle and the keys in the same angular position relative to the plate. A spring 5 . 2 . 6 is used to bring the spindle 5 . 2 . 1 back in rest position, when the pressure on the button is released. A piece 5 . 2 . 7 serves as a stop to limit the stroke of the spindle, as a guide and as a contact surface for the spring 5 . 2 . 6 . A cap 5 . 2 . 9 is inserted into the rear end of the hinge.
FIG. 7 shows a cross section B-B in the hinge 3 with an enlarged detail C. This specifies the cross shaped piece 5 . 2 . 5 that is blocked in rotation by the ergots 5 . 2 . 8 : the female part on each of the pieces 1 , 2 , and 6 and the male part on the cross shaped pieces 5 . 2 . 5 .
FIG. 8 shows three-dimensional views of a support type B′ serving as a support (use or unfolded position) and as a case or cover for transportation or storage (folded position).
FIG. 8 a shows the support B′ in the folded position (closed case). It allows to integrate a tablet computer 14 which is maintained through the hole 16 . 3 in the feet 2 (or side of the case). The straps 4 . 5 and 4 . 7 ensure the closure of the case. Folding lines 16 . 1 and 16 . 2 the hole are not used in this folded position.
FIG. 8 b shows the opening of the straps 4 . 5 and 4 . 7 .
FIG. 8 c shows the support B′ in the unfolded or use position (open) on a thigh 16 . 4 (a figure without tablet, a figure with a tablet in landscape mode and a figure with tablet in portrait mode). Folding was made along the lines 16 . 1 . The holes 16 . 2 in the two feet are superposed to attach the tablet 14 and freeze the position of the feet and the whole support assembly. The strap 4 . 7 is longer and allows surrounding the thigh for better holding and stability of the whole assembly (support+tablet). The strap 4 . 5 is shorter and allows only to lay the support on the thigh. The positions of the straps are fixed and defined for different positions thanks to Velcro® type fasteners. The hole 16 . 3 is not used in the unfolded or use position (open).
FIG. 9 shows a series of photos of a support B′ explaining its opening or closing along the fold lines and the system of holes in the feet overlapping to attach a tablet and hold the entire support in position.
FIG. 9 a shows the support (the case) in folded and locked position thanks to the straps.
FIG. 9 b shows the unfolding of the support (the opening of the case) and the release of the tablet, which was housed inside.
FIG. 9 c shows the support secured to the thigh.
FIG. 9 d shows that pushing on the corner will force the support to bend along the preset folding lines in the feet.
FIG. 9 e shows that after a first folding two shapes with holes (here circular) appear on both feet.
FIG. 9 f shows a second fold to superimpose the two holes.
FIG. 9 g shows the support in unfolded or use position (open), ready to plug the tablet.
FIG. 9 h shows the clipping or securing of the tablet computer (or its shell case) on the support with the holes in the superimposed feet.
FIG. 9 i shows the tablet attached to the support, in landscape position. We see that it offers an ergonomic working position and the use of both hands to work. The work is relaxing in the sense that there is no need to support the weight of the tablet with one hand.
FIG. 9 j shows that it is in this case possible to easily tilt the tablet. It can rotate for applications where the angle of the tablet is useful, or just to go from a portrait mode to landscape mode or vice versa.
FIG. 9 k shows the tablet in portrait mode.
FIG. 10 shows an alternative support B′ with which an electronic device such as an iPad® 14 may be secured to the support by means of magnets 16 . 5 in two different orientations (horizontal or vertical).
FIG. 11 shows the support B′ of FIGS. 8 a -8 c , from two other angles.
FIG. 12 shows a support of type A with the hinges 3 , a locking system 5 . 1 , the feet 2 and the plate 1 , all made of one piece during molding. When folded, the support forms a cavity for housing or storing one or more electronic devices 14 , 15 .
FIG. 13 shows a support that has several geometries in the plate to use either a laptop/notebook/ultrabook computer or a tablet (type iPad®/e-reader, . . . ) in a practical and ergonomic way. For use with a laptop or notebook, four small notches are designed into the plate to receive the feet of the laptop or notebook and prevent from slipping. For use with an iPad® and its Smartcover® (or other case on the market), two working positions are foreseen thanks to two grooves or slots on the plate: one groove in the bottom of the plate to hold the bottom side of the iPad® and another groove in the top of the plate to receive and hold the Smartcover® (cover in use or open position). The working angle is then the sum of the angles of the support and the Smartcover®. In this position, the iPad® will rather be used to work, type in text, browse the net, . . . . Another slot in the center of the support allows to plug the iPad® to hold it in a more upright position. This allows to use the tablet for “presentations” (like powerpoint, slideshows, reading, . . . ) or watch a movie.
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Ultraportable support (A, B, B′, C, D, E), comprising at least two feet ( 2 ) attached by means of hinges ( 3 ) allowing rotation of said feet ( 2 ), a locking system ( 5 ) of the hinges ( 3 ) allowing to maintain the feet ( 2 ) into different angular positions, the support further comprises at least two straps ( 4 ) whose width is substantially constant over the entire length, each of the straps ( 4 ) being attached to the two opposed feet ( 2 ) at a location of the foot distant from the hinges ( 3 ).
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This application is a continuation of application Ser. No. 08/040,860, filed on Mar. 31, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine.
2. Description of the Prior Art
When threading the needle thread pulled out from a spool on a sewing machine, the needle thread is passed sequentially through a thread guard, a thread guide, a needle thread tension regulator, a thread takeup device and the eye of a needle. When changing the needle thread, the spool is replaced with another spool and the needle thread pulled out from another spool is threaded on the sewing machine, or the needle thread of the old spool is cut at a position near the spool, the free end of the needle thread of another spool and the trailing end of the needle thread threaded on the sewing machine are tied up and the needle thread extended through the eye of the needle is pulled to thread the needle thread of another spool on the sewing machine.
However, whichever threading methods may be used, the change of the needle thread takes time and the tension of the needle thread must be adjusted every time the needle thread is changed, which also takes time.
Incidentally, a sewing machine disclosed in U.S. Pat. No. 4,590,875 is provided with a sewing head provided with a needle bar, and capable of being removed from the arm and of being replaced with another sewing head provided with a needle bar according to desired stitching operation, such as lock stitching operation or zigzag stitching operation. However, since the spool pin, the needle thread tension regulator and the yarn guides and the like of this sewing machine are arranged on the arm, the needle thread needs to be threaded on the sewing machine when the sewing head is changed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a sewing machine facilitating the threading of another needle thread thereon when changing the needle thread threaded thereon for another needle thread.
A sewing machine in a first aspect of the present invention comprises: a bed; an arm having a vertical portion set upright on the bed, and a horizontal portion horizontally extending from the upper end of the vertical portion; an arm shaft extended within and journaled on the arm; a sewing head detachably joined to the extremity of the arm; a needle bar incorporated into the sewing head, supported so as to be driven for vertical reciprocation on the sewing head by the arm shaft, and capable of being removed from the arm together with the sewing head; a motion converting means detachably connected with the needle bar to convert the rotation of the arm shaft into the reciprocation of the needle bar; a needle thread feed means disposed on the sewing head to feed a needle thread to a needle attached to the lower end of the needle bar; and a thread takeup means disposed on the arm, and capable of operating in synchronism with the vertical reciprocation of the needle bar to draw up the slack needle thread and of releasing the needle thread. Preferably, the thread takeup means comprises a thread takeup lever provided with a guide groove for guiding the needle thread, from which the needle thread can be released, and a cover for closing and opening the guide groove.
In this sewing machine, the needle thread pulled out from a spool is guided by the needle thread feed means disposed on the sewing head, and the thread takeup means disposed on the arm to the needle attached to the lower end of the needle bar, and the sewing head can be removed from the arm. Therefore, when changing the needle thread threaded on the sewing machine for another needle thread, the needle thread threaded on the needle thread feed means is removed from the thread takeup means, the sewing head is removed from the arm together with the needle thread, and another sewing head on which another needle thread is threaded is joined to the arm. Thus, the needle thread need not be threaded on the needle thread feed means when changing the needle thread.
A sewing machine in a second aspect of the present invention comprises: a bed; an arm having a vertical portion set upright on the bed, and a horizontal portion horizontally extending from the upper end of the vertical portion; an arm shaft extended within and journaled on the arm; a sewing head detachably joined to the extremity of the arm; a needle bar incorporated into the sewing head, supported so as to be driven for vertical reciprocation on the sewing head by the arm shaft, and capable of being removed from the arm together with the sewing head; a motion converting means detachably connected with the arm shaft to convert the rotation of the arm shaft into the reciprocation of the needle bar; a needle thread feed means disposed on the sewing head to feed a needle thread to a needle attached to the lower end of the needle bar; and a thread takeup means disposed on the sewing head, and capable of operating in synchronism with the vertical reciprocation of the needle bar to draw up the slack needle thread and of releasing the needle thread. In this sewing machine, the needle thread is threaded only on the sewing head.
In this sewing machine, both the needle thread feed means and the thread takeup means are disposed on the sewing head, and the needle thread is threaded only on the sewing head. Accordingly, when changing the needle thread, the needle thread can be simply removed from the arm together with the sewing head.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which;
FIG. 1 is a perspective view of a sewing machine in a first embodiment according to the present invention;
FIG. 2 is a fragmentary, partly cutaway perspective view of the sewing machine of FIG. 1;
FIG. 3 is a sectional view of the sewing machine of FIG. 1;
FIG. 4 is a thread takeup device included in the sewing machine of FIG. 1;
FIG. 5 is a perspective view of a sewing head included in the sewing machine of FIG. 1;
FIG. 6 is a fragmentary, partly cutaway perspective view of a sewing machine in a second embodiment according to the present invention;
FIG. 7 is a sectional view of the sewing machine in the second embodiment; and
FIG. 8 is a fragmentary perspective view showing the construction of a joint formed in an arm shaft included in the sewing machine in the second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A sewing machine in a first embodiment according to the present invention will be described hereinafter with reference to FIGS. 1 to 5.
Referring to FIG. 1, a sewing machine 1 in a first embodiment according to the present invention comprises a bed 2, an arm 3 having a vertical portion set upright on the bed, and a horizontal portion horizontally extending from the upper end of the vertical portion, and a sewing head 4 detachably joined to the free end, i.e., the left end as viewed in FIG. 1, of the arm 3. The sewing head 4 has an outer end wall swingable on a hinge 7 attached to the lower end thereof in the direction of the arrow A to open the sewing head 4. The upper wall of the sewing head 4 is provided with a circular through hole 6. The side surface 6a of the through hole 6 is finished in a rounded, smooth surface as shown in FIG. 3 to prevent damaging a needle thread 12 that slides along the side surface 6a.
Referring to FIGS. 2 and 3, a spool pin 8 is set upright on and fastened with a nut 9 to the bottom wall 4b of the sewing head 4, and a spool 10 is removably put on the spool pin 8. A telescopic yarn guide post 11 is held on the sewing head 4. The yarn guide post 11 consists of a fixed section 11a fastened to the bottom wall 4b in an upright position, an adjusting section 11b axially slidably inserted in the fixed section 11a, and a L-shaped guide section 11c axially slidably inserted in the adjusting section 11b. An eyelet 11d is formed in the extremity of the guide section 11c. The adjusting section 11b is moved axially relative to the fixed section 11a, and the guide section 11c is moved axially relative to the adjusting section 11b to adjust the vertical position of the eyelet 11d. Both a first thread tension regulator 13 and a second thread tension regulator 14 for regulating the tension of the needle thread 12 and both a first needle thread guide 16 and a second needle thread guide 17 for guiding the needle thread 12 are attached to the front wall of the sewing head 4. A thread takeup device 15, which will be described later, is disposed on the arm 3 at a position near the sewing head 4. The aforementioned yarn guide post, and first and second needle thread guides together comprise needle thread feed means. The needle thread 12 pulled out from the spool 10 through the eyelet 11d of the thread guide post 11 is guided via the first thread tension regulator 13, the second thread tension regulator 14, the thread takeup device 15, the first needle thread guide 16 and the second needle thread guide 17 in that order to the eye 19a of the needle 19. The sewing head 4 is provided with a presser assembly, not shown, for pressing down a work during sewing operation. The presser assembly may be of a manually operated type or of an electrically operated type operated by signals given thereto through the arm 3. When the presser assembly is of an electrically operated type, signals are transmitted by a signal transmission device which can be divided into a unit mounted on the arm 3 and a unit mounted on the sewing head 4.
Referring to FIG. 4, the thread takeup device 15 consists of a thread takeup lever 15a provided with a guide groove 15b, and a cover member 15c capable of closing the guide groove 15b. The cover member 15c has one end pivotally joined to the thread takeup lever 15a and the other end provided with a roller 15d capable of being fitted in the guide groove 15b. When threading the thread takeup device 15 with the needle thread 12 or disengaging the needle thread 12 from the thread takeup device 15, the roller 15d is removed from the guide groove 15b to open the guide groove 15b. Thus, the needle thread 12 can be removed from the thread takeup device 15 without cutting off the needle thread 12.
A joint detachably joining together the arm 3 and the sewing head 4 will be described hereinafter with reference to FIG. 3. A female joining part 3a is formed on the extremity of the arm 3 facing the sewing head 4, and a male joining part 4a mating with the female joining part 3a is formed on one end of the sewing head 4. The female joining part 3a and the male joining part 4a have shoulders 3b and 4b, respectively. When joining the sewing head 4 to the arm 3, the respective end surfaces of the arm 3 and the sewing head 4 are put in contact with the shoulders 3b and 4b, respectively, to set the sewing head 4 in place on the arm 3.
A positioning device 20 is disposed on the lower end of the female joining part 3a of the arm 3. The positioning device 20 comprises a ball 21, a spring 22 having one end in contact with the ball 21 and biasing the ball 21 toward the inner surface of the female joining part 3a, and a fastening member 23 fastening the other end of the spring 22 to the female joining part 3a of the arm 3. The positioning device 20 determines the angular position of the sewing head 4 relative to the arm 3. A fastening pin 25 is inserted detachably in through holes formed in the respective upper parts of the female joining part 3a and the male joining part 4a.
When joining the sewing head 4 to the arm 3, the male joining part 4a of the sewing head 4 is fitted in the female joining part 3a of the arm 3 so that the ball 21 of the positioning device 20 is fitted in a recess 24 formed in the outer surface of the male joining part 4a. In fitting the male joining part 4a of the sewing head 4 in the female joining part 3a of the arm, the ball 21 is depressed by the outer surface of the male joining part 4a and drops into the recess 24 when the sewing head 4 is set at a correct angular position on the arm 3. After the sewing head 4 has been thus correctly positioned on the arm 3, the pin is inserted in the through holes to secure the sewing head 4 on the arm 3.
A motion converting mechanism 30 interlocking a needle bar 18 with an arm shaft 26 will be described hereinafter.
The motion converting mechanism 30 converts the rotation of the arm shaft 26 detachably connected with the needle bar 18 into the reciprocation of the needle bar 18. The arm shaft 26 is supported in a bearing 27 on the arm 3, and a thread takeup crank 31 is fastened to the extremity of the arm shaft 26 with a screw 32. A thread takeup rod 62 holding the thread takeup lever 15, and a needle bar crank 33 are mounted on the thread takeup crank 31. A connecting part 33a having U-shaped section is formed at the extremity of the needle bar crank 33. When the sewing head 4 is joined to the arm 3, the connecting part 33a engages a needle bar stud 18a fixed to the needle bar 18. When rotated, the arm shaft 26 drives the needle bar 18 for vertical reciprocation through the thread takeup crank 31, the thread takeup rod 62 and the needle bar crank 33.
An annular indexing groove 40 is formed in a portion of the needle bar 18 projecting from the lower wall of the sewing head 4, and an indexing means or member 41 is attached to the lower surface of the sewing head 4. When power supply to the sewing machine 1 is stopped, the sewing machine 1 stops with the needle bar 18 positioned at its top dead center. In this state, the indexing groove 40 of the needle bar 18 coincides with the indexing member 41. Accordingly, the needle bar stud 18a fixed to the needle bar 18 is able to engage the connecting part 33a of the needle bar crank 33 and the sewing head 4 can be easily joined to the arm 3, because the needle bar stud 18a fixed to the needle bar 18 coincides with the connecting part 33a of the needle bar crank 33 only if the needle bar 18 is positioned so that the indexing groove 40 coincides with the indexing member 41. When the needle bar 18 is positioned at its top dead center, a positioning mark 49a formed on a hand wheel 49 coincides with a positioning mark 48 formed on the arm 3. Therefore, even if the hand wheel 49 is turned after the sewing machine 1 has stopped, the arm shaft 26 can be set at an angular position corresponding to the top dead center of the needle bar 18 by aligning the positioning mark 49a of the hand wheel 49 with the positioning mark 48 of the arm 3.
As shown in FIG. 5, the portion of the needle bar 18 projecting from the lower wall of the sewing head 4 can be covered with a needle cover 34 to protect the needle 19 attached to the lower end of the needle bar 18 particularly when the sewing head 4 is removed from the arm 3. When attaching the needle cover 34 to the sewing head 4, the upper edge 34a of the needle cover 34 is snapped in a holding groove, not shown, formed in the lower surface of the sewing head 4 round the needle bar 18. The needle cover 34 has, for example, a cylindrical shape as shown in FIG. 5. In this embodiment, the needle cover 34 is designed so that the indexing groove 40 of the needle bar 18 coincides with the indexing member 41 when the needle cover 34 is attached to the sewing head 4. Accordingly, when the sewing head 4 with the needle cover 34 attached thereto is joined to the arm 3, the needle bar stud 18a can be easily connected to the connecting part 33a.
A procedure of changing the needle thread 12 for another needle thread will be described hereinafter. During sewing operation, the needle thread 12 pulled out from the spool 10 put on the spool pin 8 travels through the eyelet 11d, the first thread tension regulator 13, the second thread tension regulator 14, the thread takeup lever 15, the first needle thread guide 16 and the second needle thread guide 17 and passes through the eye 19a of the needle 19. When changing the needle thread 12 for another needle thread, the cover 15c attached to the thread takeup lever 15 is opened to open the guide groove 15b of the thread takeup lever 15, the needle thread 12 is removed from the thread takeup lever 15, the fastening pin 25 is removed, and then the sewing head 4 is removed from the arm 3. Then, the male joining part of another sewing head, which is identical with the sewing head 4, threaded with another needle thread is fitted in the female joining part 3a of the arm 3, and then fastening the pin 25 is inserted in the through holes formed in the sewing head and the arm 3 to fasten another sewing head to the arm 3. Then, the needle thread of another sewing head is threaded on the thread takeup lever 15 to complete the procedure of changing the needle thread 12.
Thus, the needle thread 12 in use can be changed for another needle thread by replacing the sewing head 4 threaded with the needle thread 12 with another sewing head threaded with another needle thread. Accordingly, when another sewing head is joined to the arm 3, operations for threading another needle thread on another sewing head and for adjusting the tension regulators are unnecessary. Furthermore, since the needle thread 12 can be removed from the thread takeup lever 15, the sewing head 4 can be changed without cutting off the needle thread 12 even if the thread takeup lever 15 is disposed on the arm 3. Since the thread takeup lever 15 and the motion converting mechanism 30 interlocking the arm shaft 26 with the needle bar 18 are disposed on the arm 3, the sewing head 4 can be formed in a lightweight construction.
A sewing machine in a second embodiment according to the present invention will be described hereinafter with reference to FIGS. 6 to 8, in which parts like or corresponding to those of the first embodiment are denoted by the same reference characters.
A sewing machine 51 in the second embodiment is substantially the same in construction as the sewing machine 1 in the first embodiment, except that the sewing machine 51 has a sewing head 54 provided with a thread takeup lever 15 as shown in FIG. 6. The sewing head 54, similarly to the sewing head 4 of the first embodiment, is joined detachably to an arm 53.
As shown in FIG. 7, an arm shaft 55 has a first section 58 supported in a bearing 57 on the arm 53, and a second section 59 supported in a bearing 56 on the sewing head 54. As shown in FIG. 8, the first section 58 of the arm shaft 55 is provided with a reduced part 58a on its extremity, and a projection 58b formed on the circumference of the reduced part 58a. The second section 59 of the arm shaft 55 is provided with a central hole 59a in one end thereof, and a recess 59b formed in the same end thereof. When the first section 58 and the second section 59 of the arm shaft 55 are joined together, the reduced part 58a is fitted in the hole 59a, and the projection 58b engages the recess 59b to restrain the first section 58 and the second section 59 from turning relative to each other.
As shown in FIG. 7, a motion converting mechanism 30 comprising a thread takeup crank 31, a thread takeup rod 62 and the needle bar crank 33 is disposed on the sewing head 54.
In the sewing machine 51, the needle thread is threaded only on the sewing head 54. Therefore, the needle thread can be changed for another needle thread simply by replacing the sewing head 54 with another sewing head threaded with another needle thread.
The present invention is applicable also to an embroidery machine provided with a feed dog capable of being driven for XY movement.
As is apparent from the foregoing description, a sewing machine in accordance with the present invention enables the change of a needle thread in use for another needle thread by replacing a sewing head in use with another sewing head, eliminates operations for troublesome threading and thread tension adjustment, and curtails time required for changing the needle thread.
The indexing mark formed on the needle bar, and the indexing member attached to the sewing head ensure the correct vertical reciprocation of the needle bar after the sewing head provided with the needle bar has been joined to the arm.
The male joining part of the sewing head, the female joining part of the arm, the positioning device and the fastening pin enable the sewing head to be joined to and removed from the arm without using any too, such as a screw driver or the like.
Although the invention has been described in its preferred forms with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.
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A sewing machine is comprised of a bed, an arm having a vertical portion set upright on the bed, and a horizontal portion horizontally extending from the upper end of the vertical portion, an arm shaft extended within and journaled on the arm, a sewing head detachably joined to the extremity of the arm, a needle bar incorporated into the sewing head, supported so as to be driven for vertical reciprocation on the sewing head by the arm shaft, and capable of being removed from the arm together with the sewing head, a motion converting means detachably connected with the needle bar to convert the rotation of the arm shaft into the reciprocation of the needle bar, a needle thread feed device disposed on the sewing head to feed a needle thread to a needle attached to the lower end of the needle bar, and a thread takeup device disposed on the arm and capable of operating in synchronism with the vertical reciprocation of the needle bar to draw up the slack needle thread and of releasing the needle thread.
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BACKGROUND OF THE INVENTION
The objective of the present invention is to drastically improve on the traditional prior art apparatus and method of separating comestibles and other product components of differing specific gravity by flotation. When a product such as clam meat and shells are introduced into a flotation tank containing a saline solution of sufficient concentration, the lighter clam meat will float to the surface and can be scooped up while the heavier shells remain at the bottom of the tank. Variations of this procedure are known in the prior art including separator tanks equipped with product infeed and removal conveyors.
The main difficulty with the prior art flotation process is that the salinity concentration of the flotation bath constantly drops and therefore some of the meat or other light product component being harvested sinks to the bottom of the tank and is discarded with the shells or other waste component, resulting in valuable product loss and lessened production. Also, the cost of salt in the prior art method is very high.
The present invention completely eliminates these drawbacks in the prior art by providing a simple and economical fresh water product separator and method of wide versatility in terms of its ability to separate many different types of product components including shellfish and other comestibles. In lieu of a saline bath to effect the separation of lighter product components from heavier components by differential flotation, the present invention utilizes an artificially induced circulation of the fresh water or another fluid in one zone of the apparatus to effect the desired separation of product components having different specific gravities. More particularly, a pumping system induces a current up-flow through one side of a foraminous elevator means for the product causing the lighter product component to rise to the top of and then to overflow a submerged divider and to then settle on the foraminous elevator means on the side thereof remote from the heavier product component which is unable to overflow the top of the submerged divider. The thus separated product components continue to be conveyed upwardly through the fresh water bath beyond the controlled buoyance zone for further washing prior to the discharge of the separated components into separate receivers beyond the top of the elevator means. The process is very efficient and the apparatus used to practice the process is reliable and economical. There is virtually no usable product waste and the necessity for using expensive salt and constantly adjusting salinity is entirely avoided.
A very important aspect of the invention resides in the fact that the product components undergoing separation are able to travel upwardly continuously without interruption while passing through the controlled buoyancy zone and thereafter until the separated components reach the discharge station. It is unnecessary to interrupt continuous product transport through the system while induced flotation separation is being carried out. This renders the process faster and therefore more economical.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation, partly in cross section, of an apparatus employed in the practice of the method.
FIG. 2 is an enlarged transverse vertical section taken on line 2--2 of FIG. 1.
FIG. 3 is an end elevation of the apparatus looking toward its product discharge end.
DETAILED DESCRIPTION
Referring to the drawings in detail wherein like numerals designate like parts, a separator apparatus for comestibles and other products comprises an open top tank 10 of wedge formation including a bottom wall 11 sloping at about 30 degrees to the horizontal, a vertical wall 12 defining one end of the tank, namely its deep end, and a short opposite end wall 13 defining the shallow end of the wedge-like tank. The tank 10 also includes parallel vertical side walls 14. The tank is preferably formed of stainless steel and is supported in a level attitude by suitable framework 15 including legs and a support member or members 16 beneath the inclined bottom wall of the tank. During the practice of the method, the tank is maintained substantially filled with fresh water up to a level L, as illustrated. Tank water supply and drainage means are conventional.
Spaced above the tank bottom wall 11 in parallel relation thereto is a product elevator in the form of a powered endless conveyor belt 17 preferably formed of stainless steel mesh which allows water or other fluid to circulate freely therethrough. The upper run of the belt 17 is disposed generally centrally in the wedge-like tank and emerges from the top of the tank near the shallow end thereof to pass around an upper conveyor roll 18 above the tank and somewhat downstream from the end wall 13. A second conveyor belt roll 19 is deeply submerged in the tank near its bottom corner defined by the juncture of the walls 11 and 12. Either of the rolls 18 or 19 may be powered by conventional means, not shown.
Next to the interior side of the conveyor roll 19, a baffle plate 20 rises from the tank bottom wall 11 at right angles thereto and extends to the top of the tank and completely between its side walls 14. The top and bottom runs of conveyor belt 17 pass through slots formed in the baffle plate 20. A parallel baffle plate 21 rises from the tank bottom wall 11 near the longitudinal center of such wall and includes a top extension 21' terminating at the top of the tank 10, with a suitable opening 34' being provided for the passage of the heavier product component 33 between the lower edge of plate extension 21' and the upper run of mesh belt 17. The space between the baffle plates 20 and 21-21' forms a zone of controlled buoyancy or flotation in the separator tank, as will be further discussed.
As shown in FIG. 2, the belt 17 spans the tank 10 completely between its side walls 14. At the transverse center of the tank and belt, an upper divider plate 22 extends forwardly from the baffle plate 20 and has a submerged horizontal top edge 23 within the controlled buoyancy zone defined by baffle plates 20 and 21 and the two tank side walls. Beyond this zone, the upper divider plate 22 has an inclined extension 24 following the top run of the belt 17 to the top thereof and the extension 24 curves about the roll 18 at 24' and terminates in a pair of downwardly divergent product deflectors 25 at the product component discharge station of the apparatus.
In the mentioned zone between the baffle plates 20 and 21, a fixed intermediate tank divider 26 is provided at the transverse center of the tank and a lower divider plate 27 in the same zone is similarly provided below the bottom run of the belt 17.
Within provided openings of the lower divider plate 27 are placed pumping propellers 28 mounted on rotary shafts 29 extending beyond one tank side wall 14, FIG. 2, and supported by sealed bearings 30. Pairs of the propellers 28 are driven by motors 31 whose drive shafts are coupled through suitable gearing 32 with the propeller shafts 29. When driven at proper speeds, the several propellers can induce a continuous circulation of tank water in the direction of the arrows shown in FIG. 2 upwardly through the foraminous belt 17 on one side of the tank divider plates and downwardly on the other side, the circulating current of water flowing over the top edge 23 of upper divider plate 22 in the zone of controlled buoyancy between the baffle plates 20 and 21. The speed of rotation of the several propellers can be adjusted to meet requirements.
The described apparatus is used in the practice of the method in the following manner. With the tank 10 substantially filled with fresh water as indicated and with the foraminous belt 17 traveling continuously at a predetermined speed in the direction of the arrow, the product such as clam shells 33 and clam meat 34 is placed randomly in the separator tank substantially at the baffle plate 20 and on one side of upper divider plate 22, FIG. 2. The meat and shells at this time are mixed randomly and require separation in accordance with the invention.
The propellers 28 are operated at the required speed to create the water circulation in the controlled buoyancy zone, as previously described. There is an up-flow or current through the top run of belt 17 in this zone immediately ahead of the baffle plate 20. This controllable up-flow or current lifts the lighter product component, namely the meat 34 of the described product. The induced up-flow pushes the meat 34 upwardly on one side of the separator plate 22 in the controlled buoyancy zone between the baffle plates 20 and 21. Upon reaching the top level edge 23 of fixed divider plate 22, the induced current resulting from the operation of the propellers 28 will cause the elevated meat to flow over the edge 23 and settle downwardly on the far side of divider plate 22 away from the shells 33. The shells 33 being of greater specific gravity than the meat will not rise with the induced current of water or if they rise slightly from the belt 17, they will never flow over the top edge 23. The downward component of the induced water current, FIG. 2, also assists the meat particles 34 in rapidly settling back onto the continuously moving belt 17 after they have been separated from the shells, as described. The separation process can be carried out with a wide variety of comestibles and other non-food products having components of differing specific gravities.
When the separated product passes beyond the downstream end of the controlled buoyancy zone, that is beyond the baffle plate 21, the product is no longer subjected to the circulating or pumping action of the propellers 28 and the tank water in which the product is still immersed for further washing is substantially calm. The divider extension 24 keeps the separated product components 33 and 34 from comingling in the bath until the belt 17 finally lifts them from the top of the tank 10 and delivers them around the roll 18 which defines the product discharge station. At this station, the curved divider portion 24 and deflectors 25 cause the two product components to pass separately into suitable receivers, not shown, positioned below the discharge station, such as further tanks or further processing conveyor means.
In lieu of simply circulating water in the controlled buoyancy zone, another fluid such as air can be pumped in to induce lifting of the lighter product component. In lieu of having the pumping propellers 28 on horizontal axis drive shafts, they could, if desired, be operated by vertical axis shafts at the bottom of the separating zone and on the left-hand side of dividers 22, 26 and 27 in FIG. 2. The same ultimate result would still be produced. Other types of pumping means, such as jet pumps and the like, could be used in lieu of propellers. The invention apparatus is not limited in the invention to the preferred form of apparatus shown in the drawings.
In the controlled buoyancy zone, a delicate control of buoyancy can be achieved by regulating the speed of the pumping means. The tank water has a buoyant effect on all products being handled according to their specific gravities and volume. Some product components will require only a very gentle induced current or circulation to push them up and over the top edge 23. Other components which are much heavier will require a stronger circulation which can be achieved by faster pumping action. It can be seen that the apparatus and method are extremely versatile in this respect.
The essence of the method, therefore, resides in the use of a fresh water flotation tank in which continually travels a submerged product elevator or conveyor, a stationary tank divider preferably at the middle of the foraminous conveyor and having a submerged top edge at least in a defined zone of controllable buoyancy, and means to regulate such buoyancy.
It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.
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To avoid using salt in a costly flotation separator process for various products of differing specific gravities, a fresh water flotation system is employed having a controlled buoyancy zone in which an induced current or up-flow elevates the product component of lesser specific gravity causing it to overflow a product conveyor divider member and to settle on that side of the conveyor away from the product component of greater specific gravity. The separation of clam meat from clam shells is envisioned.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to methods of manufacturing impellers for centrifugal fans, and to centrifugal fans as well.
2. Description of the Related Art
Device downsizing and performance upgrading of electronic equipment in recent years have entailed demands for the scaling down of cooling fans installed in such electronic devices. As one among such attempts, a centrifugal fan in which the impeller has been reduced in diameter, and the individual vanes constituting the impeller have been thinned and arranged at a denser spacing has been proposed.
Meanwhile, inasmuch as centrifugal-fan impellers have traditionally been manufactured by injection molding, various techniques for enhancing the quality of the manufactured product have been developed. Examples of such techniques include a method in which in advance of infusing a mold with thermoplastic resin, the mold is evacuated, as well as a method in which excessive exhausting of gases during the molding operation is prevented by sufficiently drying the thermoplastic material beforehand and then melting it. Another example utilizes highly fluid liquid crystal polymers as base materials to make it possible to mold impellers having longer vanes.
Nevertheless, to proceed to make the vanes thinner is to make it impossible to mold an impeller stably by traditional methods. In particular, designing the individual vanes of a centrifugal fan to be both thinned and elongated in order to improve the fan's performance would make it impossible to charge the inside of the mold sufficiently with thermoplastic resin.
Centrifugal-fan impellers are sometimes furnished with a ring section that links the tips of the vanes. The objective in such configurations is to enhance the impeller rigidity by tying the vane tips together. The ring section is vital to implementations in which an impeller is axially extensive and its vanes are thin. For ultra-miniature centrifugal fans (e.g., centrifugal fans whose outer diameter is 25 mm or less), however, if an impeller having a ring section is to be injection molded, the flow of thermoplastic resin inside the mold would be restrained such that the ring-forming portion of the mold could not be charged sufficiently with the resin. Or, even if it could be thus charged, then meld lines would form in the ring area, deteriorating the strength of the ring section. Such phenomena are detrimental to throughput during production, and invite increases in post-manufacturing breakage.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention, brought about in order to resolve the problems discussed above, is to make available a method of manufacturing, by injection molding and at high throughput, impellers for micro-diameter centrifugal fans—in particular, impellers whose axial length has been extended in order to improve the impeller's characteristics.
In the present invention, in order to heighten throughput in the injection-molding manufacture of ultra-miniature impellers for centrifugal fans, the thickness of the ring section is secured, and at the same time a fixed or greater axial length for the ring section is secured. In this way securing the dimensions of the ring facilitates the flow of the thermoplastic resin in the area of the mold interior that corresponds to the ring.
The causative factor behind deterioration in the strength of the ring section in ultra-miniature impellers originates in insufficiency in the flow of thermoplastic resin into the ring-forming portion of the mold, which makes it likely that meld lines will form. In the present invention, the thickness and length of the ring section are rendered fixed dimensions or greater in order to avert this problem. Doing so keeps meld lines from forming within the ring-forming portion of the mold to enhance the strength and durability of the ring section, even in impeller molding implementations in which the gate is positioned in the end of the mold opposite the ring section. In a further aspect of the present invention, the formation of meld lines is also held in check by increasing the vane thickness in the area in which the vanes connect to the ring section.
Such improvement is particularly pronounced in implementations in which thermotropic liquid-crystal polymers are employed as the base material-implementations that are especially vulnerable to strength deterioration where the polymer melds.
When an ultra-miniature impeller as described above is to be molded in an injection mold, in addition to sufficiently drying the thermoplastic resin base material beforehand, the inside of the mold must be evacuated during the molding operation. The evacuation port is advantageously provided along the rim of the vanes, in the end of the mold opposite its gate. For example, the port can be provided in the lateral surface of the cavity that corresponds to the ring section, or in the vicinity of the borderline between the ring section and the vane tips.
In order to make the flow of thermoplastic resin inside the ring-forming portion of the mold more definite and reliable, the resin may be forced out through the evacuation port and then cut off.
As another means of enhancing the strength of the ring section, a ring-shaped element formed from metal or other suitable material may be placed into a position inside in the mold equivalent to the ring section and then the thermoplastic resin infused into the mold. Exploiting such an insert-molding technique also contributes to enhancing the strength of the ring section of an ultra-miniature impeller.
From the following detailed description in conjunction with the accompanying drawings, the foregoing and other objects, features, aspects and advantages of the present invention will become readily apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a vertical section view illustrating a centrifugal fan involving a first embodiment of the present invention;
FIG. 2 is an elevational view representing the centrifugal fan;
FIG. 3 is a transverse sectional view depicting the centrifugal fan;
FIG. 4 is a chart setting forth process flow in the manufacture of an impeller by injection molding;
FIG. 5 is a sectional view of a mold;
FIG. 6 is a view depicting a portion of the mold in section;
FIG. 7 is a view showing the mold with its core having been drawn out;
FIG. 8 is a sectional view illustrating a mold in an implementation in which a ring element is used to form a reinforcing ring;
FIG. 9 is a sectional view illustrating another example of a mold;
FIG. 10 is a sectional view illustrating yet another example of a mold;
FIGS. 11A-11C are diagrams representing arrangements of the reinforcing ring and the vanes;
FIG. 12 is a vertical section view illustrating a centrifugal-fan impeller involving a second embodiment of the present invention;
FIG. 13 is view illustrating the impeller of FIG. 12 from a lateral aspect; and
FIG. 14 is an enlarged fragmentary view showing details of the impeller as shown in FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to FIG. 1 , which is a diagram illustrating the configuration of a centrifugal fan 1 involving a first mode of embodying the present invention and represents a vertical section sliced along a plane containing the fan's center axis 10 . Reference is also made to FIG. 2 , which is an elevational view of the centrifugal fan 1 , and to FIG. 3 , which is a transverse view of the centrifugal fan 1 in section along the arrow-indexed locus A-A.
The centrifugal fan 1 is an electromotive fan utilized in order to air-cool electronic parts in the interior of electrical products and electronic devices (portable articles in particular). The centrifugal fan 1 is equipped with: an impeller 2 that by rotating generates a flow of air; a motor 3 for rotating the impeller 2 ; and a housing 4 for housing the impeller 2 and the motor 3 , and that controls the flow of air generated by the rotation of the impeller 2 , sending the air outside the fan.
The impeller 2 is approximately round-cylindrical in external form, and is furnished with: a plurality of vanes 21 for generating a flow of air; a connector section 22 for linking together and anchoring the motor-ward ends of the plurality of vanes 21 , and being the impeller end that connects to the motor 3 ; and an approximately round cylindrical reinforcing ring 23 , fixed to the vane ends on the side of the plurality of vanes 21 that is opposite the connector section 22 , that reinforces the linkage of the vanes 21 . The plural vanes 21 , the connector section 22 , and the reinforcing ring 23 are molded unitarily from a thermoplastic resin.
As shown in FIG. 3 , the plurality of vanes 21 , at a fixed distance from the impeller center axis 10 , is arrayed encompassing the center axis 10 , with the vanes spaced apart at a set pitch fp; and as indicated in FIG. 1 , the vanes each extend parallel to the center axis 10 . When the motor 3 spins, air flows through the reinforcing-ring 23 end of the impeller, into an interior space 90 that is enveloped by the plurality of vanes 21 . This means that in the impeller 2 , the reinforcing ring 23 constitutes the rim of an opening through which air is led into the space 90 . The connector-section 22 end of the space 90 is closed off by the connector section 22 being connected to the motor 3 .
The housing 4 is, as shown in FIGS. 1 and 2 , composed of a housing main unit 45 that houses the impeller 2 and the principal components of the motor 3 (as far as the environs of the motor's stator 38 ), and a cap 46 that fits snugly into the housing main unit 45 . An air inlet 41 and a venting port 42 are provided in the housing main unit 45 .
In a centrifugal fan 1 having the configuration just described, when the impeller 2 spins, air flows into the space 90 through the air inlet 41 and flows out from between the plurality of vanes 21 , traveling along the inner surface 49 of the housing 4 , and is sent out through the venting port 42 .
Herein, the outer diameter 2 r of the impeller 2 (r being the radius) illustrated in FIG. 1 is no more than 25 mm, with the length fL of the plurality of vanes 21 in terms of their extent along the center axis 10 satisfying the relation 2≦fL/r≦20. In this embodiment, the outer diameter 2 r is 12 mm, and the length fL is 27 mm (wherein the reinforcing ring length rL is 4 mm). It should be understood that although the working length of the vanes 21 , being fL−rL, is shortened owing to the extent taken up by the axial length of the ring section, in the present invention, because fL is large, performance degradation from the deficit in working vane length owing to the presence of the ring section is negligible. It should also be understood that the outer diameter 2 r of the impeller 2 is defined as not including the thickness rt, as indicated in FIG. 3 , of the reinforcing ring 23 .
In the impeller 2 , by the relation 2≦fL/r being satisfied the point of maximum flow speed of the air flowing out from between the plurality of vanes 21 is put in the vicinity of midway between the two ends of the vanes 21 . The flow volume of air is increased as a result, enabling the generation of a highly efficient flow of air. At the same time, by fL/r≦20 being satisfied, vibration is held down even at rotating speeds of more than 10,000 rpm, (for example, 20,000 rpm). The configuration is thus favorable to revving the fan at high rpm, whereby the flow volume and static pressure of the air can be heightened all the more.
Reference is now made to FIG. 4 , which is a chart setting forth process steps to manufacture for the centrifugal fan 1 an impeller 2 having fine, long vanes 21 by injection molding. In manufacturing the impeller 2 , at first preparations are made by setting a mold having a cavity, which is an interior space made to match the shape of the impeller 2 , into an injection-molding machine (step S 1 ). Reference is further made to FIG. 5 , which is a sectional view illustrating the structure of the mold 6 , and to FIG. 6 , which is a diagram illustrating a portion of a sectional plane through the mold 6 , along the arrow-indexed locus B-B in FIG. 5 . The orientation of the impeller that would be molded in FIG. 5 is right-left reversed from the orientation of the impeller 2 illustrated in FIG. 1 .
The mold 6 comprises: a first plate 61 , to which a nozzle 91 of the injection-molding machine connects; a second plate 62 in contact with the left side of the first plate 61 ; a third plate 63 that is located on the leftmost side of the mold; two side blocks 64 in between the second plate 62 and the third plate 63 , located above and below to enclose the cylindrical side of the impeller 2 being molded; and a core 65 inserted into the approximately round cylindrical space flanked by the two side blocks 64 .
A flowpath 611 through which thermoplastic resin ejected through the nozzle 91 passes is formed in the first plate 61 ; the gate 612 in the end of the flowpath 611 corresponds to the center of the connector section 22 of the impeller 2 . (The center of the impeller connector section 22 is actually where a hole is formed, through which the motor 3 is connected after molding—c.f. FIG. 1 .) The second plate 62 has an inner-side surface that corresponds to the outer-side surface of the connector section 22 , and forms a space 621 that corresponds to the connector section 22 . As shown in FIG. 6 , the core 65 is inserted into the space flanked by the two side blocks 64 , wherein the core 65 creates a conformation corresponding to the space 90 inside the impeller 2 and to the spacings between the plurality of vanes 21 (c.f. FIG. 3 ). In FIGS. 5 and 6 , the flutes in the core 65 that correspond to the vanes 21 are labeled with reference mark 651 . It will be appreciated that in FIG. 5 , on the upper side of the center line 60 , depicted is a situation in which one of the flutes 651 is present, while on the lower side, depicted is a situation in which one of gill-like regions 652 (see FIG. 6 ) of the core 65 , which are present between the plurality of flutes 651 , is present. Furthermore, a recess that extends lengthwise with respect to the center line 60 , and which corresponds to the reinforcing ring 23 , is labeled with reference mark 641 in FIGS. 5 and 6 .
The third plate 63 has an opening through which the core 65 is inserted/removed, and the right-side surface of the plate corresponds to the end face of the reinforcing ring 23 , which is the rim of the opening in the impeller 2 . In a position corresponding to the corner between the end face and lateral surface (a position pointing to the cylindrical surface) of the reinforcing ring 23 —in particular, in a position that is between the third plate 63 and one of the side blocks 64 and is in one of the flutes 651 —an evacuation port 631 is formed as a slight breach. The evacuation port 631 is connected to an evacuation passage 632 formed between the third plate 63 and the side block 64 . The evacuation passage 632 is connected to an evacuating pump in the injection-molding machine. Along the opening for the core 65 in the third plate 63 , grooves corresponding to the core's gill-like regions 652 are formed so that the core 65 can be extracted following an injection molding operation. Thus in this configuration, the flutes 651 in the core 65 , which correspond to the vanes 21 , are tangent to the inner-side surface of the side blocks 64 ; and twin walls of the grooves formed in the third-plate 63 opening through which the core 65 is introduced define projections that (where they correspond to the end faces of the vanes 21 ) close off the flutes 651 .
Once the mold 6 has been set into the injection-molding machine, the evacuating pump is run to evacuate the mold 6 interior space—that is, the mold cavity—through the evacuation passage 632 to put the cavity into a vacuum state (step S 2 ). Meanwhile, a pellet of thermoplastic source material, having been dried beforehand by heating the material 2.5 to 3 hours at 140-165° C. inside a drier under a reduced-pressure environment or under a predetermined gas environment, is fed from a hopper into the injection-molding machine, without prolonged contact with external air. Within a screw cylinder in the molding machine the thermoplastic resin is melted by heating it up to 250-330° C. using a heater. The mold 6 is maintained at 70-90° C. by means of a separate heater. It should be understood that an injection-molding machine in which pre-drying of the pellet is unnecessary may be employed.
Once the above-described preparations have been finished, the molten resin is ejected through the nozzle 91 , directed into the flowpath 611 , and the resin flows heading from the first plate 61 to the third plate 63 —in particular, heading from a location corresponding to the connector section 22 of the impeller 2 , to a location corresponding to the reinforcing ring 23 —whereby the cavity interior is filled with resin (step S 3 ). Gas evolving from the resin at the same time that the resin is flowing into the cavity is forced through the evacuation port 631 and exhausted from the cavity via the evacuation passage 632 . It will be appreciated that because the infused resin swiftly fills the cavity interior and thereafter hardens rapidly, the mold temperature is adjusted in advance to be 70-90° C. when the resin is being injected.
Utilized as the source material are thermoplastic resins whose principal component is a thermotropic liquid-crystal polymer (here indicating that half or more of the weight is a thermotropic liquid-crystal polymer, and including instances in which the resin is exclusively a thermotropic liquid-crystal polymer), which are resins that excel in fluidity, and have high post-setting strength and outstanding mechanical properties. Specifically, a fully aromatic polyester liquid-crystal polymer to which on the order of 20 weight % fibrous matter such as glass or carbon fiber has been added—a material typified by polyphenylene sulfide (PPS) or Vectra® into which fiberglass has been mixed—is utilized. Furthermore, materials in which PPS and Vectra® are intermixed, or in which other resin(s) are mixed into a thermotropic liquid-crystal polymer, may be utilized.
Notwithstanding that each of the vanes 21 is of slender form, by the exhausting of gases in the cavity interior through the evacuation port 631 formed in a region that corresponds to one end of the plural vanes 21 , and by the infusing of molten resin through the gate 612 formed in a region that corresponds to where the other end of the plural vanes 21 is (that is, a region that is associated with the other end), the cavity is appropriately filled with resin to form the vanes 21 in their entirety. Moreover, the reinforcing ring 23 , which is molded in parallel with the vanes 21 , is formed by the corresponding space inside the mold becoming appropriately filled with resin. It should be understood that, as long as the resin flows for the most part unidirectionally inside the space 651 for the vanes 21 , the gate 612 may be formed in another region of the mold 6 that corresponds to where the other end of the plurality of the vanes 21 is—for example, in a region that corresponds to the outer-side surface of the connector section 22 of the impeller 2 .
After the resin has cooled and set, the molded impeller 2 is taken out of the mold 6 (step S 4 ). Initially, the core 65 is extracted from the third plate 63 and the side blocks 64 . FIG. 7 is a sectional view depicting the core 65 having been extracted partway from the mold 6 . As described previously, grooves corresponding to the gill-like regions 652 in the core 65 are formed in the third plate 63 , wherein twin walls of the grooves define projections that oppose the end face of the vanes 21 . Thus the projections block the vanes 21 from being drawn out together with the core 65 when it is being extracted, whereby the vanes 21 remain inside the cavity, sandwiched between the two side blocks 64 .
After the core 65 has been extracted the two side blocks 64 are parted slightly, and then by pushing out the connector section 22 of the impeller 2 with a shoving member 613 provided in the vicinity of the flowpath 611 in the first plate 61 , the impeller 2 is completely separated from and taken out of the mold 6 . In the impeller 2 after having been withdrawn, in a place corresponding to the gate 612 , a hole into which a rotor yoke 31 component of the motor 3 fits is formed (c.f. FIG. 1 ).
Reference is now made to FIG. 8 , which is a sectional view depicting the recess 641 and vicinity, formed by the side blocks 64 and third plate 63 of the mold 6 . In this case, with the mold 6 having been set into the injection-molding machine, an approximately round cylindrical metal ring element 23 a , as illustrated in FIG. 8 , is inserted ahead of time into the recess 641 , and in that state the cavity interior is evacuated and the resin injected. By having the reinforcing ring 23 be a metal element in insert-molding instances, the strength of the reinforcing ring 23 is enhanced to improve the reliability of the impeller 2 .
The description turns now to FIG. 9 , which illustrates another example by which the strength of the reinforcing ring 23 is enhanced. In the mold 6 in FIG. 9 , apertures 633 are formed in a region that corresponds to the end face of the reinforcing ring 23 . Evacuation of the cavity interior is carried out through the apertures 633 . The apertures 633 are provided matching the depth of the recess 641 , within the third plate 63 , or else in between the third plate 63 and the core 65 , in a plurality of places running along the annular recess 641 . Furnishing the apertures 633 means that when the injection molding operation is carried out, some of the resin that fills the reinforcing ring 23 portion of the mold 6 will overflow through the apertures 633 .
In utilizing the mold 6 depicted in FIG. 9 to manufacture an impeller 2 , a step of removing the resin that has overflowed through the apertures 633 is added to the last of the manufacturing steps set forth in FIG. 4 , that is, after the impeller 2 has been taken out of the mold 6 . Resin that has overflowed through the apertures 633 may be removed in the course of taking the impeller 2 out of the mold 6 . In that case, before the core 65 is extracted from the impeller vanes, it is advantageous to undo the side blocks 64 , and in that state trim the vane tips and the resin portions that are sticking out.
In an implementation in which an impeller is molded in this manner, when the thermoplastic resin melds in the reinforcing ring 23 portion of the cavity, the resin in the vicinity of the meld lines flows fully, improving the joint strength along the meld lines.
FIG. 10 shows yet another example of a configuration for enhancing the strength of the reinforcing ring 23 . In this case, in the mold 6 depicted in FIG. 10 , the region in the third plate 63 that opposes the end face of the vanes 21 constitutes a projection 634 that juts out toward the side blocks 64 . Put differently, the recess 641 corresponding to the reinforcing ring 23 is elongated in the direction toward the third plate 63 . This configuration causes the reinforcing ring 23 , molded by evacuating and infusing with resin the interior of the mold cavity, to have a projecting portion that juts out from the ends of the plurality of vanes 21 . (C.f. projecting portion 23 b in later-described FIG. 11B .)
In an implementation of a mold 6 configured as shown in FIG. 10 , similarly to the implementation represented in FIG. 9 , when the thermoplastic resin melds in the reinforcing ring 23 portion of the cavity, the resin in the vicinity of the meld lines flows fully, by the amount that the recess 641 is elongated, further improving the joint strength along the meld lines.
Next, the results of actually molding impellers 2 as explained in the foregoing and testing the strength of their reinforcing rings 23 will be described. Table 1 is a tabulation setting forth three types (Characterizations 1 to 3) of injection-molded impeller 2 conformations. The units of length in Table 1 are millimeters. In the test, Vectra® was utilized as the thermoplastic resin, and samples in which, as depicted in FIG. 11A , the end face of the vanes 21 and the end face of the reinforcing ring 23 coincide were fabricated.
TABLE 1
Characterization No.
1
2
3
Impeller o.d.
12
12
12
Number of Vanes
30
34
38
Vane max. thickness ft
0.30
0.29
0.28
Vane length fL
23
23
23
Length/max. thickness
77
79
82
Ring thickness rt
0.50
0.50
0.50
Vane spacing fp
1.26
1.11
0.99
Vane spacing × 2
2.52
2.22
1.98
Ring length rL
2.0
4.0
4.0
Ring strength
X
◯
◯
In the “Ring strength” column in Table 1, “x” indicates that in taking the impellers 2 out of the mold 6 following the injection-molding operation, there was a 70% or greater likelihood that fracturing in the reinforcing rings 23 would occur, while “∘” indicates that there was a less than 10% likelihood. It may be ascertained from the table that with Characterizations 2 and 3 , in which the reinforcing rings 23 were made longer, although the thicknesses of the rings were not increased, the reinforcing ring 23 strength was sufficient.
In addition, impellers as shown in FIGS. 11 B and 11 C—of a form in which part of the reinforcing ring 23 jutted out from the vanes 21 , and of a form in which the reinforcing ring 23 was connected to the end face of the vanes 21 —were fabricated under Characterization 3 in Table 1 . In these implementations as well, the incidence of fracturing in the reinforcing ring in taking the impeller out of the mold was less than 10%, and thus strength in the reinforcing rings was secured.
Here, by having the length of the projecting portion 23 b , which from the ends of the vanes 21 juts out paralleling the center axis 10 , of reinforcing rings 23 in the FIG. 11B implementation be 1.5 times the pitch fp of the vanes 21 , the resin flowing out from the flutes 651 that correspond to the vanes 21 flows sufficiently into the extension portion of the reinforcing ring 23 , whereby sufficient strength along the meld lines is secured. (C.f. FIG. 10 .)
In molding applications in which articles of extremely slender conformation are injection-molded, as is the case with the vanes of impellers 2 of the present invention, thermotropic liquid-crystal polymers of long flow length are often employed as the molded material. Thermotropic liquid-crystal polymers during molding exhibit strong anisotropy in terms of the resin flow direction, such that degradation in strength along meld lines is serious. Utilizing the present invention, however, averts compromised strength along meld lines that form in the reinforcing ring, to enable high-strength impellers to be produced.
Next, referring to FIGS. 12-14 , an explanation of a centrifugal fan involving a second mode of embodying the present invention will be made. FIG. 12 is a vertical section view illustrating a centrifugal fan impeller 2 a , sliced through a plane containing the fan's center axis 10 , involving a second embodiment of the present invention. FIG. 13 is lateral-aspect diagram of the impeller 2 a seen from the right side in FIG. 12 , looking toward the left; and FIG. 14 is diagram in which a portion of the impeller 2 a as depicted in FIG. 13 is shown enlarged. As illustrated in FIG. 13 , in a centrifugal fan involving the second embodiment, a plurality of vanes 21 a having a transverse cross-sectional form that differs from that of the plurality of vanes 21 depicted in FIG. 3 is provided in the impeller 2 a . Apart from this feature, the configuration is similar to that of FIG. 1 through FIG. 3 , and thus in the following illustration, the same reference marks will be appended.
With the exception of being furnished with the impeller 2 a depicted in FIGS. 12-14 , a centrifugal fan involving the second embodiment is similar to that of FIG. 1 , and thus the structure and form of the motor 3 and housing 4 are the same as that shown in FIG. 1 through FIG. 3 . The plural vanes 21 a , the connector section 22 , and the reinforcing ring 23 are molded unitarily from a thermoplastic resin whose principal component is a thermotropic liquid-crystal polymer. In FIGS. 13 and 14 also, likewise as in FIG. 3 , the pitch of the plural vanes 21 a is labeled with reference mark fp, and the impeller 2 a outer diameter is labeled with reference mark 2 r.
In the impeller 2 a , as indicated in 14 , along each of the plural vanes 21 a the thickness ft 2 of the region (called “ring joint” hereinafter) 211 connected to the reinforcing ring 23 is thicker than the thickness dimension of the rest of the vane 21 a , wherein each vane 21 a gradually diminishes in thickness as the dimension parts away from the reinforcing ring 23 . Thus the minimum thickness ft1 is in the verges 212 at the inner-peripheral side of the vanes 21 a , (with the roundness attendant on rounding off the vane edges not being deemed thickness).
The process flow in manufacturing the impeller 2 a by injection molding is the same as the flow, set forth in FIG. 4 , for manufacturing the impeller 2 involving the first embodiment, and the configuration of the mold employed in manufacturing the impeller 2 a , except for the conformation of the cavity corresponding to the vanes 21 a , is also the same as that of the mold 6 depicted in FIG. 5 .
Next, the results of molding impellers 2 a and testing the strength of their reinforcing rings 23 will be described. Table 2 is a tabulation setting forth two types (Characterizations 4 and 5 ) of injection-molded impeller 2 a conformations, and as a comparative example, entered together with these characterizations is the impeller 2 conformation of Characterization 1 set forth in Table 1. In the test, Vectra® was utilized as the thermoplastic resin, and samples in which, in the same way as is the case with the vanes 21 and reinforcing ring 23 depicted in FIG. 11A , the end face of the vanes 21 a and the end face of the reinforcing ring 23 coincide were fabricated.
TABLE 2
Characterization No.
1
4
5
Impeller o.d.
12
12
5.4
Number of Vanes
30
34
24
Vane thickness ft1
0.30
0.29
0.17
Vane thickness ft2
0.30
0.35
0.20
Vane length fL
23
23
9.5
Length/max. thickness
77
66
48
Ring thickness rt
0.50
0.50
0.25
Vane spacing fp
1.26
1.11
0.7
Vane spacing × 2
2.52
2.22
1.4
Ring length rL
2.0
4.0
1.5
Ring strength
X
◯
◯
In the “Ring strength” column in Table 2, like in Table 1, “x” indicates that in taking the impellers 2 a out of the mold 6 following the injection-molding operation, there was a 70% or greater likelihood that fracturing in the reinforcing ring would occur, while “∘” indicates that there was a less than 10% likelihood. The units of length in Table 2 are also millimeters.
From the results of the test it may be ascertained that with the impellers 2 a of Characterizations 4 and 5 , in which the thickness of the vanes 21 a gradually diminishes the further away from the reinforcing ring 23 the measurement is (that is, the characterizations in which ft1 is smaller than ft2), the reinforcing rings 23 had sufficient strength.
Although methods of manufacturing centrifugal fans and impellers involving modes of embodying the present invention have been explained in the foregoing, in that various modifications of the present invention are possible, the invention is not limited to the embodiments described above.
For example, in the foregoing embodiments, examples were set forth in which prior to the injection molding operation the cavity in the mold 6 was evacuated to bring it into a vacuum state, but the evacuation may be carried out in parallel, for the most part, with the molding operation. Additional examples are that in the third side plate 63 a minute evacuation port may be formed to carry the evacuation out through a position corresponding to the end face of the reinforcing ring 23 , and that the minute evacuation port may be formed in the base of the recess 641 corresponding to the reinforcing ring 23 .
In any of the examples of FIG. 5 and FIG. 8 through FIG. 10 , the reinforcing ring 23 may join the plurality of vanes 21 along the inner side of the vanes 21 (the same being true of the vanes 21 a and reinforcing ring 23 of the second embodiment). Also, in the FIG. 9 implementation, in which a portion of the resin for the reinforcing ring 23 overflows, the direction in which the resin overflows does not have to be parallel to the center axis, but may be perpendicular to the center axis. And the opening through which the resin overflows may be formed in a position corresponding to the lateral (cylindrical) surface of the reinforcing ring 23 .
In the implementation illustrated in FIG. 10 , from the perspective of facilitating reduction of the outer diameter of the reinforcing ring 23 , it is preferable that the projecting portion 23 b (c.f. FIG. 11 ) be formed parallel to the center axis, but the projecting portion may be rendered in a form in which it expands outward or projects inward from the reinforcing ring 23 .
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A tiny-diameter, lengthwise extensive impeller utilized in an ultra-small centrifugal fan is molded by an injection molding operation. In order to avert difficulties attendant on injection-molding ultra-miniature parts, the thickness and length of a reinforcing ring on the tip of the impeller are set to within predetermined ranges. Further, the thickness of each of the vanes that constitute the impeller is made maximum where they join to the impeller ring section.
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RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Ser. No. 60/687,059, entitled “Methods and Apparatus for Recognizing and Processing Barcodes Associated with Mail,” filed on Jun. 3, 2005, which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates generally to systems and methods used for the automated sorting of mail and, more specifically, to systems and methods used to correlate information relating to an item of mail with the associated item of mail.
BACKGROUND
[0003] Barcodes are used by the United States Postal Service (USPS) to sort mail. Automated mail sorting systems can read barcodes on mail and sort mail based on final destination or other factors. This allows for efficient mail processing. Mail sorting systems currently used by the USPS have the ability to recognize and process conventional two-state barcodes, such as POSTNET barcodes. POSTNET barcodes encode zip code and delivery point code information using bars having two possible states, short or tall.
[0004] Barcodes for mail sorting have been developed that allow more information to be encoded relative to two-state barcodes. These barcodes are referred to as four-state barcodes because each bar of the barcode may have one of four variations. Specifically, each bar of a four-state barcode consists of a small bar that can have an ascender above it, a descender below it, or both. Two such barcodes are the Flat ID code sort (FICS) barcode and the Intelligent Mail (IM) barcode. FICS barcodes are barcodes that are applied to letters that do not have delivery information recognized by a mail sorter. A FICS barcode encoding sorting information will be printed on a label that is affixed to the letter. IM barcodes are used by mass mailers to identify mail with delivery information and other information (e.g., customer data and/or sender information).
[0005] Currently, mail sorting systems used by the USPS lack the ability to recognize and process four-state barcodes, such as FICS and IM barcodes. Accordingly, there is a need for system that can recognize and process four-state barcodes and interface with existing mail sorting systems used by the USPS.
SUMMARY OF THE INVENTION
[0006] In view of the foregoing, there is a need for system that can recognize and process four-state barcodes and interface with existing mail sorting systems used by the USPS. So that the barcode data or other data generated by the system can be used by a mail sorting system, e.g., to sort an item of mail, the data must be correlated with the item of mail from which it was derived. Accordingly, aspects of the present invention relate to systems and methods for correlating data relating to an item of mail with the associated item of mail. The data may comprise information from a FICS barcode, information from an IM barcode, or other information relating to the item of mail.
[0007] One embodiment of the invention is directed to a method for correlating an item of mail, subject to sorting by a mail sorter, with data, stored by a processing unit, relating to the item of mail. The method comprises acts of associating the item of mail with a first counter value; associating the data with a second counter value; and corresponding the first counter value with the second counter value to correlate the data with the item of mail.
[0008] Another embodiment of the invention is directed to a system, comprising a mail sorter to sort an item of mail; a processing unit to generate data relating to the item of mail; a first counter adapted to generate a first counter value when the item of mail is at a predetermined position within the mail sorter; memory to store the data relating to the item of mail with a second counter value such that the data and the second counter value are linked in the memory; and means for corresponding the first counter value with the second counter value to correlate the data with the item of mail.
[0009] A further embodiment of the invention is directed to a processing unit, comprising an input to receive information for identifying an item of mail from a mail sorter; an input to receive an image of at least a portion of the item of mail from a camera; one or more processors to identify a barcode and generate sortable data relating to the barcode; means for correlating a unique identifier with the sortable data using the information; and an output for transmitting the unique identifier and the sortable data to the mail sorter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 illustrates a block diagram of one embodiment of a system for processing and sorting mail;
[0011] FIG. 2 illustrates a block diagram of the barcode processing server 7 of FIG. 1 according to an embodiment of the invention;
[0012] FIG. 3 illustrates a block diagram of the barcode processing server 7 according to another embodiment of the invention; and
[0013] FIGS. 4 a and 4 b illustrate data structures for storing information within a shared memory of the barcode processing server 7 .
DETAILED DESCRIPTION
[0014] The United States Postal Service (USPS) delivers more than 206 billion pieces of mail each year to over 142 million delivery addresses. Automating the process of sorting mail improves the speed and accuracy with which mail is sorted. One system used by the USPS for automating the process of sorting mail is the Upgraded Flats Sorting Machine (UFSM 1000) manufactured by Lockheed Martin Corporation of Bethesda, Md. This system comprises a conveyor to transport mail and robotic handling to sort the mail based on POSTNET barcodes and/or address block information. The UFSM 1000 is used in connection with a camera and an object recognition system to acquire images of the mail and recognize and process POSTNET barcodes and address block information in the images. While the UFSM 1000 is able to recognize and process POSTNET barcodes, it cannot recognize and process four-state barcodes.
[0015] FIG. 1 illustrates one embodiment of a system for processing and sorting mail that is capable of recognizing and processing both conventional two-state barcodes and four-state barcodes. The system comprises a mail sorter 1 , which may be the UFSM 1000 system described above, a camera 3 for acquiring images of the mail passing through the mail sorter 1 , an optical character recognition (OCR) processor 5 for recognizing and processing address information and conventional two-state barcodes, a FICS look-up server 9 for processing flat ID code sort (FICS) barcodes, a barcode processing server 7 for recognizing four-state barcodes, processing Intelligent Mail (IM) barcodes, and serving as an interface between the mail sorter 1 and the FICS look-up server 9 . Each of mail sorter 1 , camera 3 , OCR processor 5 , FICS look-up server 9 , and barcode processing server 7 may be a separate component linked to the other components via an external data link. Thus, one or more of mail sorter 1 , camera 3 , OCR processor 5 , FICS look-up server 9 , and barcode processing server 7 may be remotely located from the other components. Alternatively, one or more of the components may be integrated to form a unitary component.
[0016] As an item of mail passes through mail sorter 1 , it is imaged by camera 3 . According to one exemplary implementation, camera 3 is a line scan camera, model number AV 1520, manufactured by Accu-Sort Systems, Inc. of Telford, Pa. However, other cameras capable of capturing grayscale and/or binary images of mail may alternatively be used. Camera 3 comprises three ports. Two of these ports are used to couple the camera 3 to OCR processor 5 , and the other is used to couple the camera to barcode processing server 7 . As will be discussed, OCR processor 5 is used to recognize and process address block and two-state barcode information. Barcode processing server 7 , in connection with FICS look-up server 9 , is used to recognize and process FICS and IM four-state barcodes.
[0017] Two-state barcode and address block information is processed by the system of FIG. 1 in a conventional manner. Specifically, camera 3 transmits images acquired to OCR processor 5 so that address block and two-state barcode information included in the images may be recognized and processed. In the exemplary system of FIG. 1 , OCR processor 5 is a Flats Mail Optical Character Recognition (FMOCR) system manufactured by Siemens AG of Munich, Germany. OCR processor 5 decodes the barcode and/or converts the image of the address block to a readable format. This processed information is transmitted to OCR communication interface 11 within mail sorter 1 . Mail sorter 1 then sorts the mail according to the received information.
[0018] Four-state barcode information is processed by the system of FIG. 1 using the barcode processing server 7 and various interfaces provided to FICS look-up server 9 , mail sorter 1 and camera 3 . Barcode processing server 7 interfaces with a Time Interval Counter (TIC) I/O 13 and a barcode processing server communication interface 15 of mail sorter 1 . These interfaces, as well as the operations and functions of barcode processing server 7 , will be described in detail in connection with FIG. 2 .
[0019] FIG. 2 illustrates a block diagram of barcode processing server 7 and the interfaces of the barcode processing server 7 to the mail sorter 1 , camera 3 , and FICS look-up server 9 previously discussed. The processing of mail having four-state barcodes will now be discussed. As an item of mail passes through mail sorter 1 , its location is tracked by a Time Interval Counter (TIC) 10 coupled to TIC I/O interface 13 shown within the mail sorter 1 of FIG. 1 . The TIC 10 generates a count that is incremented as the conveyor of mail sorter 1 is moved, and thus may be correlated with a location of the item of mail within mail sorter 1 . Thus, the TIC 10 may be used to track to movement of mail through the mail sorter 1 so that the location of a given item of mail may be known as it passes through the mail sorter 1 . One suitable TIC that may be used is counter/timer board, model number PCI-CTR05, manufactured by Measurement Computing Corporation of Middleboro, Mass.
[0020] After an item of mail enters mail sorter 1 and is imaged by camera 3 , the image 19 is transmitted to a camera communication interface 17 within barcode processing server 7 and is stored in shared memory. The shared memory may be located, for example, within the barcode processing server 7 . Image 19 may be stored in shared memory with a TIC count 21 requested from mail sorter 1 . For example, FIG. 4 b shows an exemplary data structure 42 , comprising TIC count 21 and a pointer to image 19 , that may be stored in shared memory. TIC count 21 represents a count of the TIC 10 at the time when the image 19 was acquired by camera 3 , or at another predetermined time. TIC count 21 is transmitted from the TIC 10 via a TIC I/O interface 13 ( FIG. 1 ) of mail sorter 1 . TIC count 21 is received at the Enhanced Induction Station (EIS) communication interface 23 of barcode processing server 7 , and then stored in shared memory with image 19 (or a pointer thereto) as described above. At the same time that TIC count 21 is requested by barcode processing server 7 , a TIC count 25 is also read by mail sorter 1 from the TIC 10 . Mail sorter 1 associates TIC count 25 with a mail piece identifier 27 , which is a unique identifier assigned to an item of mail. TIC count 25 and mail piece identifier 27 are also transmitted to EIS communication interface 23 of barcode processing server 7 via TIC I/O interface 13 ( FIG. 1 ) of mail sorter 1 and stored together in shared memory. For example, FIG. 4 a shows an exemplary data structure 40 , comprising TIC count 25 and mail piece identifier 27 , that may be stored in shared memory. As will be discussed herein, TIC counts 21 and 25 and mail piece identifier 27 are used to associate barcode data processed by barcode processing server 7 with a particular item of mail being handled by mail sorter 1 .
[0021] Although TIC count 25 is described as being generated by the TIC 10 of mail sorter 1 and being transmitted to the barcode processing server 7 , TIC count 25 may alternatively be generated by a second TIC associated with the barcode processing server. For example, as shown in FIG. 3 , barcode processing server 7 may comprise a TIC 20 that generates TIC count 25 . The TIC 20 may be synchronized with the TIC 10 ( FIG. 1 ) such that the TIC 20 increments at the same rate and at the same times as TIC 10 . A data connection (e.g., a wireless connection or an Ethernet connection) may be provided between TIC 10 and TIC 20 to transmit synchronization signals. Once generated, TIC count 25 is transmitted to FICS processor 29 and treated in the same manner as described in connection with FIG. 2 .
[0022] Referring again to FIG. 2 , when image 19 is received by camera communication interface 17 , it is transmitted to optical character recognition (OCR) communication interface 31 by a processor 29 . OCR communication interface 31 will in turn transmit image 19 to one of OCR engines 33 and 35 . OCR engines 33 and 35 may have identical functionality, and thus allow parallel processing of images and other data. OCR communication interface 21 selects one of OCR engines 33 and 35 based on which OCR engine is available, and transmits image 19 to that OCR engine. In the example of FIG. 2 , image 19 is transmitted to OCR engine 35 . Each of the OCR engines 33 and 35 may use Lockheed Martin Symbol Recognition (LMSR) software to process a received image and return all barcode data identified in the image. Specifically, the LMSR software returns the type of barcode and the data of the barcode (i.e., all digits for the barcode) for each barcode identified. The barcode type and barcode data corresponding to image 19 , collectively data 37 , is stored in shared memory with image 19 and TIC count 21 , as shown in FIG. 4 b . OCR engine 35 then notifies OCR communication interface 31 that the processing of image 19 is complete and that the results of such processing have been stored in memory.
[0023] The OCR communication interface 31 will then determine, based on data 37 , what type of barcode(s) were contained within image 19 . If the OCR communication interface 31 determines that data 37 comprises a FICS barcode 41 , a message is transmitted to processor 29 , following which processor 29 notifies FICS look-up server interface 39 that a FICS barcode is ready to be processed. FICS look-up server (FLS) interface 39 transmits the FICS barcode 41 to FICS look-up server 9 . FICS look-up server 9 may be a REMLOC server manufactured by Northrop Grumman Corporation of Los Angeles, Calif., or another processor that may be used to perform a lookup to determine sortable data relating to the FICS barcode 41 . For example, FICS look-up server 9 may store zip code information associated with a particular barcode. Sortable data 43 determined by FICS look-up server 9 based on the FICS barcode 41 is transmitted back to FICS look-up server interface 39 and stored in shared memory with the corresponding image 19 .
[0024] Returning again to the data 37 generated by OCR engine 35 , if the OCR communication interface 31 determines that data 37 comprises an IM barcode, one of OCR engines 35 and 37 performs a lookup to determine sortable data 38 relating to the IM barcode. Sortable data 38 determined by the OCR engine based on the IM barcode is stored in shared memory with the corresponding image 19 .
[0025] Once the four-state bar codes have been recognized by barcode processing server 7 , processed by the barcode processing server 7 and/or FICS look-up server 9 , the resulting sortable data 45 , which may correspond to sortable data 43 returned by FICS look-up server 9 or sortable data 38 returned by OCR engines 33 or 35 , is stored in shared memory. For example, sortable data 45 may be stored as part of data structure 42 previously described in connection with FIG. 4 b . After sortable data 45 has been stored, the results are ready to be returned to mail sorter 1 . If FICS look-up server 9 has completed processing a FICS barcode, EIS communication interface 23 will be notified that sortable data is ready to be returned to mail sorter 1 . Similarly, if OCR engine 33 or 35 has completed processing an IM barcode, OCR communication interface 31 notifies EIS communication interface 23 that sortable data is ready to be returned to mail sorter 1 .
[0026] EIS communication interface 23 matches TIC count 21 , which is stored in memory with the sortable data 45 as shown in data structure 42 of FIG. 4 b , with TIC count 25 , which is stored in memory with mail piece identifier 27 as shown in data structure 40 of FIG. 4 a , by comparing the values of the TIC counts. For example, the TIC counts 25 and 21 encircled by an oval in FIGS. 4 a and 4 b have corresponding values; thus, the mailpiece identifier 27 associated with the encircled TIC count 25 corresponds with the sortable data 45 associated with the encircled TIC count 21 . In this manner, EIS communication interface 23 is able to correlate sortable data 45 with a corresponding mail piece identifier 27 . Sortable data 45 and its related mail piece identifier 27 are then returned to mail sorter 1 . Mail sorter 1 uses mail piece identifier 27 to determine a corresponding item of mail being processed, and may use sortable data 45 to determine how the item of mail should be sorted. For example, mail sorter 1 may use the sortable data 45 to sort the item of mail by zip code.
[0027] It should be appreciated that data structures 40 and 42 are one example of how TIC count 21 , TIC count 25 , mailpiece identifier 27 , data 45 , and/or image 19 may be stored in memory, however many implementations are possible. For example, a single data structure with all of the data in data structures 40 and 42 may alternatively be used. In addition, other formats for storing data, other than a data structure, may alternatively be used.
[0028] It should be appreciated that the system shown in FIG. 1 represents one exemplary implementation of a system for performing the various functions described herein, however other configurations are possible. The components of the system are shown for illustrative purposes, and need not be limited to the specific components shown. For example, while mail sorter 1 is the UFSM 1000 in the embodiment of FIG. 1 , other mail sorters may be used. Camera 3 also may be implemented using any suitable line scan camera or other device or apparatus capable of imaging address and barcode information on mail. FICS look-up server 9 may or may not be included in the overall system, depending on whether it is desired that the system be capable of processing FICS barcodes. In addition, barcode processing server 7 may be implemented as one or more computing systems and is not limited to the particular configuration shown. Further, although the system has been described in the context of processing barcodes, the invention is not so limited. The principles described herein for correlating data with an item of mail may also be applied to other information relating to items of mail (e.g., recipient information or postage information).
[0029] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
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Embodiments of the invention relate to systems and methods of correlating data relating to an item of mail, such as barcode information, with the associated item of mail. This allows the item of mail to be sorted using the data relating to the item of mail. According to one embodiment of the invention, a method is provided for correlating an item of mail, subject to sorting by a mail sorter, with data, stored by a processing unit, relating to the item of mail. The method comprises acts of associating the item of mail with a first counter value, associating the data with a second counter value, and corresponding the first counter value with the second counter value to correlate the data with the item of mail.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electron microscopy employing a CCD detector in order to acquire a backscattered electron image, a transmission electron image, or a scanning transmission electron image.
2. Description of the Related Art
When an electron beam enters a specimen in an electron microscopy, a part of the electron beam is scattered at a large angle by an atom in the specimen. Then, the scattered electron beam discharges electrons (backscattered electrons) from the surface of the specimen while losing little energy. Another part of the electron beam discharges electrons (transmission electrons) behind the specimen, without being absorbed in the specimen.
The backscattered electrons can be mainly classified into two types: high angle backscattered electrons scattered at high angles from the surface of the specimen and low angle backscattered electrons scattered at low angles from the surface of the specimen. The high angle backscattered electrons mainly have information on composition distribution, while the low angle backscattered electrons mainly have information on depression and projection. By discriminating these two types of backscattered electrons from each other, higher composition contrast and higher depression and projection contrast can be obtained.
For example, elastically scattered electrons having energy equal to that of the incident electron beam are mainly scattered at high angles, have information on the vicinity of the surface of the specimen, and include little information on the inside of the specimen. Therefore, a surface composition image of comparatively high resolution can be obtained by discriminating and detecting only the electrons scattering at high angles.
Various methods are used as the method for such discrimination, including: a method of colliding backscattered electrons with an electrode for low angle and an electrode for high angle, respectively, converting the backscattered electrons into secondary electrons, and detecting the secondary electrons; a method of selectively detecting high angle backscattered electrons and low angle backscattered electrons by use of an aperture; and a method of emphasizing stereoscopic effects by dividing a detecting face of a backscattered electron detector into two to five, and calculating a signal between each of the divided detecting faces.
On the other hand, the information on the inside of the specimen is reflected in a scanning transmission electron image (STEM image). The information in the STEM image is classified into a bright field image and a dark field image in accordance with a scattering angle of the transmission electron. A bright field image signal includes information on density of the specimen and information on electron diffraction. In the case of the dark field image, different information is visualized depending on a detected angle. Since a heavier element causes the transmission electrons to scatter at larger scattering angles, a difference of the atomic number of the specimen can be visualized. For this, discrimination of the bright field from the dark field is important. Discrimination of the bright field from the dark field has been conventionally performed using a selected area aperture.
For example, WO2000/19482 has disclosed a method of converting low angle backscattered electrons into secondary electrons, and detecting the secondary electrons while attaining a short working distance. Japanese Patent Application Publication No. 2002-110079 has disclosed a method of adding low angle backscattered electrons, high angle backscattered electrons, which are discriminated from each other and detected, and the secondary electrons at any selected ratio. Japanese Patent Application Publication No. Hei 11-273608 has disclosed a method of selectively detecting high angle backscattered electrons and low angle backscattered electrons using an aperture. Additionally, Japanese Patent No. 3776887 has disclosed a method of changing a range of the scattering angles of the transmission electrons to be detected, by making a position of a transmission electron detector variable.
SUMMARY OF THE INVENTION
Discrimination of the backscattered electrons or the transmission electrons has been performed with such conventional methods. However, such conventional methods cannot offer sufficient discrimination, and can no longer meet needs for an analysis in recent years.
An object of the present invention is to provide a detector that can perform discrimination of backscattered electrons or transmission electrons with more accuracy, and can detect the backscattered electrons or the transmission electrons as needed by an observer.
Using, as a detector, a CCD detector having a CCD element to which a scintillator is closely fixed, a backscattered electron image or a scanning transmission image is obtained by the following method.
The detector is disposed directly under an objective lens to obtain the backscattered electron image. The detector has a structure thin enough to be mounted between the objective lens and a specimen. When one point of the specimen is irradiated with an electron beam, backscattered electrons generated from the specimen collide with the scintillator, thus causing the scintillator to emit light, so that a luminescent pattern is formed on the scintillator. The CCD detector detects this pattern and stores the pattern in a memory as data. This processing is sequentially repeated for each of irradiation positions to acquire all the patterns in an electron beam scanning range.
Next, arithmetic processing is performed on each of the acquired patterns to convert it into an image. Usually, image data for one pixel is calculated from one pattern. The backscattered electron image in the electron beam scanning range can be obtained by sequentially repeating this arithmetic processing. Distribution of scattering angles of the backscattered electrons is reflected in a shape of the pattern, while the number and energy of the detected backscattered electrons are reflected in luminance. Accordingly, the backscattered electron image in any selected scattering angle range can be easily obtained by extracting and integrating only the data in the selected region on the pattern.
In the case of the scanning transmission image, the scanning transmission electron image in any selected scattering angle arbitrary range can be similarly obtained by disposing the detector under the specimen.
According to the present invention, discrimination of the backscattered electrons and the transmission electrons can be performed at any scattering angle. Accordingly, it is possible to obtain the backscattered electron image and the scanning transmission electron image on the basis of discrimination at appropriate scattering angles even when thickness, inclination, and composition of the specimen are changed. Thereby, the backscattered electron image or the scanning transmission electron image can be obtained as needed by the observer.
Furthermore, once a pattern is acquired, an image having any changed discrimination angle can be obtained from the pattern by calculation. Consequently, it is unnecessary to take the data again, and operability thus improves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view showing an embodiment of the present invention;
FIG. 2 is an explanatory view of backscattered electrons and transmission electrons;
FIG. 3 shows a backscattered electron pattern image;
FIG. 4 shows a transmission electron pattern image;
FIG. 5 is a schematic diagram of a structure of a CCD backscattered electron detector;
FIG. 6 shows a scanning electron microscopic image of a copper mesh;
FIG. 7 is a distribution map of electrons detected by irradiation of a charged particle beam in vacuum;
FIG. 8 is a backscattered electron distribution map obtained when irradiating copper with the charged particle beam;
FIG. 9 is a map of composition information; and
FIG. 10 shows comparison of backscattered electron distribution information or transmission electron distribution information in different irradiation positions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, with reference to the drawings, an embodiment of the present invention will be described in detail.
FIG. 1 is a schematic diagram of the embodiment of the present invention.
A primary electron beam 3 is discharged from a cathode 1 by a voltage V 1 applied to the cathode 1 and a first electrode 2 , and is accelerated by a voltage Vacc applied to a second electrode 4 to advance to an electromagnetic lens system at a rear stage.
The acceleration voltage Vacc and the V 1 are controlled by a high voltage control circuit 20 . The primary electron beam 3 is converged by a first converging lens 5 controlled by a first converging lens control circuit 22 . Here, the specimen irradiation current of the primary electron beam 3 is restricted by an objective lens aperture 6 . In order for the center of the electron beam to pass through a hole center of the objective lens aperture 6 , an electron-beam center-axis adjustment aligner 28 , an aligner control circuit 21 , and an electron beam center adjustment deflector 29 for scanning the electron beam on the objective lens aperture 6 are provided.
Then, the primary electron beam 3 is converged again by a second converging lens 7 controlled by a second converging lens control circuit 23 , and narrowly focused onto a specimen 15 by an objective lens 10 controlled by an objective lens control circuit 25 . Furthermore, the specimen 15 is two-dimensionally scanned by an upper deflecting coil 8 and a lower deflecting coil 9 connected with a deflection control circuit 24 .
The specimen 15 is placed on a specimen fine moving device 14 controlled by a specimen fine moving control circuit 27 . Backscattered electrons 18 , which have comparatively higher energy among signals generated from a primary electron beam irradiation point of the specimen 15 , are detected by a backscattered electron detector 11 , and are amplified by an amplifier 16 . Moreover, secondary electrons 47 having lower energy are wound up by a magnetic field of the objective lens 10 . The secondary electrons 47 are detected by a secondary electron detector 12 , while deviation of an optical axis of the primary electron beam 3 is prevented by a crossed electromagnetic field (E×B) unit 13 disposed above the objective lens 10 . Then, the secondary electrons 47 are amplified by an amplifier 17 .
Transmission electrons 38 that transmit through the specimen 15 are detected by a transmission electron detector 19 , and amplified by an amplifier 37 . The amplifier 17 is controlled by a signal control circuit 26 , and the amplifiers 16 and 17 are controlled by a CCD controller 36 . The various control circuits 20 to 27 and the CCD controller 36 are controlled by a computer 290 that controls the whole apparatus. A signal of the amplified backscattered electrons is shown on a screen of a display unit 30 as an enlarged image of the specimen. In addition, the computer 290 is connected with an image acquiring means 31 for acquiring an observed image displayed on the display unit 30 as image information, an image processing means 32 for performing various kinds of image processing on the observed image, a calculating means 33 for performing various calculations on the basis of a result of the image processing, a memory 34 for storing the observed image and the calculation results, and an input means 35 for inputting observation conditions or the like.
FIG. 2 shows scattering of the backscattered electrons 18 and the transmission electrons 38 . Contrast of composition information on the specimen is intensely detected from the backscattered electrons 18 the reflection angles of which from a specimen surface are in a high range, while contrast of depression and projection information is intensely detected from the backscattered electrons 18 the reflection angels of which are in a low range.
In the conventional method, a scintillator, a semiconductor, or a metal electrode that converts backscattered electrons into secondary electrons is used as a detector for discriminating and detecting the low angle backscattered electrons and the high angle backscattered electrons. However, it is difficult for the detector to have a multi-divided structure in any of the above-mentioned cases. Generally, the detector has a two-divided structure. Since a threshold of the scattering angle for discrimination is determined by the structure of the detector, a threshold cannot be selectively set.
It is also impossible to extract only the backscattered electrons in a selected range of the scattering angles, not even by using an aperture. Since a threshold and a range of extracted angles for discrimination are determined by a diameter of the aperture, the threshold and the range of extracted angles cannot be selectively set. The scattering angle of the backscattered electron changes depending on inclination and composition of the specimen. However, a scattering angle for detection cannot be appropriately set with the conventional method. Accordingly, accurate discrimination is difficult.
In the present invention, the deflection controlling circuit 24 is controlled in synchronization with control of the CCD backscattered electron detector 11 . Thereby, a pattern image of the backscattered electrons is detected for each irradiation point (irradiation position) of the electron beam by the CCD backscattered electron detector 11 , and recorded in the memory 34 .
FIG. 3 shows an example of a backscattered electron pattern image 39 . This backscattered electron pattern image 39 corresponds to one pixel of an enlarged image. The image processing means 32 and the calculating means 33 are used to integrate or average only information on a region a of the backscattered electron pattern image 39 , and data for one pixel is obtained. By performing this processing on each backscattered electron pattern image 39 obtained from each irradiation point of the electron beam, an image of only the high angle backscattered electrons is obtained. Similarly, an enlarged image formed only on the basis of information on a region b is an enlarged image of only the low angle backscattered electrons.
After the backscattered electron pattern image 39 of the specimen surface to be observed is thus recorded, by designating any selected region on the pattern, the designated region on the pattern can be converted into a high angle backscattered electron image or a low angle backscattered electron image. An arbitrary region can also be designated by use of a component element or inclination of the specimen.
FIGS. 6 to 8 show distribution of a backscattered electron image obtained for each of the irradiation positions, according to the present invention. As shown in FIG. 6 , a copper mesh is used as the specimen. FIG. 7 shows a state of distribution of the backscattered electrons which is obtained by the backscattered electron detector when the electron beam is applied in vacuum. The upper diagram shows a distribution image (distribution information) of the backscattered electrons in the irradiation position, and the lower graph shows signal amounts plotted along a white line of the above-mentioned diagram.
FIG. 8 shows a state of distribution of the backscattered electrons which is obtained by the backscattered electron detector when a copper is irradiated with the electron beam. The upper diagram shows a distribution image (distribution information) of the backscattered electrons in the irradiation position, and the lower graph shows signal amounts plotted along a white line of the above-mentioned diagram.
The result of the experiments shows that the above-mentioned spot appears in the same position in spite of shifting the irradiation position when copper exists in the irradiation position.
It turned out that the composition of the irradiation position of the primary electron beam can be identified by using this result of the experiments. Since identification of an incident position is limited to four in a four-divided detector, for example, in the conventional case, the composition cannot be identified even when the composition information is reflected. In the present invention, since distribution information (distribution map) on the backscattered electrons is acquired for every irradiation position, the composition can be accurately identified.
By retaining information on the spot position of the backscattered electrons in each substance in advance, the composition at each irradiation position can be found. Further, a map on the composition information on the specimen as shown in FIG. 9 can be also created.
FIG. 2 shows scattering of the backscattered electrons 18 and the transmission electrons 38 . Density information and electron diffraction information on the specimen 15 are included in a bright field picture signal of the transmission electrons 38 which has a lower scattering angle among the transmission electrons 38 that transmit through the specimen 15 . In the case of a dark field image signal of the transmission electrons 38 which has a higher scattering angle, information visualized is different depending on the detection angle. A heavier element causes the transmission electrons 38 to scatter at a higher scattering angle.
Discrimination in accordance with the scattering angle of the transmission electron has the same problem as in the case of the backscattered electron since the scattering angle varies in accordance with the thickness or composition of the specimen. Some types of electron microscopy employ a method of shifting the detector on the optical axis and controlling the angle for detection. Such a method, however, has a problem that a mechanism becomes complicated.
In the present invention, the deflection controlling circuit 24 is controlled in synchronization with control of the CCD backscattered electron detector 11 . Thereby, a pattern image of the transmission electron is detected for each irradiation point (irradiation position) of the electron beam by the CCD backscattered electron detector 11 , and recorded in the memory 34 .
FIG. 4 shows an example of a pattern image 40 of the transmission electrons. This transmission electron pattern image 40 corresponds to one pixel of an enlarged image. The image processing means 32 and the calculating means 33 are used to integrate or average only information on a region c of the transmission electron pattern image 40 , and data for one pixel is obtained. The light field image is formed by performing this processing on the transmission electron pattern image 40 obtained from each irradiation point of the electron beam. Similarly, the dark field image is an enlarged image formed only by information on a region d.
It is expected that the contrast of the backscattered electron image or the transmission electron image should be further improved by using discrimination in accordance with luminance of the pattern image in addition to discrimination in accordance with selection of the region in the pattern image.
As mentioned above, variety of information can be acquired by acquiring and storing the distribution information on (distribution image of) the backscattered electrons or the transmission electrons for every irradiation position.
For example, as shown in FIG. 10 , the distribution information is observed, only a signal of a detection position that appears in a spot form is extracted, and a signal of a detection position that has a spread region is removed. Thereby, only the composition information can be extracted with the projection and depression information on the specimen being removed. This can be attained by subtracting the information on a region having an area not less than a predetermined value from the distribution image. Conversely, when only the information having an area not less than the predetermined value is extracted, the information other than the composition information can be extracted.
With respect to this point, conventionally, while the backscattered electrons or the transmission electrons enter a divided detecting surface, the backscattered electrons or transmission electrons that enter the same detecting surface are all collected as one signal irrespective of the information (depression and projection information, composition information) that the electron has. For that reason, the composition information and the projection and depression information are mixed, and are detected.
In the present invention, the information that the backscattered electron or the transmission electron has can be isolated with more accuracy.
Furthermore, as shown in FIG. 10 , by comparing distribution information (distribution image) for every different irradiation position, only a part common to each distribution image can be extracted, or only the information unique to each distribution image not included in the distribution image of other irradiation position can be extracted.
FIG. 5 is a schematic diagram of a structure of the CCD backscattered electron detector 11 .
A scintillator 44 is fixed to a CCD element 46 with a buffer layer 45 in between. An electron beam passing hole 43 for passing the primary electron beam 3 through is provided in a central portion of the detector 11 . The number of pixels of the image that can be captured is approximately 1500 to 1700 wide by approximately 1000 to 1200 long.
The CCD backscattered electron detector 11 is disposed between the objective lens 10 and the specimen 15 to acquire the backscattered electron image, and under the specimen 15 to acquire the scanning transmission electron image. The CCD backscattered electron detector 11 measures approximately 40 mm wide by 30 mm long by 5 to 10 mm thick, which is small enough to be mounted on.
In the conventional detector employing the CCD element, the size of the CCD element is approximately 6 μm. For that reason, light generated from the scintillator inevitably enters multiple CCD elements. Accordingly, the light needs to be converged with a lens. The light generated in the scintillator is therefore converged by the lens disposed between the scintillator and the CCD element, and subsequently, the converged light enters the CCD element. Accordingly, the conventional detector employing the CCD element is large-sized, and cannot be disposed between the objective lens and the specimen.
In the present invention, the size of a detection element of the CCD is 20 μm, which is larger than the conventional one. Accordingly, the CCD backscattered electron detector 11 has a structure in which the light discharged from the scintillator 44 is detected without being converged with a lens.
The thickness of the scintillator is determined depending on the size of the CCD element. When the scintillator is too thick, the light spread within the scintillator enters multiple CCD elements, so that accuracy of the incident position deteriorates.
The above-mentioned experiment shows that at least not less than 10 bits of the CCD element is needed in order to obtain accurate observation of the peak as shown in FIG. 8 .
The CCD backscattered electron detector 11 may be configured to be movable in an optical axis direction by a moving means 41 according to a purpose. For example, when detecting all dark field signals to be generated, the CCD backscattered electron detector 11 may be brought closer to the specimen 15 . Moreover, for example, when a part of the dark field signals is to be discriminated, the CCD backscattered electron detector 11 may be moved away from the specimen 15 so that a discrimination angle can be set finely.
Detection elements, such as CCD elements, that are two-dimensionally arranged (for example, arranged in lattice pattern) and that the incident position of the electron is identifiable therein are used as the detection elements for the detector of the backscattered electron and the transmission electron.
While the above-mentioned embodiment has been described using the CCD detector, the present invention is not limited to this. It is also possible to use a detector of any other form that can identify the incident position of the electron and can be inserted between the specimen and the objective lens. Moreover, it is also possible to use a detector of a type in which multiple detection elements are arranged regularly in a plane (for example, in lattice pattern) for identification of the incident position of the electron.
EXPLANATION OF REFERENCE NUMERALS
1 . . . cathode, 2 . . . first electrode, 3 . . . electron beam, 4 . . . second electrode, 5 . . . first converging lens, 6 . . . objective lens aperture, 7 . . . second converging lens, 8 . . . upper deflecting coil, 9 . . . lower deflecting coil, 10 . . . objective lens, 11 . . . backscattered electron detector, 12 . . . secondary electron detector, 13 . . . crossed electromagnetic-field apparatus, 14 . . . fine moving device, 15 . . . specimen, 16 and 17 . . . amplifier, 18 . . . backscattered electron, 19 . . . transmission electron detector, 20 . . . high voltage control circuit, 21 . . . aligner control circuit, 22 . . . first converging lens control circuit, 23 . . . second converging lens control circuit, 24 . . . deflection controlling circuit, 25 . . . objective lens control circuit, 26 . . . signal control circuit, 27 . . . specimen fine moving control circuit, 28 . . . electron beam central axis adjustment aligner, 30 . . . display device, 31 . . . image acquiring means, 32 . . . image processing means, 33 . . . calculating means, 34 . . . memory, 35 . . . input means, 36 . . . CCD controller, 37 . . . amplifier, 38 . . . transmission electron, 39 . . . backscattered electron pattern image, 40 . . . transmission electron pattern image, 41 . . . moving means, 42 . . . transmission electron detector moving means, 43 . . . electron beam passing hole, 44 . . . scintillator, 45 . . . buffer layer, 46 . . . CCD element, 47 . . . secondary electron, 290 . . . computer,
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Using, as a detector, a CCD detector having a CCD element to which a scintillator is closely fixed, a backscattered or scanning transmission image is obtained by the following method. The detector is disposed directly under an objective lens to obtain the backscattered electron image. When one point of a specimen is irradiated with an electron beam, backscattered or transmission electrons generated from the specimen collide with the scintillator to form a luminescent pattern. This pattern is detected by the CCD detector, and stored in a memory. This processing is sequentially repeated for each irradiation position to obtain all the patterns in an electron beam scanning range. Arithmetic processing is performed on each pattern to convert it into an image. Usually, image data for one pixel is calculated from one pattern. By sequentially repeating this, a backscattered or transmission electron image in the electronic beam scanning range can be obtained.
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FIELD OF THE INVENTION
The present invention relates to acoustical, fiber-free air ducts and methods of making same.
BACKGROUND OF THE INVENTION
Air circulation systems are incorporated into most building structures. Such air circulation systems typically include air ducts which extend from a central source to regions throughout the building. The central source may include means for heating, ventilating, and/or cooling the air. The air itself is usually forced or blown throughout the system by means of fans or blowers, respectively.
Historically, air ducts have been made of sheet metal. However, those skilled in the art will recognize that sheet metal air ducts contribute to the distribution of unacceptably loud noise. In particular, metal air ducts tend to transmit sound with little or no attenuation, thereby placing an entire building in communication with noise made by the heating, ventilating, and/or cooling equipment, as well as noise made by other operations taking place within the building. A major impact of mechanical noise through duct work is noise that interferes with verbal communications resulting in diminished speech intelligibility in spaces in which verbal communications is a function of the activities within the space. The resulting "noise pollution" can reduce productivity and may, in extreme cases, lead to hearing damage.
One prior art "solution" to the noise problems associated with air ducts has been to line or replace the metal air ducts with fiberglass panels. Those skilled in the art will recognize that fiberglass is suitable for both thermal and acoustical insulation. However, those skilled in the art will also recognize that fiberglass is coming under ever greater scrutiny, being perceived by many as a potential health hazard. The primary concern centers around the fibrous nature of fiberglass relative to the established hazards associated with asbestos fibers.
Although suitable substitutes to fiberglass are being introduced for thermal insulation purposes, the same cannot be said for noise attenuation applications. Thus, a need exists for an air duct and/or an air duct liner which attenuates noise without introducing known health hazards into a building's environment. Ideally, any such air duct and/or air duct liner should comply with current building code requirements and be compatible with current construction methods.
SUMMARY OF THE INVENTION
The present invention provides air ducts and air duct liners which are acoustical and fiber free, as well as methods of making same. In a preferred embodiment, a reinforcing material is disposed on one side of a foam sheet, and a coating material is disposed on an opposite side of the foam sheet. The foam sheet is folded into an air duct configuration with the reinforcing material on the outside and the coating material on the inside.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the Figures of the Drawing, wherein like numerals represent like parts and assemblies throughout the several views,
FIG. 1 is an isometric view of a four-sided air duct constructed according to the principles of the present invention;
FIG. 2 is an isometric view of a three-sided air duct constructed according to the principles of the present invention;
FIG. 3 is an isometric view of a six-sided air duct constructed according to the principles of the present invention;
FIG. 4 is an isometric view of a eight-sided air duct constructed according to the principles of the present invention;
FIG. 5 is an end view of a sheet of foam which is part of the air duct of FIG. 1;
FIG. 6 is an end view of the sheet of foam of FIG. 5, with an outer layer of material connected thereto;
FIG. 7 is an end view of the combination of FIG. 6, with notches cut into the sheet of foam;
FIG. 8 is a sectioned end view of the combination of FIG. 7, with an inner layer of material connected thereto; and
FIG. 9 is a perspective view of a pre-existing metal air duct retrofitted with a foam liner in accordance with according to the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment air duct constructed according to the principles of the present invention is designated as 100 in FIG. 1. The air duct 100 has four sides or walls which cooperate to define a rectangular configuration. Each of the walls includes an intermediate layer of foam 110, an outer layer of reinforcing material 120, and an inner layer of coating material 130. The air duct 100 is secured in its rectangular configuration by means of an overlapping portion 122 of the reinforcing material 120 and adhesive tape (not shown).
The foam 110 may be described as non-fibrous, contrary to fiberglass and asbestos. The foam 110 may also be described as acoustical, meaning it has an NRC rating of @ 0.80. In the preferred embodiment 100, the foam 110 is an open cell, melamine formaldehyde polymer with a melamine resin base and a density of about 0.7 pounds per cubic inch. The foam 110 is manufactured by BASF in Germany, and is marketed worldwide under the trademark WILLTEC by Illbruck, Inc. of Minneapolis, Minn. (the assignee of the present invention). This particular foam 110 is considered superior to polyurethane foams because of its Class 1 rating, and it is considered superior to phenolic foams because of its resistance to crumbling.
The reinforcing material 120 may be described as a facing material. The material 120 is flexible, yet strong, and functions as the outer shell of the air duct 100. In this regard, the material 120 effectively seals the foam 110 from its external environment and contributes to the rigidity of the air duct 100. The material 120 may be selected from among a group of suitable materials, including (but not limited to) a foil scrimmed KRAFT paper (FSK) and a foil scrimmed vinyl (FSV) KRAFT paper comprises a strong paper or cardboard made from sulfate-process wood pulp.
The inner coating 130 may be described as a film or sealant which separates the foam 110 from the internal conduit extending through the air duct 100. The coating 130 protects the foam 110 against erosion and airborne contaminants, but does not significantly obstruct or prevent absorption of noise by the foam 110. The coating 130 may be selected from among a group of suitable materials, including polymeric materials such as (but not limited to) HYPALON, TEDLAR, and TYVEC all of which are sold by DuPont. These materials are known to function in a manner which may be described as accoustically transparent.
A preferred method of making the air duct 100 is described with reference to FIGS. 5-8. The first step is to obtain a sheet of foam 110, as shown in FIG. 5. The width of the foam sheet 110 is defined between a first side 111 and a second, opposite side 112. The foam sheet 110 extends lengthwise in a direction perpendicular to the end of the sheet shown in FIG. 5. The thickness of the foam sheet 110, as measured perpendicular to the width and the length, is generally a function of design parameters.
The second step is to secure the facing or outer layer of material 120 to the foam sheet 110. A non-flammable, water-based adhesive provides a suitable connecting means for such purpose. The material 120 is the same length as the foam sheet 110 but slightly wider, as measured between a first side 121 and a second, opposite side 122. The thickness of the material 120 is exaggerated in the Figures for ease of reference. The resulting combination is shown in FIG. 6.
The third step in the preferred method of manufacture is to cut or otherwise form notches 119 in the foam sheet 110. The notches 119 are cut in the surface opposite the material 120 and extend through the foam 110 to vertices or corners proximate the material 120. The number of notches 119 and the magnitude of their angles or miter cuts are a function of the number of sides of the air duct. In the preferred embodiment 100, the notches 119 include three "full notches" (or interior notches) and two "half notches" (or end notches) which are formed by cutting into the foam sheet 110 at 45 degree angles. The resulting configuration is shown in FIG. 7.
The fourth step is to coat all exposed portions of the foam sheet 110 with the material 130. The coating material 130 is sprayed or otherwise deposited onto the foam 110, including the ends thereof. The coating material 130 extends from a first side 131 to a second, opposite side 132. The thickness of the coating material 130 is also exaggerated for ease of reference. A sectioned view of the resulting product is shown in FIG. 8. The resulting sheet product may be formed into its final configuration either prior to shipping or at the job site.
A three-sided air duct 200 is shown in FIG. 2. The triangular air duct 200 includes an intermediate layer of foam 210, an outer layer of facing material 220 connected to an outer side of the foam 210, and an inner layer of coating material 230 connected to an inner side and the ends of the foam 210. In this embodiment 200, only two interior notches are cut into the foam 210. An overextending flap 222 of facing material 220 helps secure the air duct 200 in its intended configuration.
A six-sided air duct 300 is shown in FIG. 3. The hexagonal air duct 300 includes an intermediate layer of foam 310, an outer layer of facing material 320 connected to an outer side of the foam 310, and an inner layer of coating material 330 connected to an inner side and the ends of the foam 310. In this embodiment 300, five interior notches are cut into the foam 310. An overextending flap 322 of facing material 320 helps secure the air duct 300 in its intended configuration.
An eight-sided air duct 400 is shown in FIG. 4. The octagonal air duct 400 includes an intermediate layer of foam 410, an outer layer of facing material 420 connected to an outer side of the foam 410, and an inner layer of coating material 430 connected to an inner side and the ends of the foam 410. In this embodiment 400, seven interior notches are cut into the foam 410. An overextending flap 422 of facing material 420 helps secure the air duct 400 in its intended configuration.
Yet another embodiment of the present invention is designated as 590 in FIG. 9. This improved air duct 590 includes a conventional sheet metal air duct 599 into which a foam air duct liner 500 has been inserted. The liner 500 is made of the same melamine foam 510 as the other embodiments but lacks the outer and inner layers.
The present invention has been described with reference to specific embodiments and applications. However, the scope of the present invention is limited only to the extent of the claims which follow.
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An air conveying duct has a foam core sealed on the inside and reinforced on the outside. The duct absorbs noise and neither introduces impurities into the air nor collects impurities from the air.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND
[0003] The present invention relates generally to methods and apparatus for gripping and manipulating pipe. More particularly, the present invention relates to methods and apparatus for facilitating the connection and disconnection of sections of drill pipe.
[0004] Drill strings used in rotary drilling are often constructed from individual lengths of drill pipe connected in series to form a drillstring. The individual lengths of drill pipe are commonly joined by threaded connections. Because of the loads incurred by the drillstring, the connections have to be pre-loaded with a certain amount of torque in order to maintain a satisfactory connection during use.
[0005] Pipe tongs are one tool used for facilitating the connection and disconnection, or making and breaking, of drill pipe connections. Pipe tongs are generally located at the drill floor and operate by gripping a connection between two adjacent lengths of pipe and applying torque to loosen or tighten the connection. Many pipe tongs operate by gripping above and below the junction between two adjacent pipe sections. The tongs then rotate the two sections of pipe relative to each other. This rotation often has a very limited rotational range but is performed with sufficient torque to properly make or break the connection. The torque applied to a given connection can be on the order of tens of thousands of foot-pounds.
[0006] Because of the high torque loads applied to the pipe, pipe tongs have been known to scar the outer diameter of the pipe, especially if the pipe slips within the tong. In order to minimize this slippage, as well as to ensure the proper torque requirements are met, the interface between the pipe and the tong is critical. In some cases, pipe tongs have been known to partially collapse the pipe with an excessive clamping force. Excessive damage to the pipe is often a result of the pipe not being centered within the pipe tong causing the gripping mechanism of the tong to apply uneven force to the pipe.
[0007] Thus, there remains a need to develop methods and apparatus for facilitating the connection and disconnection of pipe sections, which overcome some of the foregoing difficulties while providing more advantageous overall results.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0008] A tong assembly comprising a body and a center member slidable relative to said body. A pair of clamping arms are rotatably connected to said body. The clamping arms are connected to said center member such that as said center member slides relative to said body, said clamping arms rotate relative to said body. The assembly also comprises a plurality of die assemblies, wherein at least one die assembly is mounted to each clamping arm and at least one die assembly is mounted to said center slider.
[0009] One embodiment comprises a tong assembly comprising a body and a center member slidable relative to said body. A pair of clamping arms are rotatably connected to said body. The clamping arms are connected to said center member such that as said center member slides relative to said body, said clamping arms rotate relative to said body. The assembly includes a plurality of die assemblies, wherein at least one die assembly is mounted to each clamping arm and at least one die assembly is mounted to said center slider. In some embodiments, a hydraulic cylinder is operable to slide said center member relative to said body.
[0010] In certain embodiments, the die assemblies that are mounted to the clamping arms are rotatable relative to the clamping arms and the die assembly that is mounted to the center slider is not rotatable relative to the center slider. Each die assembly may comprise a die, a holder adapted to receive the die; and a retainer supporting the holder such that the holder is rotatable relative to the retainer, wherein the retainer is attached to one of the clamping arms.
[0011] The tong assembly may also comprises a pair of connecting links, wherein each of the connecting links is pivotally connected to the center member and one of the clamping arms by a pin connection that connects to one of the connecting links; and a pivot connection that connects to the body, wherein the clamping arm rotates about the pivot connection, wherein the distance from the pin connection to the pivot connection is equal to the distance from the pivot connection to the center of the die assembly. In some embodiments, the body is a unitary weldment having an open side and the center member and the clamping arms are installed in the body through the open side.
[0012] In another embodiment, the tong assembly may comprise an upper tong, a back-up tong aligned with and below the upper tong, a slider connected between the upper tong and the back-up tong, wherein the slider establishes a center point about which the upper tong and the back-up tong can rotate. A pair of first hydraulic cylinders operable to rotate the upper tong relative to the back-up tong, wherein the pair of first hydraulic cylinders have first ends connected at a single attachment to one of the tongs and second ends attached at separate points to the other of the tongs such that the tongs rotate relative to each other as one of the first cylinders retracts and the other of the first cylinders extends.
[0013] Thus, the present invention comprises a combination of features and advantages that enable it to overcome various problems of prior devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
[0015] FIG. 1 is an elevation view of a tong assembly constructed in accordance with embodiments of the invention;
[0016] FIG. 2 is a plan view of the tong assembly of FIG. 1 , with the upper tong removed;
[0017] FIG. 3 is a plan view of a tong assembly in an open position;
[0018] FIG. 4 is a plan view of the tong assembly of FIG. 3 in a closed position;
[0019] FIG. 5 is a plan view of the operating components of the tong assembly of FIGS. 3 and 4 ;
[0020] FIG. 6 is a partial plan view of one embodiment of a die assembly;
[0021] FIG. 7 is a cross-sectional elevation view of one embodiment of a die assembly; and
[0022] FIG. 8 is a partial sectional plan view of one embodiment of a die assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring now to FIG. 1 , tong assembly 100 includes top tong 102 and back-up tong 104 rotatably connected by slider 106 and torquing cylinders 108 . FIG. 2 shows tong assembly 100 with top tong 102 removed. Cylinders 108 are connected to top tong 102 at pins 110 and to back-up tong 104 at pin 112 . Slider 106 allows cylinders 108 to rotate top tong 102 relative to back-up tong 104 while maintaining proper alignment between the tongs.
[0024] Tong assembly 100 transfers torque produced by cylinders 108 to a threaded connection between two adjacent tubular members that are engaged by clamping arms 110 . Cylinders 108 may be hydraulically linked to one another such that the piston (extend) side 114 of one cylinder is coupled to the rod (retract) side 116 of the other cylinder. In this manner, hydraulic pressure can be applied simultaneously from the same source to extend one cylinder and retract the other cylinder, thus optimizing the torque applied to the threaded connection.
[0025] Referring now to FIG. 3 , a tong 200 is shown including body 202 with its top plate 204 partially cut away to show clamping assembly 206 . Body 202 is preferably formed from a unitary weldment substantially enclosed on all but one side, which is left open to accept clamping assembly 206 . Clamping assembly 206 comprises center slider 208 , clamping arms 210 , connecting links 212 , slider guides 214 , and die assemblies 216 A-C. Pins 218 and 220 pivotally attach connecting links 212 to center slider 208 and clamping arms 210 , respectively. Pins 222 provide a pivoting connection between clamping arms 210 and body 202 . Pins 222 also carry the load that is applied by the torquing cylinders from body 202 to clamping arms 210 . Clamping assembly 206 is actuated by hydraulic cylinders 224 , which preferably act in unison to actuate the clamping assembly.
[0026] Referring now to FIG. 4 , as hydraulic cylinders 224 extend, center slider 208 is moved toward tubular member 226 . Center slider 208 pushes connecting links 212 and rotates clamping arms 210 about pins 222 until die assemblies 216 A and 216 B engage tubular member 226 . Die assembly 216 C moves toward tubular member 226 with center slider 208 . Slider guides 214 maintain alignment between center slider 208 and tubular member 226 to ensure proper operation of the tong assembly. In the preferred embodiments, all three die assemblies 216 A-C engage tubular member 226 at the same time and with equal amounts of force.
[0027] Referring now to FIG. 5 , the actuating components of clamping assembly 206 are shown engaged with tubular member 228 . In the preferred embodiments, clamping assembly 206 operates such that, within a given size range, tubular member 228 is substantially centered, and evenly engaged by die assemblies 216 A-C. Therefore, clamping assembly 206 is arranged such that as die assembly 216 C moves toward the center of tubular member 228 , die assembles 216 A and 216 B also move toward the center of the tubular member at substantially the same rate.
[0028] Clamping arms 210 are arranged such that distance 230 from pin 222 to the center of die assembly 216 B is substantially equal to the distance 232 from pin 222 to pin 220 . Pin 220 moves in unison with, and in substantially the same direction as die assembly 216 C that is mounted on center slider 208 . Because pin 220 and die assembly 216 B rotate about pin 222 at the substantially the same diameter, the distance traveled by die assembly 216 B is substantially the same as the distance traveled by pin 220 . Therefore, during actuation of clamping assembly 206 , the distance traveled by die assembly 216 B (or 216 A) is substantially the same as the distance traveled by die assembly 216 C. Because dies 216 A-C have starting positions substantially the same distance from the center of tubular member 228 , the tubular member will always be substantially centered by the die assemblies.
[0029] In order to accommodate a wide range of tubular sizes and ensure that tong 200 contacts the pipe surface as close to perpendicular as possible, die assemblies 216 A and 216 B may be rotatable relative to clamping arms 210 . Die assembly 216 C is preferably stationary so to not allow a tubular member to move off-center.
[0030] Referring now to FIG. 6 , one embodiment of a die assembly 300 is shown installed in clamping arm 210 and including die 302 and holder 304 . Die 302 is preferably constructed of a hardened material formed with teeth 308 for engaging the outside surface of a tubular member. Die also includes shoulders 310 configured to interface with grooves 312 in holder 304 . Holder 304 has a curved rear surface 314 and curved ridge 316 on both the top and the bottom of the holder.
[0031] FIG. 7 illustrates a cross-section of shows a section of a die assembly 300 assembled on a clamping arm 210 . Die 302 and holder 304 are retained in position by ridges 316 interfacing with grooves 320 on retainers 306 . Retainers 306 are fixed to clamping arm 210 by cap screws 328 . Gaps 322 ensure that as die 302 is compressed, the load is transferred into clamping arm 210 and not into retainers 306 .
[0032] Referring now to FIG. 8 , a partial sectional view of die assembly 300 is shown so that the interface between ridge 316 and groove 320 can be seen. Groove 320 may be slightly longer than ridge 316 in order to allow holder 304 to rotate relative to the retainer. Each retainer 306 has a groove 320 for supporting rotation of holder 304 , but the grooves on the two retainers may be different. Retainer 306 is preferably arranged so as to facilitate easy assembly and disassembly of die assembly 300 to support fast changing of die 302 .
[0033] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied, so long as the pipe gripping and manipulating apparatus retain the advantages discussed herein. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
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A tong assembly comprising a body and a center member slidable relative to said body. A pair of clamping arms are rotatably connected to said body. The clamping arms are connected to said center member such that as said center member slides relative to said body, said clamping arms rotate relative to said body. The assembly also comprises a plurality of die assemblies, wherein at least one die assembly is mounted to each clamping arm and at least one die assembly is mounted to said center slider.
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CROSS REFERENCE TO RELATED APPLICATIONS
The invention disclosed herein relates to communication and control systems. The following commonly assigned U.S. patent applications relate to such communication and control systems: Ser. No. 625,747, filed on June 28, 1984 by William R. Verbanets and entitled "Multipurpose Digital IC for Communication and Control Network" (W.E. Case No. 51,930); Ser. No. 625,863, filed on June 28, 1984 by William R. Verbanets and Theodore H. York and entitled "Improved Digital IC-Microcomputer Interface (W.E. Case No. 51,931); U.S. Pat. No. 4,653,072 issued Mar. 24, 1987 to Leonard C. Vercellotti and William R. Verbanets and entitled "Low Error Rate Digital Demodulator; U.S. Pat. No. 4,644,547 issued on Feb. 17, 1987 to Leonard C. Vercellotti, William R. Verbanets and Theodore H. York entitled "Digital Message Format for Two-Way Communication and Control Network"; Ser. No. 769,640, filed Aug. 26, 1985 by John C. Schlotterer entitled "Communication and Control Network Master Interface for Personal Computer" (W.E. Case No. 52,212); Ser. No. 769,642, filed Aug. 26, 1985, by Bruce L. Brodsky entitled "Computer Driver Module for Master Interface to Communication and Control Network" (W.E. Case 52,214); U.S. Pat. No. 4,646,319 issued on Feb. 24, 1987 to Joseph C. Engel, Leonard C. Vercellotti, and David L. Boomgaard, entitled "Biodirectional Bus Coupler Presenting Peak Impedance at Carrier Frequency"; and Ser. No. 199,417, filed on May 27, 1988, by Bruce T. Brodsky and D. L. Davidson, entitled "Electronic Control of Solenoid Operated Circuit Breaker" (W.E. 53,996).
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to communication and control systems and, more particularly, it pertains to electronic control of lighting panelboards.
2. Description of the Prior Art
Current technology for controlling lighting loads remotely requires the use of an interposed relay. The relay is located between the circuit breaker and the load. This technology has several disadvantages including (1) hardware relay assembly requiring a relay to be remote from a panelboard due to space limitations, (2) higher labor costs from increased wiring, (3) reliability problems due to additional functional parts such as a relay; and (4) minimal diagnostic capabilities from a controller such as determination of the status of the circuit breakers.
An object of this invention is to provide for individual control of many circuit breakers in a panelboard through an electronic control such as a computer.
DISCLOSURE OF THE INVENTION
In accordance with this invention, there is provided an integrated building electrical load management system comprising a panelboard having a plurality of circuit breakers for controlling each load, a printed circuit board having a plurality of conductor connections and of breaker connections, electronic control means for providing electronic control and diagnostics for the circuit board and having a plurality of conductors leading to the conductor connections, the panelboard and printed circuit board being contained within an enclosure and the circuit breakers being individually connected to the circuit board, and each circuit breaker including a remotely controlled solenoid for actuating the circuit breaker for opening and closing a circuit through a load and which solenoid includes control wires connected to the breaker connection, whereby the printed circuit board functions as a circuit breaker interface between the separate circuit breakers and the electronic control means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the hardware components of a prior art structure;
FIG. 2 is a schematic view of the hardware interface between the circuit breakers on a panelboard and the electronic control in accordance with this invention;
FIG. 3 is a schematic view of the panelboard showing breaker connections and output cable connections; and
FIG. 4 is a sectional view through a remotely controlled solenoid operated circuit breaker.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A prior art structure for an electronic control of a panelboard is generally indicated at 10 in FIG. 1, and it comprises a panelboard 12, a load 14, a relay 16, and an electronic control 18. The panelboard 12 includes a plurality of circuit breakers 20, each of which is connected electrically to a separate load. For example, the particular circuit breaker 20a is connected by a conductor 22 to the load 14 and the other circuit breakers 20 are separately connected to other loads not shown.
Each conductor 22 comprised a hardwire relay assembly including the relay 16 to provide control of the load by means of the electronic control 18, such as a computer, which is connected by a conductor 24 to a relay coil 26 for actuating the relay 16. This prior art structure had the disadvantage of requiring the relay to be remote from the panelboard due to space limitations on the panelboard.
In accordance with this invention, there is provided a panelboard 28 (FIG. 2) and an electronic control such as a computer 30. The panelboard 28 is contained within a box or enclosure 32 having opposite sidewalls 34 and end walls 36. The panelboard 28 comprises a plurality of circuit breakers 38 each of which is connected to a line bus bar 40. Each circuit breaker 38 is also connected to a separate load 42.
For the purpose of this invention, the several circuit breakers 38 are solenoid operated breakers which are interconnected with an interface or printed circuit board 44 by means of conductors 46, 48. However, standard circuit breakers which are not solenoid operated may also be mounted on the panelboard where control by the electronic control 30 is not necessary. A typical solenoid operated circuit breaker 38 is that shown in Pat. No. 4,654,614, which is shown in FIG. 4. It comprises a manually operated handle 50 for opening and closing contacts 52, 54 which are disposed between line and load terminals 56, 58. A solenoid 59 has a plunger 60 for operating on mechanisms within the circuit breaker in a well-known manner for opening and closing the contacts 52, 54 by remote control by a coil 62 having the conductor leads 64 (FIGS. 2, 4). Accordingly, a circuit to the load 42 may be open or closed remotely by the solenoid plunger 60 in response to operation of the electronic control 30 acting through the interface 44.
The interface 44 (FIG. 3) is a printed circuit board and card and is a modular, compact interface surface for the control circuitry wiring. It comprises a plurality of circuit breaker connections 66, one for each solenoid circuit breaker 38. The interface or circuit board 44 provides interface capability for up to forty-two circuit breakers. The interface is provided by simple plug-in connectors 68 on the conductor lead 64. The interface 44 or circuit board is mounted on or adjacent to the panelboard 28 (FIG. 2). Any number and combination of interface points up to the maximum can be used in each board.
In addition to the circuit breaker connectors 66, output cable connections 70 are provided by which the electronic control 30 is connected to the interface through a cable harness 72. For clarity, interconnections between the several circuit breaker connections 66 and corresponding output cable connectors are not shown. Each cable harness 72 includes a plug-in connector 74. The cable harness 72 comprises control wiring for a plurality of circuit breakers 38 connection between each of the several circuit breakers to the circuit breaker connectors 66 or through the plug-in connectors 68 having three pin plug-in connectors. The cable harness 72 having the plug-in connector 74 likewise comprises a three pin plug-in connection with the output cable connector 70. The electronic control or computer 30 provides control and diagnostics for the several circuit breakers 38.
In summary, the system of this device provides a true and accurate monitoring of the position of the circuit breaker whether open or closed, and an alarm for an unexpected change. It is capable of not only sending messages from the electronic control to the circuit breaker, but also in a reverse direction so as to provide a report-back function. In addition, a loss of control power does not result in loss of breakers and the relay function and the breaker functions are in one box, resulting in lower installation costs. Finally, the panelboard is independent of the controller in that the panelboard can be interfaced with any controller via the appropriate pin connector.
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An electronically controlled lighting panelboard characterized by a power line panelboard having a plurality of remotely controlled circuit breakers for opening and closing circuits to corresponding loads. Each circuit breaker is interconnected to an interface which in turn is connected by a multi-conductor cable to an electronic controller or computer.
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FIELD OF THE INVENTION
This invention relates to fluid-driven tension actuators and the method for constructing such actuators. Tension actuators convert fluid pressure energy input, for example, such as compressed air energy or the energy of pressurized hydraulic liquid, into mechanical displacement. More specifically, tension actuators convert fluid pressure energy into linear contraction displacement.
BACKGROUND
The concept of a tension actuator which contracts along its longitudinal axis when inflated is known. Such an actuator, which responds at relatively low fluid pressure, is disclosed in U.S. Pat. No. 3,645,173--Yarlott. The disclosure of Yarlott specifies a number of parameters which are markedly different from or contrary to the present invention as will be pointed out in or will become understood from the specification considered in conjunction with the accompanying drawings. In Yarlott's tension actuator:
(A) The surface area of the shell remains substantially constant in all of the various positions of the actuator. A two-way network of relatively inextensible strands,--(i) extending axially, and (ii) helically wound causes the reinforced shell to "resist elastic expansion". In other words, this reinforcing network in Yarlott's actuator is attempting to maintain substantially constant surface area in all deformed positions. However, the elastomeric shell wall must necessarily undergo a shearing deformation as the actuator is inflated for causing it to contract. This shearing of the elastomeric shell wall causes a basic incompatibility at the junction where the shell wall is attached to the rigid cylindrical coupling members at each end. Because of this shearing of the shell wall, the cylindrical end members must be of small diameter in the Yarlott actuator in order to minimize the basic incompatibility, which restricts the fluid flow through them and thus inherently slows the cycle time, i.e. causes a slow response to changes in pressure. If an attempt is made to enlarge the diameter of these cylindrical end members, in order to speed up the response time, then the basic shear versus non-shear incompatibility at the shell-to-end-member junction is accentuated leading to large localized stresses and early failure of the shell wall at this junction.
(B) The Yarlott tension actuator is particularly adapted for low pressure applications, for example, pressures in the nature of 0.25 p.s.i. gauge up to a practical limit of about 15 p.s.i. gauge; that is, up to a limit of about one atmosphere of pressure difference between internal fluid pressure and ambient pressure.
(C) The Yarlott tension actuator has extreme sensitivity to internal fluid pressure exceeding 15 p.s.i. gauge, because above that limit the elastic shell begins to expand unduly by locally bulging between the axial and helical strands, but no further axial contraction actually occurs, leading to rapid fatigue failure and likelihood of bursting when cyclically operated for more than a relatively few cycles with repeated internal pressure excursions much above 15 p.s.i. gauge. In summary, the kind of tension actuator as invented by Yarlott within its normal limited low pressure range produces a minimum of stretch of its elastic shell with a maximum of bending and flexing of the shell and considerable shear deformation of the shell near its end member connections. On the other hand, single-crossing hyperboloidal tension actuators embodying the present invention are the opposite. They do intentionally involve considerable shell stretch, and they are able to operate for hundreds of thousands of cycles with each cycle involving a pressure excursion from about 0 p.s.i. gauge up to about 30 p.s.i. gauge and back to about 0 p.s.i. gauge without any apparent significant fatigue effects.
Another device which axially contracts upon inflation is disclosed in U.S. Pat. No. 2,642,091--Morin. However, the Morin diaphragm suffers from the problem that in its neutral (deflated) state it has the geometrical configuration of a right circular cylinder, more commonly called a cylindrical surface of revolution, with inextensible threads each placed along a generating line (axially extending straight line) or each along a helix with constant pitch. Consequently, a very large increase in internal fluid pressure is needed to be applied within the Morin actuator before its reinforced hose-like wall begins to bulge for causing axial contraction.
Furthermore, if the helical threads have a pitch of 52°, and if the Morin actuator is sufficiently long that these threads make at least one complete turn (at least one complete convolution) from end to end of this cylinder of revolution, then mathematical analysis shows that no effective axial contraction will take place regardless of how high is raised the pressure of the internal fluid. In other words, even if the internal pressure in such a hose is raised to the bursting point, no significant axial contraction will occur. In summary, the Morin structure makes inefficient use of materials and causes relatively large internal stresses and strains without producing a proportional contraction in its axial length. In contrast, a tension actuator constructed in accordance with the present invention produces a much longer and more forceful contraction (longer and more forceful stroke) with the same materials and the same changes in internal fluid pressure.
U.S. Pat. No. 3,638,536--Kleinwachter et al discloses diaphragm devices for transforming a fluid pressure into torsional movement or into axial movement upon inflation. The diaphragm is elastically stretchable in preferably only one direction.
U.S. Pat. No. 2,789,580--Woods discloses a two-component mechanical transducer with an expansible cavity formed by a flexible seal having a cylindrical braided or woven metal sheath encompassing it. There is the undesirable complexity of an outer cylindrical braided sheath and a separate internal pressurizing means. An actuator embodying the present invention is a substantial simplification over the Woods' device, by virtue of being a one-component structure as distinguished from Woods' two-component structure.
U.S. Pat. No. 2,865,419--Cunningham has been reviewed by the present inventor and is considered even more remote from the present invention than the above-listed disclosures. The Cunningham structure exploits the neutral helical braid pitch of approximately 52° (as discussed above in connection with Morin's disclosure) in order to yield a dimensionally stable structure, i.e. a structure which will neither expand nor contract nor change radius upon changes of pressure in the internal fluid. This Cunningham reference is set forth as being known to the inventor in order for this discussion of known disclosures to be complete and in the event the reader might consider it to be of interest. This Cunningham patent does support the earlier explanation that a hose-like structure reinforced with two-way helical strands at a pitch of 52° and each extending for at least one full convolution is dimensionally stable; therefore, such structure has exactly the opposite characteristics from the desired long and strong stroke, fast-response axial contraction characteristics needed in high efficiency tension actuators as provided by the present invention.
SUMMARY OF THE DISCLOSURE
A tension actuator has a pair of end-connection, ring-shaped fittings of relatively large internal diameter, thereby providing a large capability for rapid fluid flow inflation and deflation of the actuator for enabling fast response, i.e. short cycle times. Multiple relatively inextensible strands are anchored to these end fittings and initially extend between them as straight lines oriented at a pitch angle in the range from 60° to 120° forming a network of tension elements constraining the actuator shell and connecting together said two end fittings.
These tension element strands define a ruled surface having the shape of an hyperboloid of revolution when the actuator is in its initially deflated (elongated or extended) position. These strands serve to constrain a resilient, flexible, stretchable, tubular, elastomeric shell of the actuator which extends between the end fittings and is secured to both end fittings in air-tight relationship. This elastomeric shell stretches and bulges outwardly into nearly a spherical surface of revolution when the actuator is in its inflated (contracted or retracted) position, thereby causing the tension strands to bow outwardly away from the axis pulling the two end fittings towards each other for providing axial contraction displacement. By virtue of the relatively large internal diameter of the two end fittings there is provided at least one relatively unrestricted port through which fluid can readily pass for rapidly inflating and deflating the elastomeric shell for efficient operation of this tension actuator at a high cyclic rate of operation.
In one embodiment, there is a single central crossing point for each of the respective tension strands, and this crossing point stabilizes the strands during cyclic inflation and deflation of the tension actuator. One such single-crossing point tension actuator is described having five strands oriented at a left-sense 72° pitch angle and five other strands oriented at a right-sense 72° pitch angle, thereby forming a total of five such crossing points. Another such single-crossing point tension actuator is described as having four strands oriented at a left-sense 90° pitch angle and four others at a right-sense 90° pitch angle, thereby forming four such crossing points.
In accordance with the present invention in one of its aspects there is provided a fluid-driven, tension actuator axially contractible upon inflation by fluid under pressure for converting fluid pressure energy into axial contraction displacement, comprising: a pair of axially aligned and axially spaced ring-shaped end fittings, a tubular resilient, flexible, stretchable, elastomeric shell extending between said end fittings and being secured in air-tight relationship to both of said end fittings, a multiplicity of relatively inextensible, flexible strands extending between said end fittings and each being effectively anchored to both of said end fittings. These strands may be bonded to the exterior surface of said tubular shell, with a first plurality of said strands extending as straight lines and each being oriented at the same first pitch angle when the end fittings of the actuator are at their maximum axial displacement from each other, and with a second plurality of said strands extending as straight lines and each being oriented at the same second pitch angle when the end fittings of the actuator are at said maximum axial displacement from each other. The first and second pitch angles have the same absolute value, but the second pitch angles are of the opposite sense from said first pitch angles. The absolute value of said first and second pitch angles are in the range from 60° to 120°, said strands all being straight lines when the end fittings of the actuator are at their maximum axial displacement from each other and each lying along a respective straight line generator element of an hyperboloid of revolution bounded at its opposite ends by said end fittings. At least one of said end fittings provides a passage therethrough communicating with the interior of said elastomeric shell for enabling said shell to be inflated and deflated, and said elastomeric shell upon inflation with fluid under pressure stretches into a generally spherical surface of revolution with said strands each bowing outwardly away from the axis approximating arcs of a great circle pulling said end fittings toward each other for producing axial contraction of the actuator.
As used herein, the term "cycle of operation" or "cycle" means an inflation plus a deflation (or conversely means a deflation plus an inflation) such that at the completion of the cycle, the tension actuator has returned to the same state as at the initiation of the cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further objects, features, aspects and advantages thereof will be more fully understood from a consideration of the following description taken in conjunction with the accompanying drawings in which like elements are designated with the same reference numerals throughout the various views. Also, the various elements are not necessarily illustrated to scale in order to enhance understanding and more clearly show and describe the invention.
FIG. 1 is a side elevational view of a fluid-driven tension actuator in the form of an hyperboloid of revolution as a ruled surface, with a pitch angle of 120° and with the straight line elements thereof pitch in both senses (left-sense and right-sense).
FIGS. 2A, 2B, 2C and 2D are a series of diagrammatic side elevational views showing the effect of changes in pitch angle.
FIG. 3 is a side elevational view of a tension actuator generally similar to that shown in FIG. 1 and illustrating both the Extended and Contracted Positions of a tension actuator embodying the present invention for comparing their relationships in a single view.
FIG. 4 is an enlarged side elevational view of another fluid-driven tension actuator embodying the invention. This view is enlarged to four times actual size, and the left end fitting and an adjacent portion of the tubular elastomeric shell are shown in section for illustrating features of construction.
FIG. 5 is a partial sectional view taken along the line 5--5 in FIG. 4 showing a portion of the slotted strand-mounting ring.
FIGS. 6A and 6B show the actuator of FIGS. 4 and 5 at actual size. FIG. 6A shows this actuator fully inflated in its axially contracted state, and FIG. 6B shows it fully deflated in its axially extended state, with the resultant stroke length being indicated.
FIG. 7 is a performance curve plotted from data obtained by testing a tension actuator constructed as shown in FIGS. 4-6.
FIG. 8 is a diagrammatic side view illustrating another tension actuator embodying the invention and being shown in its axially elongated, deflated state. This actuator has five pairs of tension elements all lying at a pitch angle of 72°, with five of them oriented in a left-sense and the other five in a right-sense, and all of them defining a hyperboloid of revolution as a ruled surface. It is to be noted that these tension elements or strands have single crossing points located at their mid-length, thus advantageously stabilizing their positions on the elastomeric shell (which is omitted for clarity of illustration).
FIG. 9 is a diagrammatic end view of the actuator of FIG. 8.
FIG. 10 is a diagrammatic side view illustrating a tension actuator generally similar to that shown in FIGS. 8 and 9, except that in FIG. 10 the actuator has four pairs of tension elements all lying at a pitch angle of 90°. Four of them are oriented in a left-sense and four are oriented in a right-sense. They define a hyperboloid of revolution as a ruled surface, and they have single-crossing points located at their mid-length, thus advantageously stabilizing their positions.
FIG. 11 is a diagrammatic end view of the actuator of FIG. 10.
FIG. 12 shows an alternative arrangement of the five pairs of tension strands for obtaining the same pattern as the tension strands in FIGS. 8 and 9. The tension elements in FIG. 12 are arranged as isosceles triangles. At the vertex of pairs of such triangles, two of the strands are half-looped around each other providing a mid-length connection as a form of a mid-length crossing point.
FIG. 13 shows an alternative arrangement of the four pairs of tension strands for obtaining the same pattern as in FIGS. 10 and 11. In FIG. 13 the tension strands are arranged as isosceles triangles. Two of the strands are half-looped around each other at the vertex of a pair of such triangles, providing a mid-length connection as a form of mid-length crossing point.
FIG. 14 is a side view of the tension actuator of FIG. 10 or 13, showing the reinforced elastomeric shell and the end fittings.
FIG. 15 shows the actuator of FIG: 14 fully inflated and axially contracted, indicating the stroke length.
DETAILED DESCRIPTION
In FIG. 1 the fluid-driven tension actuator 20 is shown in its deflated (axially elongated or axially extended) state. This actuator 20 has a pair of rigid, ring-shaped end fittings 22 which are axially aligned and axially spaced. It is to be noted that these end fittings 22 each have a relatively large diameter D and a relatively large radius R compared to the overall size of this actuator 20. A tubular, resilient flexible, stretchable, elastomeric shell 24 extends between these end fittings and is secured to them both in air-tight relationship, for example, by bonding or by wrapping a serving tightly around each end of this shell, as will be explained further below. A multiplicity of relatively inextensible, flexible strands 26 extend as tension elements between the end fittings 22, being secured at anchoring points 28 to the respective end fittings. The anchoring points 28 are located at uniformly spaced positions around the circumference of the respective end fittings 22. There are the same number of these anchoring points 28 on each end fitting, and the actuator 20 is symmetrical end-to-end.
The term "strand" is intended to include an elongated, flexible tension element made from a desired material, for example such as a fiber, and which is strong, resiliently flexible and relatively inextensible. Thus, for example, a "strand" may mean a cord, string, filament, monofilament, line, a metal wire (for example of spring alloy), and having a high flexing fatigue resistance. Suitable plastic material for fabricating such a strand is "Dacron" polyester or "Kevlar" polymer.
The tubular shell 24 is made of a suitably resilient, flexible, stretchable elastomeric material, for example, such as neoprene rubber or polyurethane. The interior of this hollow shell 24 provides a chamber which is air-tight and inflatable with a suitable fluid under pressure, for example such as compressed air or hydraulic liquid.
The rigid end fittings 22 are made of a strong, light-weight material, for example such as aluminum, polycarbonate, "Debrin" acetal resin, nylon, or high density polypropylene. Each of these end fittings includes attachment or fastening means 29, for example as will be explained later with reference to FIG. 4, for connecting the fittings 22 to associated members forming parts of a machine or system to be driven by this actuator. Each of these fittings has a large diameter axial fluid passageway 30 communicating with the fluid chamber within the interior of the tubular elastomeric shell 24.
In this actuator 20, as shown in FIG. 1, there are twelve pairs of the tension element strands 26 all having a pitch angle of 120°. One of the strands in each pair is pitched in a left-sense, and the other strand is pitched in a right-sense. In other words, starting at one of the points 28 where a pair of the strands 26 are anchored, for example starting at point "a" and looking in an axial direction toward the other end of the actuator, it will be seen that one of the pair of the strands which is anchored at point "a" is sloping toward the left of the line of view and the other is sloping toward the right of the line of view.
These tension element strands 26 extend as straight lines in FIG. 1 defining a hyperboloid of revolution as a ruled surface. The axis 32 of revolution of the hyperboloid surface defined by the straight strands 26 is the longitudinal central axis of the actuator 20. These twenty-four strands 26 lie adjacent to the outer surface of the tubular shell 24. It is to be understood that none of these straight strands 26 is parallel with the axis 32 and that the actuator 20 is in its deflated axially extended position.
The meaning of "pitch angle" or "angle of pitch" will now be explained. The "pitch angle" is the angular difference with respect to the axis 32 between the positions of the two ends of one of the straight line elements 26. For example, starting at point "b" and proceeding along a straight line 26 to the point "c" will produce a change in angular position of 120° with respect to the axis 32. In other words, going from "b" to "c" will result in going one-third of the way around the axis 32, and one-third of 360° equals 120°.
The effect of changes in pitch angle is illustrated by comparing the four FIGS. 2A-D. When the pitch angle is reduced to zero, the hyperboloidal surface entirely disappears. The surface has been changed into a right circular cylinder, more commonly called a cylindrical surface of revolution. With a pitch angle of 90°, as shown in FIG. 2B, the hyperboloid surface has a gentle saddle shape. With a pitch angle of 120°, as shown in FIG. 2C, a deeper saddle shape is formed. When the pitch angle is increased to 180°, the hyperboloid surface again entirely disappears. The surface has now been changed into two conical surfaces axially aligned and touching tip-to-tip. In accordance with the present invention the pitch angle of the hyperboloid surface defined by the straight-line tension elements when the tension actuator is in its fully extended position lies within the range from 60° to 120°.
Inviting attention to FIG. 3, it will be seen that when the chamber within the elastomeric shell 24 is fully inflated with fluid 34, for example compressed air, supplied through the passageway or port 30 from a suitable source (not shown) of controllable pressure connected to the end fitting 22 at the left in FIG. 3, then the actuator 20 contracts in an axial direction. It is to be understood that the end fitting 22 at the right is connected to part of a machine or system (not shown) being driven by the actuator, and thus the fluid passageway in this end fitting is effectively plugged for preventing loss of the fluid 34 which is inflating the actuator. The fully extended position of this end fitting at the right is shown in dashed outline at 22", and its fully retracted position is shown in full lines at 22'.
The elastomeric shell 24 stretches at full inflation to approximately a spherical surface 36 having a diameter of about 2D, where D is the diameter of an end fitting 22. The straight-line strands 26 deform into the shape of great circles of the spherical surface 36. The full stroke is 0.37D.
It is noted that in the fully extended position of this actuator 20 the hyperboloidal surface 38 has a central narrowed waist region 39 with a diameter of D/2.
FIGS. 4, 5, 6A and 6B show one practical way to construct a fluid-driven tension actuator 20A embodying the present invention. This actuator 20A is similar to the actuator 20 of FIGS. 1-3, except that this actuator 20A has twenty pairs of tension element strands 26 each at a pitch angle of 120°. The end fittings 22, for example of aluminum, include fastening or attachment means 29 in the form of pipe threads, for example with an outside diameter (O.D.) of one-half inch and a pitch of twenty threads per inch located on an axially extending outwardly projecting cylindrical end section 40 of the ring-shaped fitting 22. An end of the tubular elastomeric shell 24 is telescoped over an axially extending inwardly projecting cylindrical section 42 of the fitting 22, and this latter section includes two circumferential grooves 44 for making an air-tight seal with the shell 24 as will be explained later.
Between the two cylindrical sections 40 and 42 each end fitting 22 includes an annular ring-like shoulder 45 having twenty uniformly spaced keyhole-shaped slots 46 in its periphery as seen more clearly in FIG. 5. The tension strands 26 are formed by lacing one continuous strand back and forth for producing an effective pitch angle of 120° by passing this one continuous strand through preselected slots 46 in the respective rings 45. In order to protect the strands 26 against abrasion in their mounting slots 46, the enlarged lower end of each slot is fully rounded on both sides of the ring 45 for providing bell mouth configurations as indicated at 48 in FIG. 4. After all of the tension strands 26 have been laced into place, they and the underlying end of the tubular shell 24 are secured in place by tightly wrapping with several adjacent turns of a wound serving 50 positioned directly over the grooves 44. This tight wrapping 50 produces an air-tight connection between the shell 24 and the grooved inner section 42 of the end fitting 22. In order to avoid abrasion of the tubular shell 24, the exterior surface of this inner section 42 is rounded on its inner end at 52 where the tubular shell passes over it. The fluid passageway 30 has a clear bore with a diameter of 0.375 of an inch. The active length "L" between the inner ends of the inner sections 42 of the respective end fittings is one inch, when the actuator is fully extended as shown in FIGS. 4 and 6B, and the overall extended length between the extreme outer ends of the end fittings is 2.375 inches. After the wrapping 50 has been applied, the respective anchoring points 28 for the strands 26 are located at the inner edge of each of these wrappings.
FIGS. 6A and 6B show this actuator 20A in its actual size. FIG. 6A shows it in the axially contracted position when fully inflated, and FIG. 6B shows it in the axially extended position when fully deflated. The resultant stroke length is seen by comparing FIGS. 6A and B.
This actuator 20A was inflated with compressed air at controlled pressures and its stroke and the generated axial contraction forces under the various conditions were measured as follows:
EXAMPLE I: AT ZERO STROKE POSITION, AT VARIOUS PRESSURES
______________________________________PRESSURE: FORCE: STROKE POSITION:P.S.I. POUNDS IN INCHES______________________________________ 5 29 0.010 51 0.0015 69.5 0.0020 85 0.0025 100.5 0.0030 114.5 -0.0002______________________________________
EXAMPLE II: AT VARIOUS STROKE POSITIONS, ALL AT 30 P.S.I.
______________________________________ STROKE EFFECTIVEPRESSURE FORCE: POSITION: IN AREA:P.S.I. POUNDS INCHES IN SQ. INS.______________________________________30 117.5 -0.0009 3.9430 79 -0.050 2.6330 53.5 0.100 1.7830 33.5 0.150 1.1230 16.5 0.200 0.5530 4.0 0.245 0.13______________________________________
The effective area at any given stroke position (stroke contraction) as listed in Example II is called "A(x)" and is calculated in accordance with the following formula: ##EQU1## where "F(x)" is the measured force which is generated by the tension actuator at each given stroke position.
FIG. 7 is a plotted curve 60 of the data from Example II for showing the performance of this tension actuator 20A. The stroke values are plotted along the abcissa to the left of the origin "0", because the zero position is considered as being full extension, and the stroke is thus a contraction from the zero position.
In this actuator 20A the O.D. of the sections 42 onto which the tubular shell 24 is mounted is 0.500 of an inch. The thickness of this elastomeric shell is about 0.020 of an inch. Thus, the outside diameter D at the end fitting is 0.500+2x (0.020)=0.540 of an inch. The measured outside diameter of the inflated spherical position of the shell in FIG. 6A is 1.03 of an inch.
In FIG. 3 the theoretical diameter of the spherical shell upon full inflation is 2D, which in this example would be a value of 2×0.540=1.080 of an inch. Thus, it is seen that this actuator achieved ninety five percent of the theoretical maximum. ##EQU2##
In this actuator 20A the strands 26 were not bonded to the shell 24.
A number of interesting novel features of such a tension actuator are seen from a mathematical analysis thereof as follows:
F(x)=Measured Gauge Pressure ·A(x) (5)
This equation repeats equation (2), namely, the force F(x) measured in pounds at any given axial contraction "x" in FIG. 7 is equal to a product of the gauge pressure of the internal fluid times the effective area at that contraction "x".
The total effective volumetric displacement V(x) at any given "x" is the area under the plotted curve 60 from the origin to that value of "x", as will be seen from the following analysis: ##EQU3##
Therefore, the effective volumetric displacement can be calculated from the plot in FIG. 7.
By differentiating both sides of equation 8, it is now seen that: ##EQU4##
In other words, at any given axial contraction position "x" with a generated force at that position being F(x) and the measured gauge pressure at that position being P(x), then an incremental axial contraction is proportional to a corresponding incremented change in displacement volume.
Conversely, as seen from equation (11), the greater the effective incremental change in volume produced by an incremental axial contraction, then the greater will be the force generated by supplying a given fluid pressure 34 (FIG. 3). Thus, this last equation (11) establishes a figure of merit for such tension actuators. In order to generate larger forces for a given applied fluid pressure 34, the desire is to achieve the greatest change in effective displacement for each given incremental contraction over the full range of operation.
The total effective volumetric displacement over the full stroke length is calculated by the total area under the curve to be 0.40 cubic inches.
In the actuator 20B shown in FIGS. 8 and 9 there are five pairs of the tension strands 26 oriented at a pitch angle of 72°. The double row of small circles 46 schematically indicate the keyhole-shaped slots 46 (FIG. 5) in the existing end fittings 22 which have already been described. Thus, as seen, in order to achieve a pitch angle of 72°, the continuous strand which is used to produce the five pairs of strands 26 is laced through every fourth one of the twenty slots 46. The anchoring points 28 are indicated.
It is noted that a single-crossing point 62 between each two neighboring struds and located exactly at the mid-length of the strands 26 is achieved when the number of pairs of strands is sufficiently small that ##EQU5## The total number of crossing points 62 is five, but only three are seen in FIG. 8 because the other two are located on the other side of the elastomeric shell 24.
In the actuator 20C, shown in FIGS. 10 and 11, there are four pairs of strands oriented at a pitch angle of 90°. This pitch angle is achieved by lacing through every fifth one of the twenty mounting slots 46 in the end fittings.
The total number of mid-length crossing points 62 in this actuator 20C is four.
The advantage of these single mid-length crossing points is that they stabilize the location of the strands 26 relative to the elastomeric shell 24. Moreover, by virtue of having relatively few of the strands in accordance with formula (12), the shell is able more freely to expand into the desired spherical shape 36 as desired for achieving the 2D theoretical maximum spherical diameter.
As shown in FIGS. 12 and 13, respectively in the tension actuators 20D and 20E, two continuous strands 26A and 26B can be laced to form the five pairs and four pairs of strands 26, respectively. These two continuous strands 26A and B are half-looped, one around the other, at the mid-points 62 of the respective strands thus producing isosceles triangular patterns. The lacing assembly operation can be achieved faster when simultaneously using the two strands 26A and B as shown on FIGS. 12 and 13. Also, there is the advantage that somewhat more flexibility for expansion of the shell 24 is achieved by the half-loop mid-length crossings 62 which effectively form small hinges at the equator of the sphere 36 (FIG. 15).
FIGS. 14 and 15 show the actuator 20E of FIG. 13 or 20C of FIGS. 10 and 11 in axially extended and contracted positions, respectively, with its elastomeric shell illustrated as having domelike protrusions 64 in the lozenge-shaped (diamond-shaped) regions 66 between the strands 26 and in the isosceles-triangular-shaped regions 68 between these strands. The mid-length crossing points 62 may be formed as straight crossings 62 (FIGS. 10 and 11) or as half-loop crossings 62 (FIG. 13).
In all of the various tension actuator 20, 20A, 20B, 20C, 20D and 20E the elastomeric shell 24 itself is not reinforced when the actuator is intended for low pressure operations, i.e. at 15 p.s.i. gauge and below.
However, for high pressure operations up to 125 p.s.i. gauge or even higher then the elastomeric shell 24 is reinforced. This reinforcement may be provided in any one of several ways. For example, if the shell 24 is formed of polyurethene, then a molded grid-like square pattern of tiny straight ribs defining squares each having a side length in the range from 1/16th of an inch to 1/4 of an inch is integrally molded with the shell 24 onto either its outer or inner tubular surface for reinforcing it while still providing the desired elastic stretchability of the thin shell. This square pattern is preferably oriented at a 45° angle for approximately aligning with the expanded lozenge-shaped regions 66 in FIG. 15.
Alternatively, the reinforcement may be a separately molded plastic grid of the same pattern size as for an integrally molded grid. This separately molded grid is fitted over the elastomeric shell 24 for reinforcing it, and this grid is located beneath the strands 26.
Alternatively, the reinforcement may be a knitted sleeve for example as described in the recently filed patent application Ser. No. 754,523; Filed: July 12th, 1985 in my name as inventor.
In summary, tension actuators embodying the present invention have a fast response, high frequency cyclic response capability with high efficiency and low-fatigue characteristics, and they are designable for either low or high pressure ranges of operation and they produce a relatively long and powerful stroke even at relatively small size as shown in FIGS. 4-7 and related data and analyses. It is to be understood that with larger D sizes, as defined herein, the effective forces generated will increase proportionately to D 2 . Thus, relatively powerful axial thrusts can be generated by moderately sized actuators operating at "shop air" pressure ranges, namely, below about 125 p.s.i. gauge.
Since other changes and modifications varied to fit particular operating requirements and environments will become recognized by those skilled in the art for the various fluid-driven tension actuators the invention is not considered limited to the examples chosen for purposes of illustration, and includes all changes and modifications which do not constitute a departure from the true spirit and scope of this invention as claimed in the following claims and equivalents to the claimed elements.
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A fluid-driven tension actuator has a pair of end-connection, ring-shaped fittings of relatively large internal diameter with multiple inextensible strands anchored to them and initially extending between them as straight lines oriented at a pitch angle in the range from 60° to 120° forming a network of tension elements constraining the actuator shell and connecting together said two end fittings. These tension element strands define a ruled surface having the shape of an hyperboloid of revolution when the actuator is in its initially deflated (elongated or extended) position. These tension element strands serve to constrain the resilient, flexible, stretchable, elastomeric shell of the actuator which stretches and bulges outwardly into nearly a spherical surface of revolution when the actuator is in its inflated (contracted or retracted) position. By virtue of the relatively large internal diameter of the two end fittings there is provided at least one unrestricted port through which fluid can readily pass for efficient operation at a high cyclic rate of operation. In one embodiment, there is a single central crossing point of the respective strand elements and this crossing point stabilizes the strands during cyclic inflation and deflation of the tension actuator.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process of hydraulic seaming together of layers of nonwoven fabrics in one or two directions at a time.
2. Prior Art
Spunlacing or hydroentanglement using water jets has been used to combine layers of filament or fiber webs in continuous processes for many years. Layers of webs are manufactured using most standard spunlace equipment disclosed in prior process patents describing entangling systems, such as in Evans U.S. Pat. No. 3,485,706, incorporated begin by reference.
Hydroentangled nonwovens produced in roll form are used in the further manufacture of many products ranging from complex articles such as clothing to less complex items such as filters, filtration bags, pillow ticking, upholstery backing, etc. Bonding in selected areas is generally involved in the production of products. Seam formations used to join layers together are normally made by sewing, by use of adhesives, by thermal bonding, or by ultrasonic sewing.
Sewing produces a strong joint but is typically a slow process and leaves behind minute separations at the thread joints. Thermal bonding is suited to high speeds and automated systems but nonwovens made of certain non-thermoplastic materials, such as cotton or rayon cannot be thermally bonded due to their intrinsic characteristics. Thermal seaming of thermoplastic fabrics typically results in a stiff seam, since the seam line is like a weld. Adhesive bonding adds to the cost of the fabric due to the raw materials and additional processing equipment and processes. Further, adhesive seams can also be stiff, depending upon the type of adhesive utilized. Ultrasonic bonding or sewing has speed limitations and its efficiency is greatly influenced by the basis weight of the fabrics. Also, ultrasonic sewing is subject to the same fabric thermal property limitations as thermal bonding.
There is limited discussion in the art on using water jets to join fibrous webs together in a selected pattern. U.S. Pat. No. 4,970,104 describes using a hydroentangling process to pattern bond previously unbonded fibrous batts, as an alternative to thermal pattern bonding. U.S. Pat. No. 3,514,455 refers to the manufacture of a quilted batting where a thermally bonded polyester continuous filament fabric is joined to a staple fiber batt by means of an all over pattern of spot bonding by water jets. The quilting is achieved by forming closely spaced parallel rows of hydraulically formed “stitches” along the length of the stacked layers in the direction of travel of the fabric along a belt of a machine used to create the parallel rows of stitches.
The production of load bearing seams, such as for garment or upholstery manufacture, requires a significantly stronger seam than required for spot bonding or quilting. Preparation of quilt padding is intended primarily to hold layers in proximity and prevent interlayer slippage and bunching. Seams in apparel and upholstery are required to withstand significant stresses, applied in multiple directions, without failure.
To date there has not been proposed a process for seaming together in the direction of travel and/or in the cross direction two layers of nonwoven fabric, with the seams being suitable for use in an environment requiring softness and suppleness of the seam, in combination with a suitable degree of strength of the bond, such as when an end seam is formed in, for example, a pillow case.
SUMMARY OF THE INVENTION
According to the invention there is provided a process for seaming together at least two layers of nonwoven fabric, with the individual layers being prebonded. Manufacture of the seams is contemplated for both the direction of travel of the webs in the seaming process and/or in the cross direction, as the webs are passed through a hydroentangling station. It is an aspect of the invention that the seams produced are sufficiently strong as to withstand the stresses and tensions normal to construction seams in anticipated end use applications. It is a further aspect of the invention that the seams thus provided would be soft and supple and free of any holes, needle marks, fused areas or chemicals. It is a still further aspect of this invention that the seam width and design would be infinitely variable and that the seams would be produced continuously. It is yet another aspect of this invention that adjacent product pieces defined by the seam perimeters could be separated from each other in a continuous or batch cutting or slitting process where the seam lines provide the cut lines for such processing.
In another aspect of the invention, a nonwoven fabric assembly is provided, in which the assembly comprises at least a pair of superimposed layers of consolidated nonwoven fabrics. The assembly comprises at least one line of seam between the layers, with the seam being characterized by a concentrated and continuous line or sector of entanglement of the fibers between the fabrics, providing a durable and high strength seam, which can exceed the tensile strength of the fabric. The seam is additionally characterized as being highly flexible and devoid of any other extraneous bonding aids, such as thread, adhesives, and relatively stiff thermal bonds. Typically, seams of the present invention would preferably occupy less than about 10% and most preferably 5% of the surface area of at least one of the joined fabric layers. The remainder of the surface area of the joined layers would generally be free of seams or constructive stitches according to the methods described for the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a first general layout for the continuous assembly of nonwoven fabric layers which are seamed together using high pressure water jets of a hydroentangling machine, the seam lines here being shown formed in the direction of travel through the machine.
FIG. 2 is a second general layout for the continuous assembly of nonwoven fabric layers using high pressure water jets of a hydroentangling machine, the seam lines here are being shown formed not only in the direction of travel through the machine but in the cross direction as well.
FIG. 3 is a side view through a hydroentangling station showing a belt of templates used to produce a desired seam lane pattern.
FIG. 4 is a side view through a hydroentangling station showing a pattern drum used to define seam lines.
FIG. 5 is a cross sectional view showing how the seam strength was tested using the Instron device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in greater detail, there is illustrated therein the methodology or process of the present invention for continuous seaming together of nonwoven fabric layers using high-pressure water jets of a hydroentangling station.
The process starts with at least two separate webs of consolidated nonwoven fabrics, which can be supplied, for example, from separate rolls. The term “consolidated” as used herein refers to a web comprising fibers and/or filaments of natural and/or synthetic composition, wherein the web has been rendered coherent and dimensionally stable by a process other than weaving. The term “fibers” as used herein shall be deemed to include individual fibers as well as continuous filaments.
The preferred method of consolidation is by hydroentanglement, in which a web loose fibers is deposited upon a porous support, and the web is passed beneath one and preferably a series of manifold having a large number of small openings supplied with water under high pressure, creating fine high velocity jets which impinge the web and entangle the fibers. The details of this process are described in the above noted Evans U.S. Pat. No. 3,485,706 incorporated herein by reference. While hydroentangled or so-called spunlace fabrics are preferred, other fabrics, for example, include webs which have been thermally bonded, chemically or adhesively bonded, or mechanically bonded.
The seamed fabric can be precision slit along the seam lines to produce long segmented tubular assemblies that can by further cut to produce useful items, such as pillow cases. In the specific example illustrated in FIG. 1, the formed straight tubular sections could be slit apart along the seam lines to create bag filters for industrial filter houses.
Further, surface patterned or printed fabrics could be seamed together with the patterned or printed sides facing one another with the finished piece being turned inside out, hiding the cut finished edge of the seam as is standard for many apparel and furnishing applications.
A side view of a water jet station 14 used in the seaming process is presented in FIG. 3 . The plurality of water jets 16 in the station 14 can be specifically positioned to produce seaming in a pre-determined pattern, either simple linear 10 or two-directional 12 (along the line of motion through the station 14 and/or thereacross, as illustrated).
In this embodiment of the seaming process, barrier templates 18 are created which have a predefined pattern of openings 20 therethrough, the openings 20 defining the desired seam lines to be created in the underlying stacked webs 20 , 24 being processed through the hydroentangling station 14 . The templates 18 are joined together to create a belt 26 , one run 28 of which is positioned under jets 16 normally used for hydroentangling an entire web so that portions of the stacked webs 22 , 24 passing beneath the templates 18 are protected from the seaming jets 16 . Thus, only sections of the stacked webs which do not underlie the templates 18 (or underlie the openings 20 therein) are accessible by the jets 16 to create entangled seam lines therealong. In this manner, a hydroentangling station 14 can simply be converted into a water jet seaming station 14 .
FIG. 4 shows an example of an alternative porous drum 30 which may be used to define the seams lines.
In one prototype tested, two webs 22 , 24 were seamed together using a set of water jets 16 with 200 micrometer (0.0787″) orifices at a density of 33.33 jets 16 per inch, arranged in a predetermined seaming pattern. The jets 16 were operated at 4000 psi to achieve a level of entanglement which has strength characteristics necessary for seaming.
In another prototype tested, a rectangular template 18 was used under a 12 jet, full width entangler 14 , using jets 16 with 0.005″ orifices at a density of 50 jets 16 per inch, the jets 16 operating under the following pressure sequence—100, 100, 100, 400, 400, 400, 1600, 1600, 1600, 1600 (psi).
The base fabrics used in these trials were 1.2 osy consolidated spunlace of 75% rayon and 25% polyester, or 2 osy spunlace of 88% rayon and 12% polyester, the fibers used in creating the spunlace being of 1.5 denier and being approximately 1.5 inches in length.
The invention anticipates the use of any nonwoven base fabric, staple fiber or continuous filament, preferably bonded using any known methods including chemical, thermal, through-air and hydroentangling.
Delving into greater detail, the most preferred fabric embodiment for use in the process, as stated above, is hydroentangled staple fiber fabric or hydroentangled continuous filament fabric. The basis weight range of the substrate fabrics is 0.25-4 osy with 0.5-3.0 osy being most preferred. The denier of the staple fibers or continuous filaments in the fabrics are preferably of 1-3.5 denier. Selection of fabrics to be seamed is necessarily based on end product requirements and the process is not limited to seaming together of like fabrics only, although extremely well suited to such use.
For high pressure jets 16 specifically selected and predeterminedly arranged in patterns for predefined patterns of seaming of fabric layers 22 , 24 together, the orifices are most suitably in the range of 0.01-0.10″, at a density of 20-50 jets 16 per inch. Jet 16 pressures above 1000 are recommended with pressures greater than 3000 being most preferred, dependent upon the type and weight of fabric substrates to be seamed together. For the embodiment utilizing the template 18 to block jets 16 in the normally full width entangler 14 , adjusting the final jets 16 to greater than 1000 psi is preferred, with greater than 1500 psi being most preferred.
Using the process (method) described, layers 22 , 24 of web are selectively bonded along specific lines or sectors to produce a seamed nonwoven structure that can in turn be used to produce finished nonwoven products. After seaming, specialty chemicals, such as fire retardants, pigmented latexes, etc., could be applied, as required. The seamed webs would then be dried. After drying, precision slitting and cutting along the seam lines created would be accomplished to produce a finished products, such as pillow cases.
Using high pressure jets 16 positioned at predetermined distances from one another produces seamed webs such as shown in FIG. 2 . When webs of this example are precision slit in the seam line, a tubular nonwoven assembly is produced which has two elongate edges and one end seamed together. This tubular assembly has many useful applications. Manufacture of pillow cases, as one example, is simplified. The pillow case can be made by cutting along the seam lines and only requires sewing of a single end seam.
The machinery used to produce the examples described above was a standard hydroentangling system 14 capable of emitting water from the jets 16 at high pressure. Two entangled and imaged webs 22 , 24 were unwound into the spunlacing (hydroentangling) machine 14 in a continuous manner at 40 feet per minute, with imaged surfaces (if desired) facing each other (on the inside upon seaming together).
Once the layers 22 , 24 are seamed together and cut apart along the seam lines, the article is turned inside out to expose the imaged surfaces. In one example, continuous filament polyester webs weighing 4.6 oz/sq. yd. were entangled and patterned to a corduroy appearance using a specially designed image transfer device such as a porous roll having a three dimensional surface. Two rolls of such continuous filament web were unwound into a single station entangler 14 with the webs 22 , 24 stacked upon one another for seaming in selected areas or lines only.
The two webs 22 , 24 were unwound in a stacked configuration and seamed together using high pressure water jets 16 running at 4000 psi. The particular jets 16 used in the application were drilled with 200 micron orifices spaced 33.33 jets 16 per inch in areas where the creation of seam lines was desired. Selected areas under the row of jet 16 orifices were “blanked” using the templates 18 described above to provide areas in the layers that were unseamed, in a manner similar to that described in connection with FIG. 2 .
It will be understood that the strength of a seam must be significantly greater than the strength required for stitching which does not act as a seam. For example, stitches required to produce a quilting effect are usually less dense inasmuch as the quilting is typically used to assure that layers cannot shift relative to one another, rather than joining two layers together in an area where increased duress is applied, such as upon stuffing of a pillow. Thus, a bond strength greater than that necessary for quilting must be achieved by the seaming process.
The bond strength in the areas seamed together by the method disclosed was measured by an Instron device, as illustrated in FIG. 5 . The strength of a 1 inch by 1 inch seamed area 35 averaged 5.77 lbs. The strip tensile strength (cross-direction tensile strength) of the nonwoven filament webs that were layered was an average 12.42 lbs. Use of a single orifice jet 16 strip at 4000 psi produced the 5.77 lbs. bond strength. Use of multiple jet 16 strips and/or higher pressures could easily be incorporated to increase the bond strength.
In the test shown in FIG. 5, the strength of a strip of seamed material having layers 22 and 24 and a central seam 35 is employed. The ends of the layers 22 and 25 are moved apart at a constant rate, while the load in pounds or gram is recorded. The seam strength is determined by recording the maximum load before the seam fails. The tensile strength of the individual layers can be evaluated using the same method. Since the seam is formed solely by fiber entanglement, seam strength is directly related to the degree of entanglement, and hence, the energy employed in the hydraulic seaming process.
An added advantage is provided in that formation of seam lines with the high pressure water jets 16 provides layer to layer bonding along lines or sectors without the minute unbonded separations that occur in sewn seams between the threaded joints.
In general terms, the strength of the seam will be determined by a number of factors, including hydraulic surface applied to the seam line, the forming surface on which the seam is formed, the width of the seam, and to some extent, the basis weight and nature of the fabric being seamed. Adequate seam strength can be defined as the tensile strength of the seam relative to the cross-directional tensile strength of the fabric, if the seams run in the machine direction of the fabric. Depending on end use requirements, the seam has a tensile strength which is greater than 30% of the cross-directional strength of a single layer of the fabric and more preferably greater than 50% of said tensile strength.
A number of sample products were produced using templates 18 to protect sections of the underlying webs 22 , 24 from the effects of the high pressure water jets 16 . During the sampling, the webs 22 , 24 were fed into the hydroentangling system 14 and a simple template 18 , rectangular in shape was fed into the hydroentangling system 14 . The hydroentangling station 14 was set up with the following jet 16 pressure sequence—100, 100, 100, 400, 400, 1600, 1600, 1600, 1600, 1600 psi. The forming wire 40 was run at 25 feet per minute. The jets 16 used for all treatments had 0.005″ drilled orifices, spaced 50 per inch.
The product was bonded at the edges of the template 18 . Each laminate layer 22 , 24 was a pre-entangled and patterned 1.2 oz/sq. yd 75% rayon and 25% polyester spunlace product. Both the rayon and polyester fibers were 1.5 denier and approximately 1.5 inches long. The bond strength of the hydraulically seamed edge areas of the laminate was found to be stronger than the cumulative bond strength of the nonwovens when added together and the product could easily be converted into a bag or similar article.
Also, while parallel seaming is considered most efficient, it will be understood that provision of the templates (flat or drum form) would allow any seaming pattern to be created.
As described above the seaming process of the present invention provides a number of advantages, some of which have been described above and others of which are inherent in the invention. Also, modifications may be proposed to the process, without departing from the teachings herein. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.
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The method for hydraulic seaming together of two layers of consolidated nonwoven fabric in one or two directions simultaneously provides soft, supple seam lines, along which formed seam lines, cuts can be made for producing bag like articles from the seamed layers, such as, for example, pillow cases, or industrial filters.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates a valve spring retainer and a valve operating mechanism in an internal combustion engine.
[0002] [0002]FIG. 10 is one example of a conventional valve operating mechanism in an internal combustion engine, in which a valve spring retainer 3 is mounted at the upper end of a poppet valve 1 by a pair of cotters 2 , 2 . A valve spring 4 is provided between the lower surface of an outer flange 3 a of the valve spring retainer 3 and a cylinder head (not shown), so that the poppet valve 1 is always energized upwards by the valve spring 4 .
[0003] The numeral 5 denotes a rocker arm which is engaged on the axial end of the poppet valve 1 and which is moved up and down by a rotary cam (not shown), so that the poppet valve 1 is opened and closed.
[0004] The flange 3 a of the valve spring retainer 3 of the valve operating mechanism has a horizontal lower surface perpendicular to an axis of the valve spring retainer 3 , and is adapted to contact the upper surface of the valve spring 4 when the valve spring 4 is equipped.
[0005] It is inevitable to wear the lower surface of the flange 3 a of the retainer 3 owing to relatively rotational or radial movement of the valve spring 4 caused by vibration when the poppet valve is seated.
[0006] Especially, in an automobile engine which is accelerated or decelerated frequently, as illustrated in FIG. 11, when the valve spring 4 is compressed, the uppermost winding is twisted outwards as shown by a downward arrow, or the flange 3 a is bent upwards by reaction force to compression as shown by an upward arrow when the valve spring 4 is compressed.
[0007] In the conventional valve spring retainer 3 in which the lower inner surface of the flange 3 a is horizontal, the inner upper circumference of the first winding which is horizontal at the upper end of the valve spring is engaged with the lower surface of the flange 3 a , so that a larger surface pressure is applied.
[0008] Thus, as shown in FIG. 12, at the beginning of operation, the lower inner portion of the flange 3 a locally wears, and develops outwards as shown by dotted lines. Especially, in the valve spring retainer 3 made of Al alloy for decreasing weight, wear develops rapidly.
[0009] Also, owing to vibration in opening and closing of the poppet valve 1 or surging in the valve spring 4 , the flange 3 a of the retainer 3 is rotated with respect to the valve spring 4 , thereby causing contact surfaces to wear away. Especially, in the Al alloy valve spring retainer 3 for lightening, wear to the valve spring retainer 3 becomes larger.
[0010] As wear becomes larger, setting load of the valve spring 4 becomes smaller to decrease the maximum rotation speed of surging, thereby decreasing engine performance. Depending on degree in wear, it becomes necessary to replace the retainer 3 with a new one.
SUMMARY OF THE INVENTION
[0011] In view of the disadvantages in the prior art, it is an object of the present invention to provide a valve spring retainer in which the lower surface of a flange is modified in shape to decrease wear, thereby increasing durability and reliability.
[0012] It is another object of the present invention to provide a valve operating mechanism of an internal combustion engine in which a valve spring retainer is prevented from rotation with respect to a valve spring to keep wear of the contacting surfaces at minimum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The features and advantages of the present invention will become more apparent from the following description with respect to embodiments as shown in appended drawings wherein:
[0014] [0014]FIG. 1 is a central vertical sectional front view of the first embodiment of a valve spring retainer according to the present invention;
[0015] [0015]FIG. 2 is an enlarged sectional view thereof;
[0016] [0016]FIG. 3 is an enlarged sectional view which shows how to contact the valve spring when it is twisted;
[0017] [0017]FIG. 4 is a central vertical sectional front view of the second embodiment of a valve spring retainer according to the present invention;
[0018] [0018]FIG. 5 is an enlarged sectional view thereof;
[0019] [0019]FIG. 6 is an enlarged sectional view of the third embodiment of a valve spring retainer according to the present invention;
[0020] [0020]FIG. 7 is a front elevational view of the first embodiment of a valve operating mechanism according to the present invention;
[0021] [0021]FIG. 8 is a vertical sectional side view taken along the line A-A in FIG. 7;
[0022] [0022]FIG. 9 is an enlarged front view of the second embodiment of a valve operating mechanism according to the present invention;
[0023] [0023]FIG. 10 is a central vertical sectional front view which shows a conventional valve operating mechanism;
[0024] [0024]FIG. 11 is an enlarged sectional view of a conventional valve spring retainer which shows how to contact a valve spring when it is twisted; and
[0025] [0025]FIG. 12 is an enlarged front view thereof which shows how to wear in an outer flange.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] [0026]FIG. 1 illustrates the first embodiment of the present invention, in which a valve spring retainer 6 according to the present invention is molded by Al alloy such as Al—Si and Al—Cu and formed by T 6 treatment under the Japanese Industrial Standards. The valve spring retainer 6 comprises an inner portion 6 a which surrounds a taper bore 7 , an intermediate portion 6 b and an outer flange 6 c which is engaged with the upper end of the valve spring 4 . As shown in FIG. 2, the lower surface 8 of the outer flange 6 c is slightly inclined by an angle “a” with respect to a horizontal line “H” perpendicular to an axis “L” of the valve spring retainer 6 .
[0027] The angle “α” is determined by material of the valve spring retainer 6 or a spring constant or load to be set of the valve spring. Preferably, an ordinary Al alloy valve spring retainer for a gasoline engine may have an angle of less than 1°.
[0028] The lower surface 8 a of the outer flange 6 c is radially inclined downwards toward the outer circumference. When the valve spring 4 is mounted as shown in FIG. 2, the uppermost winding is engaged with the lower surface of the outer flange 6 c . When the engine is accelerated and decelerated, the uppermost winding of the valve spring 4 is compressed and twisted by the valve spring retainer 6 and the outer flange 6 c gives upwards. Then, the uppermost flat surface of the valve spring 4 is engaged with the lower surface 8 a of the outer flange 6 c.
[0029] The inner portion of the outer flange 6 c is prevented from wearing locally. The lower surface is prevented from wearing at broad extent. As a result, setting load of the valve spring 4 decreases, and decrease in the maximum rotation speed is prevented, so that engine performance is kept suitable for a long time.
[0030] An angle “α” of the lower surface 8 of the outer flange 6 c may be less than 1° If it is more than 1°, surface pressure of the portion which contacts the valve spring will be too high, thereby increasing wear in the circumference of the lower surface 8 .
[0031] The present invention is applied to relatively soft Al alloy valve spring retainer as mentioned above, but may be applied to an ordinary steel valve spring retainer.
[0032] In FIGS. 4 and 5, the second embodiment of the present invention will be illustrated. The lower surface 8 b of an outer flange 6 c is formed as an arcuate section. By the second embodiment of the present invention, similar advantages to the above are achieved.
[0033] In FIG. 6, the third embodiment of the present invention is illustrated. The lower surface of an outer flange 8 is formed as an inverse-trapezoid-section, and an annular recess 9 is formed between an intermediate portion 6 b and the outer flange 6 c . The width of the recess 9 is determined such that the uppermost inner edge of the valve spring does not get out of the recess 9 even if the valve spring is moved radially at maximum. In the third embodiment, if the valve spring is twisted outwards, the inner edge gets in the recess 9 to form a gap between the outer flange and the intermediate portion, thereby preventing the lower surface of the outer flange 6 c from wearing locally. In the third embodiment, only the recess 9 may be formed without projection of the lower surface 8 c of the outer flange 6 c . To prevent stress from concentrating to the recess, the recess 9 may have an arc which has relatively large radius.
[0034] In FIGS. 7 and 8, the first embodiment of a valve operating mechanism according to the present invention is disclosed. A valve spring retainer 6 is made of Al alloy, and mounted to the axial end of a poppet valve 1 via a pair of cotters 2 , 2 . On the lower surface of an outer flange 6 c of the valve spring retainer 6 , a projection 11 is partially formed and inserted into an opening “C” which is formed between the uppermost first winding 1 a and the second winding 4 b of the valve spring 4 .
[0035] Height and circumference of the projection are determined by the following way. As shown in FIG. 7, the valve spring retainer 6 is mounted such that the projection 11 is positioned in the opening “C”. The right side of the projection 11 is engaged with the end of the first winding 4 a of the valve spring 4 , and the left lower corner of the projection 11 is positioned closely to the upper surface of the second winding which is inclined upwards to the left.
[0036] In the valve operating mechanism of the present invention, if the valve spring 4 is rotated with respect to the valve spring retainer 6 around an axis, the right side of the projection 11 is engaged with the end of the first winding 4 a and the left lower corner is engaged with the upper surface of the second winding 4 b.
[0037] Thus, sliding friction between the upper end of the valve spring 4 and the outer flange 6 c almost disappears, thereby greatly decreasing wear of the valve spring retainer 6 made of Al alloy.
[0038] [0038]FIG. 9 is the second embodiment of a valve operating mechanism of the present invention, in which the lower surface of a projection 11 is inclined at almost the same angle as that of a second winding 4 b of a valve spring 4 . When the valve spring 4 and a valve spring retainer 6 are rotated in directions as shown by arrows respectively, contact area between the lower surface of the projection 11 and the upper surface of the second winding 4 b of the valve spring 4 increases to decrease surface pressure, thereby decreasing wear of the contact surfaces.
[0039] The valve operating mechanism according to the present invention is not limited to the embodiments as above. In the embodiment, the projection 11 is part of the retainer 6 , but may be separately formed and fixed to an outer flange 6 a of a valve spring retainer 6 by means of welding or a screw. The projection 11 may be made of hard steel or light Ti alloy to increase wear resistance. The valve operating mechanism of the present invention may be applied to what has a steel valve spring retainer.
[0040] The foregoing merely relate to embodiments of the present invention. Various modifications and changes may be made by person skilled in the art without departing from the scope of claims wherein:
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A valve spring retainer is mounted to the upper end of a poppet valve via a pair of cotters in an internal combustion engine of an automobile. The valve spring retainer has an intermediate portion and an outer flange which is engaged with the upper end of a valve spring. The lower surface has a gap between the outer flange and the intermediate portion to decrease wear which is caused by engagement with the valve spring. There is also provided a valve operating mechanism which has a valve spring retainer which has a projection on the lower surface so as to prevent wear.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the present invention generally relate to a method and apparatus for ex-situ cleaning of a chamber component. More particularly, embodiments of the present invention generally relate to a method and apparatus for endpoint detection during ex-situ cleaning of a chamber component used in a semiconductor processing chamber.
[0003] 2. Description of the Related Art
[0004] In semiconductor substrate processing, the trend towards increasingly smaller feature sizes and line-widths has placed a premium on the ability to mask, etch, and deposit material on a semiconductor substrate with greater precision. As semiconductor features shrink, device structures become more fragile. Meanwhile, the killer defect size, defined as the particle size which renders the device non-functional, becomes smaller and more difficult to remove from the surface. Consequently, reducing device damage is one of the major issues facing the cleaning processes. As a result, this trend towards increasingly smaller feature sizes has placed a premium on the cleanliness of semiconductor manufacturing processes including the chamber component parts used in such processes.
[0005] Currently, cleaning processes which rely on particle counting to determine the end point of a cleaning process require off-line lab analysis during the component part cleaning process. This requires the operator to cease the cleaning process and manually pull a sample of the cleaning solution used in the cleaning process. This sample is then sent to a lab for analysis. This labor intensive process not only contributes to a significant increase in the length of the cleaning process but also increases tool downtime for the tool from which the part has been removed. This increase in tool downtime leads to a corresponding increase in the cost of ownership (CoO).
[0006] Therefore, there is a need for an improved apparatus and process for cleaning chamber component parts that provide improved removal of particle contaminants from chamber parts while significantly reducing downtime for chamber maintenance and cleaning.
SUMMARY OF THE INVENTION
[0007] Embodiments of the present invention generally relate to a method and apparatus for ex-situ cleaning of a chamber component. More particularly, embodiments of the present invention generally relate to a method and apparatus for endpoint detection during ex-situ cleaning of a chamber component used in a semiconductor processing chamber. In one embodiment, a system for cleaning parts disposed in a liner with a cleaning fluid is provided. The system comprises a portable cart, a liquid particle counter (LPC) carried by the portable cart, the LPC configured for detachable coupling to a fluid outlet port formed through the liner, the LPC operable to sample rinsate solution exiting the line, and a pump carried by the portable cart and configured for fluid coupling to the liner in a detachable manner, the pump operable to recirculate rinsate solution through the liner.
[0008] In another embodiment, a system for cleaning parts disposed in a liner with a cleaning fluid is provided. The system comprises a portable cart, a liner for holding component parts to be cleaned during a cleaning process, and a liquid particle counter (LPC) carried by the portable cart, the LPC configured for detachable coupling to a fluid outlet port formed through the liner, the LPC operable to sample cleaning fluid exiting the liner.
[0009] In yet another embodiment, a method for cleaning parts disposed in a liner with a cleaning fluid is provided. The method comprises providing a liner for holding component parts to be cleaned during a cleaning process and a transducer positioned below the liner, providing a portable cart with a liquid particle counter (LPC) carried by the portable cart, the LPC configured for detachable coupling to a fluid outlet port formed through the liner, the LPC operable to sample cleaning fluid exiting the liner, positioning a component part in the liner, flowing a rinsate solution from a rinsate supply into the liner, cycling the transducer on and off to agitate the rinsate solution and remove contaminant particles from the component part, and monitoring a count of contaminant particles in the rinsate solution using the LPC, and ending the cleaning process when the count of contaminant particles drops below a previously determined level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0011] FIG. 1 is a schematic side view of one embodiment of a cleaning system comprising a surface particle endpoint detection system according to embodiments described herein;
[0012] FIG. 2 is a fluid flow circuit schematic diagram of one embodiment of a surface particle endpoint detection system according to embodiments described herein;
[0013] FIG. 3 is a schematic side view of one embodiment of a cleaning system comprising a surface particle endpoint detection system according to embodiments described herein;
[0014] FIG. 4 is a schematic view of one embodiment of a wet bench set-up according to embodiments described herein; and
[0015] FIG. 5 is a schematic side view of one embodiment of a detachable cleaning cart comprising a surface particle endpoint detection system according to embodiments described herein.
[0016] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
DETAILED DESCRIPTION
[0017] Embodiments described herein generally relate to a method and apparatus for ex-situ cleaning of chamber component parts using a real-time surface particle endpoint detection system. Currently, cleaning processes use batch liquid particle counting (LPC) tests that require off-line lab analysis during the chamber component part cleaning process. This requires the system operator to manually pull a sample of the cleaning solution or rinsate solution and send the sample off-site for particle analysis. If the sample does not meet the required specifications for particle count, continued cleaning of the part is required along with the pulling of additional samples and corresponding tool downtime for particle count analysis. This results in high cost for repeated lab analysis followed by repeated cleaning sequences.
[0018] Certain embodiments described herein provide a stand-alone LPC system for detecting liquid particles extracted on-line from the chamber component parts during the cleaning process. This real-time LPC system measures particles during the cleaning cycle until reaching a desired endpoint/baseline (end point detection). The real-time LPC system may signal the operator when the chamber component part meets the desired endpoint/baseline. The real-time LPC system reduces or eliminates the need for the labor intensive LPC lab testing and the costs associated with such testing.
[0019] FIG. 1 is a schematic side view of one embodiment of a cleaning system 100 for ex-situ cleaning of chamber component parts comprising a surface particle endpoint detection system 110 according to embodiments described herein. In one embodiment, the one or more chamber component parts are used in a semiconductor processing chamber. The chamber component parts may include any chamber component part that requires cleaning. Exemplary chamber component parts include, but are not limited to, showerheads, pedestals, rings, bell jars, disks, and chamber liners. The chamber component parts may comprise materials including, but not limited to, silicon carbide, aluminum, copper, stainless steel, silicon, polysilicon, quartz and ceramic materials. In one embodiment, the cleaning system 100 comprises a wet bench set-up 120 which comprises a cleaning vessel assembly 130 for holding the chamber component parts to be cleaned during the cleaning process and a portable cleaning cart 140 which comprises the surface particle endpoint detection system 110 detachably coupled with the wet bench set-up for supplying the selected cleaning chemistry to the cleaning vessel assembly 130 during the cleaning process. The portable cleaning cart 140 is movable and may be detachably coupled with the cleaning vessel assembly 130 prior to and during the cleaning process and may be removed from the cleaning vessel assembly 130 when cleaning is not taking place. Thus, advantageously, the portable cleaning cart 140 may be used to service different cleaning vessels at different locations. The portable cleaning cart 140 may be configured to deliver one or more cleaning fluids toward the chamber component part 220 . Cleaning fluids may include rinsate solution (e.g., deionized water (DIW)), one or more solvents, a cleaning solution such as standard clean 1 (SC 1 ), selective deposition removal reagent (SDR), surfactants, acids, bases, or any other chemical useful for removing contaminants and/or particulates from a component part. The surface particle endpoint detection system 110 , the wet-bench setup 120 , and the portable cleaning cart 140 are described in further detail with reference to FIG. 2 , FIG. 3 , and FIG. 4 .
[0020] In general, a system controller 150 may be used to control one or more controller components found in the cleaning system 100 . The system controller 150 is generally designed to facilitate the control and automation of the overall cleaning system 100 and typically includes a central processing unit (CPU) (not shown), memory (not shown), and support circuits (or I/O) (not shown). The CPU may be one of any form of computer processors that are used in industrial settings for controlling various system functions, substrate movement, chamber processes, and support hardware (e.g., sensors, robots, motors, lamps, etc.), and monitor the processes (e.g., substrate support temperature, power supply variables, chamber process time, processing temperature, I/O signals, transducer power, etc.). The memory is connected to the CPU, and may be one or more of a readily available memory, such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data can be coded and stored within the memory for instructing the CPU. The support circuits are also connected to the CPU for supporting the processor in a conventional manner. The support circuits may include cache, power supplies, clock circuits, input/output circuitry, subsystems, and the like. A program (or computer instructions) readable by the system controller 150 determines which tasks are performable on a substrate. Preferably, the program is software readable by the system controller 150 that includes code to perform tasks relating to monitoring, execution and control of the movement, support, and/or positioning of a substrate along with the various process recipe tasks and various chamber process recipe steps being performed in the cleaning system 100 . In one embodiment, the system controller 150 also contains a plurality of programmable logic controllers (PLC's) that are used to locally control one or more modules in the cleaning system 100 .
[0021] FIG. 2 is a fluid flow circuit schematic diagram of the surface particle endpoint detection system 110 according to embodiments described herein. The surface particle endpoint detection system 110 comprises a liner 210 for holding a chamber component part 220 during the rinsing process, a circulating fluid supply line 230 for supplying rinsate to rinse the chamber component part 220 , and one or more liquid particle counters (LPC) 240 fluidly coupled with the circulating fluid supply line 230 for monitoring the particle count in the circulating rinsate solution. A pump 250 may be positioned along the circulating fluid supply line 230 for pumping rinsate through the fluid supply line 230 and a filter 260 may be positioned along the rinsate fluid supply line 230 for removing particles from the rinsate solution.
[0022] The liner 210 may be positioned in the cleaning vessel assembly 130 of the wet bench setup 120 (See FIG. 3 ) during the cleaning process. The liner 210 may be positioned in the cleaning vessel assembly 130 during a portion of the cleaning process that involves the introduction of a rinsate solution, for example, deionized (DI) water into the cleaning vessel assembly. In certain embodiments where multiple cleaning and/or rinsate solutions are used during the cleaning process, a dedicated liner may be used for each separate solution. For example, in certain embodiments where the cleaning process comprises an etching step followed by a rinsing step, a dedicated etching liner may be used for the etching process and a dedicated rinsing liner may be used for the rinsing process. In certain embodiments where chamber component parts of different materials are cleaned, a dedicated liner may be used for each different material. In general, the liner may be made of plastic (e.g., polypropylene (PP), polyethylene (PE), polyvinyl difluoride (PVDF)) or coated metal (e.g., SST, aluminum with an ETFE coating) that will not be attacked by the cleaning chemistry and will not produce a significant amount of particulates which could contribute to an increased particle count by the LPC 240 thus creating a false or inaccurate endpoint reading.
[0023] The LPC 240 may be fluidly coupled with the liner 210 via the circulating fluid supply line 230 . The circulating fluid supply line may be coupled with the liner 210 via a liner inlet 232 and a liner outlet 234 . It should be understood that although a single liner inlet 232 and a single liner outlet 234 are shown; multiple liner inlets and liner outlets may be used depending upon the user's needs. The LPC 240 is used to detect and count particles in the rinsate fluid after the rinsate exits the liner 210 and the results are used to determine the endpoint of the cleaning process. In general, liquid particle counters use a high energy light source to illuminate particles as the particles pass through a detection chamber. As the particle passes through a beam generated by the light source (typically a laser) and if light scattering is used, the redirected light is detected by a photodetector. The endpoint may be determined by monitoring the light blocked by the particles of the rinsate fluid. The amplitude of the light scattered or light blocked is measured and the particle is counted and tabulated. The LPC 240 may be any LPC known to those of ordinary skill in the art. Exemplary LPC devices include, for example, the KL-28B Liquid-Borne Particle Counter available from RION Co., Ltd. of Japan and the LIQUILAZ® Particle Counter available from Particle Measuring Systems, Inc. of Boulder, Colo., USA. In certain embodiments, each LPC has its own pump.
[0024] Although shown in FIG. 2 as positioned prior to the pump 250 and filter 260 , it should be understood that the LPC 240 may be positioned after the pump 250 . However, it is believed to be preferable to position the LPC 240 prior to the pump 250 since turbulent flow created by the pump 250 may falsely increase the particle count readings by the LPC 240 leading to an inaccurate endpoint determination.
[0025] In certain embodiments, it may be desirable to use multiple liquid particle counters to achieve a more precise reading of the number of particles in the rinsate fluid. For example, in certain embodiments, a first liquid particle counter 240 may be positioned upstream relative to the pump 250 and a second liquid particle counter 270 may be positioned downstream from the pump 250 but upstream from the filter 260 .
[0026] The filter 260 may be fluidly coupled with the circulating fluid supply line 230 downstream relative to the LPC 240 . The filter 260 removes particles from the rinsate fluid allowing for the recirculation of fresh rinsate fluid into the liner 210 . Exemplary filter sizes may include 0.01 micron to 10 micron filters. Exemplary filter sizes may also include 0.04 micron to 1 micron filters. Although a single filter 260 is shown in FIG. 2 , it should be understood that the embodiments described herein contemplate the use of multiple filters of similar or varying sizes to filter particles from the rinsate solution.
[0027] FIG. 3 is a schematic side view of one embodiment of a cleaning system 300 comprising a surface particle endpoint detection system 310 according to embodiments described herein. The cleaning system 300 comprises the wet bench set-up 120 and the portable cleaning cart 140 comprising a surface particle endpoint detection system 310 . The surface particle endpoint detection system 310 is similar to the surface particle endpoint detection system 110 depicted in FIG. 2 except that the liner 210 has a rinsate fluid sample outlet 320 fluidly coupled with a dedicated fluid sampling line 330 to which the LPC 240 is fluidly coupled. The dedicated fluid sampling line 330 may be fluidly coupled with the circulating fluid supply line 230 . A dedicated sampling pump 340 for pumping rinsate through the dedicated fluid sampling line 330 may be positioned along the dedicated fluid sampling line 330 .
[0028] The portable cleaning cart 140 may further comprise a drain line 350 that fluidly couples the filter 260 with a drain 360 for removing waste material from the filter 260 .
[0029] In operation, with reference to FIG. 3 , the chamber component part 220 is placed in the liner 210 for the cleaning process. In certain embodiments where the cleaning fluid includes a rinsate solution, the rinsate solution may be supplied from a rinsate solution source (not shown) to the circulating fluid supply line 230 where the rinsate solution flows into the liner 210 via liner inlet 232 . In certain embodiments a transducer 416 may be used to agitate the rinsate solution flowing through the liner 210 and provide improved rinsing of the chamber component part 220 . The contaminated rinsate solution exits the liner 210 via liner outlet 234 where the contaminated rinsate may be pumped through filter 260 using the pump 250 to remove particles from the contaminated rinsate solution. The refreshed (e.g., filtered) rinsate solution may then be recirculated into the liner 210 for further rinsing of the chamber component part 220 . During the cleaning process, waste material from the filter 260 may be removed from the cleaning system 300 via drain line 350 and drain 360 . At any point during the cleaning process, samples of the rinsate solution may be removed from the liner 210 via sample outlet 320 . The sample of the rinsate solution will flow through the dedicated fluid sampling line 330 through the LPC 240 where a particle count is performed. If the results of the particle count are greater than a previously determined particle count, the endpoint has not been reached and the cleaning process will continue. If the results of the particle count are less than the previously determined particle count, the endpoint has been reached and the cleaning process ends. Sampling by the LPC 240 may be intermittent or continuous.
[0030] FIG. 4 is a schematic view of one embodiment of a wet bench set-up 400 according to embodiments described herein. Portions of the side view are illustrated in perspective to assist in the ease of explanation. The wet bench set-up 400 is similar to the wet bench set-up 120 ; however, the wet bench set-up 400 is configured for delivering both a cleaning solution and a rinsing solution to clean the chamber component part 220 . The wet bench set-up 400 comprises a wet bench 402 and the cleaning vessel assembly 130 . The wet bench 402 provides support for the cleaning vessel assembly 130 . The wet bench 402 may also serve as an overflow basin to catch any cleaning chemicals which overflow the cleaning vessel assembly 130 . The wet bench 402 may also function as a fume hood when used in cleaning processes which generate gases and/or particulates. Although shown with the wet bench 402 , in certain embodiments, the cleaning vessel assembly 130 is used in a standalone fashion without the wet bench 402 . For example, the cleaning vessel assembly 130 may be used without a wet bench in well ventilated areas where there is less concern about the buildup of fumes.
[0031] The wet bench 402 may comprise a frame 404 which forms an overflow basin 406 for both holding the cleaning vessel assembly 130 and capturing any fluids which may overflow the cleaning vessel assembly 130 during processing. The overflow basin 406 may include a sink drain line 408 for removing captured fluids from the overflow basin 406 .
[0032] The cleaning vessel assembly 130 comprises an outer cleaning basin 414 which circumscribes the liner 210 that holds the component part to be cleaned, a transducer 416 positioned within the outer cleaning basin 414 , and a support 418 positioned within the outer cleaning basin 414 for supporting the liner 210 .
[0033] Although shown as cylindrical in FIG. 4 , it should be understood that the outer cleaning basin 414 and/or the liner 210 may be any shape, for example, oval, polygonal, square or rectangular. In one embodiment, the outer cleaning basin 414 and/or the liner 210 may be fabricated from a material such as polypropylene (PP), polyethylene (PE)) polyvinyl difluoride (PVDF) or coated metal (e.g., aluminum with an ETFE coating) that will not be attacked by the cleaning chemistry and will not produce a significant amount of particulates.
[0034] The transducer 416 is configured to provide either ultrasonic or megasonic energy to a cleaning region within the liner 210 where the chamber component part 220 is positioned. The transducer 416 may be implemented, for example, using piezoelectric actuators, or any other suitable mechanism that can generate vibrations at ultrasonic or megasonic frequencies of desired amplitude. The transducer 416 may be a single transducer, as shown in FIG. 4 , or an array of transducers, oriented to direct ultrasonic energy into the cleaning region of the liner 210 where the component part is positioned. When the transducer 416 directs energy into the cleaning fluid in the liner 210 , acoustic streaming, i.e. streams of micro bubbles, within the cleaning fluid may be induced. The acoustic streaming aids the removal of contaminants from the component part 220 being processed and keeps the removed particles in motion within the cleaning fluid hence avoiding reattachment of the of the removed particles to the component part surface. The transducer 416 may be configured to direct ultrasonic or megasonic energy in a direction normal to an edge of the component part 220 or at an angle from normal. In one embodiment, the transducer 416 is dimensioned to be approximately equal in length to a mean or outer diameter of the component part 220 to be cleaned. The transducer 416 may be coupled to an RF power supply 422 .
[0035] While only one transducer 416 is shown positioned below the liner 210 , multiple transducers may be used with certain embodiments. For example, additional transducers may be placed in a vertical orientation along the side of the liner 210 to direct ultrasonic or megasonic energy toward the component part 220 from the side. The transducer 416 may be positioned inside the liner 210 or outside of the liner 210 for indirect ultrasonication. The transducer 416 may be positioned outside of the outer cleaning basin 414 . In one embodiment, the transducer 416 may be positioned in the overflow basin 406 to direct ultrasonic or megasonic energy toward the component part 220 . Although the transducer 416 is shown as cylindrical, it should be understood that transducers of any shape may be used with the embodiments described herein.
[0036] The wet bench set-up 400 also comprises one or more fluid delivery lines 582 a , 584 , 586 a , and 588 a for delivering cleaning fluids to the wet bench set-up and returning used cleaning fluids to the portable cleaning cart 500 (see FIG. 5 ) for recycling and reuse. The fluid delivery lines are configured to mate with corresponding fluid delivery lines 582 b , 586 b , and 588 b on the portable cleaning cart 500 using, for example, connect fittings and disconnect couplings shown as a “Quick Connect” 590 .
[0037] FIG. 5 is a schematic side view of one embodiment of a portable cleaning cart 500 showing a fluid flow circuit schematic diagram comprising a surface particle endpoint detection system 510 according to embodiments described herein. The surface particle endpoint detection system 510 may be similar to the surface particle endpoint detection systems 110 and 310 disclosed in FIGS. 1-3 . The portable cleaning cart 500 may be coupled with the system controller 150 for controlling the cleaning process and a cleaning fluid supply module 520 for supplying and recycling cleaning and rinsate solution. The system controller 150 may be separate from or mounted to the portable cleaning cart 500 .
[0038] In one embodiment, the system controller 150 comprises controller components selected from at least one of the following: a PhotoMeghelic meter 512 , a leak alarm 514 for detecting leaks within the portable cleaning cart, a programmable logic controller 516 for controlling the overall cleaning system, and an in-line heat controller 518 . In one embodiment, the leak alarm 514 is electronically coupled with a plenum leak sensor 522 for detecting the presence of fluid in the bottom of the portable cart 500 . In one embodiment, the system controller 150 is coupled with the transducer 416 via a communication line 580 and controls the power supplied to the transducer 416 .
[0039] In one embodiment, the cleaning fluid supply module 520 includes an inert gas module 524 for supplying an inert gas, such as nitrogen (N 2 ) which may be used as a purge gas during the cleaning process, a DI water supply module 526 for supplying deionized water during the cleaning process, and a cleaning fluid supply module 528 for supplying cleaning fluid and recycling used cleaning fluid.
[0040] With regard to the inert gas module 524 , as discussed above, the use of nitrogen is exemplary and any suitable carrier gas/purge gas may be used with the present system. In one embodiment, the inert gas is supplied from a nitrogen gas source 530 to a main nitrogen gas supply line 532 . In one embodiment, the nitrogen gas source comprises a facility nitrogen supply. In one embodiment, the nitrogen source may be a portable source coupled with the portable cleaning cart 500 . In one embodiment, the nitrogen gas supply line 532 comprises a manual shutoff valve (not shown) and a filter (not shown) for filtering contaminants from the nitrogen gas. A two-way valve 534 which may be an air operated valve is also coupled with the nitrogen gas supply line 532 . When the two-way valve is open, nitrogen gas flows through the supply line 532 and into the outer cleaning basin 414 . Nitrogen may be used in several different applications within the cleaning system. The nitrogen gas supply line 532 may also contain additional valves, pressure regulators, pressure transducers, and pressure indicators which are not described in detail for the sake of brevity. In one embodiment, nitrogen gas may be supplied to the outer cleaning basin 414 via fluid supply line 584 .
[0041] With regard to the DI water supply module 526 , the use of DI water is exemplary and any cleaning fluid suitable for cleaning may be used with the present cleaning system 100 . In one embodiment, the DI water is supplied from a DI water supply module 526 to a main DI water supply line 539 . In one embodiment, the DI water source comprises a facility DI supply. In one embodiment, the DI water source may be a portable source coupled with the portable cleaning cart 500 . In one embodiment, the DI water supply line 539 comprises a shutoff valve 540 and a heater 542 for heating the DI water to a desired temperature for assisting in the cleaning process. The heater 542 may be in electronic communication with the heat controller 518 for controlling the temperature. The DI water supply line 539 further comprises a two-way valve 544 which may be an air operated valve which is used for controlling the flow of DI water into the outer cleaning basin 414 . When the two-way valve 544 is open, DI water flows into the outer cleaning basin 414 . When the two-way valve 544 is closed and two-way valve 534 is open, nitrogen purge gas flows into the outer cleaning basin 414 . The DI water supply line 539 may also contain additional valves, pressure regulators, pressure transducers, and pressure indicators which are not described in detail for the sake of brevity. In one embodiment, DI water may flow into the outer cleaning basin 414 via supply line 586 . The surface particle endpoint detection system 510 may be fluidly coupled with the DI water supply line 539 . In certain embodiments, the surface particle endpoint detection system 510 is separate from the DI water supply line 586 a.
[0042] The cleaning fluid supply module 528 comprises a cleaning fluid supply tank 546 for storing cleaning fluid, a filter system 548 for filtering used cleaning fluid, and a pump system 550 for pumping cleaning fluid into and out of the cleaning fluid supply module 528 . The cleaning fluid may include rinsate solution (e.g., deionized water (DIW)), one or more solvents, a cleaning solution such as standard clean 1 (SC 1 ), selective deposition removal reagent (SDR), surfactants, acids, bases, or any other chemical useful for removing contaminants and/or particulates from a component part.
[0043] In one embodiment, the cleaning fluid supply tank 546 is coupled with a cleaning fluid supply 558 via a supply line 560 . In one embodiment, the cleaning fluid supply line 560 comprises a shut-off valve 562 for controlling the flow of cleaning fluid into the cleaning fluid supply tank 546 . The cleaning fluid supply line 560 may also contain additional valves, pressure regulators, pressure transducers, and pressure indicators which are not described in detail for the sake of brevity. In one embodiment, the cleaning fluid supply tank 546 is coupled with the outer cleaning basin 414 via supply line 588 .
[0044] In one embodiment, the cleaning fluid supply tank 546 is coupled with a cleaning fluid supply drain 566 for removing cleaning fluid from the cleaning fluid supply tank 546 . The flow of cleaning fluid through the cleaning fluid supply drain 566 is controlled by a shut-off valve 568 .
[0045] The cleaning fluid supply tank 546 may also include a plurality of fluid level sensors for detecting the level of processing fluid within the cleaning fluid supply tank 546 . In one embodiment, the plurality of fluid sensors may include a first fluid sensor 552 which indicates when the fluid supply is low and that the pump system 550 should be turned off. When the level of cleaning fluid is low, the first fluid level sensor 552 may be used in a feedback loop to signal the cleaning fluid supply 558 to deliver more cleaning fluid to the cleaning fluid supply tank 546 . A second fluid level sensor 554 which indicates that the cleaning fluid supply tank 546 is full and the pump 550 should be turned on. A third fluid sensor 556 which indicates that the cleaning fluid supply tank 546 has been overfilled and that the pump 550 should be turned off. Although one fluid level sensor 434 is shown in the embodiment of FIG. 2 , any number of fluid level sensors 434 may be included on the outer cleaning basin 414 .
[0046] Used cleaning fluid may be returned from the outer cleaning basin 414 to the filter system 548 where particulates and other contaminants may be removed from the used cleaning fluid to produce renewed (e.g., filtered) cleaning fluid. In one embodiment, used cleaning fluid may be returned from the overflow basin via fluid recycling line 582 . The recycling line 582 may also contain additional valves, pressure regulators, pressure transducers, and pressure indicators which are not described in detail for the sake of brevity. After filtration, the renewed cleaning fluid may be recirculated back to the cleaning fluid supply tank 546 via a three-way valve 570 . In one embodiment, the three-way valve 570 may also be used in conjunction with the pump system 550 to recirculate fluid through the cleaning system to flush the cleaning system 100 . In one embodiment, a two-way valve 572 which may be an air operated valve may be used to pull DI water through the input of the pump system 550 . In one embodiment, a two-way valve 574 may be used to pump out DI water to drain.
[0047] In one embodiment, a component part 220 is placed on the support 418 positioned within a cleaning liner (not shown), similar to liner 210 . A cleaning cycle is commenced by flowing cleaning solution into the cleaning liner. While the cleaning solution is in the cleaning liner, the transducer 416 is cycled on/off to agitate the cleaning solution. The cleaning solution may be purged from the cleaning liner by flowing DI water into the tank. Nitrogen gas may also be used during the purge process. The cleaning/purge cycle may be repeated until the component part 220 has achieved a desired cleanliness. The cleaning liner may then be replaced by the rinsing liner 210 and the component part 220 is placed in the rinsing liner 210 . Rinsate solution (e.g., DI water) may be supplied from the DI water supply module 526 to the fluid supply line 586 a where the rinsate solution flows into the rinsing liner 210 . The transducer 416 may be cycled on/off to agitate the rinsate solution and provide improved rinsing of the chamber component part 220 . The contaminated rinsate solution exits the liner 210 where it may be pumped through a filter where particles are removed from the contaminated rinsate solution. The refreshed rinsate solution may then be recirculated into the rinsing liner 210 for further rinsing of the chamber component part 220 . At any point during the cleaning process, samples of the rinsate fluid may be removed from the liner 210 and flown through a fluid sampling line through the LPC 240 where a particle count is performed. In certain embodiment, if the results of the particle count are greater than a previously determined particle count, the endpoint has not been reached and the rinsing process will continue. In certain embodiment, if the results of the particle count are greater than a previously determined particle count, the endpoint has not been reached and the chamber component part 220 is exposed to additional cleaning solution. If the results of the particle count are less than the previously determined particle count, the endpoint has been reached and the rinsing process ends.
[0048] While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.
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Embodiments of the present invention generally relate to a method and apparatus for ex-situ cleaning of a chamber component. More particularly, embodiments of the present invention generally relate to a method and apparatus for endpoint detection during ex-situ cleaning of a chamber component used in a semiconductor processing chamber. In one embodiment, a system for cleaning parts disposed in a liner with a cleaning fluid is provided. The system comprises a portable cart, a liquid particle counter (LPC) carried by the portable cart, the LPC configured for detachable coupling to a fluid outlet port formed through the liner, the LPC operable to sample rinsate solution exiting the line, and a pump carried by the portable cart and configured for fluid coupling to the liner in a detachable manner, the pump operable to recirculate rinsate solution through the liner.
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CROSS REFERENCE
This application is based on and claims priority to U.S. Patent Application No. 61/746,349 filed Dec. 27, 2012.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a device for limiting rotation of a wheel, and more particularly, but not by way of limitation, to a device that may be placed onto the individual wheels of a skateboard to limit rotation of the wheels.
2. Description of the Related Art
A typical skateboard has a deck, two trucks, and four wheels. In its simplest form, riding a skateboard involves standing on the deck and pushing off the ground to propel the skateboard along the ground on the wheels. It is common, however, for skateboard riders to perform tricks that involve the wheels of the skateboard leaving the ground. These tricks, and even tricks for which the wheels do not leave the ground, require balance and particular movements, both of which may be perfected through extensive practice. The wheels of the skateboard complicate such practicing, as performing a trick incorrectly or incompletely could result in the skateboard rolling away, causing the rider to fall.
Several training aids have been developed to address this problem. These typically require some modification of the skateboard, such as removing the wheels or adding additional elements. These modifications may be difficult and, more importantly, may change how the skateboard functions in some significant way: make the skateboard heavier, prevent access to elements such as the underside of the deck for balancing tricks, prevent the proper functioning of the trucks, etc. Thus, once the modifications are removed, the skateboard no longer behaves how it did when the rider was practicing, forcing the rider to re-learn certain elements.
Based on the foregoing, it is desirable to provide a device that limits the rotation of the wheels of the skateboard so that the skateboard cannot roll while the rider practices tricks.
It is further desirable for the device to allow the user to learn tricks, develop muscle memory, train reflexes, and get over fear.
It is further desirable for the device to be easy to install without tools and without removing parts or otherwise modifying the skateboard, allowing the device to be temporarily installed to the skateboard, such that it stays in place while the rider performs tricks, and easily removed so that the rider can resume normal operation of the skateboard.
It is further desirable for the device to be lightweight so that it does not affect the weight and general feel of the skateboard and does not change the center of gravity of the skateboard.
It is further desirable for the device to work with a variety of skateboard dimensions and configurations.
It is further desirable for the device to allow access to the center, nose, and tail areas of the board, allowing for contact with surfaces and obstacles such as rails, stairs, and platforms.
SUMMARY OF THE INVENTION
In general, in a first aspect, the invention relates to a device for use with a wheeled device comprising a deck and at least one wheel attached to the deck with a gap between the wheel and the deck, such as a skateboard, the device comprising a physical stop secured against one wheel of the skateboard. The skateboard may comprise multiple wheels and the device may comprise multiple physical stops, each physical stop secured against one wheel.
The physical stop may comprise a block of resilient material, where the block is thicker than the gap between the wheel and the deck and is capable of being placed in a semi-compressed or compressed state into the gap such that the block exerts pressure on the wheel sufficient to prevent the wheel from freely rotating. The block may be wider or narrower than the wheel, and may be generally parallelepiped-shaped with a recess corresponding to the wheel's location when the block is in place in the gap. The block may have an angled top surface, and may have cut out areas running horizontally through the block. The block may have a bottom surface in contact with the wheel and the bottom surface may have a coating of a material with a higher coefficient of friction than the block. The block may have at least one surface with a coating having at least one physical characteristic different from that of the block.
The physical stop may comprise a holder at least partially surrounding the wheel and at least one protrusion from the holder, where the protrusion is adjacent a rolling surface of the wheel and is capable of functioning as a chock when the protrusion is in contact with a surface upon which the wheel is attempting to roll and where the holder secures the protrusion to the wheel such that the protrusion moves with the wheel. The holder may be generally cylindrical and may surround the rolling surface of the wheel. The holder may be made of an elastic material capable of deforming for placement around the wheel but conforming to the shape of the wheel to fit securely around the wheel such that the holder prevents the wheel from rotating when on a surface. The holder may have an inner surface with a generally cylindrical cross section and an outer surface with a generally rectangular cross section. The protrusions may run crosswise along the width of the wheel, perpendicular to a path of rotation of the wheel. The holder may surround the wheel from the sides, with the protrusions extending between the sides across the rolling surface of the wheel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a skateboard with block-type devices for limiting rotation of a wheel;
FIG. 2 is a side view of a block-type device for limiting rotation of a wheel with a semi-circular recess;
FIG. 3 is a side view of a block-type device for limiting rotation of a wheel with a sloped recess;
FIG. 4 is a side view of a block-type device for limiting rotation of a wheel with a v-shaped recess;
FIG. 5 is a side view of a block-type device for limiting rotation of a wheel with a v-shaped recess and lattice cut-outs;
FIG. 6 is a side view of a block-type device for limiting rotation of a wheel with a v-shaped recess and triangular cut-outs;
FIG. 7 is a side view of a block-type device for limiting rotation of a wheel with top and bottom recesses;
FIG. 8 is an end view of a skateboard with block-type devices for limiting rotation of a wheel with square cross sections;
FIG. 9 is a side view of a block-type device for limiting rotation of a wheel with a square cross section;
FIG. 10 is an end view of a block-type device for limiting rotation of a wheel with a square cross section;
FIG. 11 is bottom view of a block-type device for limiting rotation of a wheel with a square cross section;
FIG. 12 is an end view of a skateboard with block-type devices for limiting rotation of a wheel with angled cross sections;
FIG. 13 is a side view of a block-type devices for limiting rotation of a wheel with an angled cross section;
FIG. 14 is an end view of a block-type device for limiting rotation of a wheel with an angled cross section;
FIG. 15 is a bottom view of a block-type device for limiting rotation of a wheel with an angled cross section;
FIG. 16 is a perspective view of a block-type device for limiting rotation of a wheel with an angled cross section;
FIG. 17 is an end view of a skateboard with block-type devices for limiting rotation of a wheel with parallelogram cross sections;
FIG. 18 is a side view of a block-type device for limiting rotation of a wheel with a parallelogram cross section;
FIG. 19 is an end view of a block-type device for limiting rotation of a wheel with a parallelogram cross section;
FIG. 20 is a bottom view of a block-type device for limiting rotation of a wheel with a parallelogram cross section;
FIG. 21 is a perspective view of a block-type device for limiting rotation of a wheel with a parallelogram cross section;
FIG. 22 is an end view of a skateboard with block-type devices for limiting rotation of a wheel with rotation stops;
FIG. 23 is a side view of a block-type device for limiting rotation of a wheel with a rotation stop;
FIG. 24 is an end view of a block-type device for limiting rotation of a wheel with a rotation stop;
FIG. 25 is a bottom view of a block-type device for limiting rotation of a wheel with a rotation stop;
FIG. 26 is a side view of a skateboard with chock-type devices for limiting rotation of a wheel;
FIG. 27 is a close-up side view of one end of a skateboard with a chock-type device for limiting rotation of a wheel;
FIG. 28 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with rounded protrusions;
FIG. 29 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with rectangular protrusions;
FIG. 30 is a side view of a chock-type device for limiting rotation of a wheel with rounded protrusions;
FIG. 31 is a side view of a chock-type device for limiting rotation of a wheel with rectangular protrusions;
FIG. 32 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with angled protrusions;
FIG. 33 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with a rectangular outer contour;
FIG. 34 is a side view of a chock-type device for limiting rotation of a wheel with angled protrusions;
FIG. 35 is a side view of a chock-type device for limiting rotation of a wheel with a rectangular outer contour;
FIG. 36 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with rounded protrusions;
FIG. 37 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with triangular protrusions;
FIG. 38 is a side view of a chock-type device for limiting rotation of a wheel with rounded protrusions;
FIG. 39 is a side view of a chock-type device for limiting rotation of a wheel with triangular protrusions;
FIG. 40 is a side view of a chock-type device for limiting rotation of a wheel with interior protrusions;
FIG. 41 is a side view of a rectangular chock-type device for limiting rotation of a wheel;
FIG. 42 is a side view of a wheel with a rectangular chock-type device for limiting rotation of a wheel;
FIG. 43 is a perspective view of a chock-type device for limiting rotation of a wheel;
FIG. 44 is a perspective view of a chock-type device for limiting rotation of a wheel;
FIG. 45 is a perspective view of a chock-type device for limiting rotation of a wheel;
FIG. 46 is a side view of a wheel with a chock-type device for limiting rotation of a wheel with a cage design;
FIG. 47 is an end view of a wheel with a chock-type device for limiting rotation of a wheel with a cage design;
FIG. 48 is a perspective view of the chock-type device for limiting rotation of a wheel;
FIG. 49 is a perspective view of a wheel with a chock-type device for limiting rotation of a wheel installed thereon;
FIG. 50 is a perspective view of a wheel with a chock-type device for limiting rotation of a wheel installed thereon;
FIG. 51 is a perspective view of a chock-type device for limiting rotation of a wheel with an alternate design;
FIG. 52 is a perspective view of a wheel with a chock-type device for limiting rotation of a wheel with an alternate design installed thereon;
FIG. 53 is a perspective view of a wheel with a chock-type device for limiting rotation of a wheel with an alternate design installed thereon;
FIG. 54 is a perspective view of a wheel with a chock-type device for limiting rotation of a wheel installed thereon;
FIG. 55 is a perspective view of a flanged version of a chock-type device for limiting rotation of a wheel; and
FIG. 56 is another perspective view of a flanged version of a chock-type device for limiting rotation of a wheel.
Other advantages and features will be apparent from the following description and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
The devices and methods discussed herein are merely illustrative of specific manners in which to make and use this invention and are not to be interpreted as limiting in scope.
While the devices and methods have been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the construction and the arrangement of the devices and components without departing from the spirit and scope of this disclosure. It is understood that the devices and methods are not limited to the embodiments set forth herein for purposes of exemplification.
In general, in a first aspect, the invention relates to a device for limiting rotation of a wheel for a skateboard. A typical skateboard has a deck 1 and two trucks 2 , each of which has two wheels 3 . The trucks 2 connect the wheels 3 to the underside of the deck 1 and pivot to allow the skateboard to turn. While this typical skateboard configuration is shown in FIGS. 1 , 8 , 12 , 17 , and 22 , the skateboard device of the present invention may be used with any other skateboard design, including any number of wheels attached by any means, with or without trucks, to a deck or other platform of any shape and size.
The device for limiting rotation of a wheel is generally a physical stop secured against one of the wheels 3 of the skateboard. As seen in FIG. 1 , the device may be a block 4 of resilient material, such as foam rubber, that may be wedged between the deck 1 and a wheel 3 . The block 4 may be compressed for placement between the deck 1 and wheel 3 , then released once in place to allow the block 4 to expand to fill the area between the deck 1 and wheel 3 , thus placing pressure on the wheel 3 sufficient to prevent the wheel 3 from freely rotating.
FIG. 1 shows multiple blocks 4 in place between the deck 1 and wheels 3 . One block 4 may be used with each of the wheels 3 of a skateboard, or a larger block 4 may be used in conjunction with multiple wheels 3 . Each block 4 may be wider than the width of the wheel 3 and thicker at its thinnest point than the distance between the deck 1 and wheel 3 . This allows the block 4 to maintain sufficient compression once installed between the deck 1 and wheel 3 to exert pressure upon the wheel 3 and impede its rotation.
The block 4 may have any appropriate shape, the most simple being a cuboid, although it may be desirable for the block 4 to roughly mimic the shape of the space between the deck 1 and the wheel 3 . As seen in FIG. 1 , this space in roughly flat on top, being defined by the generally flat deck 1 , and generally concave on bottom, being defined by the round wheel 3 . Shaping the block 4 to similarly have a recess in the area of the wheel 3 allows for less material to compress in the smallest space between the wheel 3 and deck 1 , increasing ease of installation, while providing sufficient material along the sides to provide pressure to not just the top but also the sides of the wheel 3 , increasing friction on the wheel 3 . Alternately, the recess may be located on the top of the block or on both the top and bottom of the block, as seen in FIG. 7 , allowing the block to conform around the wheel. The recess may have any appropriate shape, as seen in FIGS. 2 through 4 . The block 4 may additionally have cut-outs, providing greater flexibility, as seen in FIGS. 5 and 6 . The block 4 may have any appropriate cross section, such as a square cross section, as seen in FIGS. 8 through 11 ; an angled cross section, as seen in FIGS. 12 through 16 ; or a parallelogram cross section, as seen in FIGS. 17 through 21 . The block 4 may additionally have a protrusion 6 extending inward toward the truck 2 to function as a stop and prevent the block 4 from rotating laterally as the wheel 3 attempts to rotate.
Different sizes of the block 4 may be used to vary the degree of rotation allowed. This allows different blocks 4 to be used for different skill levels. Once a rider progresses, he or she may advance by using blocks 4 that allow for limited wheel rotation. Additionally, blocks 4 may be used on any number of wheels 3 , from one to all, to vary training difficulty and allow for more or less rotation.
Material for the block 4 may vary depending upon user requirements, such as different stiffnesses, changes in surface friction, reduced weight, increased durability, etc. Friction coating may be added where the block 4 contacts the wheel 3 to stop wheel rotation while minimizing preload, thus reducing the effort required to install. Additionally, not coating the other surfaces may result in minimizing the friction where the block 4 contacts the deck 1 , which also reduces the installation forces required.
The block 4 is light, portable, and temporary, can be installed without tools, and allows the rider to use his own equipment, with the actual wheels maintaining contact with the ground. Added mass is insignificant relative to the mass of the skateboard, and significantly less than other solutions currently available. Any added mass is near the center of gravity of the skateboard, resulting in insignificant changes to the dynamic rotational properties of the skateboard assembly. Another advantage is that one size of the block 4 may work with a variety of skateboard dimensions and configurations. The skateboard does not have to be disassembled to install the block 4 , which is an advantage over several currently available skateboard training devices. Several variations may use the wheel 3 for leverage to facilitate easy installation. The block 4 does not generally come into contact with the ground or other surfaces, minimizing wear. The block 4 does not cover or prevent access to the center, nose, or tail areas of the board, allowing for contact to surfaces and obstacles such as rails, stairs, or platforms. A secondary benefit of the block 4 is that it may decrease the flexibility that results in rotation of the skateboard deck about the long axis (the forward/aft axis), which helps stabilize the skateboard while learning certain tricks and training for balance. Finally, the blocks 4 may be used on skateboard assemblies in retail environments, sold as part of the packaging to prevent use while in store or during transportation.
As seen in FIGS. 26 and 27 , the device may be a wheel-mounted chock-type device 5 that surrounds a wheel 3 and has protrusions at various intervals. When the wheel 3 is in contact with a surface, the protrusions act as chocks as the wheel 3 tries to turn, limiting rotation of the wheel 3 . The chock-type device 5 may mount to the wheel 3 itself and be independent of the deck 1 and trucks 2 . The chock-type device 5 may be made of an elastic material capable of stretching for easy placement around the wheel 3 but conforming to the shape of the wheel to fit securely around the wheel 3 , preventing the wheel 3 from rotating without the device 5 also rotating.
The chock-type device 5 may have any number of protrusions, including four, as seen in FIGS. 26 through 35 ; six, as seen in FIGS. 36 through 39 ; or any other desired number. The protrusions of the chock-type device 5 may have any shape, such as rounded, as seen in FIGS. 26 , 28 , 30 , 36 , and 38 ; rectangular, as seen in FIGS. 29 and 31 ; or triangular, as seen in FIGS. 37 and 39 . The chock-type device 5 may have a rounded interior cross section to accommodate the wheel 3 , but an angular or rectangular outer cross section, as seen in FIGS. 32 and 34 and FIGS. 33 and 35 , respectively, to prevent rotation of the device 5 against a surface. The protrusions may be located on the outer surface of the chock-type device 5 , as seen in FIGS. 26 through 39 , or may be located on the inner surface of the device 5 , as seen in FIG. 40 . The device 5 may have any desired cross sectional shape, such as rectangular as seen in FIG. 41 , but may deform to fit the cylindrical wheel 3 , as seen in FIG. 42 .
As seen in FIGS. 43 through 56 , the chock-type device 5 may be generally cylindrical with the protrusions running crosswise along the width of the surface of the chock-type device 5 , perpendicular to the path of rotation of the wheel 3 . In this configuration, the chock-type device 5 may be placed onto the wheel 3 from the side. Alternately, the chock-type device 5 may be placed onto the wheel 4 from the top or bottom, as appropriate. As seen in FIGS. 43 through 45 , the space between the protrusions may be solid; alternately, as seen in FIGS. 46 through 53 , there may be openings in the spaces between the protrusions. In particular, as seen in FIGS. 46 and 47 , an alternate design of chock-type device 5 surrounds the wheel 3 from the sides, with the protrusions extending between the sides. In this configuration, the chock-type device 5 may be placed onto the wheel 3 from the side, top, or bottom, or through one of the gaps between the protrusions. The ends of the chock-type device 5 may have shoulders 6 , as seen in FIGS. 55 and 56 , to facilitate retention of the chock-type device 5 on the wheel 3 .
The configuration shown in FIGS. 48 through 53 may fit closely on the wheel, as in FIGS. 48 through 50 , or may be sized wider than the wheel to loosely surround the wheel, as in FIGS. 51 through 53 .
The chock-type device 5 may not prevent rotation of the wheel 3 when not in contact with a surface, but may allow the wheel 3 to freely rotate until it comes into contact with a surface.
In general, the chock-type device 5 may be flexible so that it can be stretched over a range of skateboard wheel diameters and widths. The chock-type device 5 may be designed so that friction and subsequent abrasion from the riding surface does not quickly wear the part out. It is desirable for the chock-type device 5 to avoid frequently departing the wheel during use, such as from striking the ground or twisting the skateboard. The retention may be accomplished through preload from stretching over the wheel, the coefficient of friction of the wheel chock material at the wheel interface, and design features that allow the device to self-center on the wheel as it comes into contact with the ground, or any combination of these. The key is that the chock-type device 5 prevents or limits rotation of the wheel when the wheel is in contact with the ground.
The chock-type device 5 shares the majority of the advantages of the block 4 , with even more universality. Additionally, the chock-type device 5 does not influence the flexibility of the skateboard. The chock-type device 5 is light, portable, and temporary, can be installed without tools, and allows the rider to use his own equipment. The chock-type device 5 has low mass, which results in insignificant changes to the mass properties of the skateboard assembly. The mass is not significant relative to the skateboard assembly, and also is considerably less than other currently available products. The mass of the chock-type device 5 is added to the wheels 3 , and thus does not change the dynamic rotational properties of the skateboard assembly. The chock-type device 5 also does not change the flexibility of the skateboard deck 1 /truck 2 combination at all, allowing the rider to adapt to the feel and weight of their own skateboard, rather than a separate training apparatus or a device that alters the skateboard flexibility. The chock-type device 5 does not require one to disassemble a skateboard to install. It does not cover or prevent access to the center, nose, or tail areas of the board, allowing for contact to surfaces and obstacles such as rails, stairs, or platforms. The chock-type device 5 is portable, and is so small and flexible that it can be carried in a shirt or pants pocket, allowing for easy transport while riding a skateboard. Anywhere from one to four chock-type devices 5 may be used to vary training difficulty, or to allow for more or less maneuvering of the skateboard. Finally, the chock-type device 5 may be used on skateboard assemblies in retail environments, sold as part of the packaging to prevent use while in a store or during transportation.
There are three specific design iterations discussed that have been manufactured and tested. Concept 1 is a cylinder design, as seen in FIG. 54 . This is one variation on the chock-type device discussed above. Concept 1 involves a simple section that covers the entire wheel's riding surface with a finite number of bumps and a band that connects all the bumps together, forming a continuous part. The cross section is uniform over entire length of the part, meaning there are no holes in the part. The device has protrusions to prevent or limit the wheel rotation. When a wheel is resting or in contact with the ground, the “band” section between the bumps rests on the riding surface. The part can be any width, but works best if it is wider than the wheel ground contact surface so that the preload and deformations from installation creates a shape that pushes on the sides of the wheel to enhance retention during use.
Concept 2 is a cage design, and functions the same as concept 1. Concept 2 could be construed as Concept 1 with holes in the bands where they would contact the wheel riding surface, as seen in FIGS. 48 through 50 . When installed, the now narrow bands connecting the bumps conform to the edges of the wheel, and not the riding surface. This enhances the wear life of the part, because the wheel is the primary element in contact with the ground, and not the band. This also enhances the retention, because the straps conform to the sides of the wheels and there are less forces acting on the part pushing it off the wheel because the part straps are not usually in contact in the ground. The bands are considerably more narrow, which can potentially make installation much easier. The grip on the wheel can be improved because the entire preload from stretching is concentrated on the sides of the wheels, making it more difficult for the part to slip off during use.
Concept 2a is an extended cage design, as seen in FIGS. 51 through 53 . It is a wider version of concept 2. This potentially enhances the retention of the part to the wheel, makes for easier installation due to increased part flexibility in the installation mode, and allows for installation on a wider range of wheel diameters and widths. It is easier to install because of the flexibility of the longer bumps. The mechanism for retaining the device in place is less reliant on preload. Because the part is a much more loose fit and because the part is wider, shifts in the location relative the wheel are less like to result in departure from the wheel during use.
Whereas, the devices and methods have been described in relation to the drawings and claims, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.
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A device for limiting rotation of a wheel, such as a wheel on a skateboard, comprising a physical stop secured against one wheel of the skateboard. Multiple physical locks may be used, each secured against single wheel. The physical stop may comprise a block of resilient material placed in a semi-compressed state into the gap between the skateboard deck and the wheel such that the block exerts pressure on the wheel sufficient to prevent the wheel from freely rotating. Alternately, the physical stop may comprise a holder at least partially surrounding the wheel and at least one protrusion from the holder adjacent a rolling surface of the wheel, where the protrusion is capable of functioning as a chock and substantially preventing the wheel from rolling against a surface.
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INCORPORATION BY REFERENCE
[0001] This application claims the benefit of U.S. Provisional Application No. 61/378,358, “Enhanced Method for Voltage Compensation in a Tester” filed on Aug. 30, 2010, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
[0003] Generally, integrated circuits (IC) testing uses automated test equipment (ATE) and an adapter board specific to an integrated circuits product to test each device under test (DUT) of the product. In an example, each packaged IC device of a product can be inserted into a socket on the adapter board, and the adapter board is suitably connected to the ATE. Then, the ATE tests the packaged IC device via the adapter board. For example, the ATE sends test signals to the packaged IC device and receives response signals from the packaged IC device via the adapter board.
SUMMARY
[0004] Aspects of the disclosure provide a method for testing an electronic device. The method includes supplying a first voltage output from a voltage regulator to a first power connection terminal of the electronic device to provide power to the electronic device, providing to the voltage regulator a second voltage on a second power connection terminal of the electronic device that is in connection with the first power connection terminal by a first circuit of the electronic device, regulating, using the voltage regulator, the first voltage based on a comparison of the second voltage and a target voltage, and determining whether the electronic device meets a performance requirement while the first voltage is regulated.
[0005] To determine whether the electronic device meets the performance requirement while the first voltage is regulated, the method includes sending test signals to first signal terminals of the electronic device, and receiving response signals from second signal terminals of the electronic device.
[0006] In an embodiment, the method includes supplying a third voltage output from the voltage regulator to a third power connection terminal of the electronic device, providing to the voltage regulator a fourth voltage on a fourth power connection terminal of the electronic device that is in connection with the third power connection terminal by a second circuit of the electronic device, and regulating, using the voltage regulator, at least one of the first voltage and the third voltage based on a voltage differential between the second voltage and the fourth voltage. In an example, the method includes regulating, using the voltage regulator, at least one of the first voltage and the third voltage so as to cause the voltage differential between the second voltage and the fourth voltage to be equal to the target voltage.
[0007] Aspects of the disclosure provide an integrated circuit (IC) that is tested according to the method.
[0008] Aspects of the disclosure also provide a test system for testing a device under test (DUT). The test system includes a tester, a voltage regulator controller and an adapter board configured for testing the DUT. The adapter board includes a first conductive path configured to supply a first voltage output from a voltage regulator to a first power connection terminal of the DUT to provide power to the DUT, and a second conductive path configured to provide to the voltage regulator the second voltage on a second power connection terminal of the DUT that is in connection with the first power connection terminal by a first circuit within the DUT. The voltage regulator controller is configured to cause the voltage regulator to regulate the first voltage based on the second voltage received by the voltage regulator and a target voltage. The tester is configured to perform a functional test of a circuit on the DUT while the first voltage is regulated.
[0009] In an embodiment, the adapter board further includes multiple testing paths configured to send the test signals generated by the tester to first signal connection terminals of the DUT and to receive response signals from second signal connection terminals of the DUT.
[0010] According to an aspect of the disclosure, the adapter board includes a third conductive path configured to supply a third voltage output from the voltage regulator to a third power connection terminal of the DUT, and a fourth conductive path configured to provide to the voltage regulator a fourth voltage on a fourth power connection terminal of the DUT that is in connection with the third power connection terminal by a second circuit within the DUT.
[0011] Aspects of the disclosure also provide the adapter board that is configured to test the DUT.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Various embodiments of this disclosure that are proposed as examples will be described in detail with reference to the following figures, wherein like numerals reference like elements, and wherein:
[0013] FIG. 1 shows a block diagram of a test system example 100 according to an embodiment of the disclosure;
[0014] FIG. 2 shows a block diagram of another test system example 200 according to an embodiment of the disclosure;
[0015] FIG. 3 shows a flowchart outlining a process example 300 for the test system 100 to test the device under test (DUT) 130 according to an embodiment of the disclosure; and
[0016] FIG. 4 shows a flowchart outlining a process example 400 for the test system 200 to test the DUT 230 according to an embodiment of the disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0017] FIG. 1 shows a block diagram of a test system example 100 that tests a device under test (DUT) 130 according to an embodiment of the disclosure. The test system 100 includes a tester 120 , a voltage regulator 140 , and an interface module 110 . These elements are coupled together as shown in FIG. 1 .
[0018] The DUT 130 can be any suitable device, such as an integrated circuit (IC) chip, a packaged IC device, and the like. The DUT 130 includes connection terminals, such as signal connection terminals 137 , and power connection terminals 135 A and 13513 , and the like. In an example, the connection terminals 137 , 135 A and 135 B are pads on an IC chip. In another example, the connection terminals 137 , 135 A and 135 B are pins of a pin grid array (PGA) package. In another example, the connection terminals 137 , 135 A and 13513 are solder balls of a ball grid array (BGA) package.
[0019] According to an aspect of the disclosure, the power connection terminals 135 A and 135 B are configured to have substantially the same voltage potential during operation. In an embodiment, the power connection terminals 135 A and 13513 are configured to provide a power supply, such as VDD, VSS, and the like, to circuits within the DUT 130 during operation. In an example, the power connection terminals 135 A and 135 B are coupled together internally by an internal circuit 131 of the DUT 130 , such as an internal power bus, a power distribution grid, a pad bonded to the two terminals, and the like. Thus, a voltage V″ on the power connection terminal 135 B is a function of a voltage V′ on the power connection terminal 135 A. In an embodiment, the voltage V′ on the power connection terminal 135 A is substantially the same as the voltage V″ on the power connection terminal 13513 . It is noted that the DUT 130 can include other power connection terminals that are configured to provide other power supply of same or different voltage, such as ground and the like.
[0020] The interface module 110 provides suitable interfaces for coupling the voltage regulator 140 and the tester 120 with the DUT 130 during testing to test the DUT 130 . In an embodiment, the interface module 110 is an adapter board having printed circuits coupled with probe contactors. The interface module 110 is suitably configured to connect selected terminals on the DUT 130 to the tester 120 and the voltage regulator 140 . The interface module 110 is installed on a prober (not shown). The prober is suitably connected to the tester 120 and the voltage regulator 140 via suitable connectors, such as Universal Serial Bus (USB), Peripheral Component Interconnect (PCI), PCI Extensions for Instrumentation (PXI), Local Area Network (LAN), General Purpose Interface Bus (GPIB), and the like. Further, the prober is suitably configured to force the probe contactors to make electrical contacts with the signal connection terminals 137 , and the power connection terminal 135 A and 135 B.
[0021] In another example, the interface module 110 is an adapter board having printed circuits coupled with a socket. The socket has suitable contactors, such as pin contactors configured to make electrical contacts with pins, solder ball contactors configured to make electrical contacts with solder balls, and the like. The interface module 110 is installed on a handler (not shown) and the handler is suitably connected with the tester 120 and the voltage regulator 140 via suitable connectors, such as USB, PCI, PXI, LAN, GPIB, and the like. During testing, the DUT 130 is plugged into the socket, and the contactors of the socket are forced to make electrical contacts with the signal connection terminals 137 and the power connection terminals 135 A and 135 B.
[0022] The interface module 110 includes various leads, such as solder traces, wires, cables, ribbon cable, jumpers, and the like, and suitable electrical components, such as resistors, capacitors, diodes, transistors, and the like, that form paths, such as conductive paths, signal traces and the like, between the DUT 130 and the tester 120 or the DUT 130 and the voltage regulator 140 .
[0023] According to an embodiment of the disclosure, the interface module 110 includes separate paths PATH 1 and PATH 2 that are suitably configured to respectively interface the power connection terminals 135 A and 1358 with the voltage regulator 140 . For example, in an embodiment, the path PATH 1 is configured to have relatively high conductivity for providing power supply to the power connection terminal 135 A and the path PATH 2 is configured to prevent direct current flowing through, such that a voltage drop on the path PATH 2 is substantially equal to zero. In an example, the path PATH 1 includes printed wires of relatively large width and/or thickness. The path PATH 2 is connected to a sense pin of the voltage regulator 140 that has relatively high input impedance, such that no current flows on the path PATH 2 and the voltage drop on the path PATH 2 is substantially equal to zero. In another embodiment, the path PATH 2 includes a buffer (not shown) configured to have relatively high input impedance to prevent current flowing through. In another embodiment, the path PATH 2 includes a low pass filter (not shown) to remove noises.
[0024] The voltage regulator 140 is configured to provide one or more power supplies to the DUT 130 . In addition, in an embodiment, the voltage regulator 140 includes one or more sense pins configured to have relatively high input impedance. The voltage regulator 140 is configured to sense voltages provided on the sense pins. In an example, the path PATH 2 is coupled to a sense pin of the voltage regulator 140 . According to an aspect of the disclosure, the voltage regulator 140 is configured to adjust a voltage V of a power supply output to the path PATH 1 based on a voltage V″′ received from the path PATH 2 . In addition, in an embodiment, the voltage regulator 140 receives a target voltage that is a reference voltage. Then, the voltage regulator 140 regulates the voltage V output to the path PATH 1 based on a comparison of the voltage V″′ received from the path PATH 2 and the target voltage. In an example, the voltage regulator 140 regulates the voltage V output to the path PATH 1 to cause the voltage V″′ received from the path PATH 2 to be equal to the target voltage.
[0025] In an embodiment, the tester 120 is configured to provide test signals to the DUT 130 via the interface module 110 and to receive response signals of the DUT 130 via the interface module 110 . Based on the response signals, the tester 120 then determines whether the DUT 130 passes or fails tests. It is noted that the paths on the interface module 110 for delivering the test signals and the response signals are suitably configured according to suitable signal delivering requirements.
[0026] According to an aspect of the disclosure, contact resistance of the contactors on the interface module 110 with the connection terminals 137 , 135 A and 135 B on the DUT 130 may vary. In an example, contact resistance is different for different DUTs 130 of same design. In another example, when the contactors are released from a first contact with a DUT 130 , and are forced to make a second contact with the same DUT 130 , such as during a retest, the contact resistance of the first contact is different from the contact resistance of the second contact.
[0027] According to an embodiment of the disclosure, the power connection terminals 135 A and 135 B, the internal circuit 131 , the paths PATH 1 and PATH 2 and the voltage regulator 140 form a feedback loop during testing. The feedback loop is configured to compensate for variation, such as the contact resistance variation, temperature variation, and the like, and thus to keep the voltage V′ of the power supply within the DUT 130 to be substantially the same, for different DUTs 130 or for retests.
[0028] During testing, in an example, the voltage regulator 140 outputs the power supply having the voltage V to the path PATH 1 . The path PATH 1 is configured to deliver the power supply to the power connection terminal 135 A. The path PATH 1 has a voltage drop that varies for a different DUT 130 or retest due to the variation of the contact resistance, for example. Thus, the voltage V′ on the power connection terminal 135 A is different from the voltage V output to the path PATH 1 . Further, the voltage V″ on the power connection terminal 135 B is substantially the same as the voltage V′ on the power connection terminal 135 A. The voltage V″ is sensed and feedback by the path PATH 2 to the voltage regulator 140 . In an example, the path PATH 2 is configured to have substantially zero voltage drop, thus the voltage V″′ received by the voltage regulator 140 from the path PATH 2 is substantially the same as the voltage V″ on the power connection terminal 135 B. Then, the voltage regulator 140 regulates the voltage V provided to the path PATH 1 based on the voltage V″′ received from the path PATH 2 . It is noted that, in an example, when the voltage regulator 140 regulates the voltage V provided to the path PATH 1 to keep the voltage V″′ to be a specific value, the voltage V′ on the power connection terminal 135 A is also equal to the specific value.
[0029] In an example, the voltage regulator 140 receives a target voltage, and regulates the voltage V provided to the path PATH 1 to cause the voltage received from the path PATH 2 to be equal to the target voltage, or some other predefined relationship to the target voltage. Thus, the voltage V′ on the power connection terminal 135 A is equal to the target voltage.
[0030] Further, in an embodiment, while simultaneously to monitoring and adjusting the voltage V, the tester 120 provides test signals to the DUT 130 and receives response signals from the DUT 130 . Based on the response signals, the tester 120 determines whether the DUT 130 passes or fails the tests. Thus, for a different DUT 130 or a retest, tests are taken under substantially the same power supply condition that the voltage V′ on the power connection terminal 135 A is substantially the same, for example, being equal to the target voltage or some other predefined relationship to the target voltage.
[0031] It is noted that, in an example, different DUTs 130 consume different current due to process variation, temperature variation, and the like. In another example, different tests, such as different test vectors, and the like, cause the same DUT 130 to consume different current. The different current causes the voltage drops on the path PATH 1 to be different. In the example, the voltage regulator 140 regulates the voltage V provided to the path PATH 1 to cause the voltage V″′ received from the path PATH 2 to be equal to the target voltage or some other predefined relationship to the target voltage. Thus, in an embodiment, the voltage V′ on the power connection terminal 135 A can be maintained at substantially the same level for different DUTs 130 , and for different tests so as to provide a controlled testing environment.
[0032] FIG. 2 shows a block diagram of another test system example 200 for testing a DUT 230 according to an embodiment of the disclosure. The test system 200 includes a tester 220 , and a handler (not shown). An adapter board 210 with a socket 211 is suitably installed on the handler to interface the tester 220 with the DUT 230 . The tester 220 includes a voltage regulator 240 for providing power supplies during testing. These elements are coupled together as shown in FIG. 2 .
[0033] In the FIG. 2 example, the DUT 230 is in a ball grid array (BGA) package with solder balls 235 A, 235 B, 236 A and 236 B. The DUT 230 includes a first power bus 231 and a second power bus 232 . In the FIG. 2 example, the first power bus 231 is a VDD bus that couples the solder balls 235 A and 235 B, such that a voltage VDD′ on the solder balls 235 A is substantially the same as a voltage VDD″ on the solder ball 235 B. Similarly, the second power bus 232 is a VSS bus that couples the solder balls 236 A and 236 B, such that a voltage VSS′ on the solder balls 236 A is substantially the same as a voltage VSS″ on the solder ball 236 B.
[0034] The adapter board 210 with the socket 211 includes various leads and suitable circuit components that form conductive paths, signal traces, and the like between the DUT 230 and the tester 220 .
[0035] Specifically, in an example, the socket 211 includes ball contactors 212 configured to make electrical contacts with the solder balls 235 A, 235 B, 236 A and 236 B of the DUT 230 . According to an embodiment of the disclosure, the contact resistance of the ball contactors 212 to the solder balls 235 A, 235 B, 236 A and 236 E of the DUT 230 varies for different DUT 230 . In addition, when the solder ball contactors 212 are released from a first contact and then are forced to make a second contact with the solder balls 235 A, 235 B, 236 A and 236 B of the same DUT 230 , the contact resistance of the first contact can be different from the contact resistance of the second contact.
[0036] Further, in the FIG. 2 example, the adapter board 210 includes a first path PATH 1 for interfacing the solder balls 235 A with the voltage regulator 240 and a second path PATH 2 for interfacing the solder ball 235 B with the voltage regulator 240 . The first path PATH 1 delivers a power supply provided by the voltage regulator 240 to the solder balls 235 A, and the second path PATH 2 delivers a sensed voltage on the solder balls 235 B back to the voltage regulator 240 . Further, the adapter board 210 includes a third path PATH 3 for interfacing the solder balls 236 A with the voltage regulator 240 and a fourth path PATH 4 for interfacing the solder ball 236 B with the voltage regulator 240 . The third path PATH 3 delivers a power supply, such as Ground, provided by the voltage regulator 240 to the solder balls 236 A, and the fourth path PATH 4 delivers a sensed voltage on the solder balls 23613 back to the voltage regulator 240 .
[0037] According to an embodiment of the disclosure, the paths PATH 1 , PATH 2 , PATH 3 and PATH 4 are suitably configured according to signal or power delivering requirements. For example, in an embodiment, the first path PATH 1 includes first printed wires in a first layer of the adapter board 210 . The first layer has relatively large thickness, and the first printed wires have relatively large width. Thus, the first path PATH 1 is configured to have relatively good conductivity. Similarly, the third path PATH 3 includes second printed wires in a second layer. The second layer has relatively large thickness, and the second printed wires have relatively large width. Thus, the third path PATH 3 has relatively good conductivity. However, the first path PATH 1 and the third path PATH 3 have voltage drops or rises. In addition, due to the variation of the contact resistance, the voltage drops also vary. Specifically, in an example, the voltage regulator 240 provides a voltage VDD, for example, a positive voltage, to the first path PATH 1 for delivering, and the voltage VDD drops to the voltage VDD′ on the solder balls 235 A. Similarly, the voltage regulator 240 provides a voltage VSS, such as Ground, a negative voltage, and the like, to the third path PATH 3 for delivering, and the voltage VSS rises to the voltage VSS′ on the solder balls 236 A.
[0038] In another embodiment, a voltage differential changes due to the voltage drop and/or rise on the first path PATH 1 and the third path PATH 3 , and the variation of the contact resistance. Specifically, in an example, the voltage regulator 240 provides a voltage VDD, for example, a positive voltage, to the first path PATH 1 for delivering, and the voltage VDD drops to the voltage VDU on the solder balls 235 A. Similarly, the voltage regulator 240 provides a voltage VSS, such as Ground, a negative voltage, and the like, to the third path PATH 3 for delivering, and the voltage VSS rises to the voltage VSS′ on the solder balls 236 A. A voltage differential of the voltage VDU on the solder balls 235 A to the voltage VSS′ on the solder balls 236 A varies as a function of the voltage drop on the first path PATH 1 , the voltage rise on the third path PATH 3 , and the variation of the contact resistance.
[0039] Further, the second path PATH 2 and the fourth path PATH 4 are configured to deliver the sensed voltages to the voltage regulator 240 . In an embodiment, the second path PATH 2 and the fourth path PATH 4 are connected to the sense pins of the voltage regulator 240 . The sense pins are configured to have relatively high input impedance, such that there is no current on the second path PATH 2 and the fourth path PATH 4 , and voltage drops on the second path PATH 2 and the fourth path PATH 4 are substantially equal to zero. Thus, a voltage VDD″′ received by the voltage regulator 240 from the second path PATH 2 is substantially the same as the voltage VDD″ on the solder ball 235 B, and a voltage VSS″′ received by the voltage regulator 240 from the fourth path PATH 4 is substantially the same as the voltage VSS″ on the solder ball 236 B. It is noted that, in an example, the second path PATH 2 and the fourth path PATH 4 may include suitable circuits, such as buffers, to prevent direct current flowing there through.
[0040] In addition, in an embodiment, the second path PATH 2 includes a low pass filter network 217 , and the fourth path PATH 4 includes a low pass filter network 218 . The low pass filter networks 217 and 218 are configured to reduce noises in the delivered voltage signals. It is noted that, in another embodiment, the low pass filter networks 217 and 218 are omitted.
[0041] The voltage regulator 240 is configured to provide power supplies to the DUT 230 . In addition, in an embodiment, the voltage regulator 240 includes sense pins configured to have relatively high input impedance. The voltage regulator 240 is configured to sense voltages provided on the sense pins. In an example, the second path PATH 2 and the fourth path PATH 4 are respectively coupled to sense pins of the voltage regulator 240 . According to an aspect of the disclosure, the voltage regulator 240 is configured to adjust the voltage VDD of a first power supply output to the first path PATH 1 based on the voltage VDD″′ received from the second path PATH 2 , and adjust the voltage VSS of a second power supply output to the third path PATH 3 based on the voltage VSS″′ received from the fourth path PATH 4 .
[0042] In addition, in an embodiment, the voltage regulator 240 receives one or more target voltages that are reference voltages, and regulates the voltage VDD and the voltage VSS based on comparisons of the voltages VDD″′ and VSS″′ to the one or more target voltages. In an example, the voltage regulator receives a first target voltage and a second target voltage that are reference voltages. The voltage regulator 240 regulates the voltage VDD to cause the voltage VDD″′ to be equal to the first target voltage, and regulates the voltage VSS to cause the voltage VSS″′ to be equal to the second target voltage. In another example, the voltage regulator 240 regulates at least one of the voltages VDD and VSS based on a comparison of the sensed voltage differential (VDD″′ VSS″′) and the target voltage. In an example, the voltage regulator 240 regulates the voltage VDD output to the first path PATH 1 and the voltage VSS output to the third path PATH 3 to cause the voltage differential (VDD″′-VSS″′) received from the second path PATH 2 and the fourth path PATH 4 to be equal to the target voltage.
[0043] It is noted that the adapter board 210 can include other paths (not shown) for providing test signals from the tester 220 to the DUT 230 , and/or providing response signals from the DUT 230 to the tester 220 . In an embodiment, while maintaining the voltage differential (VDD″′-VSS″′) at a controlled level, various functional tests, such as logic tests, memory tests, and the like are performed on circuitry in the DUT 230 . Based on the response signals, the tester 220 then determines whether the DUT 230 passes or fails tests.
[0044] According to an aspect of the disclosure, contact resistance of the ball contactors 212 with the solder balls on the DUT 230 varies. In an example, contact resistance is different for different DUT 230 . In another example, contact resistance is different when contactors are released from a first contact with a DUT 230 , and are forced to make a second contact with the same DUT 230 , for example, during a retest.
[0045] According to an embodiment of the disclosure, the solder balls 235 A and 235 B, the first power bus 231 , the first path PATH 1 , the second path PATH 2 and the voltage regulator 240 form a first feedback loop during testing. The first feedback loop is configured to compensate for the variation of the contact resistance, and thus to keep the voltage VDD′ on the solder balls 235 A to be substantially the same for different DUT 230 or for a retest. Further, the solder balls 236 A and 236 B, the second power bus 232 , the third path PATH 3 , the fourth path PATH 4 and the voltage regulator 240 form a second feedback loop during testing. The second feedback loop is configured to compensate for the variation of the contact resistance, and thus to keep the voltage VSS′ on the solder balls 236 A to be substantially the same for different DUT 230 or for a retest.
[0046] Specifically, during testing, the voltage regulator 240 provides the voltage VDD onto the first path PATH 1 of the adapter board 210 . The first path PATH 1 delivers the voltage VDD′ onto the solder balls 235 A of the DUT 230 that provides a positive power supply to internal circuits of the DUT 230 . It is noted that, in an example, due to the voltage drop on the first path PATH 1 , the voltage VDD′ on the solder balls 235 A is different from the voltage VDD provided by the voltage regulator 240 onto the first path PATH 1 . In addition, due to the variation of the contact resistance, the voltage drop from the voltage VDD to the voltage VDD′ may vary from DUT to DUT or from test to test.
[0047] Further, the voltage VDD″ on the solder ball 235 B is substantially the same as the voltage VDD′ on the solder balls 235 A, and the second path PATH 2 is configured, in an embodiment, to have substantially zero voltage drop, thus the voltage VDD″′ received by the voltage regulator 240 is substantially equal to the voltage VDD″ on the solder ball 235 B and is substantially equal to the voltage VDD′ on the solder ball 235 A. Then, the voltage regulator 240 regulates the voltage VDD supplied to the first path PATH 1 based on the voltage VDD″′ to keep the voltage VDD′ on the solder ball 235 A to be substantially the same for different DUT 230 or retests, for example.
[0048] Similarly, the voltage regulator 240 provides the voltage VSS onto the third path PATH 3 of the adapter board 210 . The third path PATH 3 delivers the voltage VSS′ onto the solder balls 236 A of the DUT 230 that provides, for example, Ground to internal circuits of the DUT 230 . It is noted that, in an example, due to the voltage rise on the third path PATH 3 , the voltage VSS′ on the solder balls 236 A is different from the voltage VSS provided by the voltage regulator 240 onto the third path PATH 3 . In addition, due to the variation of the contact resistance, the voltage rise from the voltage VSS to the voltage VSS′ may vary.
[0049] Further, the voltage VSS″ on the solder ball 236 B is substantially the same as the voltage VSS′ on the solder balls 236 A, and the fourth path PATH 4 is configured to have substantially zero voltage rise, thus the voltage VSS″′ received by the voltage regulator 240 is substantially equal to the voltage VSS″ on the solder ball 236 B and is substantially equal to the voltage VSS′ on the solder ball 236 A. Then, the voltage regulator 240 regulates the voltage VSS supplied to the third path PATH 3 based on the voltage VSS″′ to keep the voltage VSS′ on the solder ball 236 A to be substantially the same for different DUT 230 or retests, for example.
[0050] In an example, the voltage regulator 240 receives a target voltage that is a reference voltage, and regulates at least one of the voltage VDD supplied to the first path PATH 1 and the voltage VSS supplied to the third path PATH 3 to cause the voltage differential (VDD″′-VSS″′) received from the second path PATH 2 and the fourth path PATH 4 to be equal to the target voltage. Thus, the voltage differential (VDD′-VSS′) to the internal circuits of the DUT is substantially equal to the target voltage.
[0051] In an embodiment, the tester 220 waits for a time period for the voltage regulator 240 to stably maintain the voltage differential (VDD″′-VSS″′) equal to the target voltage. Then, the tester 220 provides test signals to the DUT 230 and receives response signals from the DUT 230 through signal leads, which are not seen in FIG. 2 . Based on the response signals, the tester 220 determines whether the DUT 230 passes or fails the tests.
[0052] In an embodiment, the test system 200 includes a voltage regulator controller 245 . The voltage regulator controller 245 provides control parameters, such as the target voltage, and the like, to the voltage regulator 240 to cause the voltage regulator 240 to regulate its output voltages in a desired manner, for example, as a function of input voltages. It is noted that the voltage regulator controller 245 can be implemented in various portions of the test system 200 , such as in the tester 220 , on the adapter board 210 , within the voltage regulator 240 , and the like.
[0053] FIG. 3 shows a flowchart outlining a process example 300 for the test system 100 to test the DUT 130 according to an embodiment of the disclosure. The process starts at S 301 and proceeds to S 310 .
[0054] At S 310 , the first path PATH 1 delivers a power supply from the voltage regulator 140 to a first power connection terminal, such as a power connection terminal 135 A of a DUT 130 . Specifically, the voltage regulator 140 generates the power supply having the voltage V, and supplies the voltage V onto the first path PATH 1 of the interface module 110 . In an embodiment, the first path PATH 1 is configured to have relatively large conductivity for delivering the power supply. However, due to the current flowing through the first path PATH 1 , the first path PATH 1 has a voltage drop, and the voltage V′ on the power connection terminal 135 A in FIG. 1 is different from the voltage V supplied to the first path PATH 1 . In addition, due to the variation of the contact resistance of a contactor on the interface module 110 with the power connection terminal 135 A, the voltage drop of voltage actually supplied to the DUT 130 may be different for different DUTs 130 or retests. Within the DUT 130 , the internal circuit 131 couples the power connection terminal 135 A with the power connection terminal 136 B, thus the voltage V″ on the power connection terminal 135 B is substantially the same as the voltage V′ on the power connection terminal 135 A.
[0055] At S 320 , the second path PATH 2 delivers a sensed voltage from a second power connection terminal, such as the power connection terminal 135 B, of the DUT 130 in FIG. 1 to the voltage regulator 140 . Specifically, the second path PATH 2 is configured to connect to the tester sense input which is a high impedance pin, thus the voltage drop on the second path PATH 2 is substantially equal to zero. Thus, the voltage V″′ received by the voltage regulator 140 from the second path PATH 2 is substantially equal to the voltage V″ on the power connection terminal 135 B, and is substantially equal to the voltage V′ on the power connection terminal 135 A.
[0056] At S 330 , in an embodiment, the voltage regulator 140 regulates the voltage V supplied to the first path PATH 1 based on the voltage V″′ received from the second path PATH 2 . In an embodiment, the voltage regulator 140 regulates the voltage V supplied to the first path PATH 1 to keep the voltage V″′ received from the second path PATH 2 to be substantially the same for different DUT 130 or retests. Thus, the voltage V′ on the power connection terminal 135 A is kept substantially the same for different DUTs 130 or retests. In an example, the voltage regulator 140 receives a target voltage, and regulates the voltage V supplied to the first path PATH 1 to keep the voltage V″′ equal to the target voltage. Thus, the voltage V′ on the power connection terminal 135 A is substantially equal to the target voltage for different DUT 130 or retests.
[0057] At S 340 , in an embodiment, the tester 120 provides test signals to signal connection terminals 137 of the DUT 130 and receives response signals from the signal connection terminals 137 . In an embodiment, when the voltage regulator 140 stably regulates the voltage V supplied to the first path PATH 1 to keep the voltage V″′ received from the second path PATH 2 equal to the target voltage, the tester 120 provides test signals to signal connection terminals 137 of the DUT 130 and receives response signals from the signal connection terminals 137 . Based on the response signals, the tester 120 determines whether the DUT 130 passes or fails the tests. Then the process proceeds to S 399 and terminates.
[0058] FIG. 4 shows a flowchart outlining a process example 400 for the test system 200 to test the DUT 230 according to an embodiment of the disclosure. The process starts at S 401 and proceeds to S 410 .
[0059] At S 410 , the first path PATH 1 delivers the power supply VDD from the voltage regulator 240 to the power connection terminal 235 A of the DUT 230 , and the third path PATH 3 delivers the power supply VSS from the voltage regulator 240 to the power connection terminal 236 A of a DUT 230 .
[0060] At S 420 , the second path PATH 2 delivers a sensed voltage VDD″′ from the power connection terminal 23513 , of the DUT 230 to the voltage regulator 240 and the fourth path PATH 4 delivers a sensed voltage VSS″′ from the power connection terminal 236 B, of the DUT 230 to the voltage regulator 240 .
[0061] At S 430 , the voltage regulator 240 regulates at least one of VDD and VSS based on a voltage differential (VDD″′-VSS″′). In an embodiment, the voltage regulator 240 regulates at least one of VDD and VSS to maintain the voltage differential (VDD″′-VSS″′) to be substantially the same for different DUT 230 or retests. In an example, the voltage regulator 240 receives the reference target voltage, and regulates at least one of VDD and VSS to keep the voltage differential (VDD″′-VSS″′) to be substantially equal to the reference target voltage.
[0062] At S 440 , the tester 220 provides test signals to the DUT 230 and receives response signals from the DUT 230 while maintaining the voltage differential at a controlled level. Based on the response signals, the tester 220 determines whether the DUT 230 passes or fails the tests. Then the process proceeds to S 399 and terminates.
[0063] While the invention has been described in conjunction with the specific embodiments thereof that are proposed as examples, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, embodiments of the invention as set forth herein are intended to be illustrative, not limiting. There are changes that may be made without departing from the scope of the invention.
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Aspects of the disclosure provide a method for testing an electronic device. The method includes supplying a first voltage output from a voltage regulator to a first power connection terminal of the electronic device to provide power to the electronic device, providing to the voltage regulator a second voltage on a second power connection terminal of the electronic device that is in connection with the first power connection terminal by a first circuit of the electronic device, regulating, using the voltage regulator, the first voltage based on a comparison of the second voltage and a target voltage, and determining whether the electronic device meets a performance requirement while the first voltage is regulated.
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This application claims the benefit of U.S. Provisional Application No. 60/483,570 filed on Jun. 27, 2003, which is hereby incorporated herein by reference in its entirety.
The present invention relates generally to fluid transfer devices and more particularly to a seal for preventing fluid leakage along a drive shaft of the device.
BACKGROUND OF THE INVENTION
Shaft seals are known devices to prevent fluid leakage along a drive shaft of a pump, motor or other fluid transfer device. One known type of shaft seal is a viscous seal. The viscous seal acts like a screw pump, forcing any leaking fluid back into the housing of the fluid transfer device. In a conventional design, the viscous seal is attached to the housing and the drive shaft rotates within a bore in the housing that is sealed by the viscous seal. The viscous seal, if working properly, will not be lubricated by the leaking fluid over its entire length since the leakage will be stopped before reaching the outboard end of the seal. Thus, the drive shaft and the viscous seal will be dry and free from lubrication over a portion thereof. For this reason, prior art viscous seals are designed not to contact the drive shaft to prevent damage to the seal or galling of the drive shaft. The effectiveness of the seal is directly proportional to the radial gap between the seal and the drive shaft. The seal can be made more effective by reducing the gap.
Prior art viscous seals have been effective for preventing leakage of relatively viscous fluids having a viscosity of about 10,000 centipoise or higher. The effectiveness of viscous seals, however, decreases as the viscosity of the leakage fluid decreases. At relatively low viscosities on the order of about 100 centipoise, other means are needed to increase the effectiveness of the viscous seal. As above noted, viscous seal performance can be improved by decreasing the clearance between the drive shaft and the seal, but there are practical limits to maintaining the alignment between the drive shaft and seal in order to prevent contact between the drive shaft and seal. Another technique is to increase the viscosity of the leakage fluid at the seal by cooling the fluid, either actively or passively. The known cooling techniques, however, may not always be suitable for a given application or can introduce undesired additional cost and/or maintenance.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a viscous seal for fluid transfer devices that deviates from the conventional wisdom of avoiding contact between the seal and a rotating drive shaft of the fluid transfer device. Instead of avoiding contact, contact between the seal and drive shaft is used to effect axial alignment of a sealing sleeve with the shaft. As a result, the viscous seal is compliant in that the sealing sleeve can follow the axis of the drive shaft. Accordingly, the sealing sleeve can fit snugly around the drive shaft for more effective prevention of leakage of low or any viscosity fluid along the drive shaft, but without any significant radial load being applied to the sealing sleeve that might cause undue wear or damage due to galling. Moreover, the viscous seal can be manufactured easily and inexpensively.
According to the present invention, a compliant viscous seal for a drive shaft comprises an outer body having a shaft hole for passage therethrough of drive shaft to be sealed by the viscous seal, and a sealing sleeve extending axially in the hole and having an inner surface closely surrounding the shaft to effect light contact therewith such that the sealing sleeve can track any angular shifting or radial translating movement of the drive shaft. The inner surface has formed therein a helical groove for preventing leakage of fluid along the shaft when the shaft is rotated within the sealing sleeve. An annular gap is provided between coextensive axial portions of the outer body and sealing sleeve to permit limited pivotal movement of the sealing sleeve relative to the outer body for allowing the sealing sleeve to coaxially align with the shaft when in use, and an annular seal is provided both to seal the annular gap thereby to prevent leakage around the outside of the sealing sleeve and to support the sealing sleeve within the outer body while allowing the sealing sleeve to pivot with a gimbal action within the outer body.
The annular seal preferably is flexible and most preferably is resilient. The annular seal can be radially interposed between the sealing sleeve and outer body. In particular, the annular seal, such as an O-ring, can be retained in an annular groove formed in one of the outer body and sealing sleeve, and most preferably in the sealing sleeve. The portion of the annular gap in the region of the resilient annular seal can have a radial dimension less than the radial dimension more remote from the resilient annular seal for more effective sealing of the gap.
Further in accordance with the invention, an anti-rotation device is provided to inhibit rotation of the annular seal relative to the outer body while allowing the sealing sleeve to pivot with a gimbal action within the outer body. The anti-rotation device preferably includes one or more keys and slots. For example, aligned slots can be formed in the inner surface of the hole and an outer surface of the sealing sleeve, and a key can be disposed in the radially aligned slots to prevent rotation of the sealing sleeve relative to the outer body, while still permitting the aforesaid pivoting movement.
The outer body of the viscous seal can be formed by an outer annular sleeve that can be attached to the housing of the fluid transfer device. In another configuration, the outer body can be unitary with the housing of the fluid transfer device.
The compliant viscous seal of the invention generally can be used in any fluid transfer device and has particular application in a gear pump.
Further features of the present invention will become apparent to those skilled in the art upon reviewing the following specification and attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a fluid transfer device showing a compliant viscous seal according to the present invention in relation to a cover plate forming part of the fluid containment housing of the fluid transfer device.
FIG. 2 is an inner view of the cover plate and compliant viscous seal of FIG. 1 , with a drive shaft extending through the compliant viscous seal.
FIG. 3 is an enlarged fragmentary cross-sectional view taken along the line 3 - 3 of FIG. 2 , with the drive shaft removed.
FIG. 4 is an enlarged inner axial portion of FIG. 3 .
FIG. 5 is an exploded view of another embodiment of a compliant viscous seal according to the present invention, configured for mounting to a housing of a fluid transfer device.
FIG. 6 is an outer view the compliant viscous seal of FIG. 5 .
FIG. 7 is a cross-sectional view taken substantially along the lines 8 - 8 of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings and initially to FIGS. 1 and 2 , a fluid transfer device is indicated generally at 10 . The fluid transfer device 10 may be of any design aside from the provision of a compliant viscous seal according the present invention, an exemplary embodiment of which is indicated generally at 12 . Consequently, there is shown only the part of the housing 14 of the fluid transfer device through which a drive shaft 16 extends. As illustrated, such housing part is a cover plate 18 . As will be appreciated by those skilled in the art, the fluid transfer device will include other components for carrying out its particular function, be it a fluid pump, fluid motor, etc. In addition, the housing will contain a fluid whose leakage along the drive shaft is stopped by the compliant viscous seal 12 . Although not shown, one or more packing or lip seals can be provided outwardly of the compliant viscous seal, as deemed necessary, to provide a static, fluid tight seal between the drive shaft and the outer body.
The compliant viscous seal 12 for the drive shaft 16 comprises an outer body 20 having a shaft hole 22 for passage therethrough of the drive shaft 16 , and a sealing sleeve 24 extending axially in the hole 22 . In the illustrated embodiment, the outer body 20 is formed by an outer sleeve that if fixed, as by press-fitting, in a through bore in the cover plate 18 of the housing 14 . The outer body can be otherwise configured and secured to the housing, or the outer body can be unitary (formed as one piece) with the cover plate or other part of the housing, as may be desired for different applications.
The sealing sleeve 24 has an inner surface 30 closely surrounding the drive shaft 16 , preferably with a snug fit such that there is essentially no or a minute clearance between the inner surface 30 and corresponding outer surface of the drive shaft. The inner surface 30 has formed therein one or more helical grooves 32 for preventing leakage of fluid along the drive shaft 16 when the drive shaft is rotated within the sealing sleeve. Rotation of the drive shaft within the sealing sleeve provides a motive force to any leakage fluid, causing the fluid to be reversely pumped back toward the interior of the housing 14 by virtue of the oppositely turned helical groove or grooves 32 , as is well known in the art. That is, the helical groove or grooves have an opposite or reverse “hand” or flight direction as the rotation of drive shaft, such that when drive shaft rotates, the groove or grooves “pump” any fluid leaking down along drive shaft back toward the interior of the housing. The herein reference to a helical groove, unless otherwise indicated, is intended to encompass any known and future equivalents that perform substantially the same function as the helical groove.
While the inner generally cylindrical surface 30 of the sealing sleeve 24 can be of a conventional configuration, the outer surface 34 of the sealing sleeve is uniquely configured in relation to the inner surface of the outer body 20 . As best seen in FIGS. 3 and 4 , the outer, preferably cylindrical, surface 34 of the sealing sleeve is smaller in dimension (diameter) than the inner, preferably cylindrical, surface 36 of the outer body, thereby to provide an annular radial gap 38 between coextensive axial portions of the outer body and sealing sleeve. This gap permits limited pivotal and/or radial translational movement of the sealing sleeve relative to the outer body for allowing the sealing sleeve to coaxially align with the shaft 16 when in use. If, for example, the drive shaft is out of axial alignment with the hole 22 in the outer body, the sealing sleeve can pivot and/or radially shift relative to the outer body to align axially with the drive shaft and/or maintain its axial alignment with the drive shaft, as described in more detail below.
As seen in FIGS. 3 and 4 , a resilient annular seal 40 is interposed between the sealing sleeve 24 and outer body 20 to seal the annular gap 38 thereby to prevent leakage around the outside of the sealing sleeve. The resilient annular seal also performs a second function, this being to support the sealing sleeve within the outer body while allowing the sealing sleeve to pivot with a gimbal action within the outer body and/or to shift radially (translate) relative to the outer body. This gimbal and/or shifting action allows the sealing sleeve to align axially with the drive shaft with little force being exerted on the sealing sleeve. As a result, the sealing sleeve will carry only a nominal radial load that will not cause undue wear or galling. Of course, suitable materials should be selected to withstand this nominal radial load. Such materials can be conventional tool steels for the outer body and sealing sleeve, and conventional resilient materials for the annular seal. By way of further example, the outer body and/or sealing sleeve can be formed of a material (e.g., steel or bronze) appropriate for the particular application. Alternatively, such components could be formed of a non-metal, such as a carbon, silicon carbide, ceramic or plastic. In applications where operating temperatures vary over a wide range, it is best that the sealing sleeve and shaft, in particular, be made of materials having similar coefficients of thermal expansion.
The resilient annular seal 40 , such as an elastomeric O-ring, preferably is retained in an annular groove 42 formed in one of the outer body 20 and sealing sleeve 24 , and most preferably in the sealing sleeve as shown. The portion of the annular gap 38 in the region of the resilient annular seal can have a radial dimension less than the radial dimension more remote from the resilient annular seal for more effective sealing of the gap. That is, a conventional O-ring clearance gap, such as about 0.002-0.004 inch on the radius, can be provided in the region surrounding the O-ring and the groove therefor, while a larger radial gap, such as about 0.0125 to 0.015 inch on the radius, can be provided elsewhere to accommodate the desired range of movement of the sealing sleeve relative to the outer body. The O-ring 40 functions as a gimbal support for the sealing sleeve and its resilience also permits radial shifting of the sealing sleeve within the hole in the outer body. Preferably, the sealing sleeve is axially constrained in the outer body by any suitable means, for example to prevent internal fluid pressure from axially forcing the sealing sleeve out of the hole in the outer body. Such constraint could be provided by other parts which radially overlap one or both axial ends of the hole in the outer body.
As will be appreciated by those skilled in the art, other annular seal devices can be used to seal and support the sealing sleeve 24 . Such devices can be internal to the housing 14 of the source of fluid leakage as shown, or it can be attached externally to the housing. For example, a radially extending flange can be provided on the sealing sleeve, and an O-ring or gasket can be applied to the flange, on one or both sides. The flange itself can be polished in order to provide a seal, and the flange or the sealing sleeve itself can be made thin enough in construction to provide a flexible seal that allows angular misalignment to be accommodated, merely by flexing the material of the flange or sleeve. The invention is intended to encompass these and other equivalent mounting configurations.
Further in accordance with the invention, an anti-rotation device 48 is provided to inhibit rotation of the sealing sleeve 24 relative to the outer body 20 while allowing the sealing sleeve to pivot with a gimbal action and/or radially translate within the outer body. The anti-rotation device preferably includes one or more keys and slots. For example, aligned slots 50 and 52 can be formed respectively in the inner surface of the hole 22 and an outer surface 34 of the sealing sleeve, and a key 54 can be disposed in the radially aligned slots to prevent rotation of the sealing sleeve relative to the outer body, while still permitting the aforesaid pivoting and/or translating movement. The keys, which can be in the form of pins, can be circumferentially equally spaced around the axis of the sealing sleeve. A suitable retention means can be provided for axially retaining the pins in the slots.
Referring now to FIGS. 5-7 , another embodiment of a compliant viscous seal according the invention is disclosed, such be indicated generally at 58 . The seal is in substantial part identical to the seal of FIGS. 1-4 , and thus like reference numerals are used to denote like parts. The only difference is that the outer body 60 is formed by a circular housing configured for external mounting to a housing of a fluid transfer device 10 . To this end the circular seal housing has a plurality of bores 62 for accommodating bolts used to attach the seal housing to the housing of the fluid transfer device 10 and thus close an opening in the housing through which the drive shaft 16 of the device extends.
The compliant viscous seal 12 of the invention generally can be used in any fluid transfer device 10 and has particular application in a gear pump. By way of further example, the fluid transfer device could be a pump for melted synthetic fiber, an extrusion pump, a petroleum distillate pump, a hot melt adhesive pump, etc. The device also can be operated as a pump or motor, depending on whether the shaft is being used to move fluid, or the fluid is being used to move the shaft.
The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular form described as it is to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the scope and spirit of the invention as set forth in the appended claims.
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A viscous seal for fluid transfer devices that deviates from the conventional wisdom of avoiding contact between the seal and a rotating drive shaft of the fluid transfer device. Instead of avoiding contact, contact between the seal and drive shaft is used to effect axial alignment of a sealing sleeve with the shaft. As a result, the viscous seal is compliant in that the sealing sleeve can follow the axis of the drive shaft. Accordingly, the sealing sleeve can fit snugly around the drive shaft for more effective prevention of leakage of low or any viscosity fluid along the drive shaft, but without any significant radial load being applied to the sealing sleeve that might cause undue wear or damage due to galling.
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IDENTIFICATION OF RELATED PATENT APPLICATIONS
This application is a continuation of application Ser. No. 10/192,336, which was filed on Jul. 10, 2002, now U.S. Pat. No. 6,860,039 and is related to four other patent applications, namely U.S. patent application Ser. No. 10/192,555, entitled “Snow Plow Having an In-Line Frame Design and Method of Making the Same,” U.S. patent application Ser. No. 10/192,224, entitled “Cushion Stop and Method for Absorbing Bidirectional Impact of Snow Plow Blade Tripping,” now U.S. Pat. No. 6,618,965, U.S. patent application Ser. No. 10/192,577, entitled “Spring Bracket Design and Method for Snow Plow Blade Trip Mechanism,” now U.S. Pat. No. 6,701,646, and U.S. patent application Ser. No. 10/192,230, entitled “Back Blade Wearstrip for Efficient Backward Operation of Snow Plows and Method for Facilitating the Same,” now abandoned, all assigned to the assignee of the present patent application, which four patent applications are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates generally to snow plows for use with light and medium duty trucks, and more particularly to an improved snow plow with a hitch mounting mechanism and method which enables the snow plow to be easily and quickly mounted to and detached from a truck.
Once the exclusive domain of municipality-operated heavy trucks, snow plows have been used with light and medium duty trucks for decades. As would be expected in any area of technology which has been developed for that period of time, snow plows for light and medium duty trucks have undergone tremendous improvement in a wide variety of ways over time, evolving to increase both the usefulness of the snow plows as well as to enhance the ease of using them. The business of manufacturing snow plows for light and medium duty trucks has been highly competitive, with manufacturers of competing snow plows differentiating themselves based on the features and enhanced technology that they design into their products. Two types of features that are particularly important are the ease of installation (and removal) and features bringing an enhanced level of performance in plowing snow.
In the past several years one of the most important of these features has been the ease of installation of a snow plow. While the first snow plows were bolted onto supports which were typically welded onto the frame of a truck at the front end thereof, it will be appreciated by those skilled in the art that such an installation mechanism makes the installation both difficult and time consuming. Since snow plows for light and medium duty trucks weigh hundreds of pounds and are somewhat unwieldy, merely getting the snow plow into the proper position for installation can be a problem. In addition, bolting the snow plow onto the supports can also be difficult to accomplish. Even when it is straightforward, it is time consuming and awkward, particularly when done during the winter when the weather is cold.
Thus, it is apparent that one of the most important improvements which can be made to the design of a snow plow is the inclusion of a mechanism for mounting the snow plow on a truck which improves the snow plow installation process. A number of attempts at designing such mechanisms have been made, but they have all been of a less than optimal design. One problem is that many such hitch mechanisms require such a precise degree of accuracy in the interconnection of the snow plow-mounted hardware and the truck-mounted hardware that they are difficult and time consuming to install.
Another problem is that some previously known hitch mechanisms are unduly complex, both in construction and in operation, which means that they are both expensive to manufacture and difficult to operate. Still another problem with some existing hitch mechanisms is that they provide a less than secure and robust connection between the snow plow and the truck. Yet another problem with them is that many of them have mechanisms which are bulky, reducing the ground clearance between the bottom of the hitch mechanisms and the ground significantly.
It is accordingly the primary objective of the present invention that it provide an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. It is a related objective of the snow plow hitch mounting mechanism of the present invention that it require no physical effort to connect or disconnect the snow plow from the truck. It is another related objective of the snow plow hitch mounting mechanism of the present invention that the process of connecting or disconnecting the snow plow to or from the truck is so simple and easy to use that it can be done by a single person without requiring assistance.
It is a further objective of the snow plow hitch mounting mechanism of the present invention that it be mechanically simple both in construction and in operation. It is a still further objective of the snow plow hitch mounting mechanism of the present invention that it provide a robust connection between the snow plow and the truck. It is yet a further objective of the snow plow hitch mounting mechanism of the present invention that it be of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention must also be of construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the snow plow hitch mounting mechanism of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the snow plow hitch mounting mechanism of the present invention be achieved without incurring any substantial relative disadvantage.
SUMMARY OF THE INVENTION
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a snow plow hitch mounting mechanism with four points of attachment between a snow plow-mounted hitching apparatus and a hitch frame nose piece mounted at the front of a truck under the bumper as is conventional is provided. Two of the four points of attachment are located on each of the left and right sides of the hitching mechanism, with upper and lower points of attachment being used on each side. One of the points of attachment on each side is made by engaging the snow plow-mounted hitching apparatus with the hitch frame nose piece, and the other attachment point on each side is engaged by using a releasable retaining mechanism.
In the preferred embodiment, the lower points of attachment are made by engaging the snow plow-mounted hitching apparatus with the hitch frame nose piece, with the upper points of attachment being engaged by using the releasable retaining mechanism. The hitch frame nose piece has a pair of spaced-apart hitch brackets mounted on each side thereof, with each of the hitch brackets having a rectangular notch located in the front side thereof. Located in the bottom of each of the rectangular notches is a slot, and located above the notch in each of the hitch brackets is an aperture. All of the notches in the hitch brackets are aligned laterally with each other, and all of the apertures in the hitch brackets are also aligned laterally with each other.
The snow plow-mounted portion of the hitching mechanism is based upon a plow A-frame which has a pair of pins mounted at the rear side thereof. The pins extend laterally, and one pin is mounted at each side of the plow A-frame. These pins are mounted to the plow A-frame such that both ends of the pins are free, and it is these ends of the pins which are received in the rectangular notches in the hitch brackets, where they will rest in the slots located in the hitch brackets. Mounted on these pins for pivoting movement are the two mounting supports for a lift bar, and the ends of the pins protrude from these mounting supports for the lift bar. A portion of the mounting supports will also be engaged by the pairs of hitch brackets.
The lift bar is actuated by a mechanical linkage which is driven by a hydraulic cylinder which will cause it to pivot between a first forward position and a second rearward position. Located on each of the mounting supports above the location of the pins are apertures, which, when the lift bar is in the second rearward position, will be aligned with the apertures in the hitching plates. When the apertures in the mounting supports are so aligned with the apertures in the hitching plates, a pin may be placed into the apertures on each side of the snow plow and the hitch frame nose piece to retain the snow plow in the hitch frame nose piece. Following installation of the snow plow onto the hitch frame nose piece, the hydraulic cylinder and the mechanical linkage will operate to raise and lower the plow blade.
In the preferred embodiment, the snow plow also includes a stand which supports the rear of the snow plow when it is not mounted on a truck. In this embodiment, the mechanical linkage also serves to operate this stand. When the snow plow is not connected to the truck, actuating the hydraulic cylinder which drives the mechanical linkage causes the stand to begin to raise, which in turn causes the rear end of the snow plow to lower, since the base of the stand is still resting on the ground. This allows the pins located at the rear of the snow plow to be brought to a height at which they may be engaged by the hitch frame nose piece.
The truck may then be driven forward so that these pins are engaged by the hitch frame nose piece 300 (they enter the rectangular notches in the hitch brackets). Once the pins are so engaged by the hitch frame nose piece, further actuation of the hydraulic cylinder causes the stand to continue to raise and the rear end of the snow plow to lower, allowing the pins to drop into the slots in the bottom of the rectangular notches in the hitch brackets. Still further actuation of the hydraulic cylinder will lift the stand off of the ground, at which point it may be pivoted out of the way.
Simultaneously, actuation of the hydraulic cylinder also causes the lift bar to pivot toward its second position, at which point the apertures in the mounting supports of the lift bar will be aligned with the apertures in the hitching plates of the hitch frame nose piece. At this point, pins may be inserted from each side of the snow plow and the hitch frame nose piece into the aligned apertures, thereby retaining the snow plow in position on the truck. Further operation of the hydraulic cylinder which drives the mechanical linkage with the snow plow mounted onto the truck will serve to raise and lower the snow plow blade, which is mounted at the front of the snow plow.
It may therefore be seen that the present invention teaches an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. The snow plow hitch mounting mechanism of the present invention requires no physical effort to connect or disconnect the snow plow from the truck. The process of connecting or disconnecting the snow plow to or from the truck with the hitch mounting mechanism of the present invention is so simple and easy to use that it can be done by a single person without requiring assistance.
The snow plow hitch mounting mechanism of the present invention is mechanically simple, both in construction and in operation. The snow plow hitch mounting mechanism of the present invention provides a robust connection between the snow plow and the truck. The snow plow hitch mounting mechanism of the present invention is of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow hitch mounting mechanism of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved by the snow plow hitch mounting mechanism of the present invention without incurring any substantial relative disadvantage.
DESCRIPTION OF THE DRAWINGS
These and other advantages of the present invention are best understood with reference to the drawings, in which:
FIG. 1 is a perspective view of a plow A-frame;
FIG. 2 is a partial cross-sectional view of the plow A-frame illustrated in FIG. 1 ;
FIG. 3 is a perspective view of a plow swing frame which will be pivotally mounted on the front end of the plow A-frame illustrated in FIGS. 1 and 2 and which will support a plow blade therefrom;
FIG. 4 is a cross-sectional view of the plow swing frame illustrated in FIG. 3 ;
FIG. 5 is a bottom plan view of the plow swing frame illustrated in FIGS. 3 and 4 ;
FIG. 6 is a perspective view of a pivoting lift bar which will be pivotally mounted at the rear end of the plow A-frame illustrated in FIGS. 1 and 2 ;
FIG. 7 is a perspective view of a hitch frame nose piece which will be mounted on a truck under the front bumper thereof;
FIG. 8 is a perspective view of a bellcrank which is used to operate the pivoting lift bar illustrated in FIG. 6 ;
FIG. 9 is a perspective view of a lift link which connects the bellcrank illustrated in FIG. 8 to the pivoting lift bar illustrated in FIG. 6 ;
FIG. 10 is a cutaway view of the various components of the snow plow frame assembled together, showing the hydraulic cylinder used to pivot the lift bar;
FIG. 11 is a perspective view of a plow blade from the rear side which will be mounted onto the plow swing frame illustrated in FIGS. 3 through 5 ;
FIG. 12 is an exploded view of the plow blade illustrated in FIG. 11 , showing the assembly of a moldboard made of man-made material onto the plow blade frame;
FIG. 13 is a partial cross-sectional view of the top of the plow blade illustrated in FIG. 11 , showing how the top of the moldboard is retained by the plow blade frame;
FIG. 14 is a partial cross-sectional view of the bottom of the plow blade illustrated in FIG. 11 , showing how the bottom of the moldboard is retained by the plow blade frame and the plow cutting edge;
FIG. 15 is a partial cross-sectional view of a side edge of the plow blade illustrated in FIG. 11 , showing how the side of the moldboard is retained by the plow blade frame;
FIG. 16 is a partial perspective view of the rear of the plow blade illustrated in FIG. 11 , showing the installation of a wear strip onto the rear of the plow blade;
FIG. 17 is an exploded, partial cross-sectional view showing the assembly of the plow swing frame illustrated in FIGS. 3 through 5 onto the plow A-frame illustrated in FIGS. 1 and 2 ;
FIG. 18 is a partial cross-sectional view showing the plow swing frame and the plow A-frame illustrated in FIG. 17 assembled together;
FIG. 19 is a perspective view of a blade stop cushion;
FIG. 20 is a cross-sectional view from the side showing the installation of the blade stop cushion illustrated in FIG. 19 onto the plow swing frame, with the plow blade in its normal position as stopped by the blade stop cushion;
FIG. 21 is a cross-sectional view of the components illustrated in FIG. 20 , from the top side thereof;
FIG. 22 is a cross-sectional view from the side similar to the view of FIG. 20 , but with the plow blade in a rotated position as stopped by the blade stop cushion;
FIG. 23 is a perspective view of portions of the plow blade and the plow swing frame, showing the spring mounts on one side of the plow blade and the plow swing frame, and also showing two springs in phantom lines;
FIG. 24 is a partial rear plan view of the plow blade, the plow swing frame, and the spring mounts illustrated in FIG. 23 ;
FIG. 25 is a perspective view of an alternate embodiment similar to the view shown in FIG. 23 , but with a single spring mount on one side of the plow blade and the plow swing frame, and also showing a spring in phantom lines;
FIG. 26 is a partial rear plan view of plow blade, the plow swing frame, and the spring mount illustrated in FIG. 25 ;
FIG. 27 is a cross-sectional view from the side of the assembled plow blade and the plow swing frame, showing the plow blade in its normal position;
FIG. 28 is a cross-sectional view from the side of the assembled plow blade and the plow swing frame, showing the plow blade in its rotated position;
FIG. 29 is a perspective view of the assembled snow plow of the present invention;
FIG. 30 is a top view of the assembled snow plow illustrated in FIG. 29 ;
FIG. 31 is a partial view from the top showing the hitch mounting mechanism on one side of the snow plow illustrated in FIGS. 29 and 30 prior to installation;
FIG. 32 is a partial view from the top showing the components illustrated in FIG. 31 in a mounted position;
FIG. 33 is a partial cross-sectional view from the front showing the components illustrated in FIGS. 28 and 29 in a mounted position with the retaining pin inserted;
FIG. 34 is a side view of the snow plow illustrated in FIGS. 29 and 30 as the hitch frame nose piece is brought into engagement with a mounting pin on the pivoting lift bar;
FIG. 35 is a schematic depiction of the engagement of the mounting pin with a slot in the hitch frame nose piece;
FIG. 36 is a side view similar to that of FIG. 34 , with the pivoting lift bar beginning to pivot to bring the mounting pin into engagement with the slot in the hitch frame nose piece;
FIG. 37 is a side view similar to that of FIGS. 34 and 36 , with the pivoting lift bar pivoted to bring the mounting holes in the pivoting lift bar into alignment with the mounting holes in the hitch frame nose piece; and
FIG. 38 is a perspective view of an alternate embodiment snow plow having blade shoes mounted thereupon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention is illustrated in a series of figures, of which the FIGS. 1 through 9 and 11 are components of the snow plow which embodies the present invention. FIGS. 10 , 12 through 24 , and 27 through 29 illustrate the assembly of the snow plow embodying the present invention, and FIGS. 30 through 37 illustrate the manner in which the snow plow is attached to the hitch. Finally, FIGS. 25 , 26 , and 38 illustrate two alternate embodiments. The snow plow of the present invention includes five novel aspects: a novel frame design which has a lower profile and an enhanced linear strength which is attained by that design; a novel hitch quick connect, quick release design; a novel plow blade trip spring placement; a novel plow blade stop design which uses replaceable cushion stop blocks to absorb the impact of plow blade movement between extreme positions; and a novel back blade wearstrip which allows the plow blade to be used to plow backward as well as forward.
The first of these five novel aspects of the snow plow of the present invention resides in the innovative design of its two-piece frame. Referring first to FIGS. 1 and 2 , the first of these two pieces, a plow A-frame 50 , is illustrated. The plow A-frame 50 as illustrated in FIG. 2 has its front end shown at the left of FIG. 2 and its rear end shown at the right of FIG. 2 , and is symmetric around an axis running from the front to the rear thereof. The plow A-frame 50 tapers from a narrower width at the front thereof to a wider width at the rear thereof.
The basic shape of the plow A-frame 50 is formed by a top plate 52 and a bottom plate 54 , which are essentially parallel and are spaced apart from each other. The configurations of the top plate 52 and the bottom plate 54 as viewed from the top (or from the bottom) resemble a portion of the capital letter “A,” with the portions of the sides of the “A” above the crossbar of the “A” being absent. There is a large aperture extending through each of the top plate 52 and the bottom plate 54 above the crossbar of the “A,” which apertures resemble an isosceles trapezoid. The top plate 52 and the bottom plate 54 are preferably made of steel plate.
Mounted between the sides of the top plate 52 and the bottom plate 54 at the location of the crossbar of the “A” and extending rearwardly so as to resemble abbreviated legs of the “A” below the crossbar are two lugs 56 and 58 made of flat bar stock. The lugs 56 and 58 are also preferably made of steel, and are welded onto the sides of the top plate 52 and the bottom plate 54 . The portion of the lug 56 which extends rearwardly from the top plate 52 and the bottom plate 54 has an aperture 60 extending therethrough, and the portion of the lug 58 which extends rearwardly from the top plate 52 and the bottom plate 54 has an aperture 62 extending therethrough.
Portions of three sides of the top plate 52 are bent downwardly at a ninety degree angle to extend to the top of the bottom plate 54 . Only one of these sides, a left side 64 , is visible in FIGS. 1 and 2 . The left side 64 of the top plate 52 extends from just in front of the lug 58 , and extends approximately two-thirds of the way toward the front end of the plow A-frame 50 . A right side of the top plate 52 (which is the mirror image of the left side 64 of the top plate 52 ) and a rear side of the top plate 52 extending between the lugs 56 and 58 are also bent downwardly at ninety degree angles to extend to the top of the bottom plate 54 . These three sides are all welded to the bottom plate 54 to create a box-like structure. A rectangular plate 66 is located just in front of the isosceles trapezoid-shaped apertures in the top plate 52 and the bottom plate 54 , and extends between the sides of the top plate 52 and the bottom plate 54 . The rectangular plate 66 is also preferably made of steel, and all four sides of the rectangular plate 66 are welded onto-the top plate 52 (including the left side 64 and right side thereof) and the bottom plate 54 to provide the fourth side of the box-like structure.
Extending from the sides of the lugs 56 and 58 are U-shaped swing cylinder mounts 76 and 78 , respectively. The swing cylinder mounts 76 and 78 are also preferably made of steel, and are welded onto the lugs 56 and 58 , respectively, with the legs of the U's of the swing cylinder mounts 76 and 78 being located on the top and the bottom of the plow A-frame 50 . An aperture 80 is located in each leg of the U in the swing cylinder mount 76 , and an aperture 82 is similarly located in each leg of the U in the swing cylinder mount 78 .
Located between the rear of the top plate 52 at the location of the crossbar of the “A” and the rear of the bottom plate 54 at the location of the crossbar of the “A” are two lift cylinder mounts 84 and 86 . The cylinder mounts 84 and 86 are parallel both to each other and to the plane which divides the plow A-frame 50 into left and right sides thereof. The cylinder mounts 84 and 86 each extend from slots 88 and 90 , respectively, located in the crossbar of the “A” of the top plate 52 and slots 92 and 94 , respectively, located in the crossbar of the “A” of the bottom plate 54 . The cylinder mounts 84 and 86 are also preferably made of steel, and their ends are welded into the slots 88 and 90 , respectively, in the top plate 52 and the slots 92 and 94 , respectively, in the bottom plate 54 . The cylinder mounts 84 and 86 each have an aperture 96 or 98 , respectively, located therein which apertures 96 and 98 are coaxial.
Located at the top of the aperture in the “A” in the plow A-frame 50 are two parallel, spaced-apart, pivot mount plates 100 and 102 . The pivot mount plates 100 and 102 are also preferably made of steel, and are welded onto the rectangular plate 66 , the portion of the top plate 52 adjacent thereto, and the portion of the bottom plate 54 adjacent thereto. The pivot mount plates 100 and 102 are mounted on opposite sides of the centerline of the plow A-frame 50 , and extend rearwardly and upwardly from the rectangular plate 66 , and are beneath a portion of the bottom plate 54 . Located near the rearmost and uppermost ends of the pivot mount plates 100 and 102 are apertures 104 and 106 , respectively, which are coaxial.
Mounted near the front of the plow A-frame 50 are two hollow cylindrical swing frame pivots 108 and 110 . The swing frame pivots 108 and 110 are centrally mounted near the front end of the plow A-frame 50 in apertures 112 and 114 , respectively, which are located in the top plate 52 and the bottom plate 54 , respectively. The swing frame pivots 108 and 110 are also preferably made of steel, and are welded into the apertures 112 and 114 , respectively. The swing frame pivots 108 and 110 are coaxial and are orthogonal to the top plate 52 and the bottom plate 54 .
Located on the inside of each of the legs of the “A” of the plow A-frame 50 near to the top of the “A” are two support sides 116 and 118 . The support sides 116 and 118 extend perhaps one-fourth of the way from the top of the opening of the “A” toward the crossbar of the “A.” The ends of the support sides 116 and 118 oriented closest to the crossbar of the “A” extend between the top side of the top plate 52 and the bottom side of the bottom plate 54 , and the support sides 116 and 118 increase in height above the top plate 52 and below the bottom plate 54 as the support sides 116 and 118 extend towards the front of the plow A-frame 50 . The support sides 116 and 118 are preferably made of steel, and are welded to the top plate 52 , the bottom plate 54 , and the rectangular plate 66 .
Four U-shaped ribs 120 , 122 , 124 , and 126 extend between the support sides 116 and 118 and the swing frame pivots 108 and 110 . The bases of the “U” of each of the U-shaped ribs 120 , 122 , 124 , and 126 are much wider than the legs of the “U” are tall. The U-shaped ribs 120 and 122 are mounted on top of the top plate 52 , and the bases of the “U's” of the U-shaped ribs 120 and 122 are located close adjacent the right and left sides, respectively, of the top plate 52 . The U-shaped rib 124 and 126 are mounted on the bottom of the bottom plate 54 , and the bases of the “U's” of the U-shaped ribs 124 and 126 are located close adjacent the right and left sides, respectively, of the bottom plate 54 . In the preferred embodiment, the U-shaped rib 120 , the support side 116 , and the U-shaped rib 124 are manufactured as a single component, and likewise the U-shaped rib 122 , the support side 118 , and the U-shaped rib 126 are also manufactured as a single component.
One leg of the U-shaped rib 120 extends between the base of the “U” and the support side 116 , and the other leg of the U-shaped rib 120 extends between the base of the “U” and the swing frame pivot 108 . One leg of the U-shaped rib 122 extends between the base of the “U” and the support side 118 , and the other leg of the U-shaped rib 122 extends between the base of the “U” and the swing frame pivot 108 . One leg of the U-shaped rib 124 extends between the base of the “U” and the support side 116 , and the other leg of the U-shaped rib 124 extends between the base of the “U” and the swing frame pivot 110 . One leg of the U-shaped rib 126 extends between the base of the “U” and the support side 118 , and the other leg of the U-shaped rib 126 extends between the base of the “U” and the swing frame pivot 110 .
The U-shaped ribs 120 , 122 , 124 , and 126 are preferably made of steel, and the U-shaped ribs 120 and 122 are welded onto the top plate 52 , while the U-shaped ribs 124 and 126 are welded onto the bottom of the bottom plate 54 . As mentioned above, the U-shaped ribs 120 and 124 may be made integrally with the support side 116 , while the U-shaped rib 122 and 126 may be made integrally with the support side 118 . The swing frame pivots 108 and 110 define an axis upon which a swing frame which will be described below in conjunction with FIGS. 3 through 5 will be mounted, and the area between the top plate 52 and the bottom plate 54 and in front of the rectangular plate 66 is the area in which the swing frame will be mounted.
Referring next to FIGS. 3 through 5 , a swing frame 140 is illustrated which will be mounted as described above on the plow A-frame 50 (illustrated in FIGS. 1 and 2 ). The swing frame 140 is based upon a rectangular swing frame tube 142 having a hollow cylindrical pivot 144 extending through the thinner cross section thereof at the midpoint of the length of the rectangular swing frame tube 142 . The rectangular swing frame tube 142 has an aperture 146 located in the top side thereof and another aperture 148 located in the bottom side thereof. The apertures are closer to the rear side of the rectangular swing frame tube 142 than they are to the front side thereof. Both the rectangular swing frame tube 142 and the pivot 144 are preferably made of steel, and the pivot 144 is welded to the rectangular swing frame tube 142 . The pivot 144 extends slightly above and below the top and bottom, respectively, of the rectangular swing frame tube 142 .
A guide plate 150 extends from the rear of the rectangular swing frame tube 142 . The guide plate 150 is shaped like an isosceles trapezoid with a low triangle mounted on the top thereof, with the base of the isosceles trapezoid mounted onto the rectangular swing frame tube 142 . The width of the guide plate 150 is perhaps half of the length of the rectangular swing frame tube 142 , and the guide plate 150 is centrally mounted both as to the length of the rectangular swing frame tube 142 and as to its height as well. The guide plate 150 is preferably also steel, and is welded onto the rectangular swing frame tube 142 .
Mounted on the rear edge of the guide plate 150 is a guide/stop bar 152 which is made of a segment of flat stock which is wider than the height of the rectangular swing frame tube 142 . The guide/stop bar 152 is bent to conform to the guide plate 150 , and its ends contact the rear side of the rectangular swing frame tube 142 . The guide plate 150 and the guide/stop bar 152 together form a T-shaped configuration in cross-section, as best shown in FIG. 4 . The guide/stop bar 152 thus extends both slightly above and slightly below the rectangular swing frame tube 142 , as is also best shown in FIG. 4 . The guide/stop bar 152 is preferably made of steel, and is welded onto the guide plate 150 , with the ends of the guide/stop bar 152 being welded onto the rear of the rectangular swing frame tube 142 . When the swing frame 140 is mounted onto the plow A-frame 50 (illustrated in FIGS. 1 and 2 ), the guide/stop bar 152 will contact the rectangular plate 66 when the swing frame 140 is rotated between its extreme positions, with the guide/stop bar 152 thus acting to prevent rotation of the swing frame 140 in either direction beyond these positions.
Four triangular swing cylinder mounting plates 154 , 156 , 158 , and 160 are mounted onto the rectangular swing frame tube 142 at positions approximately halfway between the center and the ends of the rectangular swing frame tube 142 , and project rearwardly. The swing cylinder mounting plates 154 and 156 are mounted on the top of the rectangular swing frame tube 142 near the rear edge thereof and the right and left sides thereof, respectively. The swing cylinder mounting plates 158 and 160 are mounted on the bottom of the rectangular swing frame tube 142 near the rear edge thereof and the right and left sides thereof, respectively. The swing cylinder mounting plates 154 , 156 , 158 , and 160 are preferably made of steel, and are welded onto the rectangular swing frame tube 142 .
The swing cylinder mounting plates 154 , 156 , 158 , and 160 each have a slot 162 , 164 , 166 , or 168 , respectively, cut therein to receive an end of the guide/stop bar 152 . The ends of the guide/stop bar 152 fit into these slots 162 , 164 , 166 , or 168 and are welded therein. Located in each of the swing cylinder mounting plates 154 , 156 , 158 , and 160 near the rearmost corner thereof is an aperture 170 , 172 , 174 , or 176 , respectively. The apertures 170 and 174 are coaxial, and the apertures 172 and 176 are coaxial.
Four blade pivot mounts 178 , 180 , 182 , and 184 are mounted on the rectangular swing frame tube 142 in spaced-apart pairs located at each end thereof. The blade pivot mounts 178 , 180 , 182 , and 184 have rectangular apertures 186 , 188 , 190 , and 192 , respectively, extending therethrough to receive therein the rectangular swing frame tube 142 . The blade pivot mount 178 is mounted at the end of the rectangular swing frame tube 142 which will be on the right when the swing frame 140 is mounted on the plow A-frame 50 (illustrated in FIGS. 1 and 2 ), and the blade pivot mount 180 is spaced away from the blade pivot mount 178 on the rectangular swing frame tube 142 .
Similarly, the blade pivot mount 184 is mounted at the end of the rectangular swing frame tube 142 which will be on the left when the swing frame 140 is mounted on the plow A-frame 50 , and the blade pivot mount 182 is spaced away from the blade pivot mount 184 on the rectangular swing frame tube 142 . The spacing between the blade pivot mount 178 and the blade pivot mount 180 , and between the blade pivot mount 182 and the blade pivot mount 184 is sufficient to admit cushion stops which will be discussed below in conjunction with FIG. 19 . The blade pivot mounts 178 , 180 , 182 , and 184 are preferably also made of steel, and are welded onto the rectangular swing frame tube 142 .
It should be noted that the blade pivot mounts 178 , 180 , 182 , and 184 are identical in construction, with each extending forwardly in front of the rectangular swing frame tube 142 (as best shown in FIG. 4 ) and rearwardly and upwardly behind the rectangular swing frame tube 142 . Located near the front of the blade pivot mounts 178 , 180 , 182 , and 184 are apertures 194 , 196 , 198 , and 200 , respectively, which will be used to pivotally mount the snow plow blade (illustrated below in FIG. 11 ). The apertures 194 , 196 , 198 , and 200 are coaxial. Located in the blade pivot mounts 178 , 180 , 182 , and 184 intermediate the apertures 194 , 196 , 198 , and 200 , respectively, and the front of the rectangular swing frame tube 142 are apertures 202 , 204 , 206 , and 208 , respectively, which will be used to retain cushion stops which will be discussed below in conjunction with FIG. 19 . The pairs of apertures 202 and 204 , and 206 and 208 are coaxial.
As mentioned above, each of the blade pivot mounts 178 , 180 , 182 , and 184 also extends rearwardly of the rectangular swing frame tube 142 , resembling the profile of a vertical tail fin of a plane as best shown in FIG. 4 . Mounted to each pair of each pair of the blade pivot mounts 178 and 180 , and 182 and 184 , are two trip spring brackets 210 and 212 . The trip spring brackets 210 and 212 are preferably also made of steel, are generally oval in configuration, and are mounted with the wider sides being oriented between the left and right sides of the swing frame 140 . The trip spring bracket 210 is welded onto the blade pivot mounts 178 and 180 , and the trip spring bracket 212 is welded onto the blade pivot mounts 182 and 184 . The trip spring bracket 210 has apertures 214 and 216 disposed near opposite ends thereof, and similarly the trip spring bracket 212 has apertures 218 and 220 disposed near opposite ends thereof.
Completing the swing frame 140 are two additional components which are used both to act as a stop for rotational movement of the plow blade (which will be discussed below in conjunction with FIG. 11 ) as well as to help define an enclosure for the cushion stops (which will be discussed below in conjunction with FIG. 18 ). A stop 222 is mounted at the top of, intermediate, and at the bottom of the blade pivot mounts 178 and 180 . The stop 222 extends rearwardly from a point above the apertures 202 and 204 , drops down in front of the rectangular swing frame tube 142 , and extends rearwardly below the rectangular swing frame tube 142 to a point halfway between the front edge of the rectangular swing frame tube 142 and the pivot 144 .
Similarly, a stop 224 is mounted at the top of, intermediate, and at the bottom of the blade pivot mounts 182 and 184 . The stop 224 extends rearwardly from a point above the apertures 206 and 208 , drops down in front of the rectangular swing frame tube 142 , and extends rearwardly below the rectangular swing frame tube 142 to a point halfway between the front edge of the rectangular swing frame tube 142 and the pivot 144 . The stops 222 and 224 are both preferably also made of steel, and are welded to the blade pivot mount pairs 178 and 180 , and 182 and 184 , respectively.
Referring next to FIG. 6 , a lift bar 230 is illustrated which forms part of the hitch mechanism of the snow plow. The lift bar 230 has two lift bar support members 232 and 234 , which are located on the right and left sides, respectively, of the lift bar 230 . Each of the lift bar support members 232 and 234 has a configuration consisting of three segments: rear mounting supports 236 and 238 , respectively, which extend upward vertically; central support arms 240 and 242 , respectively, which extend forwardly and upwardly from the top of the rear mounting supports 236 and 238 , respectively; and front light bar supports 244 and 246 , respectively, which extend upwardly from the forwardmost and upwardmost ends of the central support arms 240 and 242 , respectively. The lift bar support members 232 and 234 are preferably made of steel plate.
Extending inwardly from the rear sides of rear mounting supports 236 and 238 are segments of angled stock 248 and 250 , respectively. It should be noted that the angle defined by each of the segments of angled stock 248 and 250 is less than ninety degrees, as, for example, approximately seventy degrees. The reason for this angle will become apparent below in conjunction with the discussion of FIGS. 31 and 32 . The angled stock segments 248 and 250 are also preferably made of steel, and are welded onto rear mounting supports 236 and 238 , respectively, so that the rear mounting supports 236 and 238 and the angled stock segments 248 and 250 together form vertically-oriented channels which are essentially U-shaped. Referring for the moment to FIG. 1 in addition to FIG. 6 , the space between the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 is designed to admit the lug 56 of the plow A-frame 50 with space between the lug 56 and the inside of the angled stock segment 248 , and similarly the space between the angled stock segment 250 , and the rear mounting support 238 of the lift bar 230 is designed to admit the lug 58 of the plow A-frame 50 with space between the lug 58 and the inside of the angled stock segment 250 .
Referring again solely to FIG. 6 , a rectangular reinforcing segment 252 (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support 236 and the angled stock segment 248 , and is welded to the bottoms of the rear mounting support 236 and the angled stock segment 248 . Similarly, a rectangular reinforcing segment 254 (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support 238 and the angled stock segment 250 , and is welded to the bottoms of the rear mounting support 238 and the angled stock segment 250 .
Not illustrated in the figures but used to reinforce the construction of the lift bar 230 are two additional rectangular reinforcing segments which are respectively located above the reinforcing segments 252 and 254 . On the right side of the lift bar 230 , the first of these additional reinforcing segments (preferably also made of steel) is located near the top of the U-shaped channel formed by the rear mounting support 236 and the angled stock segment 248 , and is welded to the tops of the rear mounting support 236 and the angled stock segment 248 . Similarly, the other of these reinforcing segments (preferably also made of steel) is located at near the top of the U-shaped channel formed by the rear mounting support 238 and the angled stock segment 250 , and is welded to the tops of the rear mounting support 238 and the angled stock segment 250 .
Extending between the lift bar support members 232 and 234 are a larger diameter hollow round upper pin support tube 256 and a smaller diameter round light bar brace 258 . The upper pin support tube 256 and the light bar brace 258 are both also preferably made of steel. One end of the upper pin support tube 256 extends through an aperture 260 located in an intermediate position in the central support arm 240 of the lift bar support member 232 , and the other end of the upper pin support tube 256 extends through an aperture 262 located in an intermediate position in the central support arm 242 of the lift bar support member 234 . The ends of the upper pin support tube 256 are welded onto the central support arms 240 and 242 . One end of the light bar brace 258 is welded onto the lift bar support member 232 at the intersection of the central support arm 240 and the light bar support 244 , and the other end of the light bar brace 258 is welded onto the lift bar support member 234 at the intersection of the central support arm 242 and the light bar support 246 .
Two upper pin hanger plates 264 and 266 are mounted on the upper pin support tube 256 in spaced-apart fashion near the middle of the upper pin support tube 256 . The upper pin hanger plates 264 and 266 have apertures 268 and 270 , respectively, extending therethrough near one end thereof, and the upper pin support tube 256 extends through these apertures 268 and 270 . The upper pin hanger plates 264 and 266 are both also preferably made of steel, and are welded onto the upper pin support tube 256 in a manner whereby they are projecting forwardly. A tubular upper pin 272 extends through apertures 274 and 276 in the upper pin hanger plates 264 and 266 , respectively, near the other end thereof. The upper pin 272 is also preferably made of steel, and is welded onto the upper pin hanger plates 264 and 266 .
Located in the rear mounting support 236 , the angled stock segment 248 , the angled stock segment 250 , and the rear mounting support 238 near the bottoms thereof are apertures 278 , 280 , 282 , and 284 , respectively, which are aligned with each other and which together define a pivot axis about which the lift bar 230 will pivot when it is mounted onto the plow A-frame 50 (Illustrated in FIG. 1 ). Located in the rear mounting support 236 , the angled stock segment 248 , the angled stock segment 250 , and the rear mounting support 238 nearer the tops thereof than the bottoms thereof are apertures 286 , 288 , 290 (not shown in FIG. 6 ), and 292 , which are aligned with each other.
The apertures 286 and 288 define a first location into which a retaining pin (not shown in FIG. 6 ) will be placed to mount the snow plow of the present invention onto a truck, and the apertures 290 and 292 define a second location into which another retaining pin (not shown in FIG. 6 ) will be placed to mount the snow plow of the present invention onto the truck. Located in the light bar support 244 are three apertures 294 , and located in the light bar support 246 are three apertures 296 . The apertures 294 and 296 will be used to mount a light bar (not illustrated in FIG. 6 ) onto the lift bar 230 .
Referring now to FIG. 7 , a hitch frame nose piece 300 which will be mounted onto a truck under the front bumper (not illustrated in FIG. 7 ) thereof is illustrated. The hitch frame nose piece 300 has a square hitch frame tube 302 which is horizontally oriented. Four hitch brackets 304 , 306 , 308 , and 310 are mounted on the square hitch frame tube 302 in spaced-apart pairs located nearer the ends of the square hitch frame tube 302 than the center thereof. The hitch brackets 304 , 306 , 308 , and 310 have square apertures 312 , 314 , 316 , and 318 , respectively, extending therethrough to receive therein the square hitch frame tube 302 . Both the square hitch frame tube 302 and the hitch brackets 304 , 306 , 308 , and 310 are preferably made of steel, and the hitch brackets 304 , 306 , 308 , and 310 are welded onto the square hitch frame tube 302 .
Referring for the moment to FIG. 6 in addition to FIG. 7 , the space between the hitch bracket 304 and the hitch bracket 306 of the hitch frame nose piece 300 is designed to admit the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 , and similarly the space between the hitch bracket 308 and the hitch bracket 310 of the hitch frame nose piece 300 is designed to admit the angled stock segment 250 and the rear mounting support 238 of the lift bar 230 . The hitch brackets 304 , 306 , 308 , and 310 have rectangular notches 320 , 322 , 324 , and 326 , respectively, cut into the front sides thereof.
Located in the hitch brackets 304 , 306 , 308 , and 310 in the bottoms of the rectangular notches 320 , 322 , 324 , and 326 , respectively, are slots 328 , 330 , 332 , and 334 , respectively. The slots 328 , 330 , 332 , and 334 have rounded bottoms, and are axially aligned. Also located in the hitch brackets 304 , 306 , 308 , and 310 above the tops of the rectangular notches 320 , 322 , 324 , and 326 , respectively, are apertures 336 , 338 , 340 , and 342 , respectively. The apertures 336 , 338 , 340 , and 342 are also axially aligned.
Unlike the hitch brackets 306 and 308 which are flat, the hitch brackets 304 and 310 have their forward-most portions flanged outwardly to act as guides to direct the lift bar 230 (illustrated in FIG. 6 ) into engagement with the hitch frame nose piece 300 . Thus, the portions of the hitch brackets 304 and 310 at the front of the rectangular notches 320 and 326 , respectively, extend outwardly, both on the top of the rectangular notches 320 and 326 and on the bottom of the rectangular notches 320 and 326 . It should be noted that, if desired, the hitch brackets 304 and 310 may also be flat. The ramifications of having them flat instead of flanged will eliminate the utility of the right and left sides of the lift bar 230 .
The respective ends of the square hitch frame tube 302 are mounted onto mounting plates 344 and 346 . The mounting plates 344 and 346 are also preferably made of steel, and the ends of the square hitch frame tube 302 are welded onto the mounting plates 344 and 346 . Located in the mounting plates 344 and 346 are a plurality of apertures 348 and 350 , respectively, which will be used to mount the hitch frame nose piece 300 onto the frame of a truck (not shown in FIG. 7 ) using mounting brackets (not shown in FIG. 7 ) in a manner which is conventional.
Referring next to FIG. 8 , a bellcrank 360 is illustrated. The bellcrank 360 has parallel, spaced apart triangular pivot plates 362 and 364 . One of the sides of the triangle is shorter than the other two in each of the pivot plates 362 and 364 . A gusset plate 366 is mounted between the pivot plates 362 and 364 with one side thereof near the shortest side of the triangle to support the pivot plates 362 and 364 in their spaced-apart configuration. In the preferred embodiment, both the pivot plates 362 and 364 and the gusset plate 366 are made of steel, and are welded together.
The pivot plates 362 and 364 have apertures 370 and 372 , respectively, located therein near a first corner of the triangle which will be used to mount the bellcrank 360 for pivotal movement from the apertures 104 and 106 of the pivot mount plates 100 and 102 , respectively (illustrated in FIG. 1 ). The pivot plates 362 and 364 have apertures 374 and 376 , respectively, located therein near a second corner of the triangle which will be connected via the element to be discussed in FIG. 9 below to drive the upper pin 272 of the lift bar 230 (illustrated in FIG. 6 ). The pivot plates 362 and 364 have apertures 378 and 380 , respectively, located therein near the third corner of the triangle will be connected to a hydraulic cylinder (not shown in FIG. 9 ). The short side of the triangle is between the first and third corners of the triangle. The side of the gusset plate 366 adjacent this short side will act as a lift stop to limit pivotal movement of the gusset plate 366 when this side of the gusset plate 366 contacts the pivot mount plates 100 and 102 (illustrated in FIG. 1 ).
Referring now to FIG. 9 , a lift link 390 is illustrated. The lift link 390 has parallel, spaced apart arms 392 and 394 . A gusset plate 396 is mounted between the arms 392 and 394 in their spaced-apart configuration. The side of the gusset plate 396 which is oriented toward one end of the arms 392 and 394 has a notch 398 cut therein. In the preferred embodiment, both the arms 392 and 394 and the gusset plate 396 are made of steel, and are welded together. The one end of the arms 392 and 394 have apertures 400 and 402 , respectively, located therein, and the other ends of arms 392 and 394 have apertures 404 and 406 , respectively, located therein.
Referring next to FIG. 10 , the linkage used to attach the snow plow of the present invention to the hitch frame nose piece 300 is illustrated. The components which are linked together are the plow A-frame 50 , the lift bar 230 , the bellcrank 360 , and the lift link 390 . Accordingly, reference may also be had to FIGS. 1 , 6 , 8 , and 9 as well as to FIGS. 31 and 32 in the following description of the interconnection of these components. The lift bar 230 is pivotally mounted on the plow A-frame 50 using two pins 408 and 410 (the pin 410 is not shown in FIG. 10 ) which are each of a length longer than distance between the opposite-facing sides of the pairs of the hitch brackets 304 and 306 , or 308 and 310 (illustrated in FIG. 7 ). The pins 408 and 410 are preferably made of steel.
In the preferred embodiment, a hollow cylindrical collar 409 (shown in FIGS. 31 and 32 ) having a setscrew 411 (also shown in FIGS. 31 and 32 ) is used with the pin 410 as a spacer. A similar collar which a setscrew (not shown in the drawings) is used with the pin 408 as a spacer. The collar 409 will be located intermediate the lug 58 on the plow A-frame 50 and the angled stock segment 250 on the lift bar 230 . The setscrew 411 on the collar 409 may be used to lock the collar 409 in place on the pin 410 . The other collar will be located intermediate the lug 56 on the plow A-frame 50 and the angled stock segment 248 on the lift bar 230 , with a setscrew in that collar being used to lock that collar in place on the pin 408 .
The pin 408 will thus extend sequentially through the aperture 278 in the rear mounting support 236 of the lift bar 230 , the aperture 60 in the lug 56 of the plow A-frame 50 , the collar, and the aperture 280 in the rear mounting support 238 of the lift bar 230 . The pin 408 will be retained in place by the setscrew on the collar, which will contact the pin 408 when it is screwed into the collar. Approximately equal lengths of the pin 408 extend outwardly beyond the rear mounting support 236 and the angled stock segment 248 at each end of the pin 408 . Alternately, the pin 408 may be welded in place on the rear mounting support 236 and the angled stock segment 248 of the lift bar 230 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin 408 at locations which correspond to the ends of the collar.
The pin 410 will thus extend sequentially through the aperture 282 in the angled stock segment 250 of the lift bar 230 , the collar 409 , the aperture 62 in the lug 58 of the plow A-frame 50 , and the aperture 284 in the rear mounting support 238 of the lift bar 230 . The pin 410 will be retained in place by the setscrew 411 on the collar 409 , which will contact the pin 410 when it is screwed into the collar 409 . Equal lengths of the pin 410 extend outwardly beyond the angled stock segment 250 and the rear mounting support 238 at each end of the pin 410 . Alternately, the pin 410 may be welded in place on the angled stock segment 250 and the rear mounting support 238 of the lift bar 230 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin 410 at locations which correspond to the ends of the collar 409 .
It will thus be appreciated by those skilled in the art that the lift bar 230 is pivotally mounted onto the plow A-frame 50 using the pins 408 and 410 . When the snow plow of the present invention is mounted onto a vehicle using the hitch frame nose piece 300 , the ends of the pins 408 and 410 will be received in the pairs of slots 328 and 330 , and 332 and 334 in the hitch frame nose piece 300 (illustrated in FIG. 7 ). Thus, the pins 408 and 410 function both to pivotally mount the lift bar 230 onto the plow A-frame 50 , and to help to mount the snow plow onto the hitch frame nose piece 300 .
The bellcrank 360 is pivotally mounted on the plow A-frame 50 using two bolts 412 and two nuts 414 . The pivot plates 362 and 364 of the bellcrank 360 will fit outside of the pivot mount plates 100 and 102 , respectively. One of the bolts 412 will extend through the aperture 104 in the pivot mount plate 100 of the plow A-frame 50 and the aperture 370 in the pivot plate 362 of the bellcrank 360 , and one of the nuts 414 will be mounted on that bolt 412 to retain it in place. The other one of the bolts 412 will extend through the aperture 106 in the pivot mount plate 102 of the plow A-frame 50 and the aperture 372 in the pivot plate 364 of the bellcrank 360 , and the other one of the nuts 414 will be mounted on that bolt 412 to retain it in place.
The bolts 412 allow the bellcrank 360 to pivot on the plow A-frame 50 . In the preferred embodiment, a spacer and two washers (not shown) may be used with each of the bolts 412 , the spacer going through the apertures in the parts being pivotally joined and being longer than the combined thickness of the apertures in the parts, and a washer being located on either end of the spacer to facilitate free rotation of parts, here movement of the bellcrank 360 with reference to the plow A-frame 50 . It will be understood by those skilled in the art that a spacer and two washers will preferably be used at other points of relative movement between two elements of linkage of the snow plow described herein, although the spacer and two washers will not be specifically mentioned in conjunction with each of these pivoting connections made between two elements using a bolt. In addition, it will be understood by those skilled in the art that a pin retained by a cotter pin (not shown herein) could be used instead of a bolt and nut in many of the applications for a fastener used in the linkage discussed herein.
A hydraulic cylinder 416 is mounted at one end to the cylinder mounts 84 and 86 of the plow A-frame 50 using a bolt 418 which extends through the aperture 96 in the cylinder mount 84 and the aperture 98 in the cylinder mount 86 , with a nut 420 being used to retain the bolt 418 in place. The other end of the hydraulic cylinder 416 drives the third corner of the triangular pivot plates 362 and 364 of the bellcrank 360 , with a bolt 422 extending between the aperture 378 in the pivot plate 362 of the bellcrank 360 and the aperture 380 in the pivot plate 364 of the bellcrank 360 . A nut 424 is used to retain the bolt 422 in place. The bolts 418 and 422 allow the hydraulic cylinder 416 to move as it drives the bellcrank 360 . Spacers (not shown herein) may be used on each side of the other end of the hydraulic cylinder 416 on the insides of the pivot plates 362 and 364 to center the hydraulic cylinder 416 .
The lift link 390 is used to connect the bellcrank 360 to pivot the lift bar 230 . A bolt 426 is used to connect the lift link 390 to the lift bar 230 , with the bolt 426 extending sequentially through the aperture 404 in the arm 392 of the lift link 390 , the upper pin 272 from the end extending through the upper pin hanger plate 264 to the end extending through the upper pin hanger plate 266 of the lift bar 230 , and the aperture 406 in the arm 394 of the lift link 390 . A nut 428 is used to retain the bolt 426 in place. The bolt 426 allows the lift link 390 to pivot on the lift bar 230 , and a spacer and two washers may also be used as mentioned hereinabove.
The second corner of the triangle formed by the pivot plates 362 and 364 of the bellcrank 360 drives the ends of the arms 392 and 394 of the lift link 390 which are not connected to the lift bar 230 . Two bolts 430 are used to connect the bellcrank 360 to the lift link 390 , with one of the bolts 430 also being used to mount a stand 432 . The stand 432 is described in U.S. Pat. No. 5,894,688, to Struck et al., which patent is assigned to the assignee of the inventions described herein. U.S. Pat. No. 5,894,688 is hereby incorporated herein by reference.
One bolt 430 (not shown) extends through the aperture 400 in the arm 392 of the lift link 390 and the aperture 374 of the pivot plate 362 of the bellcrank 360 , with a nut 434 being used to retain the first bolt 430 in place, and a spacer and two washers may also be used as mentioned hereinabove. The other bolt 430 extends sequentially through an aperture (not shown) in the upper portion of the stand 432 , the aperture 376 of the pivot plate 364 of the bellcrank 360 , and the aperture 402 in the arm 394 of the lift link 390 , with a nut 434 being used to retain the second bolt 430 in place. The second bolt 430 allows the lift link 390 to pivot on the bellcrank 360 , and a spacer and two washers may again be used as mentioned hereinabove. A removable pin (not shown) extending through an aperture near the top of the stand 432 and apertures located in the lift link 390 is used to link the stand 432 with the lift link 390 .
The hydraulic cylinder 416 is shown in FIG. 10 nearly in its fully retracted position. When the hydraulic cylinder 416 is fully extended, it will be appreciated by those skilled in the art that the lift bar 230 will rotate counterclockwise from the position in which it is shown in FIG. 10 , and the stand 432 will be lowered to engage the ground (not shown) and thereby tend to lift the rear end of the plow A-frame 50 upwardly. It will also be appreciated that once the pins 408 and 410 are in engagement with the slots 328 , 330 , 332 , and 334 in the hitch brackets 304 , 306 , 308 , and 310 , respectively, of the hitch frame nose piece 300 , the hydraulic cylinder 416 may be used to align the apertures 286 , 288 , 290 , and 292 on the lift bar 230 with the apertures 336 , 338 , 340 , and 342 , respectively, in the hitch brackets 304 , 306 , 308 , and 310 , respectively, of the hitch frame nose piece 300 .
Turning next to FIGS. 11 through 16 , a plow blade 440 and various aspects thereof are illustrated. The plow blade 440 has a frame which may be fundamentally thought of as a horizontal top plow frame member 442 , a bottom plow frame member 444 , and a plurality of vertical ribs 446 , 448 , 450 452 , 454 , 456 , and 458 extending between the top plow frame member 442 and the bottom plow frame member 444 . The top plow frame member 442 is made of a triangular tube as best shown in FIG. 13 . The bottom plow frame member 444 is made of a three sided channel resembling a wide, inverted “U” with the tops of the legs of the “U” angling outwardly as best shown in FIG. 14 .
The right side rib 446 is located on the right side of the plow blade 440 , and the left side rib 458 is located on the left side of the plow blade 440 . The ribs 448 , 450 , 452 , 454 , and 456 are located at evenly spaced intervals intermediate the right side rib 446 and the left side rib 458 . Note that all of the ribs 446 , 448 , 450 452 , 454 , 456 , and 458 have an arcuate shape when viewed from the side. The ribs 448 , 450 , 452 , 454 , and 456 all extend between the back side of the top plow frame member 442 and the top side of the bottom plow frame member 444 , while the right side rib 446 and the left side rib 458 are mounted on the ends of the top plow frame member 442 and the bottom plow frame member 444 , thereby overlying them as best shown in FIGS. 11 through 14 . The top plow frame member 442 , the bottom plow frame member 444 , and the ribs 446 , 448 , 450 452 , 454 , 456 , and 458 are all preferably made of steel, and are welded together.
Located in front of the ribs 450 and 454 are curved reinforcing plates 460 and 462 which serve to strengthen the ribs 450 and 454 , which will be used to mount the plow blade 440 to the swing frame 140 (shown in FIGS. 3 through 5 ). The rib 450 has a mounting aperture 464 which extends therethrough and which is located near to the bottom end of the rib 450 . Similarly, the rib 454 has a mounting aperture 466 which extends therethrough and which is located near to the bottom end of the rib 454 . The curved reinforcing plates 460 and 462 are welded to the ribs 450 and 454 , respectively, and to the top plow frame member 442 and the bottom plow frame member 444 .
Four arcuate torsional stiffeners 468 , 470 , 472 , and 474 are used to provide stiffness to the configuration of the plow blade 440 . The torsional stiffener 468 extends from the bottom of the rib 448 to a position near the top of the right side rib 446 . The torsional stiffener 470 extends from the bottom of the rib 450 to a position near the top of the rib 448 . The torsional stiffener 472 extends from the bottom of the rib 454 to a position near the top of the rib 456 . The torsional stiffener 474 extends from the bottom of the rib 456 to a position near the top of the left side rib 458 . The torsional stiffeners 468 , 470 , 472 , and 474 are also preferably made of steel, and are welded to other components in the plow blade 440 .
Located on the left side of the right side rib 446 and on the right side of the left side rib 458 are curved support plates 476 and 478 , respectively. The curved support plates 476 and 478 are recessed back from the front edges of the right side rib 446 and the left side rib 458 , respectively, as best shown in FIG. 15 for the curved support plate 478 . The curved support plates 476 and 478 are preferably also made of steel, and are welded to other components in the plow blade 440 . The frontmost portions of the top plow frame member 442 , the curved support plate 476 , the rib 448 , the curved reinforcing plate 460 , the rib 452 , the curved reinforcing plate 462 , the rib 456 , and the curved support plate 478 together define a curved support surface which will support a moldboard 480 thereupon. The right side rib 446 and the left side rib 458 extend slightly forward of the top plow frame member 442 , the bottom plow frame member 444 , and the ribs 448 , 450 , 452 , 454 , and 456 , to thereby prevent the moldboard 480 from moving laterally. The moldboard 480 may be made of a man-made material such as polycarbonate, which may be clear, or other man-made materials such as ultra-high molecular weight (UHMW) polyethylene, or steel.
Extending across the front side of the top plow frame member 442 is a moldboard retainer strip 482 (best shown in FIG. 13 ), into which the top edge of the moldboard 480 fits and is retained. The moldboard retainer strip 482 is bent slightly toward the top plow frame member 442 , which ensures that the top edge of the moldboard 480 fits snugly therein. Thus, it will be appreciated that the top, right, and left sides of the moldboard 480 are retained in position on the plow blade 440 . The front of the bottom plow frame member 444 extends forwardly with respect to the curved moldboard support surface defined by the frontmost portions of the top plow frame member 442 , the curved support plate 476 , the rib 448 , the curved reinforcing plate 460 , the rib 452 , the curved reinforcing plate 462 , the rib 456 , and the curved support plate 478 . The bottom edge of the moldboard 480 comes just to the top of the bottom plow frame member 444 , as best shown in FIG. 14 .
The front of the bottom plow frame member 444 has a plurality of tapped apertures 484 located therein across the entire width thereof. A wearstrip 486 which is approximately the same width as the bottom plow frame member 444 has a matching plurality of apertures 488 located therein. The wearstrip 486 is preferably made of a high carbon steel such as AISI 1080 high carbon steel. The wearstrip 486 is bolted onto the bottom plow frame member 444 with a plurality of bolts 490 . Alternately, if the apertures 484 are not tapped, bolts and nuts could be used to mount the wearstrip 486 onto the bottom plow frame member 444 . Optionally, the apertures 488 in the wearstrip 486 may be countersunk to recess the heads of the bolts 490 to the level of surface of the wearstrip 486 . The front of the bottom plow frame member 444 is arranged and configured such that the wearstrip 486 will be mounted with its bottom edge angled forwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred.
The wearstrip 486 retains the bottom of the moldboard 480 in place, and it will at once be appreciated that the moldboard 480 may be replaced by merely removing the wearstrip 486 , making the replacement substantially easier than in earlier snow plow blade designs. When the wearstrip 486 is bolted to the bottom plow frame member 444 , it will be appreciated by those skilled in the art that it extends well below the bottom of the bottom plow frame member 444 , so that as it is worn down, the bottom plow frame member 444 will not be damaged by contact with the ground.
Mounted on the back of the ribs 450 and 454 , respectively, are two trip spring brackets 492 and 494 . The trip spring brackets 492 and 494 are mounted approximately three-quarters of the way up the ribs 450 and 454 , and are bent at a ninety degree angle, the bends being on an axis parallel to the lateral axis of the plow blade 440 . The portions of the trip spring brackets 492 and 494 facing forward have notches 496 and 498 , respectively, cut into them from the forwardmost edges thereof to the bends therein. The rear edges of the ribs 450 and 454 fit into the notches 496 and 498 , respectively, and the portions of the spring brackets 492 and 494 facing rearwardly fit against the ribs 450 and 454 , respectively. The spring brackets 492 and 494 are also preferably made of steel, and are welded onto the ribs 450 and 454 , respectively. The rear-facing portion of the trip spring bracket 492 has two apertures 500 and 502 located therein on which lie on opposite sides of the rib 450 , and the rear-facing portion of the trip spring bracket 494 has two apertures 504 and 506 located therein on which lie on opposite sides of the rib 454 .
Located on the right side of the plow blade 440 in the right side rib 446 near the top thereof are two apertures 512 . Similarly, located on the left side of the plow blade 440 in the left side rib 458 near the top thereof are two apertures 514 . The apertures 512 and 514 serve to allow a marker bar or the like (not shown in FIGS. 11 through 13 ) to be attached to the plow blade 440 .
Located at the rear of the plow blade 440 at the bottom thereof is a back blade wearstrip 516 , which is mounted onto the bottom plow frame member 444 and extends substantially across the width of the plow blade 440 . The back blade wearstrip 516 has a plurality of apertures 518 therein, and the bottom plow frame member 444 has matching tapped apertures 520 located in the rear-facing side thereof. Bolts 522 are used in the back blade wearstrip 516 to mount it onto the bottom plow frame member 444 . Alternately, if the apertures 520 are not tapped, bolts and nuts could be used to mount the back blade wearstrip 516 onto the bottom plow frame member 444 . Optionally, the apertures 518 in the back blade wearstrip 516 may be countersunk to recess the heads of the bolts 522 to the level of surface of the back blade wearstrip 516 .
The back blade wearstrip 516 is permanently mounted at an optimum angle with respect to the ground which is defined by the angle of the rear side of the bottom plow frame member 444 . The rear of the bottom plow frame member 444 is arranged and configured such that the back blade wearstrip 516 will be mounted with its bottom edge angled rearwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred. In the preferred embodiment, the wearstrip 486 and the back blade wearstrip 516 will be mounted at the same angles, but with the wearstrip 486 being angled forwardly and the back blade wearstrip 516 being angled rearwardly.
In the preferred embodiment, the back blade wearstrip 516 is made of an UHMW polyethylene material which is used instead of steel to decrease the weight of the plow blade 440 . Alternately, the back blade wearstrip 516 could be made of rubber, urethane, steel, aluminum, or any other suitable material. Also, if desired, the back blade wearstrip 516 can be manufactured as multiple identical narrower segments if desired.
Turning next to FIGS. 17 and 18 , and making reference also to FIGS. 1 and 3 through 5 , the installation of the swing frame 140 onto the plow A-frame 50 is illustrated. The rectangular swing frame tube 142 of the swing frame 140 is inserted between the top plate 52 and the bottom plate 54 of the plow A-frame 50 , with the pivot 144 of the swing frame 140 being brought into alignment intermediate the swing frame pivot 108 and the swing frame pivot 110 of the plow A-frame 50 . A pivot pin 524 having a threaded distal end 526 is inserted sequentially through the swing frame pivot 108 in the plow A-frame 50 , the pivot 144 in the swing frame 140 , and the swing frame pivot 110 in the plow A-frame 50 , and is retained in place by a locking nut 528 . Washers (not shown herein) may also be used if desired.
Thus, the swing frame 140 is pivotally mounted on the plow A-frame 50 , and it will be appreciated by those skilled in the art that the movement of the swing frame 140 is limited by the guide/stop bar 152 on the swing frame 140 which interacts with the rectangular plate 66 on the plow A-frame 50 to limit movement to approximately thirty degrees either to the right or to the left. The swing frame 140 will be pivoted by two hydraulic cylinders, the installation of which will be described later in conjunction with FIG. 30 .
It will be appreciated by those skilled in the art that the design of the plow A-frame 50 and the swing frame 140 represents a substantial improvement over past snow plow frame designs since their centerlines are in the same horizontal plane. Thus, rather than having the swing frame 140 being located on top of the plow A-frame 50 , the swing frame 140 is located in the same plane as is the plow A-frame 50 . In the preferred embodiment, the apertures 60 and 62 in the lugs 56 and 58 , respectively, as well as the pins 408 and 410 , are also in the same horizontal plane.
Moving now to FIG. 19 , a cushion block 530 is illustrated which will be used to absorb the impact of the plow blade 440 (shown in FIG. 11 ) as it moves between its limits. Such movement of the plow blade 440 is caused by the plow blade 440 striking an object, and is designed to prevent damage to the snow plow by allowing the plow blade 440 to “trip,” that is, for the bottom of the plow blade 440 to move rearwardly and the top of the plow blade 440 to simultaneously move forward, resulting in a rotation of the plow blade 440 around a horizontal axis. Such a rotation is inhibited by springs, which act as a shock absorbing mechanism, and which return the plow blade 440 to a normal or “trip return” position. The springs are quite strong, since they must prevent the plow blade 440 from rotating when it is plowing snow, and the metal-to-metal impacts of both a blade trip and a blade trip return can be substantial. The cushion block 530 is designed to cushion the impacts on both the blade trip and the blade trip return.
The cushion block 530 is brick-shaped with a corner cut off to create a beveled face 532 , and will be mounted with the beveled face 532 of the cushion block 530 facing both forwardly and downwardly. Above the beveled face 532 of the cushion block 530 and facing forwardly when the cushion block 530 is mounted is a front face 534 . Extending laterally through the cushion block 530 at a central location is an aperture 536 , which will be used to mount the cushion block 530 on the swing frame 140 (shown in FIGS. 3 through 5 ). A cushion block 530 will be mounted between each pair of the blade pivot mounts 178 and 180 , and 182 and 184 . The apertures 202 and 204 in the blade pivot mounts 178 and 180 , respectively, will align with the aperture 536 in one cushion block 530 , and the apertures 206 and 208 in the blade pivot mounts 182 and 184 , respectively, will align with the aperture 536 in the other cushion block 530 .
Turning next to FIGS. 20 through 22 , and referring also to FIGS. 3 , 11 , and 19 , the installation of both the cushion blocks 530 and the plow blade 440 onto the swing frame 140 is illustrated. One of the cushion blocks 530 is shown installed between the blade pivot mounts 182 and 184 , with a bolt 538 extending sequentially through the aperture 208 in the blade pivot mount 184 , the aperture 536 in the cushion block 530 , and the aperture 206 in the blade pivot mount 182 , and with a nut 540 being used to retain the bolt 538 in place. The top and the rearwardly facing side of the cushion block 530 are retained in position by the stop 222 in the swing frame 140 . The other cushion block 530 would be similarly mounted between the blade pivot mounts 178 and 180 . Alternately, silicone adhesive (or any other suitable type of adhesive) may be used instead of bolts to retain the cushion blocks 530 in place. Another alternate retaining mechanism would be to have the cushion blocks 530 fit in place with an interference fit.
The plow blade 440 will pivot around an axis defined by the mounting apertures 464 and 466 located in the ribs 450 and 454 , respectively, and is mounted onto the swing frame 140 using two pins 542 . One of the pins 542 extends sequentially through the aperture 200 in the blade pivot mount 184 , the mounting aperture 466 in the rib 454 , and the aperture 198 in the blade pivot mount 182 . The other one of the pins 542 extends sequentially through the aperture 196 in the blade pivot mount 180 , the mounting aperture 464 in the rib 450 , and the aperture 194 in the blade pivot mount 180 . Retaining pins 544 are installed into diametrically extending apertures located in the distal ends of each of the pins 542 , and retain the pins 542 in place, thereby pivotally mounting the plow blade 440 on the swing frame 140 .
The plow blade 440 thus may pivot between the trip return position shown in FIG. 20 and the tripped position shown in FIG. 22 . It will be appreciated by those skilled in the art that when the plow blade 440 hits an object on the ground sufficiently hard, it will be driven to the tripped position shown in FIG. 22 , at which time the portion of the rib 454 and also the portion of the rib 450 (which is not shown in FIG. 22 ) below the pins 542 will contact the beveled faces 532 of the cushion blocks 530 , which will absorb the impact. Similarly, when the plow blade 440 is driven back into the trip return position shown in FIG. 20 , the portion of the rib 454 and also the portion of the rib 450 (which is not shown in FIG. 22 ) above the pins 542 will contact the front face 534 of the cushion blocks 530 , which will absorb the impact. In the preferred embodiment, the cushion blocks 530 are made of polyurethane, such as, for example, Quazi formulated methylenebisdiphenyl diisocyanate (MDI) polyester-based 93 durometer (Shore A scale) polyurethane, available commercially from Kryptonics, Inc. under the trademark Kaptane 93 black.
Referring now to FIGS. 23 and 24 , portions of the left side of the swing frame 140 and the plow blade 440 are illustrated in the blade trip return position. In the principal design described herein and shown in the drawings, four trip springs 550 , 552 , 554 , and 556 (the first two of which are not shown in FIGS. 23 or 24 ) will be used to bias the plow blade 440 into the trip return position, and to resist movement of the plow blade 440 into the tripped position. Two trip springs 550 and 552 , or 554 and 556 will be located on each side of the swing frame 140 and the plow blade 440 . The trip springs 554 and 556 are shown in phantom lines in FIG. 23 , with the trip spring 554 being connected between the aperture 218 of the trip spring bracket 212 and the aperture 504 of the trip spring bracket 494 , and the trip spring 556 being connected between the aperture 220 of the trip spring bracket 212 and the aperture 506 of the trip spring bracket 494 .
It will at once be appreciated by those skilled in the art that the trip springs 554 and 556 are located immediately on either side of the pivoting connection between the plow blade 440 and the swing frame 140 . The trip springs 554 and 556 exert a force in a plane which is parallel to the plane of rotation defined by the pivoting connection between the plow blade 440 and the swing frame 140 . Thus, the trip springs 554 and 556 do not pull in a direction which is even in part at an angle to the plane of rotation. This represents a major advantage over previously known snow plow trip spring mounting designs, which without exception are located at an angle to the plane of rotation defined by the pivoting connection between the plow blade and the swing frame of such previously known snow plows. The design of the snow plow described herein utilizes all of the trip spring force for the blade trip operation, and thus provides more consistent blade trip operation as well as eliminating lateral trip spring force being exerted on the frame of the plow blade 440 .
Turning next to FIGS. 25 and 26 , an alternate embodiment is illustrated in which two trip springs are used to bias the plow blade 440 into the trip return position, and to resist movement of the plow blade 440 into the tripped position. One trip spring will be located on each side of the swing frame 140 and the plow blade 440 (the trip spring 560 on the left side of the swing frame 140 and the plow blade 440 is illustrated in the blade trip return position in FIG. 25 ). In the alternate embodiment illustrated in FIGS. 25 and 26 , the design of the trip spring brackets which are mounted on the back of the ribs 450 and 454 differs from the design of the trip spring brackets 210 and 212 (shown in FIGS. 3 through 5 ). A trip spring bracket 562 having a single aperture 564 located therein is mounted on the blade pivot mounts 182 and 184 . The trip spring bracket 562 is also preferably made of steel, and is welded onto the blade pivot mounts 182 and 184 with the aperture 564 being located between the blade pivot mounts 182 and 184 . An identical spring trip bracket (not shown) would also be used on the right side of the swing frame 140 .
In the alternate embodiment illustrated in FIGS. 25 and 26 , the design of the trip spring brackets which are mounted on the back of the ribs 450 and 454 also differs from the design of the trip spring brackets 492 and 494 (shown in FIGS. 11 and 12 ). A trip spring bracket 566 is mounted approximately three-quarters of the way up the rib 454 , and is bent at a ninety degree angle, the bend being on an axis parallel to the lateral axis of the plow blade 440 . The portion of the trip spring bracket 566 facing forward has a notch 568 cut into it from the forwardmost edge thereof to the bend therein. The rear edge of the rib 454 fits into the notch 568 , and the portion of the spring bracket 566 facing rearwardly fits against the rib 454 . The rear-facing portion of the trip spring bracket 566 has an aperture 570 located therein which lies in the same plane as the rib 454 . The spring bracket 566 is also preferably made of steel, and is welded onto the rib 454 . An identical spring trip bracket (not shown) would also be used on the right side of the plow blade 440 .
It will be appreciated by those skilled in the art that the trip spring 560 is located, and exerts a force, in the plane of rotation defined by the pivoting connection between the plow blade 440 and the swing frame 140 . Thus, the trip spring 560 does not pull in a direction which is even in part at an angle to the plane of rotation (unlike previously known snow plow trip spring mounting designs). The alternate embodiment design of the snow plow of FIGS. 25 and 26 utilizes all of the trip spring force for the blade trip operation and provides more consistent blade trip operation as well as eliminating lateral trip spring force being exerted on the frame of the plow blade 440 .
Referring next to FIGS. 27 and 28 , the movement of the plow blade 440 between the trip return position shown in FIG. 27 and the fully tripped position shown in FIG. 28 is illustrated. From these figures (and also by looking at the orientation of the trip springs 550 , 552 , 554 , and 556 in the top plan view of FIG. 30 ), it will be appreciated that the trip springs 550 , 552 , 554 , and 556 (which are already under tension even in the trip return position) are all further stretched as the plow blade 440 moves from the trip return position to the tripped position, and thus serve to return the plow blade 440 to the trip return position when the force which caused the plow blade 440 to be tripped is removed.
Turning next to FIGS. 29 and 30 , the assembly of several additional components is illustrated. First, all four of the trip springs 550 , 552 , 554 , and 556 are illustrated as mounted onto the swing frame 140 and the plow blade 440 . In addition, right and left light support towers 572 and 574 , respectively, are mounted on the light bar supports 244 and 246 , respectively, of the lift bar 230 , and a light support bar 576 is mounted on the top ends of the right and left light support towers 572 and 574 . Lights (not shown herein) would be mounted on the light support bar 576 , in a manner well known to one skilled in the art.
In addition, right and left swing cylinders 578 and 580 , respectively, are mounted between the plow A-frame 50 and the swing frame 140 . The right swing cylinder 578 extends between the swing cylinder mount 76 on the plow A-frame 50 (where it is secured with a pin 582 ) and the swing cylinder mounting plates 154 and 158 on the swing frame 140 (where it is secured with a pin 584 ), and the left swing cylinder 580 extends between the swing cylinder mount 78 on the plow A-frame 50 (where it is secured with a pin 586 ) and the swing cylinder mounting plates 156 and 160 on the swing frame 140 (where it is secured with a pin 588 ). It will be understood that the pins 582 , 584 , 586 , and 588 are all retained in place with cotter pins (not shown) as is well known to those skilled in the art.
Also not shown or discussed herein is the hydraulic system to operate the snow plow, the construction and operation of which is also well known to those skilled in the art. The right and left swing cylinders 578 and 580 are used to pivot the swing frame 140 and the plow blade 440 on the plow A-frame 50 . The hydraulic cylinder 416 (shown in FIG. 10 ) is used to operate the stand 432 (also shown in FIG. 10 ) prior to the snow plow being mounted onto a truck, to facilitate the mounting of the snow plow onto the truck (as will become apparent below in conjunction with the discussion of FIGS. 31 through 37 ), and to raise and lower the plow A-frame 50 , the swing frame 140 , and the plow blade 440 after the snow plow has been mounted onto the truck. The hydraulic system for the snow plow may be mounted on the plow A-frame 50 at the front thereof, and if so mounted would have a hydraulic system cover 590 mounted thereupon to protect it, as shown in phantom lines.
Referring now to FIGS. 31 through 37 , the operation of the mounting system used to mount the snow plow on the hitch frame nose piece 300 is shown. Referring first to FIGS. 31 through 33 , in conjunction with FIGS. 1 , 6 , 7 , and 10 , the mechanism used to connect the snow plow to the hitch frame nose piece 300 is shown. In the discussion herein, all references are to the left side of the snow plow and the hitch frame nose piece 300 , but those skilled in the art will understand that the principles thereof are equally applicable to the right side of the snow plow and the hitch frame nose piece 300 .
The snow plow is mounted onto the hitch frame nose piece 300 with the plow standing on the stand 432 (shown in FIG. 10 ). In this position, the pin 410 which extends laterally at the rear of the snow plow on the left side will be at a height such than when the truck having the hitch frame nose piece 300 mounted thereon moves forward, the pin 410 will fit into the rectangular notches 324 and 326 at the front of the hitch brackets 308 and 310 , respectively. The pin 410 is brought fully into the rectangular notches 324 and 326 by moving the truck forward. It will be noted that the flange at the front of the hitch bracket 310 as well as the approximately seventy degree bend in the angled stock segment 250 will assist in guiding the rear mounting support 238 and the angled stock segment 250 of the lift bar 230 into position intermediate the hitch bracket 308 and 310 .
A this point, the hydraulic cylinder 416 (shown in FIG. 10 ) is actuated to begin to retract it to raise the stand 432 (also shown in FIG. 10 ), causing the pin 410 to drop into the slots 332 and 334 in the hitch brackets 308 and 310 , respectively. By continuing to actuate the hydraulic cylinder 416 to retract it, the lift bar 230 is pivoted to bring the apertures 290 and 292 in the angled stock segment 250 and the rear mounting support 238 , respectively, of the lift bar 230 into alignment with the apertures 340 and 342 in the hitch brackets 308 and 310 , respectively, of the hitch frame nose piece 300 . At this point, a retaining pin 592 having a handle 594 may be inserted sequentially through the aperture 342 in the hitch bracket 310 , the aperture 292 in the rear mounting support 238 , the aperture 290 in the angled stock segment 250 , and the aperture 340 in the hitch bracket 308 . The retaining pin 592 has an aperture 596 extending through near the distal end thereof, and a retaining spring pin 598 is used to retain the retaining pin 592 in place.
Referring next to FIGS. 34 through 37 , the installation of the snow plow onto the hitch frame nose piece 300 mounted on a truck 600 (shown in phantom lines in FIG. 37 ) is illustrated. In FIG. 34 , the snow plow is shown in its stored position, supported on the stand 432 . In this position, the hydraulic cylinder 416 is in its fully extended position, and the rear end of the snow plow is raised. In this position, the pin 408 (not shown in FIGS. 34 through 37 ) at the right rear of the snow plow will be received by the rectangular notches 320 and 322 (not shown in FIGS. 34 through 37 ) at the front of the hitch brackets 304 and 306 (not shown in FIGS. 34 through 37 ), respectively, at the right side of the hitch frame nose piece 300 . Similarly, the pin 410 at the left rear of the snow plow will be received by the rectangular notches 324 (not shown in FIGS. 34 through 37 ) and 326 at the front of the hitch brackets 308 (not shown in FIGS. 34 through 37 ) and 310 , respectively, at the left side of the hitch frame nose piece 300 . The truck 600 may be driven forward to fully engage the pins 408 and 410 with the hitch frame nose piece 300 as shown in FIG. 34 .
Next, as shown in FIG. 36 , as the hydraulic cylinder 416 begins to retract, the plow A-frame 50 will lower at the rear end thereof as the stand 432 begins to move upwardly relative to the plow A-frame 50 . This causes the pin 408 (not shown in FIGS. 34 through 37 ) to drop into the slots 328 and 330 (not shown in FIG. 36 ) in the hitch brackets 304 and 306 (not shown in FIG. 36 ), respectively, at the right side of the hitch frame nose piece 300 . Similarly, the pin 410 drops into the slots 332 (not shown in FIG. 36) and 334 in the hitch brackets 308 (not shown in FIG. 36) and 310 , respectively, at the left side of the hitch frame nose piece 300 . This initial retraction of the hydraulic cylinder 416 also causes the lift bar 230 to begin to rotate clockwise as viewed from the left side of the snow plow, as is evident from the movement of the right light support towers 572 and 576 and the light support bar 576 .
As shown in FIG. 37 , as the hydraulic cylinder 416 continues to retract, the lift bar 230 rotates clockwise until the light support towers 572 and 576 are oriented nearly vertically. As this further rotation occurs, the pin 408 (not shown in FIG. 37 ) remains in the slots 328 and 330 in the hitch brackets 304 and 306 , respectively (none of which are shown in FIG. 37 ). Similarly, the pin 410 remains in the slots 332 (not shown in FIG. 37) and 334 in the hitch brackets 308 (not shown in FIG. 37) and 310 , respectively. On the right side of the lift bar 230 and the hitch frame nose piece 300 (best shown in FIGS. 6 and 7 ), the apertures 286 and 288 in the rear mounting support 236 and the angled stock segment 248 , respectively, of the lift bar 230 move into engagement with the apertures 336 and 338 in the hitch brackets 304 and 306 , respectively, of the hitch frame nose piece 300 . Likewise, on the left side of the lift bar 230 and the hitch frame nose piece 300 (portions of which are also best shown in FIGS. 6 and 7 , respectively), the apertures 290 and 292 in the angled stock segment 250 and the rear mounting support 238 , respectively, of the lift bar 230 move into alignment with the apertures 340 and 342 in the hitch brackets 308 and 310 , respectively, of the hitch frame nose piece 300 .
At this point, one of the retaining pins 592 is inserted sequentially through the aperture 336 in the hitch bracket 304 , the aperture 286 in the rear mounting support 236 , the aperture 288 in the angled stock segment 248 , and the aperture 338 in the hitch bracket 306 (all of which are best shown in FIGS. 6 and 7 ). The other one of the retaining pins 592 is inserted sequentially through the aperture 342 in the hitch bracket 310 , the aperture 292 in the rear mounting support 238 , the aperture 290 in the angled stock segment 250 , and the aperture 340 in the hitch bracket 308 (many of which are also best shown in FIGS. 6 and 7 ). The retaining spring pins 598 are then inserted into the apertures 596 near the distal ends of the retaining pins 592 to retain the retaining pins 592 in place. At this point, the stand 432 may also be moved to a stowed position by disconnecting it from the lift link 390 (by removal of the pin (not shown)) and rotating it to the stowed position as is taught in U.S. Pat. No. 5,894,688, which was incorporated by reference above.
Also shown in FIG. 37 is a marker bar 602 , one of which may be mounted on each side of the plow blade 440 at the top thereof using the apertures 512 and 514 (not shown in FIG. 37 ) on the right and left sides of the plow blade 440 , respectively, using bolts 604 and nuts (not shown herein). The marker bars 602 are used to allow the driver of the truck 600 to see where the front of the plow blade 440 is at any given time (since the driver may not be able to see the plow blade 440 over the hood of the truck 600 from the cab of the truck 600 ).
Referring finally to FIG. 38 , a snow plow having an alternate embodiment is illustrated in which shoes 610 and 612 are installed on the plow blade 440 . The shoes 610 and 612 are designed to ride in sliding contact with the surface to be plowed, and are particular useful on gravel or during the spring when the ground may not be fully frozen. The shoes 610 and 612 are mounted to the plow blade 440 using shoe mounts 614 and 616 , respectively. The shoe mount 614 is mounted on the bottom plow frame member 444 near the right side thereof, and the shoe mount 616 is mounted on the bottom plow frame member 444 near the left side thereof. The shoe mounts 614 and 616 are preferably made of steel and are welded onto the bottom plow frame member 444 .
The shoes 610 and 612 are mounted on posts 618 and 620 , respectively, which posts 618 and 620 are received by the shoe mounts 614 and 616 , respectively. The shoes 610 and 612 are adjusted using a combination of washers and tubular spacers, which are placed on the posts 618 and 620 either below or above the shoe mounts 614 and 616 to adjust the height of the shoes 610 and 612 . The position of the shoes 610 and 612 relative to the plow blade 440 may be adjusted to adjust the height of the plow blade 440 relative to the surface to be plowed. This allows the degree to which the wearstrip 486 scrapes the surface to be plowed to be controlled. Retaining pins 622 and 624 are used on the posts 618 and 620 , respectively, to retain them in the shoe mounts 614 and 616 .
The shoes 610 and 612 are typically made out of cast iron. It should be noted that although the back blade wearstrip 516 is not shown in the embodiment illustrated in FIG. 38 , it can in fact be used with the shoes 610 and 612 , so long as the shoe mounts 614 and 616 extend sufficiently back to clear the back blade wearstrip 516 . The shoes 610 and 612 have feet which are adapted to ride in sliding contact with the surface to be plowed. The position of the feet relative to the plow blade may be adjusted to adjust the height of the plow blade relative to the surface to be plowed. In this way, the degree to which the blade edge scrapes the surface to be plowed may be controlled.
It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it teaches an improved hitch mounting mechanism and method of operating the same which allows the snow plow to be both connected to and disconnected from a truck easily and simply, without requiring tools. The snow plow hitch mounting mechanism of the present invention requires no physical effort to connect or disconnect the snow plow from the truck. The process of connecting or disconnecting the snow plow to or from the truck with the hitch mounting mechanism of the present invention is so simple and easy to use that it can be done by a single person without requiring assistance.
The snow plow hitch mounting mechanism of the present invention is mechanically simple, both in construction and in operation. The snow plow hitch mounting mechanism of the present invention provides a robust connection between the snow plow and the truck. The snow plow hitch mounting mechanism of the present invention is of a construction which provides a high ground clearance between the bottom of the hitching mechanism and the ground, thereby not presenting a problem even when plowing on hilly or uneven terrain.
The snow plow hitch mounting mechanism of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow hitch mounting mechanism of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved by the snow plow hitch mounting mechanism of the present invention without incurring any substantial relative disadvantage.
Although an exemplary embodiment of the snow plow hitch mounting mechanism of the present invention has been shown and described with reference to particular embodiments and applications thereof, it will be apparent to those having ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. All such changes, modifications, and alterations should therefore be seen as being within the scope of the present invention.
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An improved snow plow for use with light and medium duty trucks is disclosed which has a hitch mounting mechanism and method that enables the snow plow to be easily and quickly mounted to and detached from a truck without requiring tools. The snow plow hitch mounting mechanism has four points of attachment between a snow plow-mounted hitching apparatus and a hitch frame mounted at the front of a truck, two points of attachment being at each side. The lower points of attachment are made by initially engaging the snow plow-mounted hitching apparatus with the hitch frame, with the upper points of attachment being engaged by using a releasable retaining mechanism.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/SG2010/000045, filed Feb. 09, 2010, entitled A METHOD OF COMMUNICATION, which claims priority to Singapore patent application number 200901050-5, filed Feb. 12, 2009.
FIELD OF THE INVENTION
The present invention relates to a method of communication, a relay station, a base station, a communication network, a user equipment and an integrated circuit, and relates particularly though not solely to distributed rate setting and coding schemes.
BACKGROUND
The following abbreviations may be used in this specification:
MAC multiple access channels CMAC cooperative MAC MARC multiple access relay channels BRC broadcast relay channels DF decode-and-forward SNR signal to noise ratio FER frame error rate RSC recursive convolutional code LO local oscillator AWGN additive white Gaussian noise BPSK binary phase shift keying CC convolutional code BS base station UE user equipment OFDM orthogonal frequency division multiplex SCCP single carrier cyclic prefix OFDMA orthogonal frequency division multiple access SC-FDMA single-carrier frequency division multiple access DFT-Spread-OFDM discrete Fourier transform spread OFDM FEC forward error correction STBC space time block code LLR log-likelihood ratio IR incremental redundancy CP cyclic prefix TDMA time division multiple access RS relay station MIMO multiple input multiple output ACK acknowledgement NACK negative acknowledgement SDMA spatial division multiple access EXIT extrinsic information transfer S source R relay D destination CC(●) convolutional code with settings in parenthesis PCC(●) parallel concatenated code with settings in parenthesis P out (●) probability of information outage I(●) mutual information γ AB the SNR from A to B SNR AB (N) the SNR from A to B in the N-th time slot
SUMMARY OF THE INVENTION
In general terms the invention relates to combining distributed Alamouti space-time coding with decode-and-forward cooperative relay strategy using distributed rate-compatible error correction codes. This may have one or more advantages such as:
1. a simple and/or systematic technique for designing a code for a cooperative relay network may provide increased wireless capacity and link quality; 2. a coding technique for a cooperative relay network with a low implementation complexity, for example using convolutional codes; and/or 3. a code design for a cooperative relay network which may have an error performance that is close to the theoretical optimum.
In a first particular expression of the invention there is provided a method of communication according to claim 1 .
In a second particular expression of the invention there is provided a RS as claimed in claim 11 .
In a third particular expression of the invention there is provided a RS as claimed in claim 12 .
In a fourth particular expression of the invention there is provided a BS as claimed in claim 13 .
In a fifth particular expression of the invention there is provided a communication network as claimed in claim 14 .
In a sixth particular expression of the invention there is provided a UE as claimed in claim 15 .
In a seventh particular expression of the invention there is provided an IC as claimed in claim 16 .
The invention may be implemented according to any of the embodiments in claims 2 to 10 .
BRIEF DESCRIPTION OF THE DRAWINGS
One or more example embodiments of the invention will now be described, with reference to the following figures, in which:
FIG. 1 is an illustration of a simple 3-node relay channel model according to a first example embodiment,
FIG. 2 is a graph of a Distributed Turbo coding at destination for a relay network with α=0.5, γ SD =−3 dB and γ RD =−2.1 dB,
FIG. 3 is a graph of an Enhanced Turbo code at relay for a relay network with α=0.75, γ SR =0.1 dB, γ SD =−3 dB and γ RD =−1.2 dB,
FIG. 4 is a graph of an Enhanced Turbo Code at destination for a relay network with α=0.75, γ SR =0.1 dB, γ SD =−3 dB and γ RD =−1.2 dB,
FIG. 5 is a graph of a Distributed multiple Turbo code at relay for a relay network with α=0.75, γ SR =−0.2 dB, γ SD =−3 dB and γ RD =−1.5 dB,
FIG. 6 is a graph of a Distributed multiple Turbo code at destination for a relay network with α=0.75, γ SR =−0.2 dB, γ SD =−3 dB and γ RD =−1.5 dB,
FIG. 7 is a graph of an outage and FER of distributed Turbo coding at destination for a relay network with α=0.5,
FIG. 8 is a graph of an outage and FER of an enhanced Turbo coding and multiple Turbo coding at destination for a relay network with α=0.75,
FIG. 9 is an illustration of a two-user CMAC system according to a second example embodiment,
FIG. 10 is an illustration of a two-user MARC system according to a third example embodiment,
FIG. 11 is an illustration of a two-user BRC system according to a forth example embodiment,
FIG. 12 is a graph of a Multiple Turbo code at destination for a cooperative network with α 1 =α 2 =0.375, γ S 1 D =γ S 2 D =−3.3 dB,
FIG. 13 is a graph of an outage and FER of a multiple Turbo coding and an enhanced Turbo coding at destination for a cooperative network,
FIG. 14 is an illustration of the Network configurations,
FIG. 15 is an illustration of the CMAC: 1 st and 2 nd time slot,
FIG. 16 is an illustration of a CMAC: 3 rd time slot without cooperation,
FIG. 17 is an illustration of a CMAC: 3 rd time slot with cooperation,
FIG. 18 is a flowchart of the Joint network and channel encoding,
FIG. 19 is an illustration of the MARC: 1 st and 2 nd time slot,
FIG. 20 is an illustration of a MARC: 3 rd time slot without cooperation,
FIG. 21 is an illustration of a MARC: 3 rd time slot with cooperation,
FIG. 22 is an illustration of a BRC: 1 st time slot,
FIG. 23 is an illustration of a BRC: 2 nd time slot without cooperation,
FIG. 24 is an illustration of a BRC: 2 nd time slot with cooperation, and
FIG. 25 is a flowchart of the encoding structures for distributed coding.
DETAILED DESCRIPTION
In the following one or more example embodiments are described including a simple relay channel and three MAC network topologies in which multiple users need to exchange information sequences (packets) with a base station, namely, CMAC, MARC and BRC. In MARC, one or more dedicated relays are deployed to assist users' transmission to the base station, whereas in CMAC, no dedicated relays are available. In BRC, only one user is broadcasting with the help of one or more dedicated relays.
1. System Model
FIG. 1 shows a relay channel model 100 , with a S, R and D. The channel coefficients between S-R, S-D and R-D nodes are g 0 , g 1 , and g 2 , respectively. We assume a quasi-static fading channel, where the channel coherence time is considerably larger than the code word. The channel coefficients are independent and identically-distributed random variables, which remain constant over the whole duration of the codeword, given by Equation 1:
g i = h i d i β / 2 , ( 1 )
where h i and d i are the channel gains and distances between the transmitter and receiver, respectively. The attenuation exponent is β (e.g., β=2 for free-space propagation).
The relay operates in half-duplex mode, where the transmitting and listening modes cannot occur simultaneously. In the DF protocol, the block of symbols with length n is split into two phases. In the first phase, the relay is in listening mode and receives the signal from the source. At the end of this phase, the relay decodes the source information message. The relay then switches to transmitting mode in the second phase and sends symbols to help the destination decode the source message. During the first phase, the signal received by the relay is given by Equation 2:
y r,k =g 0 x s,k +v k , k= 1, 2, . . . , α n, (2)
and the signal received by the destination is given by Equation 3:
y k =g 1 x s,k +w k , k= 1, 2, . . . , α n. (3)
where x s,k denotes the codeword that is to be transmitted from the source, v k denotes the additive noise introduced in the channel between the source and the relay, and w k denotes the additive noise introduced in the channel between the source and the destination. α denotes the proportion of symbols that is to be devoted to the first phase.
During the second phase (i.e. the relay transmitting phase), the signal received by the destination is given by Equation 4:
y k =g 1 x s,k +g 2 x r,k +w k , k=αn+ 1, . . . , n. (4)
Here, x s =[x s,1 . . . x s,n ] T a is the source codeword, drawn from the code χ s . We assume that the symbols x r,k transmitted by the relay are from an auxiliary code x r with length n. Only the last (1−α)n symbols of a codeword are effectively transmitted in the second phase. In the first phase, the relay is idle because of the constraints of half-duplex communication.
The noise variables v k ˜CN(0,σ v 2 ) and w k ˜CN(0,σ w 2 ) at the relay and destination, respectively, are mutually independent. v k and w k are complex variables and the notation ˜CN(●) denotes a complex Gaussian distribution. We also impose the same per-symbol average power constraint for both the source and the relay in Equation 5:
E[|x s,k | 2 ]≦E s and E[|x r,k | 2 ]≦E s (5)
where E s , denotes the symbol energy and E[ ] denotes an expectation operation. The SNRs of the S-D and the S-R links are defined as γ=E s /σ w 2 and {tilde over (γ)}=E s /σ v 2 , respectively. σ v 2 and σ W 2 can be chosen such that σ v 2 =σ W 2 .
2. Alamouti-DF Scheme
A DF protocol with the relay code χ r such that the signal received at the destination forms an Alamouti constellation, shall be referred to as the Alamouti-DF scheme. Assuming that the relay can decode the signal, the signal transmitted by the relay at time k is given by Equation 6:
x r , k = { x s , k + 1 * , k = α n + 1 , α n + 3 , … - x s , k - 1 * , k = α n + 2 , α n + 4 , … . ( 6 )
x s,k+1 * denotes the complex conjugate of x s,k+1 . The signal seen by the destination for αn+1≦k≦n is an Alamouti constellation. Through linear processing of the received signal, the destination obtains the sufficient statistics for decoding, as are given by Equation 7:
y ~ k = { g 1 x s , k + w k , k = 1 , … , α n g 1 2 + g 2 2 x s , k + w ~ k , k = α n + 1 , … , n , ( 7 )
where the statistical properties of {tilde over (w)} k are identical to those of w k . The mutual information per symbol at the destination is given by Equation 8:
I (γ, g 1 ,g 2 )=α I (| g 1 | 2 γ)+(1−α) I ((| g 1 | 2 +|g 2 | 2 )γ) (8)
On the other hand, if the source does not transmit during the second phase, the mutual information is given by Equation 9:
I (γ, g 1 ,g 2 )=α I (| g 1 | 2 γ)+(1−α) I (| g 2 | 2 γ) (9)
With a large n, the probability of a FER is the information outage probability which is defined in Equation 10:
P out (γ, R )= Pr{I (γ, g 1 ,g 2 )≦ R}, (10)
where R is the target transmission rate in bits per channel use. For large SNR, the P out is given in Equation 11:
P out (γ, R )˜κγ −d , (11)
where κ is the coding gain independent of γ and d is referred to as SNR exponent or diversity.
3. Distributed Coding FEC
A distributed turbo coding scheme may use a recursive convolutional code (RSC). When decoding the message at the relay, the interleaved message is encoded with another RSC code. To further improve the decoding capability at the relay, an enhanced turbo code scheme may be used. Instead of the RSC, a turbo code may be used at the source node in the distributed turbo coding scheme. In addition to the systematic bits, the source node transmits a punctured sequence of parity bits from the first and second constituent encoders. The relay then transmits all the punctured parity bits. The punctured turbo code has more parity bits at the destination, resulting in an enhanced turbo code. Note that in all the above mentioned schemes, systematic codes are used. The distributed turbo coding and the enhanced turbo code schemes may be combined to produce a multiple turbo code at the destination. For the distributed multiple turbo code scheme, the source also transmits using a turbo code. Instead of sending the punctured parity bits at the relay, the interleaved message is encoded with another constituent code.
The coding techniques (such as but not limited to RSC, turbo codes or their corresponding constituent codes) may optionally employ puncturing.
In the following, we assume an AWGN channel (i.e., the channel gain h i =1) where the SNR of source-destination channel is insufficient to support the desirable rate R.
The setup for the distributed turbo coding scheme is as follows. The non-systematic RSC C 1 at the source is CC(4/7) with R 1 =1 and the RSC C 2 at the relay is CC(7/5) with R 2 =1. These codes are used together with BPSK modulation as shown in Equation 12:
x s,k ={−√{square root over ( E s )},√{square root over ( E s )}}, (12)
producing an overall rate of R=1/2 bits per channel use for half-duplex mode with α=0.5. The SNR of the S-D channel is set as shown in Equation 13:
γ SD =10 log 10 (| g 1 | 2 γ)=−3.0 dB, (13)
which may be sufficient for 1/2 bits per channel use. The relay transmits the codeword from C 2 , assuming the SNR of the S-R channel γ SR is high enough for the relay to decode the message reliably. FIG. 2 illustrates the EXIT chart for this distributed turbo coding scheme when the SNR of the R-D channel is set as out in Equation 14:
γ RD =10 log 10 (| g 2 | 2 γ)=−2.1 dB. (14)
The average decoding trajectory is also included. A tunnel exists to allow for the convergence of iterative decoding towards a low error rate. A rate of ½ bits per channel use is achievable for γ RD =−2.6 dB. Hence, this code operates approximately 0.4 dB from the theoretic limit.
When γ SR is low, the enhanced turbo code scheme is required for the message to get across reliably to the relay. Again, we select our target rate to be R=½ bits per channel use for half-duplex mode. Since γ SR is low, we need to increase α to get the message across to the relay. We select α=0.75. The SNR for the S-D channel is set at γ SD =−3.0 dB. The codeword sent by the source is formed by puncturing the turbo code which is made up of constituent codes C 1 and C 2 . The puncturing patterns for C 1 and C 2 are [1011] and [1110], respectively. Since the relay only receives data in the first time slot, the relay would only see C 1 and C 2 , which constitutes a rate 2/3 punctured turbo code. The EXIT chart for the iterative decoding algorithm is given in FIG. 3 . A tunnel exists to allow for convergence of iterative decoding towards a low error rate at γ SR =0.1 dB. The SNR limit for a rate 2/3 is −0.7 dB. The relay then transmits the punctured parity bits to the destination. FIG. 4 illustrates the EXIT chart for the iterative decoding at the destination. A tunnel exists to allow for convergence of iterative decoding towards low error rate at γ RD =−1.2 dB. The theoretical SNR limit is −2.3 dB. Hence, this code is operating approximately 1.1 dB from the theoretic limit.
Instead of sending the punctured parity bits, the relay uses a encoder in the distributed multiple turbo code scheme. The encoder can optionally use puncturing in its coding scheme. The constituent codes C 1 , C 2 and C 3 are CC(4/7), CC(4/7) and CC(3), respectively. In FIG. 5 , a tunnel exists to allow for convergence of iterative decoding towards low error rate at γ SR =−0.2 dB, which is lower than the enhanced turbo code scheme in FIG. 3 . The convergence of iterative decoding towards low error rate is possible at γ RD =−1.5 dB, as shown in FIG. 6 . This code is operating approximately 0.8 dB from the theoretical limit.
4. Alamouti-DF Scheme with Distributed Coding
According to an example embodiment, an Alamouti-DF scheme is used with a distributed turbo code, an enhanced turbo code and a multiple turbo code schemes. The fading coefficients {h i } are Rayleigh distributed as represented in Equation 15:
p ( h i )=2 h i e −h i 2 , h i ≧0 (15)
FIG. 7 shows the outage probability and FER performance of an Alamouti-DF scheme with distributed turbo code. The setting of the relay is such that d 1 −β =1 and d 2 −β =1.23, where d 1 denotes the distance between the source and the destination and d 2 denotes the distance between the relay and the destination. The slot allocation is α=0.5 and the target rate is R=0.5. With BPSK modulation, the outage probability has a diversity of 2. The FER of the distributed turbo code (C 1 and C 2 ) is about 1 dB from the outage limit and has the same order of diversity.
FIG. 8 shows the outage probability and FER performance of an Alamouti-DF scheme with enhanced turbo code and multiple turbo code. We set α=0.75, d 1 −β =1 and d 2 −β =1.51. The outage probability has a diversity of 2 only if R≦(1−α). With R=0.5, only a diversity of one may be achieved. Similarly, the FER of the enhanced turbo code PCC(4/7+5/7) and the multiple turbo code PCC(3+4/7+4/7) is around 1 dB from the outage limit with diversity one.
5. Rate Setting
According to the first example embodiment a node (for example the relay) acquires the channel state information, e.g., the SNR parameters, via, e.g., estimation based on preambles sent by the node, or feedback from the other nodes in the network. The transmission rate is set based on the channel state information by using a rate setting algorithm.
Firstly a target rate is set for the user. If the channel quality information shows that the target rate can be supported, then direct link transmission is used. If the target rate cannot be supported by direct link transmission, then distributed coding is used.
For distributed coding, given the SNRs of the network, parameters may be selected to ensure reliable transmission is possible. For example, the slot duration for each phase of transmission should be minimized, e.g., by using high-rate coded modulation, so as to improve the overall efficiency. The slot duration in some communication phases can be optimized by, e.g., using an information theoretical approach to obtain the rate region of the protocol adopted. This rate region provides a minimum SNR threshold which is required for operating at a certain rate. With these values, the minimum power to support the target rate can be obtained. If the SNR is below the minimum threshold, the target rate is reduced and the rate setting procedure starts all over again.
As discussed later a FEC approach is taken to achieve the selected rate. The rate information and the FEC parameters are transmitted to the nodes in the network and the nodes then start the transmission based on the set rate, code, and protocol.
6. Transmission Protocol
The transmission protocol for the relay network in FIG. 1 will now be described. A Node S works in cooperation with a Node R to deliver its packets to a Node D. In the 1 st time slot Node S transmits and Node R receives the coded bits and tried to decode its information. We consider two distributed coding scheme: (i) incremental bits and (ii) joint network and channel coding. Their encoding structures are shown in FIG. 25 . For incremental bits, Node S sends the codeword (c 11 ,c 21 ) during the first time slot. c 11 is the codeword produced by Encoder 1 and c 21 is the codeword produced by Encoder 2 during the first time slot. When joint network and channel coding is used, Node S sends the codeword (c 1 ,c 2 ). c 1 and c 2 respectively are the codewords produced by Encoder 1 and Encoder 2. ACK/NACK information is sent out from node R to Node S and D.
In the 2 nd time slot, if NACK is received from Node R, the source will operate in anon-cooperative mode. If ACK is received, Node S and D will operate in a cooperative mode. In cooperative mode Node R sends either (c 12 ,c 22 ) or (c 3 ) with the source using a STBC. c 12 and c 22 are the codewords produced by Encoder 1 and Encoder 2 respectively during the 2 nd time slot while c 3 is the codeword produced by Encoder 3. In the non-cooperative configuration, Node S transmits additional coded bits during the 2 nd and last time slot for additional redundancy. For incremental bits, S 1 sends (c 12 ,c 22 ) while for joint network and channel coding, S 1 sends (c 3 ).
7. Encoding Scheme
Two types of distributed coding schemes are shown in FIG. 25 . Firstly the incremental bit encoders are rate 1 convolutional or recursive convolutional codes with appropriate puncturing patterns. The rate of codeword (c 11 ,c 21 ) is optimized for the SNR of the source to relay channel, while the rate of codeword (c 11 ,c 12 ,c 21 ,c 22 ) is optimized for the SNR of the relay to destination and the source to destination channel. Optimization of the code is done by pairing the extrinsic information transfer function of each of the component code, so that the SNR of the decoding threshold is minimized.
The joint network and channel coding encoders are rate 1 convolutional or recursive convolutional codes with appropriate puncturing patterns. The rate of codeword (c 1 ,c 2 ) is optimized for the SNR of the source to relay channel, while the rate of codeword (c 1 ,c 2 ,c 3 ) is optimized for the SNR of the relay to destination and the source to destination channel. Similarly, extrinsic information transfer functions are used to minimize the SNR of the decoding threshold.
With Incremental bits, in the cooperation phase, the source and the relay act like a virtual MIMO system and send the codeword (c 21 ,c 22 ) using a STBC. With joint network and channel coding, in the cooperation phase, the source and the relay act like a virtual MIMO system and send codeword (c 3 ) using a STBC.
8. Extension to Other Systems
The Alamouti-DF scheme with distributed coding for the relay network can also be extended to other systems, like the second example embodiment CMAC shown in FIG. 9 , the third example embodiment MARC shown in FIG. 10 and the forth example embodiment BRC shown in FIG. 11 . Orthogonal channels can be assigned to each pair by using, e.g., TDMA, OFDMA, SC-FDMA, DFT-Spread-OFDM or SDMA.
8.1 CMAC Topology
We consider two users, S 1 and S 2 , communicating with the BS using OFDM/SCCP in FIG. 9 . The cooperative distributed coding and Alamouti transmission may use three time slots to complete one cooperation cycle.
8.8.1 Time Slot 1
S 1 transmits a FEC-coded and OFDM/SCCP modulated sequences, where the FEC code rate is given in Equation 16:
R 1 ≦α 1 I (SNR S 1 S 2 (1) ) (16)
where α 1 is the fraction of time slot 1 and SNR S 1 S 2 (1) is the SNR from S 1 to S 2 . The coding scheme used in the transmission from S 1 may optionally employ puncturing.
8.1.2 Time Slot 2
S 2 transmits FEC-coded and OFDM/SCCP modulated sequences, where the FEC code rate is given in Equation 17:
R 2 ≦α 2 I (SNR S 2 S 1 (1) ) (17)
where α 2 is the fraction of time slot 2 and SNR S 2 S 1 (1) is the SNR from S 2 to S 1 .
8.1.3 Time Slot 3
In this time slot, Alamouti-DF scheme with the enhanced turbo code and the multiple turbo code schemes can be used. The procedure of encoding for the enhanced turbo code scheme is the same as that for the relay network illustrated in FIG. 1 . As for the multiple turbo code scheme, each user interleaves the two information sequences separately, followed by feeding the sequences alternatively to an encoder.
S 1 and S 2 then transmit the sequence with distributed Alamouti STBC. The Alamouti STBC provides diversity gain and reduces outage in a fading channel. The BS collects the received sequence, and computes the LLR based STBC decoding for the IR. It then performs FEC decoding using all the LLR information collected during the 3 time slots.
The rate region for time slot 3 for the enhanced turbo code scheme is similar to that for the relay network. For the multiple turbo code scheme, the rate region is given by Equation 18:
R 1 ≦α 1 I (SNR S 1 D (1) )+α 3 I (SNR S 1 D (2) +SNR S 2 D (2) )
R 2 ≦α 2 I (SNR S 2 D (1) )+α 3 I (SNR S 1 D (2) +SNR S 2 D (2) ) (18)
R 1 +R 2 ≦α 1 I (SNR S 1 D (1) )+α 1 I (SNR S 2 D (1) )+α 3 I (SNR S 1 D (2) +SNR S 2 D (2) )
where α 3 is the fraction of time which slot 3 occupies,
∑ t = 1 3 α t = 1.
The achievable rate of the system is given by the intersection of the rate regions. Note that Users 1 and 2 do not have any new information to send during this slot.
8.1.4 BS Processing
At the BS, iterative decoding is performed to decode the information bits of Users 1 and 2, which is the same as the relay network if the enhanced turbo code scheme is used. For the multiple turbo coding scheme, iterative decoding is also used for the information sequences.
FIG. 12 illustrates the EXIT chart for the multiple turbo coding scheme when γ S 1 D =γ S 2 D =−3.3 dB in an AWGN channel. γ S 1 D and γ S 2 D respectively denote the SNRs of the S 1 -D and the S 2 -D links. The settings of the network is such that d S 1 D −β =1 and d S 2 D −β =1. d S 1 D denotes the distance between S 1 and D while d S 2 D denotes the distance between S 2 and D. The slot allocation used is α 1 =α 2 =0.375 and the target rate is R 1 =R 2 =0.25. S 1 and S 2 use the multiple turbo code PCC(3+4/7+4/7). The upper bound curve 1200 and the lower bound curve 1206 respectively illustrate the extrinsic log-ratios from C 1 and C 2 for the EXIT function I(u (1) ;E (1) (u 1 )E (2) (u 1 )) of S 1 , where u (1) denotes the information bits from S 1 , while E (1) (u 1 ) and E (1) (u 2 ) denote the extrinsic LLR from the C 1 and C 2 of S 1 . Each vertical step in the EXIT chart corresponds to an activation of the iterative decoding for S 1 , until convergence occurs. Similarly, each horizontal step corresponds to the activation of the iterative decoding for S 2 until convergence occurs. The step curve 1202 corresponds to the mutual information measured at the output of the decoders under such an activation scheme. For lower complexity, we considered the activation of S 1 (C 1 −C 2 −C 3 ) and S 2 (C 1 −C 2 −C 3 ). The step curve 1204 corresponds to the mutual information measured at the output of the decoders. The convergence of iterative decoding towards low error rate is possible since a tunnel exists at −3.3 dB. The theoretic limit for the target rates is −3.6 dB.
FIG. 13 shows the outage probability and FER performance. The outage probability of the multiple turbo code has a diversity of 2, which is higher that of the enhanced turbo code scheme, which has a diversity of 1. The multiple turbo code PCC(3+4/7+4/7) has an outage that is around 0.3 dB from the outage limit.
8.1.5 Training for Channel Estimation
Normal training for time slot 1 and time slot 2 and orthogonal training sequence, e.g., the training sequences of [a a] for S 1 , [a −a] for S 2 .
8.1.6 Time and Frequency Synchronization
Conventional time and frequency synchronization can be used for time slot 1 and time slot 2 . For time slot 3 , the two sequences should be aligned within the CP at BS so as to maintain subcarrier orthogonality. The two users should also use the same LO reference, e.g., the BS LO frequency, for easier frequency synchronization at BS.
8.1.7 Transmission Protocol
For the CMAC network in FIG. 9 , S 1 and S 2 work in cooperation to deliver their packets to a common destination BS. In the 1 st time slot Node S 1 transmits, while Node S 2 transmits in the 2 nd time slot. Each S node receives the coded bits sent by its partner node and attempts to decode its partner information. The transmission scheme for these 2 time slots is shown in FIG. 15 . The codeword transmitted depends on which distributed coding scheme is used. For incremental bits, Node S 1 sends the codeword (c 11 ,c 21 ). When joint network and channel-coding is used, Node S 1 sends the codeword (c 1 ,c 2 ). If decoding is successful, then this information will be relayed to the destination BS. ACKs/NACKs information is sent out from the source nodes to indicate whether they are cooperating or not in the 3 rd time slot.
In the 3 rd time slot, cooperation occurs when both the sources send ACKs. Otherwise, the sources will operate in a non-cooperative mode. In the cooperative configuration, as shown in FIG. 17 , Node S 1 and S 2 encode both information bit streams either jointly or separately and transmit them to the destination BS using a STBC. For separate encoding, the codeword (c 12 ,c 22 ,{tilde over (c)} 12 ,{tilde over (c)} 22 ) is sent by S 1 and S 2 using STBC. For joint network and channel encoding, as shown in FIG. 18 , S 1 and S 2 send the codeword (c 3 ′) to the destination, also using STBC. c 12 and c 22 are the codewords sent by S 1 while {tilde over (c)} 12 and {tilde over (c)} 22 are the codewords sent by S 2 .
In the non-cooperative configuration, as shown in FIG. 16 , Node S 1 and S 2 transmit their own additional coded bits in turn during the 3 rd and last time slot for additional redundancy. For incremental bits, S 1 sends (c 12 ,c 22 ) while for joint network and channel coding, S 1 sends (c 3 ).
8.2 MARC Topology
FIG. 10 shows S 1 and S 2 , communicating with a BS through a RS using OFDMA. Orthogonal subcarrier sets are assigned to the two users.
The proposed cooperative incremental redundancy space-time-coded relay transmission may need two time slots to complete one cooperation cycle.
8.2.1 Time Slot 1
S 1 transmits punctured FEC-coded and OFDM modulated sequences, where the FEC coded-modulation rate is R S 1 R according to Equation 19:
R S 1 R ≦α 1 I (SNR S 1 R (1) )= R 1 (1) (19)
α 1 is the fraction of time slot 1 . When TDMA is used for user multiple access, α 1 denotes the fraction of time user 1 occupies in slot 1 .
8.2.2 Time Slot 2
S 2 transmits punctured FEC-coded and OFDM/SCCP modulated sequences, where the FEC coded-modulation rate is R S 2 R according to Equation 20:
R S 2 R ≦α 2 I (SNR S 2 R (1) )= R 2 (1) (20)
α 2 denotes the fraction of time slot 2 used for transmitting S 2 's information. For frequency division-based orthogonal multiple access such as OFDMA, SC-FDMA and DFT-Spread-OFDM, α 1 =α 2 . For TDMA, α 2 denotes the fraction of time that S 2 occupies in slot 2 . R S 1 R and R S 2 R may or may not be the same. The BS and RS collect the received sequence. The RS will also decode the information sequence from S 1 and S 2 . The BS then computes and stores the LLR.
8.2.3 Time Slot 3 and 4
The RS re-encodes the information sequences of S 1 and S 2 with their original rate-compatible FEC. The RS then maps the punctured coded bits to symbols, and then uses OFDMA to modulate the modulated symbols of the two users.
S 1 and S 2 will also produce the same codeword and map the punctured coded bits to the same symbols as that of the RS, and then to the assigned subcarriers for OFDM transmission processing. Then S 1 , S 2 , and the RS transmit the signals simultaneously to the BS, using Alamouti coding scheme.
The overall rate region is given by Equation 21:
R 1 ≦α 1 I (SNR S 1 D (1) )+α 3 I (SNR S 1 D (2) +SNR RD (2) )= R 1 (2)
R 2 ≦α 1 I (SNR S 1 D (2) )+α 4 I (SNR S 2 D (2) +SNR RD (2) )= R 2 (2) (21)
where α 3 and α 4 are the fraction of resource which S 1 and S 2 used, respectively. The overall achievable rates are given by Equation 22:
R 1 ≦min( R 1 (1) ,R 1 (2) ),
R 2 ≦min( R 2 (1) ,R 2 (2) ) (22)
However, if multiple turbo code is used with joint network-channel coding, STBC cannot be employed. The rate region is similar to that of the CMAC.
8.2.4 Rate Setting
Select a target rate for S 1 and S 2 , while assuming values for the SNR S 1 D and SNR S 2 D . The values of SNR S 1 D and SNR S 2 D may for example be estimated through the process of channel estimation. If the channel is found to have a transmission rate that is sufficiently high, a direct transmission mode may be used. For example, if both SNR S 1 D and SNR S 2 D are above a predetermined threshold, a direct transmission mode may be used.
For given values of SNR S 1 R (1) and SNR S 2 R (2) , we can select α 1 and α 2 such that reliable transmission is possible on both channels. The slot duration should be minimized, i.e., using high-rate coded modulation, so as to improve the overall efficiency based on two considerations. The first consideration is, for decode-forward scheme to work, the RS needs to be close to the source nodes; The second consideration is, the transmission in these two slots do not have any space-time diversity at the BS, whereas the second slot sequences have.
With α 3 , α 4 and the rate region, we can look for a minimum SNR RD (2) threshold which satisfies the target rate. If SNR RD (2) is too low, we will have to lower our target rate and start all over again. Once the rate is determined, a FEC scheme can be chosen to approach this rate.
8.2.5 Receiver Processing
The decoding process is similar to that for the relay network.
8.2.6 Training for Channel Estimation
Training signals can be transmitted in both time slots. In this case, constant-modulus training signals can be used by the S nodes in time slot 1 with which the S-RS channel estimates can be obtained and constant-modulus training signals can be used by the RS in time slot 3 with which the RS-BS channel estimates can be obtained.
Alternatively, we can choose to transmit training signals only in time slot 3 . In this case, orthogonal training sequences need to be used between the S and the RS in the respective subcarriers from which the S-BS and the RS-BS channel coefficients can be obtained.
8.2.7 Time and Frequency Synchronization Concurrent transmissions should be aligned within the CP at the receiving node so as to maintain subcarrier orthogonality; S 1 , S 2 and RS should also use the same LO reference, e.g., the LO reference of the BS, for easier frequency synchronization at the D or the R.
8.2.8 Transmission Protocol
Two source nodes S 1 and S 2 work in cooperation with the RS to deliver their packets to the BS. In the 1 st time slot, node S 1 transmits while node S 2 transmits in the 2 nd time slot. The R receives the coded bits sent by both nodes and attempts to decode their information as shown in FIG. 19 . For incremental bits, the node S 1 sends the codeword (c 11 ,c 21 ). For joint encoding, the node S 1 sends the codeword (c 1 ,c 2 ). If decoding is successful, then this information will be relayed to the destination BS. ACK/NACK information is sent out from the RS to indicate whether they are cooperating or not in the 3 rd time slot.
In the 3 rd time slot, cooperation occurs when the relay sends an ACK. Otherwise, S 1 and S 2 will operate in a non-cooperative mode. In the cooperative configuration that is shown in FIG. 21 , the information is decoded correctly. The RS can encode both information bit streams separately and transmit the additional coded bits with the corresponding source together with a STBC, or the RS can jointly encode both information bit streams and transmit to the BS.
If the RS fails to decode information from either of S 1 or S 2 , then S 1 and S 2 will operate in a non-cooperative mode. In FIG. 20 , Nodes S 1 and S 2 transmit their own additional coded bits in turn during the 3 rd and last time slot for additional redundancy in the non-cooperative configuration. Similarly, for incremental bits, S 1 sends (c 11 ,c 22 ) and for joint encoding, S 1 sends (c 3 ).
8.3 Broadcast Relay System
FIG. 10 shows a downlink scenario where the BS communicates with two users, S 1 and S 2 through a RS using OFDMA.
The proposed cooperative incremental redundancy space-time-coded relay transmission may use two time slots to complete one cooperation cycle.
8.3.1 Time Slot 1
To communicate with S 1 , BS transmits a punctured FEC-coded and OFDM modulated sequence, where the FEC coded-modulation rate is R 1 . The rate is set such that the BS can decode the data correctly with a high probability, according to Equation 23:
R 1 ≦α 1 I (SNR BR (1) ) (23)
where α 1 is the fraction of time slot 1 and SNR BR (1) is the SNR from the BS to the RS.
To communicate with S 2 , the BS transmits a punctured FEC-coded and OFDM modulated sequence, where the FEC coded-modulation rate is R 2 . The rate is set such that the BS can decode the data correctly with a high probability. According to Equation 24:
R 2 ≦α 2 I (SNR BR (1) ) (24)
where α 2 denotes is the remaining fraction of time slot 1 .
S 1 , S 2 and the RS use the received sequences for decoding. The RS will decode both the information sequences meant for S 1 and S 2 . S 1 and S 2 will then compute and store the LLR.
8.3.3 Time Slot 2
The BS and the RS will both transmit concurrently as follows. The RS re-encodes the information sequences of S 1 and S 2 with their original rate-compatible FEC. The RS then maps the punctured coded bits to symbols and then OFDMA modulates the modulated symbols of S 1 and S 2 .
The BS will also produce the same codeword and maps the punctured coded bits or new coded bits to the same symbols as that in the RS, and then to the assigned subcarriers for OFDM transmission processing. The BS and the RS then transmit the signals simultaneously to S 1 and S 2 , using an Alamouti coding scheme.
The rate region for time slot 2 is given by Equation 25:
R 1 ≦α 1 I (SNR BS 1 (1) )+α 3 I (SNR BS 1 (2) +SNR RS 1 (2) )
R 2 ≦α 2 I (SNR BS 2 (1) )+α 4 I (SNR BS 2 (2) +SNR RS 2 (2) ) (25)
where α 3 and α 4 respectively are the fraction of resources in which User 1 and User 2 will use. The overall achievable rates for both slots are constrained by the right-hand side of the above inequalities. Thus according to Equation 26:
R 1 ≦min(α 1 I (SNR BR (1) ),α 1 I (SNR BS 1 (1) )+α 3 I (SNR BS 1 (2) +SNR RS 1 (2) ))
R 2 ≦min(α 2 I (SNR BR (1) ),α 2 I (SNR BS 2 (1) )+α 4 I (SNR BS 2 (2) +SNR RS 2 (2) )) (26)
8.3.4 Transmission Protocol
The BS works in cooperation with RS to deliver its packet to S 1 and S 2 . In the 1 st time slot, the BS transmits, as shown in FIG. 22 . For incremental bits, node S 1 sends the codeword (c 11 ,c 21 ). For joint encoding, node S 1 sends the codeword (c 1 ,c 2 ). The RS receives the coded bits and attempts to decode its information. If decoding is successful, this information will then be relayed to S 1 and S 2 . Alternatively if it fails, the BS will operate in a non-cooperative mode. The ACK/NACK information is sent out from the RS to indicate whether the nodes are cooperating or not in the 2 nd time slot.
In the 2 nd time slot, cooperation occurs when the RS sends an ACK. Otherwise, S 1 and S 2 will operation in a non-cooperative mode. For the cooperative configuration in FIG. 24 where the information is decoded correctly, the BS and the RS jointly transmits additional codewords (c 12 ,c 22 ) or (c 3 ) to both destinations using a STBC.
In the non-cooperative configuration illustrated in FIG. 23 , the BS transmits additional coded bits during the 2 nd and the last time slots for additional redundancy. The codeword (c 12 ,c 22 ) is sent if an incremental bit is used, and the codeword (c 3 ) is sent when joint encoding is used.
The hardware such as the ICs, UE (eg: S 1 and S 2 ), RS, BS, the central office and other network equipment may be programmed with software to operate according to one or more of the example embodiment methods, and otherwise compatible with common standards such as 3G, pre4G and/or 4G. These standards are incorporated herein by reference.
Whilst example embodiments of the invention have been described in detail, many variations are possible within the scope of the invention as will be clear to a skilled reader.
In this specification, the terms “user”, “user equipment” (or its abbreviation “UE”), node S 1 and node S 2 are to be interpreted as equivalents. In some network topologies such as CMAC, other users may act as a RS, and RS and R are to be interpreted accordingly.
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A method of communication comprising determining whether to use distributing coding between a source (S), relay (R) and destination (D), based on a predetermined transmission rate; if the determination is positive, determining a forward error correction scheme using distributed Alamouti space-time coding, wherein the scheme is determined based on the predetermined transmission rate, a channel signal-to-noise ratio (SNR) and a network topology; relaying coded data from the S to the D using the determined forward error correction.
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FIELD OF THE INVENTION
[0001] The present invention relates to electroluminescent devices, and more particularly relates to contrast enhancement filters that are applied to electroluminescent devices.
BACKGROUND OF THE INVENTION
[0002] Known contrast enhancement filters include optical interference filters as described in U.S. Pat. No. 5,049,780 to Dobrowoiski and U.S. Pat. No. 6,411,019 to Hofstra, the contents of which are incorporated herein by reference. In certain teachings of Dobrowolski and Hofstra contrast enhancement is provided by an optical interference member that is placed in front of a reflective rear electrode or reflective rear cathode. As more particularly described therein, reflections of ambient light off of the rear electrode or rear cathode are used in conjunction with the optical interference member to create at least two, out-of-phase, wave forms of ambient light, which interfere with each other to cause at least some cancellation of each other and thereby reduce unwanted reflections of ambient light from the display.
[0003] Other known contrast enhancement filters include light absorbing materials that coat the reflective electrode or cathode. See, for example, WO 00/25028 to Berger et al, which contemplates the use of a graphite to coat a reflective rear cathode. These purely absorbing materials then reduce reflections of ambient light that enter the front of the display, by effectively converting that ambient light into heat.
[0004] However, these prior art structures may not be suitable where it is desired to actually utilize the reflectivity of the rear cathode in order to boost the amount of light emitted from the device. Put in other words, while the above-mentioned prior art devices reduce ambient light that reaches the rear cathode of the display, the prior art devices also tend to reduce the light that is backwardly emitted towards the rear of the display. Indeed, in certain prior art OLED displays it is known to select an appropriate emitting region portion of the light emitting layer, to cooperate with the reflective electrode, in order to achieve a total phase shift of rearwardly emitted light of about 360°, such that the two light waves constructively interfere, thereby enhancing the brightness of the device.
[0005] Presuming an ideal reflector and that the two light waves are thus equal in magnitude when they interfere, the intensity will be:
Irf =( Ef+Er ) 2
Ef=Er=E
Irf=4E 2 , where Ef=electrical field of the forward emitted light and Er=electrical field of the rear emitted light, and Irf is the intensity seen by the viewer using a reflective rear electrode.
[0006] If Er is absorbed, as is the case with a dark electrode, the equations become simply:
Idk =( Ef+Er ) 2
Ef=E, Er=0
Idk=E 2 , where Idk is the intensity seen by the viewer using a dark rear electrode. Thus Idk/Irf=¼=0.25 and the device using the dark rear electrode is only 25% as efficient as the device using the reflective rear electrode.
[0007] While it is known to reduce ambient light reflections in the above-described display using a circular polarizer applied to the front of the display, the circular polarizer has the additional effect of absorbing some of the emitted light, in some devices typically about 56 to about 62%, and in such devices the reflective rear electrode device is about 38% to about 44% efficient.
[0008] PCT/CA03/00554 entitled Electroluminescent Device discloses a partially absorbing (semi-reflecting) layer, one or more light-emitting layers, and a fully reflecting layer that, in combination, give rise to a 180° phase shift of ambient light, along with constructive interference of light generated in the light-emitting layers. However, as with the other prior art systems discussed above, back reflection of the light generated within the light emitting layers gives rise to destructive interference, which partially negates the advantages of the constructive interference.
SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to provide a display with contrast enhancement feature that mitigates or obviates at least one of the above-identified disadvantages of the prior art.
[0010] In an aspect of the present invention, there is provided an electroluminescent display that embeds the light emitting layers within the optical interference structure itself.
[0011] In particular, light-emissive organic layers are disposes between a semi-reflecting structure and a reflective structure, wherein the thickness and material of the semi-reflecting structure is chosen to cause at least some destructive optical interference of ambient light, while the thickness of the layers between the semi-reflecting structure and fully reflective structures is chosen to provide net 0° phase shift of ambient light passing through those layers and reflected back, relative to the light reflected by the semi-reflecting structure. Moreover, the distance of the light-emitting region from the fully reflective surface is chosen to provide constructive interference of generated emitted light (i.e. emitted light rays travelling in the direction of the viewer are in phase with emitted light rays initially travelling away from the viewer and then fully reflected back toward the viewer).
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Certain preferred embodiments of the present invention will now be explained, by way of example, with reference to the attached Figures in which:
[0013] FIG. 1 shows a side sectional view of light emitting and contrast enhancing layers of an organic electroluminescent device in accordance with a general aspect of the invention;
[0014] FIG. 2 shows a side sectional view of a bottom emission organic electroluminescent device in accordance with one embodiment of the invention; and
[0015] FIG. 3 shows a side sectional view of a top emission organic electroluminescent device in accordance with a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to FIG. 1 , a semi-reflecting thin film BL 1 is disposed adjacent one side of a microcavity comprising inorganic layers such as ITO, AlSiO, etc. (identified in FIG. 1 as Inorganic 1 , Inorganic 2 ) between which are disposed light emitting layers (identified as Organic 1 , Organic 2 ), while a reflective structure BL 2 is disposed adjacent the opposite side of the microcavity. As discussed below in connection with FIGS. 2 and 3 , the layer BL 2 may either be fully reflecting, or may instead partially transmit and phase shift light that is reflected off of a further fully reflective layer (e.g. Al layer). The light emitting layers generate light through electroluminescence and are fabricated from material that is nominally transparent to ambient light entering the device, and which causes a phase shift of that ambient light, as will be discussed in greater detail below.
[0017] Semi-reflecting structure BL 1 may comprise a single-layer film or a multi-layer film, as discussed in greater detail below, and serves two purposes:
1. It splits the incoming light into a reflected ray and a transmitted ray; and 2. It phase shifts the reflected light by about 180° relative to the light reflected from the rear electrode. Note that approximately 10-15% of the light is reflected back towards the viewer.
[0020] However, in order to achieve the destructive interference which leads to the device having low reflectance and thus appearing black, the total relative phase shift provided by the organic layers located between the semi-reflecting and reflecting thin films should be about 0°. This net 0° total phase shift occurs as the light travels two times through the organic layers: once as it is entering the structure and once upon reflection (i.e. 2×180°=360°=0°).
[0021] According to the invention, destructive interference of ambient light can be achieved while maintaining constructive interference conditions by choosing the total thicknesses of the organic layers and also any ITO or other inorganic layers, and BL 2 layers (where the BL 2 is only partially reflecting) to provide an approximate net 0° phase shift for light travelling through them, reflecting off of the rear cathode and travelling back out of the device, relative to the light reflected from the semi-reflecting structure in front, while independently controlling the distance between the emitting region at the interface of Organic 1 , Organic 2 and the reflective rear electrode.
[0022] It should be noted that, in a single film BL 1 structure, light reflected from the first layer is reflected from both the front surface and the rear surface thereof. It is the resulting sum of these 180° phase shifted light rays that cancel, and thus the thickness of this layer is chosen to provide the 180° phase shift. In a multi-layer BL 1 structure, light is reflected from the first layer, phase shifted in the following layer(s), and then reflected off of the following layer(s).
[0023] In order to achieve a low reflectance value from the device of FIG. 1 , the material of BL 1 will generally have some degree of absorption associated with it, i.e. an optical absorption constant k, whereas the optical density is defined by the index of refraction, n. The combination of n, k and thickness is chosen to achieve both the phase shift and the desired degree of reflection.
[0024] The combination of the absorption constant k, and the thickness of the BL 1 structure leads to light also being absorbed by the BL 1 structure. This leads to some of the emitted light being absorbed as it exits the device.
[0025] The semi-reflective structure BL 1 can be located at various places within the device, provided that it is located between the viewer and the light emitting layers Organic 1 and Organic 2 , and the total internal phase shift is about 0° relative to the light reflected from this first semi-reflective structure. For example, there is typically a layer of a transparent conductive material (Inorganic 1 ) within the device (e.g. Indium Tin Oxide) which serves to conduct current to the device as well as provide a means for the emitted light to escape the device and reach the viewer.
[0026] Also, semi-reflective structure BL 1 can be located between the viewer and the ITO, or the ITO can be located between the semi-reflective structure BL 1 and the viewer. Particularly in the latter case, the thickness of the ITO is not limited (though it may be selected in relation to desired electrical operation, such as to accord with the operating voltage of the device). In the first case the thickness of the ITO is taken into account to achieve the relative phase shift of about 0°.
[0027] It should also be noted that if the first semi-reflective layer of BL 1 were in contact with the organic layers of the device, these layers would also be selected to have an appropriate work function. On the other hand, a work-function matching layer can also be inserted as part of Inorganic 1 , between the semi-reflecting layer and the organic layers.
[0028] The organic layers typically consist of a hole injection layer (e.g. TPD) and an electron injection layer (e.g. AlQ3), where light is generated at the interface therebetween. The location of these layers depends on whether the device is a “bottom emission device” ( FIG. 2 ) in which the anode is located closest to the viewer, or a “top emission device” ( FIG. 3 ) in which the cathode is located closest to the viewer. In either case, in SMOLED devices, the light emitting region is located within 50-200 Å of the interface of these two layers. For constructive interference of the emitted light to occur, the location of this interface relative to the reflective rear electrode is carefully chosen. For destructive interference to occur the total thickness of these layers is also carefully chosen. The various distances can be controlled as well by inserting layers of conductive organic material, typically CuPc, next to either the rear or front electrodes.
[0029] Finally, the reflective structure BL 2 consists of either a single layer of metal, for example Aluminum, or a thin film device of several layers, such as is known in the prior art and which can be tuned to a particular level of reflectance. In the simplest device most light is reflected back to interfere with the light reflected from the first semi-reflecting structure. In another embodiment the reflectivity of the thin film device of several layers can be tuned to ensure that the amplitude of the light reflected from this region is similar to the amplitude of the light reflected from the first semi-reflective structure, noting that some of the light will be absorbed as it passes through the semi-reflective structures.
[0030] Also, the light reflected from these rear layers can be phase shifted to enhance the light cancellation, and add a certain degree of freedom to the phase shifting requirements of the other layers, i.e. the organic stack and first semi-reflective structure.
[0031] In another embodiment specifically relating to the top emitting structure, the first semi-reflective structure can act as the electrode, eliminating the need for a transparent conducting material, such as ITO. It can also act as a buffer layer to protect underlying organic materials from damaging processes, such as described in commonly-owned Canadian Patent Application No. 2,412,379, entitled TRANSPARENT-CATHODE FOR TOP-EMISSION ORGANIC LIGHT-EMITTING DIODES, the contents of which are incorporated herein by reference.
[0032] If the semi-reflecting structure is located in the device in such a manner as to be conducting electricity, it is likely that structure will have to be patterned into the shape of the electrode it is in contact with. However, in another embodiment this structure may be electrically isolated from the structure through the use of an insulating layer. In a top emission structure this requires depositing an insulator on top of the front electrode and then depositing the semi-reflective structure. The thickness of the insulating layer is then taken into account in the phase shift of the transmitted light. In a bottom emission device the semi-reflective structure is deposited onto the substrate along with an insulating layer to isolate it from the front transparent electrode. Again, the thickness of the insulating layer is taken into account in the phase shift of the transmitted light. The advantage is that the semi-reflective structure is no longer required to be patterned and the optical interference effect occurs between pixels as well as on the pixels themselves.
[0033] In another embodiment, if the first semi-reflective structure is itself an insulator the insulating layers can be removed.
[0034] In a further embodiment, the organic materials may be comprised of light emitting polymers or inorganic light emitting materials.
[0035] Exemplary embodiments are shown in FIGS. 2 and 3 as follows:
[0000] Bottom Emission Device ( FIG. 2 ):
[0036] The bottom emission device of FIG. 2 is fabricated on a substrate of glass or plastic. A semi-reflective (semi-absorbing) structure BL 1 is first deposited on the substrate, followed by a conductive layer of Indium Tin Oxide (ITO). Buffer layer CuPc is then deposited, followed by hole-carrier layer TPD and electron-carrier layer AlQ3. For consistency with FIG. 1 , a second, fully reflective structure BL 2 is illustrated. However, in practice, the BL 2 structure may be eliminated since full reflection is provided by the final layer of aluminium.
[0037] As discussed above, the semi-reflective structure BL 1 partially reflects incident ambient light while partially transmitting ambient light. Ambient light is reflected off the outer surface to create reflected light ray R 1 . The transmitted light is phase shifted by 90° before partially reflecting off the interface between BL 1 and the ITO layer, whereupon the reflected light is subjected to a further 90° phase shift so that R 2 is 180° out of phase with R 1 , causing destructive interference (i.e. cancellation of the reflected light). Ambient light transmitted through the ITO, CuPC, TPD and AlQ3 layers is subjected to a further 180+ 0 phase shift before reflecting off of the BL 2 (or Al) surface, whereupon the reflected light, is subjected to a further 180° phase shift, resulting in a net 360° phase shift between ambient light passing inward through the BL 1 /ITO interface relative to ambient light passing outward through the BL 1 /ITO interface. Consequently, R 3 is similar in its phase characteristics to R 2 (i.e. R 3 is subjected to destructive interference with the incident ambient light). On the other hand, light generated within the organic layers (i.e. at the interface of hole layer TPD and electron layer AlQ3) is in phase (i.e. R 4 ad R 5 are in phase), so as to benefit from constructive interference.
[0038] Exemplary thicknesses and thickness ranges for the various structural layers are set forth below, wherein it will be noted that several of the layers are completely optional (i.e. thickness of 0). Nonetheless, the overall thickness and materials are chosen to ensure indices of refraction that give rise to a net 360°=0° phase shift for ambient light passing through the layers between BL 1 and the reflecting surface (i.e. BL 2 or Al). Equally importantly, the location of the light emissive region at the interface of the TPD and AlQ3 organic layers is chosen to ensure in-phase characteristics for light generated within that region and reflecting with the microcavity structure between the semi-reflective BL 1 structure and the fully reflective BL 2 or Al layer.
[0039] BL 1 : Can be a wide range of materials and may comprise one or more layers. Typically the BL 1 structure consists of AlSiO (ratio 3:2, 5.5 nm), SiO2 (60 mm), and aluminum (10 nm)
[0040] ITO: Typical thickness is about 1200 Å, but within a range of about 0 to about 2500 Å.
[0041] CuPc: Typical thickness is about 250 Å, but within a range of about 0 to about 500 Å. The combined thickness of the ITO and CuPC layers should be about 1450 Å to provide a 180° phase shift on a single pass (assuming standard n, k values and that the organic materials (TPD and AlQ3) also provide a 180° phase shift).
[0042] TPD or Organic 1 : preferably about 450 Å, but within a range of 200-500 Å.
[0043] AlQ3 or Organic 2 : preferably about 600 Å, but with a range of 200-800 Å.
[0044] It should be noted that the sum of the thicknesses of ITO, CuPC, TPD and AlQ3 layers is preferably about 2500 Å to allow for a 360° phase shift on two passes (assuming standard n, k values) of emitted light. The buffer layer, e.g. CuPc, may be used to reduce the thicknesses of the two organic layers.
[0045] BL 2 : A wide range of materials may be used, including Aluminum Silicon Monoxide. The ratio of aluminum to silicon monoxide must be altered to provide the desired reflectance values. In an optimal device the BL 2 structure may be omitted (i.e. thickness of 0 Å) to get maximum reflection from the rear cathode (Al), as discussed above.
[0046] Al: approximately 1500 Å.
[0000] Top Emission Device ( FIG. 3 ):
[0047] In the top emission structure of FIG. 3 , a substrate of glass or plastic is provided onto which a layer of aluminium is deposited to a thickness of about 1200 Å. Next, successive layers of ITO, CuPc, TPD and AlQ3 are deposited to the same thicknesses and approximate specifications as set forth above in connection with FIG. 2 . Finally, the BL 1 structure is deposited in from one or more layers, as discussed above in connection with FIG. 1 . A typical structure consists of AlSiO(ratio 3:2, 5.5 nm), SiO2 (60 nm), and aluminum (10 nm)
[0048] ITO can be used as BL 1 when the optical constants are tailored to meet the desired requirements of a semi-reflecting structure. Aluminum or silver doped ITO is known to increase absorption (conductivity increases as a by-product). In this case, the ITO is about 450 Å thick.
[0049] Presently preferred performance of both of the embodiments of FIGS. 2 and 3 is about 0% reflectance at about 555 nm of visible light, and about 45 to about 50% efficiency as compared to the ideal case of a tuned reflective cathode device without a circular polarizer.
[0050] The above-described embodiments of the invention are intended to be examples of the present invention and alterations and modifications may be effected thereto, by those of skill in the art For example, through careful material selection, the 360 degree phase shift effect (and the 180 degree destructive effect) can be made broadband, extending over the visible range. Specified materials must be selected that have a refractive index that increases with wavelength. AlSiO mixtures give a suitable material set. By inserting specific thicknesses of these materials into the microcavity (e.g. by replacing the ITO or part of the organic materials) the optical thickness of the cavities remains approximately constant for visible wavelengths, (i.e. 400 nm to 700 nm). All such modifications and alterations are believed to be within the scope of the invention as defined by the claims appended hereto.
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An organic electroluminescent device is provided having emitting layers with materials and thicknesses that provide constructive optical interference of emitted light. The device includes additional layers that provide contrast enhancement through destructive optical interference of ambient light entering the device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional application Ser. No. 60/484,565 filed on Jul. 1, 2003, incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. § 1.14.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains generally to semiconductor memory, and more particularly to static random access memory circuits.
2. Description of Related Art
Static Random Access Memory (SRAM) is a form of electronic data storage which retains data as long as power is supplied. Static RAMs are widely utilized within all manner of electronic devices, and are particularly well-suited for use in portable or hand-held applications, as well as in high performance device applications. In portable or hand-held device applications, such as cell phones, SRAMs provide stable data retention without support circuits, thus keeping complexity low while providing robust data retention. In high performance applications, such as microprocessor caching, since the SRAM can provide fast access times while not requiring the cell data refresh operations required in Dynamic Random Access Memory (DRAM).
FIG. 1 shows a typical SRAM cell consisting of six transistors (6T SRAM) and related peripheral circuits. For example, when node C_j is precharged at V dd (data H), mp 2 _j is turned off and mn 2 _j is turned on. Node CB_j is set V ss (data L). Therefore, mp 1 _j is turned on and mn 1 _j is turned off. Hence, as long as power is supplied, data at C and CB are maintained high and low respectively.
FIG. 2 shows a read timing diagram of the conventional 6T SRAM cell shown in FIG. 1 . In a precharge cycle, PPREi is at logic low and mpp 1 _i and mpp 2 _i are turned on. So, bit line pairs (BL_i and BLB_i) are precharged at V dd , logic high. When a word line (WL_i) is enabled, a bit line is discharged depending on the stored data. For example, node C_j is high and CB_j is low. According to the word line enabling, mn 3 _j and mn 4 _j are turned on. Since CB_j is low and mn 2 _j is turned on, the voltage of BLBi is discharged slowly through mn 4 _j and mn 2 _j. When a certain amount of voltage difference between bit line pairs arises, a sensing enable signal (PSAEi) is enabled to amplify the signal difference. The voltage difference on the bit line pairs is amplified by the sense amplifier (i) and a full CMOS output pairs (Di and Dbi) are generated at the outputs of the sense amplifier.
Since the typical 6T SRAM cell creates a signal difference on bit lines by itself, the read speed of SRAM is faster than that of DRAM, in which a charge sharing time between the bit line and cell capacitances is needed and read speed is slowed. This 6T SRAM cell has a very stable structure and is widely used in typical SRAM design. However, there is a trade-off between power consumption and read speed. As the minimum feature size (i.e. design rule) decreases and the threshold voltage of transistors is reduced to maintain performance as operating voltage is lowered, the leakage current (i.e. standby current) becomes an important factor. In this example, since C_j is at a high level and CB_j is at a low level, mp 2 _j and mn 1 _j are turned off. Even though these two transistors are in an off state, there is a current flowing through the devices referred to as a cell leakage current. At 0.18 μm technology, this leakage current is on the order of fA (10e−15) and can be substantially ignored for most applications.
However, with regard to more advanced technology such as 0.13 μm technology, since this current is then on the order of tens of nA (10e−9), the level of current can no longer be ignored. For example, for a 16 Mb SRAM, when a cell leakage current is about 10 nA, the total current is 16*1024*1024*10*1e−9=16 mA. This level of leakage current equates to a large portion of the total power consumption for the device. It should also be appreciated that this leakage current is temperature dependent, increasing in response increasing temperature. For more advanced technology such as 0.11 μm technology, the cell leakage current increases significantly. Therefore, the power consumption component which arises as a result of cell leakage current becomes quite substantial. As the systems relying on SRAM become increasingly complex, the density of SRAM will continue to increase, and the total power consumed by cell leakage currents based on conventional SRAM architectures will continue to increase.
As mentioned earlier, there is a trade-off to be made between power consumption and cell read speed. Since the cell read speed is determined by how fast a bit line node (e.g., CB_j) is discharged through the cell pull-down transistor (mn 1 _j or mn 2 _j). Therefore, the sizes of the cell access transistor (mn 3 _j or mn 4 _j) and the cell pull-down transistor (mn 1 _j or mn 2 _j) need to increase to enhance the read speed. However, when these cell access transistors and cell pull-down transistors increase in size, leakage currents flowing through these transistors also increase. In this example, when these transistors increase in size, leakage current flowing through a pair of mn 4 _j and mn 2 _j and mn 1 _j increases. Therefore, a trade-off between the cell leakage current and the cell read time makes SRAM design complicated and difficult as the operating voltage goes down.
In general, two classes of SRAM cells are implemented depending on the whether the SRAM is used with a low power or high performance application. With regard to low power applications, such as low power hand-held devices, the stand-by current (i.e. power consumption while the chip is in a stand-by mode), is often the most important consideration as these low power portable applications often rely on battery operation wherein stand-by current is a major determiner of battery life. This is in contrast to high performance applications such as cache memory, wherein cell data read speed is of critical importance. However, due to a drastic increase of the cell leakage current, the conventional 6T SRAM cell structure is facing a technical barrier to meet the design requirement. When device sizes increase and the threshold voltage of transistors decreases to meet the required speed, the power consumption due to the cell leakage current is a concern. When device sizes are scaled down and the threshold voltage of transistors increases to suppress leakage current, the cell read speed is degraded due to reduced current driving capability of the cell access and pull-down transistors.
Accordingly, a need exists for advanced SRAM circuits and methods for reducing leakage currents without sacrificing read speed. The present invention fulfills that need and others, while overcoming the drawbacks found in conventional SRAM architectures.
BRIEF SUMMARY OF THE INVENTION
A static random access memory (SRAM) circuit is described which provides reduced leakage currents and high reading speed. The novel architecture described is configured with a novel read sensing structure that can be utilized in combination with differing voltage thresholds for different functional blocks within the device. These aspects of the invention can be utilized separately or in combinations to increase the speed of memory. and/or to lower the power dissipation, such as resulting from the leakage currents.
One embodiment of the invention can be described as a memory device providing static random-access memory, comprising: (a) a static memory cell structure having a plurality of data latches; (b) a plurality of functional blocks within the cell structure including read, write and storage. By configuring at least one of the functional blocks, such as the read word circuit and/or the write word circuit, for a lower threshold voltage the leakage current for the device can be substantially reduced. In one embodiment the read word signal and write word signal are separated. An embodiment is described in which data is read through read transistors activated by the read lines whose outputs drive alternating bit lines on successive words. A sense amplifier provides differential sensing of the bit lines to drive the output data.
Another embodiment of the invention can be described as a memory device having a static random-access memory configuration, comprising: (a) a plurality of static memory cells, such as formed from data latches; (b) a plurality of word lines for the read path; (c) a plurality of word lines for the write path; (d) a plurality of functional blocks including read, write and storage. At least one of the functional blocks is preferably configured to have different voltage threshold conditions than the other functional blocks. In one embodiment a reference path circuit provides a virtual node to which read path transistors are connected between different bit lines, wherein the read lines are sensed using differential sensing by a sense amplifier, such as for suppressing leakage current of cell blocks.
Another embodiment of the invention can be described as a semiconductor memory circuit comprising: (a) a plurality of static memory storage functional blocks (cells) having a plurality of data latches configured for being read and written; (b) a memory cell reading transistor functional block having an input coupled to each storage functional block and an output coupled to one of at least two bit lines; and (c) a sense amplifier coupled between the bit lines for detecting data being read from said data latches in response to differential sensing between said bit lines. Furthermore, the read and write functional blocks can be configured with lower voltage thresholds than the memory latch transistors, while in another variation the voltage threshold of the read transistors is designed to have a lower threshold than the write transistors.
The invention may also be described in terms of a method of accessing cells of a static memory, comprising: (a) maintaining data written to transistors of a first voltage threshold level forming a data latch for a static memory cell; (b) applying a read word signal to activate read word transistors of a second voltage threshold which is less than first voltage threshold; and (c) sensing the output of the read word transistors in a sense amplifier coupled to a bit line to generate a data bit output.
The invention may also be described in terms of a method of accessing cells of a static memory, comprising: (a) maintaining data written to transistors forming a data latch for a static memory cell; (b) applying a read word signals to activate read word transistors; and (c) sensing the output of the read word transistors in a sense amplifier coupled between bit lines to generate a data bit output. Furthermore, functional blocks within the static memory can be configured with lower voltage thresholds, such as the read block, or the read and write blocks, wherein faster speeds and lower leakage currents can be exhibited by the circuit.
A number of aspects are described for the present invention, including but not limited to the following.
An aspect of the invention is an SRAM cell structure which has a plurality of functional blocks, the functional blocks including read, write and storage, wherein each functional block can have different threshold voltages.
Another aspect of the invention is an SRAM cell in which the read path has a lower threshold voltage than that of storage and write path.
Another aspect of the invention is an SRAM cell in which the read path has the lowest design threshold, the write path has a medium design threshold and the storage path has the highest design threshold voltage.
Another aspect of the invention is an SRAM cell structure in which one terminal of read path transistors are connected together with one terminal of alternating read path transistors and to a virtual node which is connected to a source transistor to suppress leakage current of cell blocks.
Another aspect of the invention is an SRAM structure which has separate functional blocks and independent word lines for read and write paths.
Another aspect of the invention is an SRAM structure which has separate functional blocks and the same word line for read and write paths.
Another aspect of the invention is a reference read path scheme with a PMOS source transistor.
Another aspect of the invention is a reference read path scheme with an NMOS source transistor.
Another aspect of the invention is the architecture for the placement of reference read paths (RRPs) and sense amplifiers (SAs) in distributed, lumped, or mixed configurations.
Another aspect of the invention is the architecture for the utilization of either shared or dedicated reference read paths (RRPs) and sense amplifiers (SAs).
Another aspect of the invention is an ability to implement various forms of SRAM memory such as multi-port SRAM, embedded forms of SRAM, and so forth according to the teachings of the present invention.
Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 is a schematic of a conventional 6T SRAM cell and peripheral circuits.
FIG. 2 is a timing diagram for the conventional 6T SRAM cell of FIG. 1 .
FIG. 3 is a schematic of an SRAM cell structure according to an aspect of the present invention, shown with sensing circuitry and circuits for controlling cell leakage current.
FIGS. 4A–4D are timing diagrams for the SRAM cell shown in FIG. 3 .
FIGS. 5A–5F are block diagrams of SRAM memory organizations according to embodiments of the present invention, showing the placement of reference and read paths.
FIG. 6 is a schematic of a dual-port SRAM cell structure according to an aspect of the present invention, showing sensing circuitry and circuits for controlling cell leakage current.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 3 through FIG. 6 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.
The new SRAM cell structure and related sensing scheme are configured for overcoming a number of the problems which arise with conventional SRAM architectures. One improvement is an architecture in which specific functional blocks can be designed with different threshold voltages to control leakage. For example, the transistors of the read circuit being configured with a lower voltage threshold than the storage transistors. As a second example, the write circuit is configured with a lower voltage threshold than the storage transistors, and the transistors of the read circuit are configured with a lower threshold than the write circuit transistors. It will be appreciated that the inaccuracies in fabrication lead to small differences in threshold voltages between devices, however, these slight random variations are not what is being addressed herein. In the present invention, the differences in threshold voltages are in response to the design of the transistors being fabricated, and the difference in threshold is preferably over about five to ten percent.
FIG. 3 illustrates an example embodiment 10 of a new SRAM cell structure and related sensing scheme according to the present invention. The new cell structure can be utilized within any size of memory block (i.e. 128WL×256BL). The new structure comprises storage cells 12 (data latches), a reference read path 14 and a sense amplifier 16 . Unlike the conventional six transistor SRAM cell structure shown in FIG. 1 , the new SRAM cell shown in FIG. 3 comprises eight transistors (mpa, mpb, mna–mnf). Six transistors (mpa, mpb and mna–mnd) are used to store the cell data and a write path to change the cell data while two transistors (mne, mnf) are used for the cell read operation. The source of the cell read transistors (mne, mnf) are connected together with that of adjacent cell read transistors and are linked to a sense amplifier. The source node of all transistors in the entire memory block or part of the entire memory block can be connected together depending on different design targets.
In this embodiment the logic threshold voltage levels are shown with storage cell 18 having a normal or high voltage threshold, for the given operating voltage, while the cell read transistor section 20 is configured with a lower voltage threshold.
In a precharge state, when WWLi (write word line) and RWLi (read word line) are at logic low, mnc, mnd and mne are turned off. When C 1 is at a high level and C 1 B is low, mpb and mna are turned off and mpa and mnb are turned on. Thereby, the data C 1 and C 1 B are maintained. Since RWLi is low, mne is off and there is no current path through mne and mnf from a bit line (BLBi) even though this bit line is precharged at V dd which is similar to that of FIG. 1 .
One of the differences between the embodied cell structure and conventional cell structures is the use of separate paths for read and write operations. In the conventional structure, the cell access transistor and the pull-down transistor need to be large for fast read and write operation. However, in that case the cell leakage current becomes a concern. In the new cell structure of the present invention, since the read (mne and mnf) and write paths (mnc and mnd) are preferably separate and the storage portion of the circuit (mpa, mpb, mna and mnb) are isolated from the read path, a fast read speed is achieved along with a significantly suppressed cell leakage current.
In the conventional cell structure, the cell transistors cannot be readily configured to support different threshold voltages due to a trade-off between leakage current and the cell read speed. When the cell transistors have a high threshold voltage to suppress the cell leakage current, the cell read speed is degraded due to the reduced current driving capability of transistors, especially the cell access and pull-down transistors. However, in the new cell structure of the present invention, the threshold voltage of transistors can be controlled more adaptively. For example, the storage block transistors (mpa, mpb, mna and mnb) and the cell access transistors (mnc and mnd) are preferably configured as high threshold voltage elements to suppress the leakage current since these parts are not related with the cell read operation. Instead, the cell read transistors (mne and mno are configured to have lower threshold voltages to improve cell read speed.
In the new cell structure of the present invention, each section of the circuit can be configured with different threshold voltages to meet design requirements. By way of example, the threshold voltages of the storage part (storage functional block) and the write path (write functional block) can be configured at higher threshold levels than that of the cell read path (read functional block). By establishing the different threshold levels the cell leakage current through the turned-off transistors of the storage part and the cell access transistors from the bit lines can be suppressed significantly while the cell read speed can be improved. It should be appreciated that the leakage current of the transistor is reduced exponentially in response to increasing the threshold voltage of the transistor. Therefore, the circuit can utilize different threshold voltages, such as for the storage part and the read and write access transistors, to arrive at a range of desired characteristics for the SRAM device. The SRAM cell structures depicted in FIG. 3 having three separate functional blocks, storage, write and read paths. Due to the design of the present SRAM each of these functional blocks can be designed with transistors having different threshold voltages depending on the design requirements.
Another important aspect of the invention is a sensing scheme related with the cell structure explained above. In the inventive cell scheme, the read path is connected to one of the bit lines. For example, in the top cell, the read transistors are connected to the bit line bar (BLBi) and for the next cell below, the read transistors are connected to the bit line (BLi). Therefore, the sensing scheme to detect the signal difference on the bit line pairs is also important. The bit line sensing scheme can realize two important design requirements, suppressing leakage current through the read transistors and increasing the speed by which signal differences on the bit line are sensed. It should be noted that the common signal BLi is preferably placed only in the submemory block or connected to the entire block. Sense amplifier 16 may be placed in respect to the bit line or shared with multiple bit lines.
A principle objective of the present invention is to suppress leakage current in the storage portion and the write path by using smaller transistors with higher threshold voltages than utilized in conventional SRAM cell structures. A separate read path is also preferably utilized which has a lower voltage threshold than utilized in the storage cell. There is another current path in the new cell, which is related with the read transistors. When the bit line pairs are precharged to V dd as in the conventional cell structure shown in FIG. 1 , even though one of the read transistors is off since the read word line (RWLi) is low, there is also leakage current flowing through these transistors. For example, C 1 is set V dd , mnf is turned on but mne is turned off since RWLi is low. However, a leakage current through transistor mne flows even though this transistor is turned off.
In one embodiment of the present invention, SRAM cell read speed is aided by increasing the size of the read transistors to about four times the conventional sizing. According to the invention, the read transistors are configured with a lower threshold voltage to improve the read speed, the leakage current flowing through the read path is much larger than that flowing through other parts. Therefore, the new sensing scheme related with the new SRAM cell structure can suppress the leakage current flowing through the read path.
One way to further suppress the leakage current is to configure the bit lines as floating in a precharge state, which results in eliminating the power supply source from the bit line. That is, the bit line precharge transistors (mpp 1 _i and mpp 2 _i) are turned off during the precharge state and then are activated prior to the read operation by setting the bit lines to V dd as in the conventional scheme. Although this structure can suppress leakage current, a problem arises with so-called “bit-line hurting” to the cell, during the write operation. When there is no power supply, the voltage of bit lines are virtually ground due to junction leakage current. When the write word line (WWLi) is enabled, transistors mnc and mmd are turned on and node C 1 and CB 1 are connected to bit lines BLi and BLBi, respectively. Since the bit line capacitance is substantially larger than that of cell transistors, around twenty times larger, when the write transistors are switched on, node C 1 and C 1 B are discharged due to a charge sharing effect until node C 1 is restored by transistor mpb. Since node C 1 is high and node C 1 B is low, the degree of discharging is different. So, in the ideal case, even though node C 1 and C 1 B is discharged due to charge sharing effect, node C 1 is discharged less and due to signal difference on node C 1 and node C 1 B, the voltage of C 1 and C 1 B can be eventually restored to V dd and V ss .
However, in the case of mismatches in transistor size and threshold voltages, a different situation can occur. For example, node C 1 can be discharged more or less, the stored data information can be changed, because the threshold voltage of transistor mpb is lower than that of transistor mpa due to fabrication process variation. That is, data on node C 1 and node C 1 B can be changed from high and low to low and high, respectively. This is a possibility which can occur in the new cell structure of the present invention.
There are additional things to consider regarding sensing operations when the bit line is floating. For instance, in order to eliminate a mismatch in the voltage of the bit line pair, it is necessary to perform an extra precharge operation to assure that invalid sensing does not arise. This extra operation represents a speed penalty as it delays the actual sensing process. The new cell structure of the present invention does not require the use of this extra precharge operation.
The embodiment shown in the figure ( FIG. 3 ) provides a novel sensing scheme which doesn't require the precharge operation mentioned above and which can suppress the leakage current flowing through the read transistors.
The sense amplifier scheme which eliminates the precharge operation and suppresses leakage current, can be implemented utilizing a new novel circuit incorporating what is referred to herein as a reference read path. The main idea of the reference read path is to provide a current path having current driving capability equal to about half that of the cell read transistors.
In fabricating the SRAM device embodiment shown in FIG. 3 , the width of each cell read transistor is ‘W’ as shown by the area of cell read section 20 surrounded by the dotted lines. Wherein two transistors having width of W are stacked and the drain of two stacked transistors is connected to a bit line and the source of two stacked transistors is connected to a virtual ground signal which is also connected to the source of two stacked transistors in other SRAM cells.
In the top cell of FIG. 3 , mne and mnf are two stacked transistors having width of ‘W’, wherein one terminal of transistor mne is connected to BLBi and one terminal of transistor mnf is connected to a virtual signal V g , shown represented as a dotted line interconnecting the two cell read sections with transistor mse(A). The other terminal of the two transistors, mne and mnf, are connected with each other. The virtual signal line is connected to a source transistor, mse, which is turned-on in read operations depending on input condition. In the reference read path two transistors, (e.g., msa, msb, msc and msd) are stacked. One terminal of each pair of transistors is connected to each bit line. For example, the drain of transistor msa is connected to BLi, and the source of transistor msb is connected to V g , which is at the drain of source transistor mse. The other two terminals of transistors msa and msb are connected together. The gate of transistor msa is connected to reference read word line (RRWLa) and the gate of transistor msb is connected to a read signal (RSi). Transistors msb, msc and msd are shown placed similarly to transistor msa. The drain of transistor msc is connected to bit line BLBI and the source of transistor msd is connected to the virtual ground signal V g . The source of transistor msc and the drain of transistor msd are connected together. The gate of transistor msc is connected to another reference read word line signal (RRWLb) and the gate of transistor msd is connected to the read signal (RSi). RRWLa and RRWLb are enabled selectively with address information, or enabled when the read path at the other line is enabled (i.e. RWLi is selected when RRWLa is selected).
It should be noted that RRWLb and RRWLa are enabled selectively with address information and are enabled when the read path on the other line. is enabled (i.e. RWLi is selected when RRWLa is selected). The source of the source transistor mse is connected to the source of transistors msb and msd, while its gate is connected to the read signal RSi and the drain of source transistor mse is connected to a power source V ss Note that the source transistor mse is a PMOS transistor in this example, however an NMOS transistor may be alternatively utilized. The order of stacked transistors, msa, msb, msc and msd, can be changed according to design implementation without departing from the invention.
The width of stacked transistors in the normal cell is ‘W’, but the width of a transistor (i.e. msa) is ‘W/2’. It means that current driving capability of stacked transistors in the reference read path is half of stacked transistors in the normal cell. Actually, the current driving capability of stacked transistors is not exactly half of stacked transistors in the normal cell but it is required to have smaller current driving capability of stacked transistors in the normal cell. The sizing of transistors in the reference read path is determined according to the desired operation (i.e. half that of read path transistors).
FIG. 4A through FIG. 4D illustrate timing aspects of the new sensing scheme. FIGS. 4A–4B depict sensing timing when RWLi is enabled. FIG. 4A depicts the case when C 1 is high and C 1 B is low, while FIG. 4B depicts C 1 being low and C 1 B being high.
In a precharge cycle, bit line pairs are set to a voltage, typically V dd .
When a word line (i.e. RWLi) is enabled the data of C 1 is high and C 1 B is low ( FIG. 4A ) wherein transistor mnf is turned on. There is a current path established through transistor mne and mnf from BLBi. The stacked transistors connected to BLi are selected in the cell that has the read transistors connected to BLBi. In other words signal RRWLa is enabled to turn on transistor msa. To read the cell data, read signal RSi is enabled.
When WWLi, RRWLa and RSi are enabled, bit lines discharge at different rates seen as the varying slopes of BLi and BLBi. Note that the width of transistor mnf is ‘W’ while that of transistor msa is ‘W/2’. Therefore, the discharging slope of BLBi is faster as shown in FIG. 4A than in FIG. 4B due to its larger transistor size and larger current driving capability. Hence, the signal difference on the bit lines is developed when the cell is selected.
When the data of C 1 is low, as a result of transistor mnf being turned off, there is no current path through stacked transistors from the bit line bar.
Therefore, BLBi remains high and only the bit line, BLi, is discharged through the reference current path, msa and msb. Hence a signal difference on the bit lines is developed.
FIGS. 4C–4D depict sensing timing when RWLj is enabled. FIG. 4C depicts the case when C 2 is low and C 2 B is high, while FIG. 4D depicts C 2 being high and C 2 B being low.
When the other cell having the cell read transistors connected to the other bit line is enabled, the stacked reference current path is selected to develop a signal difference on the bit lines. For example, when RWLj is enabled and the data of C 2 is low and C 2 B is high, transistor mnf′ is turned on and there is a current path through transistors mne′ and mnf′. Since the cell having stacked transistors is connected to BLi, the stacked transistors connected to BLBi are selected. That is, when RWLj is enabled, RRLWb is enabled and transistor msc is turned on. When the read signal, RSi, is enabled, a current path through transistors msc and msd from BLBi is formed to discharge BLBi. As explained earlier, due to smaller current driving capability of stacked transistors in the reference path, the discharging slope of BLBi is slower than that of BLi and there is a signal difference on bit lines.
When the data of C 2 is high and C 2 B is low, mnf′ is turned off and there is no current path through mne′ and mnf′. Only the bit line bar, BLBi, is discharged through msc and msd. A signal difference is developed on the bit line pairs.
Since the virtual ground signal V g is connected to the source transistor, the amount of leakage current of the cell is not the sum of the leakage current flowing through turned off read transistors of each cell but is limited by the leakage current of the source transistor mse.
It will be appreciated that the above describes read word lines activating transistors coupled to the bit lines for developing signal differences on the bit lines for detecting memory storage cell state. This sense amplifier scheme can suppress leakage current significantly. In this example, the use of a PMOS source transistor mse reduces leakage current by making all transistors in the reference read path reverse-biased. In the active mode, when RSi signal is enabled, the voltage of V g is discharged to V tp , where V tp is the threshold voltage of the source PMOS transistor. When RSi goes to low in the standby mode or when the related cell is not selected, such as when RRWLa and RRWLb are low and RSi is also low, the gates of msa, msb, msc and msd are low and the gate of the PMOS source transistor mse goes to high. Since the voltage of V g is V tp , V gs of msb and msd is −V tp , which means that transistors msb and msd are reverse-biased. Since the gate voltage of the PMOS source transistor mse is V dd and the source voltage is V tp , V gs of transistor mse is V dd −V tp , which also means that the source transistor mse is reverse-biased. Since the voltage of V g is V tp , the voltage of the source of transistor msa and the drain of transistor msb and the voltage of the source of transistor msc and the drain of transistor msd are also positive voltages.
Since the gate voltage of transistors msa and msc is low, V gs of transistors msa and msc is a negative voltage, which means that these two transistors are reverse-biased. Even when one of the reference word lines, such as RRWLa or RRWLb, is high when RSi is low, transistors msb, msd and mse are reverse-biased. Therefore, the leakage current flowing through transistors in the reference read path is suppressed significantly.
One issue related with the reference read path above is the use of different types of MOS transistors. One embodiment can be created with transistors for carrying the reference current being NMOS transistors, while the source transistors are PMOS transistors. However, creating a PMOS transistor requires an NWELL structure which results in an area penalty. To solve this problem, the PMOS source transistor can be replaced by an NMOS transistor. In this case, all transistors in the reference read path have the same type, the area penalty due to the formation of NWELL for PMOS transistors can be minimized. In case of the NMOS source transistor, when the gate voltage is low to turn off the source transistor, since the source of the NMOS source transistor is V ss , V gs of the NMOS transistor is about zero volts instead of a negative voltage. Therefore, the leakage current flowing through the reference read path can be increased somewhat, however, it is still much smaller since the leakage current of the cell block is limited by that of this NMOS source transistor.
A principal objective of the inventive sensing scheme is to have a reference read path which can be selected alternatively, that is, a current path is formed from a bit line in the normal cell and a reference current path is formed from the other bit line to develop a signal difference by different current driving of each current path.
When a signal difference is developed on the bit lines, the sensing enable signal SAE is enabled to amplify the signal difference. A reference read path is placed per a pair of bit lines or can be shared by multiple bit line pairs. A sense amplifier is also positioned by a pair of bit lines or can be shared by multiple bit line pairs. It should be appreciated that the novel SRAM device can be implemented with a number of sense amplifier structures without departing from the teachings of the present invention.
FIG. 5A through FIG. 5F illustrate by way of example embodiments having different arrangements for the placement of the reference read path and sense amplifiers. In FIG. 5A the reference read path is shown placed per small memory block (distributed) or per a memory block which is controlled by the address decoder (lumped). The sense amplifier is also placed per smaller (sub) memory block (distributed) or per a whole memory block (lumped), as shown in FIG. 5B . The reference read path and the sense amplifiers can be placed in a distributed form as in FIG. 5C or a lumped form as depicted in FIG. 5D . The sense amplifier can be shared by multiple reference read paths as shown in FIG. 5E or the reference read path can be shared by multiple sense amplifiers as depicted in FIG. 5F . It should be recognized that combinations of the above may be implemented and that variations can be introduced by one of ordinary skill in the art according to the teachings herein without departing from the present invention.
Another aspect of the invention provides a sensing scheme for the cell structure which has a read path only from one bit line. The inventive sensing scheme contains a reference read path which can provide a reference current to make a signal difference on the bit lines. The reference read path can provide a different current driving capability to eliminate an unnecessary precharge step and to generate a signal difference on the bit lines. The reference read path can be any structure to provide a reference current to develop a signal difference on bit lines.
FIG. 6 depicts a dual-port SRAM variation of the SRAM previously described. It can be seen from the schematic that the reference line is split and that two separate sense circuits are provided with the dual data outputs generated from comparisons against V ref1 and V ref2 thus providing two separate outputs. It can also be seen in the figure that the functional blocks of the circuit are configured with different voltage thresholds, for example the read sensing blocks are shown incorporating low V t transistors, which have a lower voltage threshold than the transistors of the static memory latch to reduce leakage while increasing speed. It should be appreciated that numerous similar variations of the present invention can be implemented without departing from the teachings herein.
The present invention provides new cell structures for SRAM devices and the like. The structures can incorporate separate functional blocks for write paths, read paths and storage which are preferably designed with different threshold voltages to suppress leakage current in the storage part while improving read speed. The use of separate read and write word lines is also described for reducing power requirements and facilitating low leakage read operations. A form of differential read sensing is also described in which one terminal of stacked transistors is connected to a bit line and another terminal is connected to a virtual source node which is connected to a source transistor to suppress the total leakage current of memory cell block.
Although the description above contains many details, 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. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”
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An SRAM circuit structure and method for reducing leakage currents and/or increasing the speed of the devices. Various forms of SRAM devices may be fabricated utilizing the techniques, such as single port and dual port RAM devices. By way of example the SRAM structure utilizes separate write and read lines, splits the circuit into portions which can benefit from having differing threshold levels, and can allow splitting read path transistors for connection to a first terminal and a virtual node connected to a source transistor. The structure is particularly well suited for forming transistors in a combination of NMOS and PMOS, or solely in NMOS. Memory arrays may be organized according to the invention in a number of different distributed or lumped arrangements with the reference read paths and sense blocks being either shared or dedicated.
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BACKGROUND OF THE INVENTION
The present invention relates to resilient vibration isolation mounts and more particularly to such a mount which is electro-active and can be energized by a controller to reduce the vibratory force transmitted through the resilient mount over a preselectable band of frequencies while the resilient mount supports a static load. As is understood, there is an increasing interest in controlling or reducing noise and vibration by active means, i.e., feedback controllers which energize a transducer so as to generate a cancelling noise or vibration. Such controllers typically utilize adaptive filters which are implemented digitally. The practicality and cost effectiveness of such controllers has been advanced by the availability of digital signal processors whose capabilities have advanced in correspondence with the advances in microelectronics generally.
While various active vibration isolation mounts have been proposed in the prior art e.g., U.S. Pat. Nos. 3,606,233, 4,600,863 and 5,052,510, such mounts have not been widely adopted due to their high cost and cumbersome nature. By and large the problems confronted are associated with the sensing and driving transducers which are necessary to implement a practical active vibration or noise control system. Typically, separate transducers have been required for both sensing and for generating the feedback forces. Further, these transducers have usually been separate from the resilient mount which supports the static load, e.g., the weight of the machinery which is generating the vibration.
Among the several objects of the present invention may be noted that the provision of a novel electro-active vibration isolation mount; the provision of such a mount in which an output transducer is integrated with the resilient elements which can support a static load; the provision of such a mount which incorporates a sensing means; the provision of such a mount in which a sensing transducer and an output transducer are effectively combined and integrated; the provision of such a mount which can be energized to effectively reduce the vibratory force transmitted through the mount over a pre-selectable band of frequencies; the provision of such a mount which will support a substantial static load; the provision of such a mount which is easily fabricated; the provision of such a mount which is highly reliable and which is of relatively simple and inexpensive construction. Other objects and features will be in part apparent and in part pointed out hereinafter.
SUMMARY OF THE INVENTION
An electro-active vibration mount constructed in accordance with the present invention employs a multiplicity of layers of an electro-strictive polyurethane film. Interleaved with a first plurality of the film layers are a plurality of electrodes, alternating ones of which are connected in common to respective input leads. Another pair of electrodes are provided on opposite sides of at least one additional layer of the film with those electrodes being connected to respective output leads. Accordingly, a feedback controller responsive to a force-induced voltage generated on the output leads can energize the first plurality of layers through the input leads to reduce the vibratory force transmitted through the mount over a preselectable band of frequencies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a diesel engine provided with active vibration isolating mounts in accordance with the present invention;
FIG. 2 is a diagram of one of the mounts employed in the arrangement of FIG. 1;
FIGS. 3 and 4 are diagrams illustrating one manner in which the components of the mount of FIG. 2 can be fabricated;
FIG. 5 illustrates components of the system separated for mathematical analysis;
FIG. 6 illustrates a typical controller configuration; and
FIG. 7 illustrates a controller providing characteristics particularly adapted for use in the systems illustrated in FIG. 1.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a diesel engine 11 is mounted on a bed or foundation 13 through a series, typically four, of compliant vibration isolation mounts 15 constructed in accordance with the present invention. It is an advantage of the construction of the mounts of the present invention that they may be substituted relatively easily for the more usual rubber, metal, or pneumatic passive mounts which are typically employed for mounting a vibration producing piece of machinery such as a diesel engine.
Referring now to FIG. 2 where the layers are shown in enlarged thickness for purposes of illustration, mount 15 can be seen to comprise a multiplicity of layers 21 of an electro-strictive polyurethane film. While polyurethane films are in general electro-strictive, a presently preferred type of film is that manufactured by DOW Corporation and designated by its type no. 2103-80AE. Interleaved with the film layers are a plurality of electrodes 23. The preferred manner of constructing this interleaved construction is described in greater detail hereinafter. The film and electrode layers are adhesively mounted between a pair of conventional end plates 22 and 24 carrying conventional mounting studs. The film layers are sufficiently strong to support the weight of the engine 11 i.e., the static preload without significant distortion.
As indicted previously a majority of the electro-strictive polyurethane layers 21 are employed as an output transducer. In FIG. 2 this plurality of layers is designated generally by reference character 27. Alternating ones of the electrodes 23 interleaved in this group of film layers are connected in common to respective ones of a pair of input leads 31 and 33.
A second, smaller grouping of layers, designated generally by reference character 37, are employed as a sensing transducer. While, in theory, a single additional layer of the film could be employed as such a sensor, it is presently preferred to employ a smaller grouping of the film layers. Alternating ones of the interleaved electrodes 23 in the second grouping are connected to respective output leads 41 and 43 as indicated.
As indicated previously, the polyurethane film material is electro-strictive. Accordingly, by applying a voltage to the input leads 31 and 33, a strain or displacement can be developed between the end plates 22 and 24. With the preferred polyurethane material identified, this strain can approach 1% of the height of the energized layers, i.e., in the plurality of layers 27. Preferably, as described hereinafter, the output transducer position of the mount is energized by means of a controller-generated a.c. voltage superimposed upon a d.c. bias voltage so that displacement is an approximately linear function of the a.c. control voltage.
A d.c. bias voltage is also applied across the output leads 41 and 43. Thus, when a vibratory force or strain is applied to the second group of film layers 37, an a.c. voltage will be produced across the output leads 41 and 43. This second grouping of film layers can thus be utilized as a sensor in a feedback controlling scheme as described in greater detail hereinafter. Since the basic construction of the sensing portion of the mount is essentially the same as the output transducer portion of the mount, it can be seen that the two capabilities are easily integrated in a single structure. Further, since the polyurethane material itself is inherently fairly compliant e.g., it has a modulus of about 10 7 Pa, each mount 15 can also function to a substantial extent as a passive vibration isolation mount for vibratory frequencies outside the operating frequency band of the controller.
The force responsive a.c. voltage generated on the output leads 41 and 43 is applied as an input signal to a controller 51. Controller 51 is preferably adaptive and may, for example, be of the general type characterized as a feedback controller which, within a preselectable band frequencies, energizes the output transducer i.e., the film layers in grouping 27, so as to reduce the vibratory force transmitted through the mount. In one sense, the operation of the controller may be understood to effect an activation of the mount which dynamically increases its compliance within the frequency band of operation so that vibratory forces transmitted through the mount are effectively reduced by the loop gain of the controller. While a separate control loop could be provided for each of the several mounts 15, it is generally preferable that a so called multiple input multiple output (MIMO) controller be utilized which takes into account and adjusts for the cross-coupling between the several mounts. Likewise, while a pure feedback controller may be utilized, it may also be advantageous in certain situations to implement a so-called feed-forward control system which utilizes, as an input, a tachometer or other timing signal derived from the machinery creating the vibration. In such a case the sensing component of the active mount operates as an error signal, again providing feedback but in a feed-forward context. As indicated previously, controllers of these various types, digitally implemented, are known in the art.
The preferred method of assembling the multi-layered mounts of the present invention is basically similar to the technique commonly employed for manufacturing plastic film capacitors though polyurethane film would not be appropriate for use as capacitor for a variety of reasons. This basic technique is illustrated in FIGS. 3 and 4. From respective supply rolls, 61 and 63, are drawn strips 65 and 67 of polyurethane film. Each of the strips carries a deposited electrode which covers one face of the strip except for a margin along one side, the uncoated margins being on opposite sides of the two strips. The strips are wound on a mandrel 69 to provide the interleaving of the electrodes with film layers. The wound cylinder is then removed from the mandrel and flattened to provide the flat layered arrangement illustrated in FIG. 4. It is typically not necessary to remove the rounded end portions. The ends of the flattened cylinder are then sprayed with a suitable metal to conductively connect all of the similar electrodes in common to a respective lead. The output transducer portion of the mount will typically be made up of a plurality of the flattened cylinders while the sensing portion will be made up of a single such flattened cylinder.
The characteristics for a suitable controller can be derived in the following manner. With reference to the Diagram of FIG. 5, the forces, velocities and voltages present in the system can be defined as follows:
F=ΨE.sub.c +Z.sub.m (U.sub.s -U.sub.r)
U.sub.s =U.sub.o -F/Z.sub.s
U.sub.r =F/Z.sub.r
E.sub.ms =KF
E.sub.c =-G.sub.1 E.sub.ms +G.sub.2 E.sub.ff
where
Ψ=Transformation Factor
F=Force exerted by activator
Z=Mechanical Impedance s=source, m=mount, r=receiver/foundation!
U=Velocity s=source, r=receiver/foundation!
U o =Source "free" velocity--i.e., the absence of the activator load.
E=Voltage ms=sensor, c=control, ff=feed forward!
Substituting successively into the force equation yields the following:
F=-ΨG.sub.1 E.sub.ms +ΨG.sub.2 E.sub.ff +Z.sub.m (U.sub.s -U.sub.r)
F=-ΨG.sub.1 KF+Z.sub.m (U.sub.o -F/Z.sub.s -F/Z.sub.r)+ΨG.sub.2 E.sub.ff
F=-ΨG.sub.1 KF-(Z.sub.m /Z.sub.s)F-(Z.sub.m /Z.sub.r)F+Z.sub.m U.sub.o +ΨG.sub.2 E.sub.ff
F 1+Z.sub.m /Z.sub.s +Z.sub.m /Z.sub.r ++ΨG.sub.1 K!=Z.sub.m U.sub.o +ΨG.sub.2 E.sub.ff
A generalized controller is illustrated FIG. 6 and substituting into the generalized components values derived from the above equations in the following manner ##EQU1##
∴A.sup.-1 =1+Z.sub.m /Z.sub.s -Z.sub.m /Z.sub.r
B=ΨGK
yields a controller as illustrated in FIG. 7.
In view of the foregoing it may be seen that several objects of the present invention are achieved and other advantageous results have been attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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The active vibration mount disclosed herein employs a multiplicity of layers of an electro-strictive material such as an electro-strictive polyurethane film interleaved with electrodes. A majority of the layers are employed as an output transducer while at least one layer is employed as a sensor generating a force-induced voltage. Accordingly, a feedback controller responsive to that voltage can energize the output transducer thereby to reduce the vibratory force transmitted through the mount over a preselectable range of frequencies while the mount supports a static load.
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The present invention relates generally to apparatus for cleaving an optical fiber, and more particularly to such cleaving apparatus for facing off the end of a fiber mounted within a retaining contact at a point recessed within the contact parts a predetermined amount.
BACKGROUND OF THE INVENTION
Optical fibers constructed of plastic or glass are being increasingly relied upon for the transfer of light signals. There are many situations in which an optical fiber becomes broken and it is not practical to replace the entire fiber so it is necessary to effect a connection between the broken ends.
One technique for effecting connection between two fibers or between the ends of a broken fiber is that disclosed in U.S. Pat. No. 4,483,584 to John Gresty. According to this patented technique, the cladding and buffer are removed from the end portions of the fibers to be innerconnected leaving an extent of bare fiber. A contact consisting of three cylindrical pins arranged with their peripheral surfaces in contact with each other form an interstice within which the bare fiber is held. A three-pin contact of this kind holds the fiber in the desired manner without producing undesirable torque on or compressing the bare fiber to any significant extent. Portions of the contact are crimped on the fiber cladding immediately adjacent the bare fiber portion which secures the fiber against longitudinal movement within the contact.
In mounting the fibers within the contact a necessary preliminary step is to face off the end of the fibers at very precisely 90 degrees to the longitudinal axis of the fiber and locate the facedoff end slightly recessed from the three-pin contact ends. A pair of the fibers arranged in a corresponding set of contacts are then located in an alignment bushing with the ends of the two sets of pins in contact with each other which locates the two faced-off fibers in a slightly spaced relation. Arranging the faced-off ends of two fibers slightly spaced and aligned is considered essential to achieve the optimum in signal transmission across the junction without risking undesirable torquing or stressing of the fibers.
It has become accepted practice in the past to face-off a fiber prior to mounting within a contact which necessitated handling the cleaved fiber in a very careful manner to prevent it becoming broken or the very precisely cleaved off end face from being damaged in some way and thereby reducing or totally impairing the ability to transmit an optical signal.
U.S. Pat. No. 4,530,452, to M. Balyasny and W. Lovell, assigned to the same asignee as this application, discloses an excellent technique and apparatus for cleaving an optical fiber within a three-pin contact. Although this application discloses a fully satisfactory cleaving technique, it still leaves the cleaved fiber subject to possible damage during subsequent assembly into a contact.
SUMMARY OF THE DISCLOSURE
It is a primary aim and object of the present invention to provide apparatus for cleaving a fiber assembled within a three-pin contact at a point recessed a slight predetermined amount from the outer ends of the pins. Initially, an optical fiber has an end portion stripped of its cladding and buffer leaving it bare after which it is located within the interstice of three cylindrical pins with the bare end of the fiber extending substantially beyond the outer ends of the pins and the contact assembly generally. The contact with included fiber is located within an axial opening of a rotatable drum member with the bare optical fiber end extending substantially from one face of the drum and the remainder of the contact assembly and clad optical fiber extending from the other face. The drum member is interconnected via bearings to an outer rotatable portion of the drum member. That is, the contact and included fiber are secured within an inner member such that the outer portion of the drum member can be rotated with respect to the contact and fiber. A pretensioning clamp is arranged to receive the bare end of the fiber to secure it between clamp heads which applies an axial tension to the bare fiber with respect to the contact.
A cutter blade mounted on the rotatable portion of the drum is adjustable to move a knife edge angularly toward the bare fiber to contact the bare fiber at a point recessed from the outer ends of the pins holding the fiber within the contact. Rotation of the outer portion of the drum member produces via the knife edge a circumferentially extending score line about the bare fiber. Most frequently upon the completing the complete circumferential scoring of the fiber it will break at the point producing a faced off end face that is precisely 90 degrees to the fiber longitudinal axis. Moreover, the faced off end will be spaced between below or recessed back from the outermost ends of the pins holding the fiber within the contact.
The fiber pretensioning clamp includes an actuator enabling opening of the clamping jaws and maintaining them in an open condition automatically while locating the bare end of the fiber within the clamping jaws. Then manipulation of the actuator effects gripping and spring-loading pretensioning of the fiber.
DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of the cleaving apparatus of the invention.
FIG. 2 is a top elevational view of the aparatus of FIG. 1.
FIG. 3 is a end elevational view of the apparatus in FIGS. 1 and 2.
FIG. 4 is a side elevational sectional view taken along the line 4--4 of FIG. 2.
FIG. 5 is an end elevational sectional view taken along the line 5--5 of FIG. 4.
FIG. 6 is a side elevational, sectional, partially fragmentary, enlarged view showing the scoring of the fiber contained within a contact.
FIG. 7 is an end elevational view looking into the end of a contact assembly with included fiber and showing a knife edge in scoring position.
FIG. 8 shows schematically the "jump" produced on breaking a fiber after scoring.
FIG. 9 shows in greatly enlarged depiction a production of a beveled score line from which a precise end face is obtained.
FIG. 10 is a side elevational, sectional view showing the fiber pretensioning clamping means in open condition for removal of a cleaved fiber end.
FIG. 11 shows the application of the cleaving apparatus of the present invention to a concentric type of fiber contact.
DESCRIPTION OF PREFERRED EMBODIMENTS
Turning now to the drawing and particularly FIG. 1 the fiber cleaving apparatus of the present invention is identified generally as at 20. In its major elements, the apparatus includes an elongate base 21, a fiber holding means 22, a fiber contact retention and fiber scoring means 23, and a selectively actuatable fiber pretensioning device 24. The fiber contact holder 22, fiber contact retention and scoring means 23 and pretensioning device 24 are all mounted on the common base 21 so as to form a unitary arrangement thereby making the fiber cleaving apparatus of this invention easily adaptable for use either in the field or in the laboratory.
As to operation generally, the apparatus as shown in FIG. 1 receives an optical fiber 25 having a bare end portion mounted within a contact (e.g., three-pin contact), the bare fiber end extending from the contact is placed intension by the pretensioning means 24. Rotation of a ringlike portion of the means 23 causes a knife edge 26 to produce a scoreline of predetermined character extending circumferentially about the fiber and along which the fiber is cleaved. More particularly, the cleavage of the fiber is precisely at 90 degrees to the fiber longitudinal axis and at a point recessed a predetermined amount from the outermost end of the fiber contact.
As shown best in FIG. 6, the optical fiber 25 has the cladding and buffer coating removed from an end portion leaving exposed a bare fiber portion 27. The contact illustrated generally as at 28 is the same as that disclosed in the referenced Gresty patent and includes three identically dimensioned cylindrical pins 29 which when maintained in a surface contacting relation have an interstice of such dimensions as to receive the bare fiber 27 therewithin. A deformable tubular shell 30 is crimped onto the pins 29 and included bare fiber 27 holding it into a unitary relation and as well includes a helical spring member 31 which bites into the fiber cladding thereby securing the fiber against longitudinal movement with respect to the contact 28. When appropriately mounted in the contact for the practice of the present invention, there is a length of the bare fiber extending outwardly beyond the ends of the contact pins 29.
BASE CONSTRUCTION
With simultaneous reference to FIGS. 1, 3 and 4 it is seen that the base consists of a generally U-shaped housing 32 has two side walls 32' and 33 interconnected by a top wall 34 with an open bottom 35. Also, as seen best in FIG. 4, the base has one closed end wall as at 36 and the opposite end wall open.
An elongated arm or handle 37 has an end rotatably secured as at 38 within the cavity of the base formed between the base side and top walls The handle 37 can be swung out to extend downwardly at as much as 90 degrees, or, alternatively, folded out of the way within the base. This construction of the base makes the entire cleaving apparatus readily adaptable for use at the laboratory bench, at a microscope, or in the field.
Fiber Holding Means
The fiber holding means 22 includes first and second clamping jaws 39 and 40 having facing surfaces for engaging the optical fiber over its buffer and cladding securely holding the same substantially parallel to the base top wall 34. As shown in FIG. 3, the first clamping jaw 39 is an upstanding member affixed to the base top wall which includes an L-shaped surface for receiving the fiber along an integral corner thereof. A second jaw 40 pivotally mounted to the first jaw 39 at 41 has a gripping surface 42 which is directly opposite the L-shaped surface of the first jaw. An arm 43 integral with the second jaw extends outwardly away from the pivot 41 and is manipulable to move the gripping surface 42 toward or away from the first jaw L-shaped surface. A spring 44 resiliently urges the two jaws to the closed position.
In use, the arm 43 is moved downwardly separating the first and second jaws. The fiber is then placed along the internal corner of the first jaw L-shaped surface. Release of the arm allows the spring to move the gripping surface 42 into contact with the fiber, clamping it against the first jaw.
Fiber Contact Retention and Scoring Means
Referring primarily to FIGS. 4 and 6, it is seen that the means identified generally as 23 securely holds a contact 28 mounted onto an optical fiber 25 with a bare fiber portion 27 extending forwardly. Moreover, while the fiber contact is so held, the bare fiber is scored completely about its periphery at a point slightly inwardly of the contact pins 29 ends, and the fiber is cleaved along the score line providing a fiber end face that is smooth and precisely at 90 degress to the fiber longitudinal axis.
As to constructional details, an upstanding wall member 45 has an opening 46 extending therethrough which is in general alignment with the L-shaped inside corner of the fiber holding means 22 first clamping jaw 39. Preferably, the wall member 45 is constructed integrally with the base 21.
A cylindrical member 47 fits into the opening 46 and is secured against rotation by a machine screw 48. The member has an axial bore of a first diameter portion 49 substantially larger than the contact cross-section and a smaller diameter portion 50 fittingly receiving the set of pins 29. A cylindrical rotor 51 is rotatably mounted onto the end portion of the cylindrical member 47 by means of a bearing race 52. An enlarged head on member 47 forms a shoulder against which the race 52 abuts and an internal shoulder on the rotor 51 also holds an edge of the race. A circular plate 53 secured to the side of the rotor 51 facing wall member 45 by machine screw 54 bears against the outer race 52 and spacer 53' holds the inner race 52' in place. An oversize central opening 55 in plate 53 allows the cylindrical member 47 to pass freely through the plate without impeding rotation of the rotor.
Simultaneous reference is now made to both FIGS. 4 and 5 for the ensuing description of the apparatus details for scoring the bare fiber. A generally rectangular support plate 56 is secured to the outer face of the rotor 51 by a threaded member 57. The upper edge of the plate is beveled downwardly from its outer face to its inner face adjacent the rotor and is enumerated 58, as seen best in FIG. 6. The middle portion of the plate upper edge has a groove 59 (FIG. 5) which aligns with the interstice of the contact pins 29 guiding the bare fiber 27 onto the support surface 81 of the pretensioning device 24 and thereby avoid abutting against the leading edge of the support surface (FIG. 4).
A scoring means holder 61 is held securely and fixedly against the rotor outer face directly opposite to and spaced from the support plate 56 by a bracket 62. More particularly, the bracket is affixed to the rotor 51 by bolt means 63 (FIG. 5) and has a slot 64 (FIG. 4) for receiving an end portion of holder 61. Knobs 65 and 66 are each received on the ends of stub shafts which are mounted into opposite sides of the bracket 62 and serve as means for pulling bracket 62 with knife blade 68 away from the fiber while the contact and fiber is being inserted into the drum. The springs 63' maintain constant pressure on the knife blade toward the fiber during scribing.
A parallel-sided slot 67 formed in the inner or lower edge of holder 61 fittingly receives a knife blade 68 therein with the cutting edge 69 extending outwardly toward the bare fiber 27. Specifically, the slot 67 parallel sides extend angularly with respect to the rotor front such that the knife blade is adjustably positionable along a plane that angularly intersects the fiber longitudinal axis.
A first threaded member 70 bears against the knife blade side to fix the blade within slot 67 at any position of adjustment and a second threaded member 71 has an inner end which bears against the inner edge of the knife blade (FIG. 5). That is, adjustment of the blade outward extension is accomplished by loosening threaded member 70, threading member 71 in or out as desired while holding the knife blade edge against it, and then retightening member 70 to secure the knife blade at its new adjustment.
The blade cutting edge 69 is beveled on one side only, namely, on the side opposite the rotor. In this way, precise and repeatable adjustment of the cutting can be made for achieving fiber scoring at a point recessed from the contact end a distance preferably amounting to only several ten thousandths of an inch.
In addition to the knife blade adjustment just described, the holder 61 can be moved along the rotor outer face by loosening screw 72 and 73, moving the holder as described, and tightening screws 73 and 72, in that order. Flat spring 73' is held by screw 72' and tensioned downwardly. If upward adjustment of knife blade 68 is desired, the screw 73 is loosened which allows the spring force of spring 73' to move holder 61 upward. The combination of adjustments of the holder and knife blade effect proper location of the knife edge 69 in contact with a bare fiber 27 for scoring.
Pretensioning Device
The fiber pretensioning device 24 is similar in construction and operation to the clamping means 67 of the referenced Balyasny et al. patent in that it clamps onto the end portion of the bare fiber being cleaved and applies a predetermined amount of axial tension to the fiber. For the ensuing detailed description of the pretensioning device particular reference is made to FIGS. 4 and 10.
The base end wall 36 extends upwardly to form a further wall 74. A generally L-shaped transfer block 75 is constructed to fit onto the upstanding wall 74 and end wall 36. More particularly, the transfer block has one arm 76 with an internal face 77 of dimensions and geometry identical to the outer surfaces of 74 and 36. Three transverse openings are formed in 76 accommodating two guide pins 78 and a third pin 79 with a large head limiting the travel of block 75. There are three openings in walls 74 and 36 which align, respectively, with the openings in 76 for receiving the ends of pins 78 and 79. Compression spring 80 moves the transfer block 75 outwardly from walls 74 and 36 applying tension to the fiber.
The upwardly directed support surface of the transfer block horizontal arm is substantially flat and coplanar with the groove 59 in plate 56.
Preferably, the pins 78 and 79 are slidingly received within the openings in 76 and tightly held in the walls 36 and 74. In this manner, the transfer block is movable solely along a path toward and away from walls 36, 74. The large head of the pin 79 serves as a limit stop in a way that will be described.
A fiber retention means 82 consists generally of an L-shaped member, one arm 83 of which is adapted to extend over the support surface 81 of the transfer block, and the other arm 84 extends generally parallel to the outside surface of the block 76. A pair of side plates 85 integral with the arms of 82 partially enclose the sides of the L-shaped member and include a pivot pin 86 passing therethrough which is rotatably received within the upper portion of the block 76. A holding pad 87 is affixed to the inner end surface of arm 83 and is located immediately opposite the outer end portion of the flat support area 81 of the transfer block (FIGS. 4 and 10). A compression spring 88 has one end received within a declivity in the inner surfae of the L-shaped arm 82 with the other spring end received in a similarly shaped declivity in the outside surface of the transfer block 76 (FIG. 4). In this way, the spring 88 acts to resiliently urge the fiber holding pad 87 in contact with the flat support surface 81. It is also to be noted that when the vertical arm of 82 is depressed towards transfer block 76, the movement of the block 76 toward vertical arm of 82 is limited by contact of the two.
At the lower end of the vertical arm of L-shaped member 82 is a selectively actuatable means 89 for maintaining the pad 87 spaced apart from surface 81 during the initial location of a fiber in the apparatus for cleaving. The means 89 includes a cylindrical shaft 90 with a knob 91 at one end. The shaft extends through an oversize opening 92 in the vertical arm of 82 and into a conical opening 93 in end wall 36. Rubber or elastomeric O-rings 94 received on shaft 90 coacts with the wall of 82 and a pin 95 fixed to the shaft to provide resilient mounting of the means 89. When the member 82 is pressed toward wall 36 a hook 96 on the shaft 90 locks behind end wall 36 holding pad 87 away from surface 81. Pressing knob 91 with slight lateral movement releases the means 89. This pressing and lateral movement should be made slowly to allow fiber clamp pad 87 to clamp onto the fiber and place it in tension.
Use of The Described Embodiment
The fiber 25 having its protective buffer covering removed from an extensive end portion 27 has a contact 28 appropriately mounted onto the bare fiber leaving a bare fiber portion extending outwardly of the contact. Next, the pad 87 is locked open by pressing L-shaped member 82 toward the end wall 36 (FIG. 10). The bare fiber end portion is then threaded through the retention and scoring device 23 and allowed to rest on surface 81 with the contact 28 properly located within the opening 50 in cylindrical member 47. Now, the fiber holding means 22 is clamped onto the fiber and the pretensioning device knob 91 is pressed to effect gripping and tensioning of the fiber. Finally, rotation of the scoring apparatus 23 scores the fiber which on breaking at the score line produces the desired faced -off fiber end surface.
The actual scoring achieved is shown in detail in FIGS. 8 and 9. As can be seen best in FIG. 9, the knife blade 68 is maintained at an angle to the ends of the contact pins 29 which allows the score line to be made almost exactly in the plane of the ends of the pins or even slightly recessed from the pin ends. At the completion of scoring and breaking of the fiber along the score line, the fiber tension is released and the newly cleaved fiber end will "jump" some distance d and be located recessed within the ends of the contact pins as desired.
Even where a fiber contact construction other than the three-pin one described, the present invention can be advantageously employed. In FIG. 11 a contact is shown having the bare fiber extending through an opening in the contact end wall, the end wall having a flat outer surface. In this since the knife edge 68 is held at an angle to the contact end surface a scoreline can be made on the fiber at a point very close to the outer end of the contact body. Moreover, due to fiber pretensioning or the fiber breaking at the scoreline, the fiber end will jump to a recessed position as desired.
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A bare optical fiber is located within the interstice of three cylindrical pins with the fiber end extending outwardly of the contact assembly. The contact is located within an axial opening of a rotatable drum member with the bare optical fiber end extending outwardly. The drum member is interconnected via bearings to an outer rotatable portion of the drum member. A pretensioning clamp is arranged to receive the bare end of the fiber to secure it between clamp heads which applies an axial tension to the bare fiber with respect to the contact. A cutter blade mounted on the rotatable portion of the drum is adjustable to move a knife edge angularly toward the bear fiber to contact the bare fiber at a point closely adjacent the contact pin ends. Rotation of the outer portion of the drum member scores the fiber, as desired.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 12/562,116, filed Sep. 17, 2009, which claims the benefit of European Patent Application No. EP09305452.6 filed May 18, 2009. The disclosure of each of these patent documents is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The present invention relates to a method and system for determining an optimal fare for a specific trip, particularly but not exclusively in the travel industry domain.
BACKGROUND OF THE INVENTION
Nowadays, when a user wants to search for and book a trip comprising an airline flight, the user can request fares through a specific process. Thus, the user can search for fares in airlines databases which comprise such fares. The user may alternatively use on an airline website or an online travel agency. Before booking, the user can then compare the different fares displayed on each website for a specific flight from a departure point A to an arrival point C. Often, for the same airline, a fare for a direct flight from a point A to a point C is higher than a fare for a flight from a point A to a connection C and from the connection C to the point B. Therefore, when the user wants to fly from A to C only, the user books the cheapest flight which is the one from A to B comprising the connection C. Of course, the user only flies from A to C and does not use the flight from C to B. Thus, the airline books one seat on each flight for the user whereas the user only uses one seat for the flight from A to C. The airline notices the non-use of the seat for the flight from C to B only at the time of the flight. The airline cannot anticipate such a situation. Therefore, the airline cannot generally resell the non-used seat to another user before the flight from C to B departs. This type of situation happens regularly and airlines may wish to change these uncertain circumstances. Typically this situation is brought about by incorrect management of travel fares rules from airlines. Inconsistencies may arise when the airlines add new fares. The new fares are not always compared with previous fares relating to the same city pair or to other city pairs in combination with the requested trip.
Therefore, as previously mentioned, a combination of two indirect flights from A to C and from C to B is often cheaper than a direct flight from A to C. As a consequence, the user may wish to choose the A-C-B trip i.e. the cheapest one rather than the more expensive A-C flight. When a substantial number of users choose this cheapest solution, the number of no-shows on the C-B flight increases, which induces an important economic negative impact for the corresponding airline(s).
SUMMARY OF THE INVENTION
An object of the present invention is to alleviate at least some of the problems associated with the prior art systems.
According to one aspect of the present invention, there is provided a method for determining an optimal fare for a trip comprising a departure location, an arrival location, the method comprises the steps of sending a request for the trip wherein the request comprises a departure location, an arrival location and a corresponding fare for the trip; automatically modifying the request by searching in a predetermined database to determine a set of additional requests wherein each comprises at least one of the departure location, the arrival location or one or more additional locations which may form at least a part of the requested route wherein the predetermined database comprises said additional requests and a corresponding fare for each additional request; selecting one or more additional requests to form one or more alternative requests which include at least one of the departure location or the arrival location as the request; calculating the up to date fares for each alternative request in order to determine a resulting fare for each alternative request; comparing the fare and the resulting fares in order to determine the lowest resulting fare for the trip.
According to another aspect of the present invention, there is provided a non-transitory computer readable medium having stored thereon instructions executable by a processor of a computer for controlling the computer for carrying out a method for determining an optimal fare for a trip comprising a departure location, and an arrival location. The method comprises the steps of sending a user request having a requested route for the trip, wherein the user request comprises the departure location, the arrival location, and a corresponding fare for the trip; automatically modifying the user request by searching in a predetermined database to determine a set of additional requests, wherein each additional request comprises at least one of the departure location as requested in the user request, the arrival location as requested in the user request, or one or more additional locations to form at least a part of the requested route, wherein the predetermined database comprises said additional requests and a corresponding fare for each additional request; combining one or more of the additional requests to produce one or more alternative requests which result in a route having the requested departure location and the requested arrival location; calculating up to date fares for each alternative request in order to determine a resulting fare for each alternative request; and comparing the corresponding fare for the trip and the resulting fares in order to determine a lowest resulting fare for the trip including said requested route, when said computer program is executed on a programmable apparatus.
According to a second aspect of the present invention, there is provided a system for determining an optimal fare for a trip comprising a departure location, an arrival location; wherein the system comprises a request search module for receiving a request for a trip, wherein the request comprises a departure location, an arrival location and a corresponding fare for the trip; a predetermined database for determining a set of additional requests wherein each comprises at least one of the departure location, the arrival location or one or more additional locations which may form at least a part of the requested route wherein the predetermined database comprises said additional requests and a corresponding fare for each additional request; an encompassing engine for receiving the request and the one or more alternative requests and for calculating up to date fares for each additional request and for determining a resulting fare for each alternative request and for comparing the fare and the resulting fare for determining the lowest resulting fare for the trip.
BRIEF DESCRIPTION OF DRAWINGS
Reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 is a diagram of the process for determining an optimal fare for a trip by way of example, in accordance with one embodiment of the present invention;
FIG. 2 is a diagram of a table from a learning entity module in FIG. 1 by way of example, in accordance with one embodiment of the present invention;
FIG. 3 is a diagram of another table from a learning entity module in FIG. 1 by way of example, in accordance with one embodiment of the present invention;
FIG. 4 is a flow chart of the method steps of a part 1 of the process of the FIG. 1 by way of example, in accordance with one embodiment of the present invention;
FIG. 5 is a flow chart of the method steps of another part 2 of the process of the FIG. 1 by way of example, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 shows a production traffic database 90 which relates to one or more airlines. This database 90 stores data relating to trips such as flights or routes, for example. The database 90 comprises a first database relating to fares and associated rules for each airline. A fare refers to the price of one or more flights including fees and taxes such as airport taxes and insurance fees. The database 90 also comprises a second database relating to the flights and their corresponding availabilities, for each airline. The first and the second databases provide data which include criteria such as a departure location and/or an arrival location and corresponding fare information where appropriate. The database 90 is connected to a production traffic engine 100 . The production traffic engine 100 may support one or many travel suppliers or vendors. As shown in FIG. 1 , users such as travelers, travel agents or airlines can send a first type request 80 to the production traffic engine 100 in order to find the lowest fare for a specific trip. Thus, the production traffic engine 100 regularly downloads data from the production traffic database 90 in order to find the lowest matching fares for a specific trip request. Thus, the production traffic engine 100 handles a significant amount of data relating to flights and fares.
Each first type request 80 comprises several criteria for a trip such as at least one departure location and arrival location. The result from the production traffic engine 100 comprises one flight or a combination of flights in order to identify the lowest available fare for the first type request.
When the result is one flight, this means that the lowest fare found by the production traffic engine 100 refers to a direct flight. When the result is a combination of flights, the combined flight resulting from the combination of the flights must have the same departure location and the same arrival location as these indicated in the request. In the situation where the result is a combination of flights, the combination of flights provides the lowest fare for the requested trip. Thus, the corresponding fare associated with the combined flight is lower than the fare associated with the direct flight.
In the example where the first type request 80 refers to a direct flight from a location A to a location B, the optimal result may relate to a combination of flights such as a flight from the location A to the location C and then another flight from the location C to the location B. In this case, this means that the combined flight comprising both flights from A to C and from C to B is cheaper than the direct flight from A to B.
As shown in FIG. 1 , the production traffic engine 100 is connected to a learning entity module 102 . The module 102 analyses and parses the results of the production traffic engine 100 . The module 102 identifies each first type request from users and the corresponding result from the production traffic engine 100 in order to create specific tables for associating each first type request with a corresponding result.
As indicated in FIG. 2 , each table 200 and 300 relates to a first type request, the possible corresponding result, which each comprises one flight or a combination of flights and a corresponding fare for the flight or the combined flight.
In addition, the first type request comprises elements which refer to a specific departure location, a specific arrival location and the corresponding fares at a specific date. Thus, for example in FIG. 2 , the table relates to the departure location A and the arrival location B. The table 200 gathers possible first type requests and results as found in the production traffic engine 100 . The table 200 does not only provide the lowest fare for the first type request for A to B but also indicates a number of possible first type requests for which the result includes a flight from A to B. The possible results in this example are: a round trip A to B; a combination of flights from A to B and from B to C to obtain a combined flight from A to C or a direct flight as requested from A to B. Each possible result is stored with its associated fare and its associated first type request.
The module 102 of FIG. 1 comprises a table for each departure location and arrival location encountered in the results of the production traffic engine 100 . Thus, the module 102 also comprises another table 300 as indicated in FIG. 3 for example. The table 300 relates to another first type request of departure location B and arrival location C. The table 300 indicates two possible results: a direct flight from B to C; or a combination of flights from A to B and from B to C which includes the flight from B to C.
Returning to FIG. 1 , the module 102 is connected to an encompassing request database 104 . The module 102 stores the tables in the database 104 . For example, the tables 200 and 300 are stored in database 104 .
The encompassing request database 104 is connected to an encompassing request search module 106 . The database 104 and the search module 106 can communicate with each other, i.e., the search module 106 can send a request to database 104 which can send additional requests 109 back to the search module 106 . An airline company (not shown) can send an airline request 105 to the encompassing request search module 106 . The airline request 105 is the input request which is required for the process to take place in accordance with the present invention. The airline request 105 comprises a trip including a departure location, an arrival location and a corresponding fare such as for example a departure location A, an arrival location C and a fare of C=200. The function of the search module 106 is to determine the lowest alternative requests associated with the trip as indicated in the airline request 105 from the airline company. Thus, the search module 106 has to launch a second type request 107 to the encompassing request database 104 . The second type request 107 only comprises the indication of the departure location and the arrival location from the airline request 105 . The database 104 broadens the second type request 107 to search among the stored first type request and their corresponding results and fares for all the possibilities matching the second type request 107 . Then, the database 104 returns the additional requests with expected fares and results to the search module 106 .
In case the trip from the airline request 105 is made of several departure and arrival locations, then the encompassing request search module 106 builds a list of alternative requests by assembling together additional requests from each couple of departure location and arrival location from the airline request.
The encompassing request search module 106 is connected to an encompassing engine 108 . The engine 108 calculates in real time the optimal fares associated with each alternative request received from the encompassing request search module 106 . The engine 108 also compares the fare indicated in the airline request 105 from the airline and the resulting fares as calculated for the alternative requests found from the encompassing request search module 106 .
Thus the engine 108 determines the optimal fare between the fares indicated in the airline request 105 and the fares found from the alternative requests.
The method of the system as described above will be now explained by the following steps. As shown in FIG. 4 , in the step 400 , the production traffic engine 100 receives first type requests from clients, travel agents or airlines. Then, in a step 402 , the learning entity module 102 sorts and analyses the first type requests and the corresponding first type results stored in the production traffic engine 100 . The learning entity module 102 creates tables in order to associate each first type request with a corresponding first type result and fare. Then, in a step 404 , the database stores the first type results and the corresponding fare as selected from the learning entity module 102 for each first type request.
The process steps then continue as shown in FIG. 5 . In step 500 the airline sends an airline request 105 to the encompassing request search module 106 . The airline request 105 relates to a trip and comprises a departure location and an arrival location with a corresponding fare. For example, an airline request 105 may occur when the airline has determined that the flights for a specific trip were consistently under booked over recent months. In this situation, the airline may wish to determine if such a decrease in the bookings is caused by the fare being more costly than other fares found from an encompassing request. As a result, the airline may launch a request to determine if a lower fare exists among the fares already proposed by the same or other airlines.
In step 502 , the encompassing request search module 106 then modifies the content of the airline request 105 in order to provide a second type request 107 . The modification comprises the removal of the or each fare from the request 105 . Thus, the second type request 107 does not comprise the fare or fares as indicated in the first type request 105 . In case of multiple origins and destinations in the airline request, the step 502 will build several second type request associated to each pair of origin and destination. In step 504 , the encompassing request database launches the second type request 107 to the encompassing request database 104 . In step 506 , the encompassing request database 104 uses the stored first type results in order to encompass the second type request 107 . The use of the first type results provides one or more additional requests which may form at least a part of the second type request 107 . Thus, the encompassing request database 104 builds one or more additional requests whose result comprises the departure location and arrival location of the second type request 107 . The encompassing request database 104 retrieves only a predetermined number (n) of the optimal first type requests and associated result. The predetermined number (n) can be specified in the encompassing request database 104 .
The encompassing request database 104 then sends additional requests to the encompassing request search module 106 . In Step 507 , the encompassing request search module builds alternative requests 110 by combining the additional requests 109 received from encompassing request database 104 . The encompassing request search module 106 sends both request 105 and alternative requests to the encompassing engine 108 in step 508 . In step 510 , the encompassing engine 108 calculates in real time the fares associated with the alternative requests. Subsequently in step 512 , the encompassing engine 108 compares fares and determines the optimal fare and the corresponding trip. The corresponding trip can be more expensive than the fare specified in request 105 which means that the airline presently provides the lowest price for this trip. Alternatively, the corresponding trip can be cheaper than the fare specified in the request 105 which means that the airline provides a less favourable fare for the requested trip. In order to solve the inconsistency, the airline can for example lower the fare of the requested trip or increase the fare of the alternative trip. Thus, users will preferably book the trip of the airline request.
The modification of the request 105 can be calculated in an exhaustive manner. For example, in a situation where the airline request deals with a direct flight, the calculation for the broadening of the airline request to obtain the possible corresponding round trips or combined trips will deal with many possible results. This calculation does not take into account the comparison of fares for each possible and may result in at least 1 million separate requests. This number of requests represents a significant amount of computing time. The present invention provides a broadening of the request by using a predetermined database which stores the possible additional requests with their corresponding lowest fares. Thus, in the present invention, the broadening of the airline requests only deals with possible first type results which are already relevant in terms of the fare level, destination etc. Therefore, the present invention provides a search in an improved manner by significantly reducing the computing time.
It will be appreciated that various combinations of method steps in combination of alone may be carried out for different elements of the overall process. The various combinations are not limited to those described above. It will be appreciated that this invention may be varied, in many different ways and still remained with the entirely scope and spirit of the invention. Furthermore, the person skilled in the art will understand that some or all of the functional entities as well as the processes themselves may be embodied in software or one or more software enable to modules and/or devices.
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A method for determining an optimal fare for a trip comprising a departure location, an arrival location, the method comprises the following steps: sending a request for the trip wherein the request comprises a departure location, an arrival location and a corresponding fare for the trip; automatically modifying the request by searching in a predetermined database to determine a set of additional requests wherein each comprises at least one of the departure location, the arrival location or one or more additional locations which may form at least a part of the requested route wherein the predetermined database comprises said additional requests and a corresponding fare for each additional request; selecting one or more additional requests to form one or more alternative requests which include at least on of the departure location or the arrival location as the request; calculating the up to date fares for each alternative request in order to determine a resulting fare for each alternative request; comparing the fare and the resulting fares in order to determine the lowest resulting fare for the trip.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The invention relates to a nozzle for atomization of liquid fuel by means of the air flowing through the nozzle, with an air entry area, an air exit area and a flow path which connects the air entry area to the air exit area.
[0003] 2. Description of Related Art
[0004] Generic nozzles are used, for example, in vehicle heaters. These vehicle heaters can be used, for example, as auxiliary heaters and/or stationary heaters.
[0005] The nozzle is used to supply combustion air, due to the flow of combustion air the liquid fuel, for example, diesel or gasoline, being entrained from a fuel nozzle and atomized. In this way, a mixture of combustion air and fuel is obtained which can be burned, optionally, after mixing with air supplied on other flow paths, by which the heat necessary for heating operation is produced. This heat generated by a burner then heats a heat transfer medium, for example, water or air.
[0006] Nozzles of the prior art often are made of metal, e.g. as cast parts or turned parts. The disadvantage in these components is the comparatively high production cost and the generally high thermal conductivity of the metals. The thermal conductivity can pose problems when the temperature in the area of the fuel nozzle rises unduly as a result of the heat produced in the burner. To solve the problems which are associated with metallic nozzles, it has been proposed that a ceramic nozzle be used.
[0007] The flow behavior of the combustion air is important for the mixing of the combustion air with the fuel on the common path. In order to improve the flow behavior of the combustion air, it was already proposed in DE 100 39 152 A1 and corresponding U.S. Patent Application Publication 2003/0022123 A1 that a swirl be imparted to the combustion air. In this way, it is possible to distinctly improve the atomization quality and thus the efficiency of the burner, since the combustion air speed is increased as a result of the pronounced tangential component of motion. In order to impart this swirl, a carrier with swirl blades is connected upstream of the input area of the nozzle. However, the disadvantage in this carrier with upstream swirl blades is that an additional component is needed, for which reason the tolerances which exist for undisturbed operation of the nozzle can sometimes be exceeded.
[0008] In heaters of the prior art it is, furthermore, problematical to maintain narrow tolerances with respect to positioning of the glow plug with regard to the inflowing fuel/air mixture.
SUMMARY OF THE INVENTION
[0009] The object of the invention is to make available a nozzle which can be economically produced, which has thermal conductivity which is low compared to metal, and which induces advantageous properties with respect to the flow behavior of the combustion air, and calibration problems are to be avoided.
[0010] This object is achieved by the nozzle being made of ceramic material and having an air guidance means formed as an integral part thereof in the air entry area so as to impart a swirl to the inflowing air
[0011] The invention is based on the generic nozzle in that the nozzle is made of ceramic material and the air entry area has air guidance means which impart a swirl to the inflowing air but improves thereon by the air guidance means being made as an integral part of the nozzle. In this way a nozzle is provided which can be economically produced. The ceramic material can be easily worked, numerous versions with respect to shaping being possible. In particular, the air guidance means which delivers a swirl to the combustion air outside of the air entry area can be made integrally with the nozzle. As a result of using a ceramic, there is the additional advantage that the area of the nozzle around the fuel needle which is located in the nozzle does not assume overly high temperatures, so that amounts of fuel which may be emerging from the nozzle cannot ignite. The integral execution of the air guidance means makes it possible to easily adhere to tolerances, since miscalibration of the air guidance means when the burner is being assembled is no longer possible.
[0012] The invention is advantageously developed in that the nozzle has means for holding a glow plug. The positioning of the glow plug with respect to the nozzle is an important parameter with regard to good starting behavior of the burner. In heaters of the prior art, the glow plug was generally held by the burner housing, so that, in this way, fluctuations of the positioning with respect to the nozzle could occur. These tolerances can be precluded by the property of the nozzle of the present invention in that the nozzle itself has means for holding the glow plug so that the glow plug always has the same position with respect to the nozzle.
[0013] Furthermore, the nozzle in accordance with the invention is advantageously developed in that the nozzle has at least in part an essentially cylindrical shape and that the air guidance means forms channels which are offset with respect to the radial directions. The air which is flowing in perpendicular to the axis of the nozzle is therefore not radially supplied, but supplied with an offset. This offset determines the swirl which is delivered to the combustion air, and thus, the flow behavior and ultimately also the properties and quality of combustion.
[0014] It is especially useful for the air guidance means to have essentially triangular base surfaces, the corners being rounded. In this way, the channel offset can be easily implemented. The rounding of the corners is advantageous for uniform flow behavior.
[0015] It can also be useful for the air guidance means to be made as blades. These blades can likewise provide offset channels so that, in this way, the combustion quality is benefited.
[0016] In another preferred embodiment of this invention, it is provided that the means for holding the glow plug are made as a hole which runs obliquely to the cylinder axis. The glow plug must then be simply inserted into the hole for suitable positioning. A stop on the glow plug and/or within the hole provides for the glow plug to be guided into its optimum position with respect to the nozzle.
[0017] The nozzle in accordance with the invention is developed especially advantageously in that an at least essentially cylindrical part of the nozzle has an essentially cylindrical shoulder with an increased diameter and that the means for holding the glow plug are made as a hole which penetrates the shoulder which runs obliquely to the cylinder axis. In this way, the glow plug can be held in an area in which it influences the flow behavior of the inflowing fuel/air mixture as little as possible. This can be easily managed by the cylindrical stop which has a greater diameter than the remaining nozzle body.
[0018] Likewise, it is especially advantageously provided that an at least essentially cylindrical part of the nozzle has an essentially cylindrical shoulder with an increased diameter and that the cylindrical shoulder has recesses for holding the mounting pins. These mounting pins can be securely attached, for example, to the heat shield of the burner. The relative positioning of the nozzle is fixed in this way by recesses in the shoulder and the position of the mounting pins. Thus, installation is especially simple and is possible with only low tolerances.
[0019] In an especially advantageous manner, it can be provided that the nozzle is a Venturi nozzle. The Venturi effect for atomization of the fuel emerging from the fuel needle can be advantageously combined in this way with the swirl delivered to the combustion air. The effects support one another and thus lead to high-quality combustion.
[0020] The invention is based on the finding that a nozzle which can be economically produced provided with a shape which can be varied within wide limits using a ceramic material. The shaping of the nozzle can be completed such that the air guidance means which imparts a swirl to the entering combustion air can be made integrally with the nozzle. Furthermore, the ceramic has the advantage that an undesirably high temperature can be avoided in the area of the fuel needle.
[0021] Another object consists in devising a heater for mobile applications which can be economically produced.
[0022] This object is achieved by a heater for mobile applications, especially motor vehicles which is provided with a burner for combustion of a fuel/air mixture having a nozzle in accordance with the present invention.
[0023] The invention is explained in greater detail below with reference to the accompanying drawings which shows a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a partially cutaway schematic of a heater in which the nozzle of the present invention can be used;
[0025] FIG. 2 cross-sectional side view of one embodiment of a nozzle in accordance with the invention;
[0026] FIG. 3 is a plan view of the air entry area of a nozzle in accordance with the invention; and
[0027] FIG. 4 shows a nozzle in accordance with the invention mounted on a burner.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the following description of the drawings, the same reference numbers identify the same or comparable components throughout the various figures.
[0029] FIG. 1 shows a heater 10 for use with the nozzle of the invention which has a burner 12 for combustion of a fuel/air mixture. The heater comprises an annular channel fan 14 with a fan motor 36 . Combustion air 42 is taken in through the annular channel fan 14 via an air entry connection 16 and is blown into a combustion air collecting space 18 on the pressure side. The combustion air which is available in the combustion air collecting space 18 is divided into primary air and secondary air. The primary air is conveyed into the combustion chamber 24 by a nozzle 20 which is made as a Venturi nozzle in this example. The secondary air is conveyed through secondary air holes 22 into the combustion chamber 24 . The division of the combustion air into primary air and secondary air is useful in order to provide a rich, ignitable mixture at the outlet of the nozzle 20 .
[0030] The nozzle 20 comprises a settling zone 26 and a diffusor 30 in order to produce the Venturi effect. Within the nozzle 20 , there is a fuel needle 28 . The fuel needle 28 is supplied with fuel 44 via a fuel line 82 . Due to the high flow velocity of the combustion air in the settling zone 26 , the fuel which is emerging almost unpressurized from the fuel needle 28 is pulled into filaments which then break down into droplets. The high air speeds which are necessary for good atomization can be achieved by good pressure recovery of the diffusor 30 .
[0031] Furthermore, over the course of the diffusor 30 , the flow velocity of the fuel/air mixture is drastically reduced, by which low flow velocities are accomplished in the area of the glow plug 62 which is indicated in FIG. 2 . This supports the formation and propagation of a pilot flame. After the starting process, i.e., ignition of the system by the glow plug 62 , the glow plug is turned off. It is used subsequently with the aid of resistance measurement for flame monitoring.
[0032] Within the fuel chamber 24 , there is a baffle disk 32 . The latter constitutes a flow barrier so that the air emerging from the nozzle 20 is forced to the outside. In this way, good mixing of the primary air with the secondary air takes place; this is useful with respect to good final combustion. The area between the nozzle 20 and baffle disk 32 is thus used as a mixing zone 34 and the area on the other side of the baffle disk 32 , i.e., the area which is downstream with respect to the baffle disk 32 , is used as a reaction zone 38 . The mixture produced burns in the further course of the combustion pipe 40 and is routed out of the heater 10 by the parts which carry the exhaust gas. The heat generated heats the entering cold water 46 in heat exchange with the exhaust gas-carrying parts so that hot water 48 emerges from the heater 10 . For example, air can also be used as a heat transfer medium instead of water.
[0033] FIG. 2 shows a partially cutaway side view of one embodiment of a nozzle 20 . This nozzle 20 can be used, for example, in a heater 10 , as is shown in FIG. 1 . The nozzle 20 is made of a ceramic material; this simplifies the production of the nozzle 20 as compared to metal nozzles. The nozzle 20 has an air entry area 50 and an air exit area 52 . The air entry area 50 is connected to the air exit area 52 via the flow path 54 . This flow path 54 is divided in this example into a settling zone 26 and a diffuser 30 .
[0034] In the air entry area, there is air guidance means formed of air guidance elements 56 . These air guidance elements 56 are made integrally with the ceramic nozzle 20 . The air guidance elements 56 are aligned such that a swirl is imparted to the supplied air; this is explained below with reference to FIG. 3 . In the settling area 26 , there can be a fuel needle 28 (see, FIG. 4 ) so that a mixture of fuel and air emerges from the nozzle 20 . This mixture can be ignited via a glow plug 62 which can be inserted into a hole 58 of the nozzle 20 . The positioning of the glow plug 62 is thus fixed with respect to the nozzle 20 , since the glow plug 62 is held by a hole 58 of the nozzle 20 , i.e., especially not by any other parts. Thus, very low tolerances can be maintained with respect to the installation position of the glow plug 62 . The hole 58 , advantageously, penetrates a cylindrical shoulder 64 of the nozzle 20 , which shoulder has an enlarged radius; this has the advantage that the flow behavior of the nozzle 20 is influenced only slightly by the hole 58 or by the glow plug 62 which is located in the hole 58 .
[0035] FIG. 3 shows an overhead view of the air entry area 50 of a nozzle. One possible configuration of the air entry area 50 by air guidance elements 56 is shown. The air guidance elements 56 form channels 60 for the inflowing air. These channels 60 are positioned with respect to the radii of the structure which is located essentially on an axis such that there is an offset. Air flowing in from the outside thus undergoes a swirl; this entails advantageous properties with respect to atomization of the fuel which is emerging from the fuel needle which can be located in the settling area 26 . Furthermore, in this representation, the arrangement of the opening 58 for holding the glow plug can be recognized. The opening 58 penetrates the essentially cylindrical shoulder 64 . Furthermore, the shoulder 64 is provided with recesses 66 . These recesses 66 define the installation position of the nozzle 20 ; this is explained below with respect to FIG. 4 .
[0036] FIG. 4 shows a partially cutaway view of a device in accordance with the invention. One end of the burner 12 facing the nozzle 20 is shown.
[0037] The burner 12 is bordered by a heat shield 78 . On this heat shield 78 , there are two mounting pins 68 in this sample embodiment. These mounting pins 68 can be welded to the heat shield 78 or to the burner 12 . The mounting pins 68 define the positioning of the other components which are described below. First of all, there is a seal 76 which preferably is formed of a mica layer and a graphite layer, the mica layer facing the burner 12 and the graphite layer facing the nozzle 20 . The ceramic nozzle 20 follows and is positionally fixed on the mounting pins 68 with its recesses 66 ( FIG. 3 ). A fuel feed 70 is connected to the fuel needle 28 and is seated on the nozzle 20 . This fuel feed 70 is positioned, likewise, by mounting pins 68 by means of holes 84 which are provided in a side flange. The fuel feed 70 is supplied with fuel by a fuel line 82 in which there is a fuel sensor 80 . The fuel feed 70 is followed by a spring 72 which is also seated on the mounting pins 68 . The spring 72 is held by clamping disks 74 which sit immovably on the mounting pins 68 . The spring 72 is shown in the tensioned state in which the legs of the spring 72 are, for example, parallel to the interposed disk. In the relieved state of the spring 72 , the legs of the spring 72 are bent up in the direction to the interposed disk. The glow plug, which is not shown in FIG. 4 , is positioned in agreement with the embodiment of nozzle 20 shown in FIG. 2 by this nozzle and is held by a wire spring (not shown) which is supported on the nozzle 20 .
[0038] The fuel feed 70 , and thus, the fuel needle 28 are automatically aligned in this way with respect to the nozzle 20 . Therefore, only two components are involved which influence the fuel feed and mixing of the fuel with the combustion air, so that very small tolerances can be maintained; this is possible by axial mounting on the same mounting pins 68 . Likewise, the glow plug 62 can be positioned exactly with respect to the nozzle 20 and the burner 12 . The production of the structure shown in FIG. 4 can be completely automated. In particular, the mounting direction is uniformly axial so that only “threading” of the components 76 , 20 , 70 , 72 and 74 need be performed. The seal 76 makes available heat insulation, coupling of the nozzle ceramic 20 to the metal of the heat shield 78 , and tolerance compensation. The structure can be advantageously mounted by power-controlled pressing of the clamping disks 74 onto the mounting pins 68 so that, with respect to the heat and temperature properties of the structure, uniform prerequisites can be created. Imparted by the spring force of the spring 72 , tolerances due to the varied heating of the components, different final temperatures of the components and different coefficients of temperature expansion can be compensated.
[0039] The features of the invention disclosed in the description above, in the drawings and in the claims can be important to the implementation of the invention both individually and also in any combination.
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A nozzle for atomization of liquid fuel by air flowing through the nozzle ( 20 ), with an air entry area ( 50 ), an air exit area ( 52 ) and a flow path ( 54 ) which connects the air entry area ( 50 ) to the air exit area ( 52 ), the nozzle ( 20 ) being made of ceramic material, an air guidance device ( 56 ) being provided in the air entry area ( 50 ) which imparts a swirl to the inflowing air, and the air guidance device ( 56 ) being an integral part of the nozzle ( 20 ). Furthermore, there is a heater ( 10 ) equipped with such a nozzle ( 20 ) for mobile applications.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority on U.S. Provisional Application Ser. No. 61/904,561 filed on Nov. 15, 2003, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to improvements in the wireless radio over internet protocol (RoIP) communication systems, and a method of use.
BACKGROUND OF THE INVENTION
[0003] The monopoly of public switched telephone networks (PSTNs) using twisted-pair copper wiring and circuit protocols was challenged by systems that utilized Internet Protocol (IP) telephony and voice over an Internet Protocol (VoIP), as illustrated by U.S. Pat. No. 6,141,341 to Jones. Numerous systems utilizing and extending the streaming capabilities offered by VoIP continued to develop, but were not initially concerned with RF modulation. Transmitting and receiving radio communications were subsequently facilitated by the radio over internet protocol (RoIP), which functions similar to VoIP, but utilizes an added command layer. An example is shown by the linking of two radios over the Ethernet in U.S. Patent Application Pub. No. 2006/0067266 by Ehlers.
[0004] RoIP technology converts the radio signal to baseband (i.e., demodulates the signal), then digitizes the baseband information and sends it over IP, and lastly re-modulates the baseband information for transmission at the receiving end. To accomplish demodulation (i.e., extraction of the modulation information), and also subsequent re-modulation, requires fore-knowledge of the modulation type to be converted, and the requisite ability to demodulate and re-modulate the signal. Thus, current RoIP technology cannot provide a generic (modulation transcendent or modulation agnostic) transmission of the signal over an internet connection.
[0005] Moreover, the ability to transmit captured data files over IP (e.g., emailing a captured sample file) serves to transmit complex (digital) modulation generically, but does not accomplish transmission in real-time. There is no streaming of data samples, and no attempt to simulate an active RF link between the two devices.
[0006] The present invention is conceived and adapted to provide the capability to generically transport either conventional (e.g. AM, FM, phase, or pulse) modulation or complex modulation (e.g., Gaussian Minimum Shifting Key (GMSK), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency-Division Multiplexing (OFDM), and etc.) in real time across an internet protocol link, such as Gigabit Ethernet (GBE), without the need to know anything about that modulation other than its required occupied bandwidth.
OBJECTS OF THE INVENTION
[0007] It is an object of the invention to provide an improvement to the radio over internet protocol (RoIP).
[0008] It is another object of the invention to provide a means of transmitting radio signals across an internet protocol link without requiring knowledge of the modulation type.
[0009] It is a further object of the invention to provide a means to generically transport modulation (e.g., conventional AM, FM, PM or pulse, as well as complex modulation) across an internet protocol link.
[0010] It is another object of the invention to provide a means of utilizing an internet protocol link to extend the range of transmitted radio signals in real time or near real time.
[0011] Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates use of RF digitizers and vector signal generators to establish a full duplex RF connection for streaming IQ sample data across IP in real-time.
[0013] TABLE 1 shows a chart of projected typical maximum sample rates for varying bit resolutions using a Gigabit Ethernet (GBE) connection, based on an assumed 80% packet efficiency (throughput rates would obviously have to be recalculated for different IP connections, such as 100BASE-T or 10 GigE).
DETAILED DESCRIPTION OF THE INVENTION
[0014] Voice over internet protocol (VoIP) consists of a group of technologies utilized in a method of delivering voice and even multimedia communications (e.g., a combination of text, audio, still images, animation, video, etc.) over internet protocol networks, such as the internet. The process of using VoIP as a means of internet telephony is analogous to that used for communications of digital telephony.
[0015] Internet telephony refers to the provisioning of communications (voice, fax, SMS, voice-messaging) over the internet, rather than through the public switched telephone network (PSTN). The process of originating VoIP telephone calls is similar to traditional digital telephony, and involves signaling, channel setup, digitization of the analog voice signals, and encoding. However, for digital telephony, the digitized voice signal is transmitted over a circuit-switched network, utilizing, for example, time-division multiplexing (TDM) or frequency division multiplexing (FDM) to transmit and receive independent signals over a common path. The use of TDM for circuit mode communication in digital telephony may utilize a fixed number of channels, with each having a constant bandwidth per channel, and where the time domain is divided into several recurrent time slots of fixed duration, one for each sub-channel. In the use of FDM for digital transmissions, the total bandwidth available in the medium is divided into a discrete series of frequency sub-bands, where each sub-band is dedicated to the transmission of a particular signal. One example of the use of FDM is the broadcast of radio and television signals at different frequencies through the atmosphere concurrently, while another example is shown by cable television, in which numerous different television channels are carried simultaneously across a single cable.
[0016] With internet telephony, the digital information is packetized and transmission occurs as Internet Protocol (IP) packets over a packet-switched network. The packet-switched network provides for delivery of variable-bit-rate data streams (sequences of packets) over the shared network, and serves to allocate transmission resources as required according to one or more techniques, including statistical multiplexing or dynamic bandwidth allocation.
[0017] Voice over internet protocol (VoIP) may utilize existing broadband internet access through wired Ethernet or wireless WiFi. VoIP has been implemented using both proprietary and open standard protocols. Some examples of voice over internet protocols are H.323, the Media Gateway Control Protocol (MGCP), and the Session Initiation Protocol (SIP).
[0018] Radio over internet protocol (RoIP) is a communication concept similar to VoIP which utilizes an added command layer, but instead of implementing voice-to-voice telephone communication, it may facilitate two-way radio communications to enable its users to span large geographic areas. RoIP is also not proprietary or protocol limited. RoIP may specifically be implemented with one node of the network being a radio that is connected via IP to other nodes in the network, which may also be a two-way radio, but could also be a POTS telephone, or a software application running on a personal computer (e.g., the peer-to-peer system of Skype™).
[0019] The present invention leverages RoIP through the embodiment shown in FIG. 1 , which includes using standard RF digitizers and vector signal generators to establish a full duplex RF connection capable of streaming IQ sample data across IP in real-time. In FIG. 1 , a first transceiver (“Test Transceiver # 1 ”) is coupled to transmit into an RF Digitizer, which is coupled to an LVDS/GBE (low voltage differential signaling/gigabit Ethernet) converter for communication across the internet. The four LVDS data busses in FIG. 1 represent one embodiment of the present invention that may be used to stream digitized data. The use of the LVDS/GBE converters in this embodiment are central to the power of this invention, and serve to accept real time streaming sampled RF data, and to reprocess or package the data into IP format for live transmission over the internet. However, the method of the present invention may also be accomplished using a different high speed, real time digitizer bus, instead of the LVDS/GBE (or GBE/LVDS), to stream the sampled data (e.g., a PXIe bus).
[0020] Reversing this process on the other end of an IP link, a GBE/LVDS converter may receive the streaming digitized signal (thus unpacking the IP data and streaming it out as reconstructed samples), and may be coupled to an RF signal generator so as to re-broadcast a direct facsimile of the original transmission to a second transceiver (“Test Transceiver # 2 ”). (Alternatively, for example, the streaming RF samples (e.g., IQ sample pairs in this example) could be directly ported via IP into signal analysis software for live evaluation and/or further manipulation. Another alternative would be to dump the IQ data via IP into remote memory storage for later retrieval and analysis.)
[0021] This arrangement provides the capability to generically transport conventional or complex modulation (e.g., Gaussian Minimum Shifting Key (GMSK), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency-Division Multiplexing (OFDM), etc.) in real time across an internet protocol link, such as a Gigabit Ethernet (GBE) link. Moreover, creating a similar link to that described above, but in the opposite direction, being between the second transceiver of System # 2 in FIG. 1 and Test Transceiver # 1 , demonstrates how one could simulate a complete, live, full duplex connection over an IP link.
[0022] This combination of technology permits real-time data streaming using modulation transcendent RF sampled digital data over an IP connection. This provides for unidirectional applications like live monitoring of remote RF transmitters (e.g., monitoring signal integrity, protocol activity, or performing remote signal intelligence (sigint) activities), as well as real-time bidirectional simplex, half-duplex, and full-duplex RF transceiver connectivity at distances well beyond the normal range of an RF transmitter or transceiver. (As noted above, some other alternatives include porting the sampled transmission via IP directly into signal processing software for analysis and/or further manipulation, or possibly even some remotely located memory for storage and possible later evaluation.)
[0023] Because this method is generic, all the user must know is the approximate frequency of interest and what constitutes an appropriate instantaneous sampled bandwidth, such that the modulation bandwidth of the intended signal is contained within the capture bandwidth of the digitizer. By accounting for this information, the user can set the RF digitizer's capture frequency and sampling rate. By sampling modulation generically, any RF signal (provided the sample rate is high enough to provide the required modulation fidelity for retransmission) can be linked over great distances, providing “seamless” RF connectivity between conventional, as well as software-defined RF transmitters, receivers, and transceivers, as long as the modulation technology used can endure the incurred resultant time delay inherent in the chosen IP link. Use of the forward and reverse paths described in FIG. 1 provides the capability, for example, of remote interoperability testing of a full-duplex RF system by transmitting the forward and reverse waveforms in their appropriate directions over the internet, in a system referred to herein as the radio frequency over internet protocol (RFoIP).
[0024] Successful in-house testing of this system consisted of generating an RF waveform in a facility in a first city, capturing and transmitting the signal as IQ sample pairs (i.e., digitizing a 5 MHz LTE uplink at 10 M samples/sec) using the bi-directional system of FIG. 1 over IP to a second facility in a distant second city, where the waveform was reconstructed as RF (i.e., transmitted it out of the signal generator). The waveform was then re-digitized and sent back via the same high speed IP link for signal analysis in the first city, where the LTE waveform was demodulated, observing its constellation and modulation characteristics (e.g., error vector magnitude (EVM), frequency accuracy, adjacent channel power (ACP), etc.) to validate through comparison that the signal quality of the retransmitted signal served as a reasonable and faithful facsimile of the original transmitted waveform. This simulated full-duplex RF connectivity between the first city and the second city. This system is highly applicable for advancing testing, permitting cloud based, remote, scalable, on-demand RF parametric and interoperability testing for design and production around the world, which is particularly beneficial and useful with respect to Asia and Latin America.
[0025] It should be noted that the present application is not limited to IQ data transmission as a method of establishing this live RF link. The objective of the “RF Over IP” technique is to generically stream digitized complex modulation samples in real-time or near real-time, using one of three generic (or modulation agnostic) transfer techniques. These three methods include use of:
[0026] (a) rectangular (or Vector) modulation (using IQ sample pairs); or
[0027] (b) polar modulation (magnitude and angle); or
[0028] (c) directly streaming sampled RF or down-converting to an IF and transferring raw IF samples.
[0000] Given any one of these, the other two can be mathematically derived. Consequently, the objective of the “RF Over IP” technique is to generically stream digitized complex modulation samples in real-time or near real-time using one of these three generic (or modulation agnostic) transfer techniques.
[0029] The examples and descriptions provided herein merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention. Other modifications, substitutions, omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention.
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The apparatus and methodologies used herein leverages RoIP to generically transport either conventional modulation (e.g., AM, FM, phase or pulse) or complex modulation (e.g., GMSK, CDMA, TDMA, OFDM, etc.) in real time or near real time across an internet protocol link, such as Gigabit Ethernet (GBE). The purpose of the invention is a method of creating a live, virtual, modulation transcendent link by using an internet protocol (IP) link to extend the natural range of a connection between an RF signal source (e.g. transmitter) and an RF receiving device (e.g. receiver). This methodology is referred to herein as radio frequency over internet protocol (RFoIP).
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BACKGROUND
[0001] In the dental arts the term “bitewing” has two related meanings. In one instance a bitewing refers to a dental x-ray image or film designed to show the crowns of the upper and lower teeth simultaneously. Additionally, a bitewing may be defined as the holder for an x-ray film or sensor that includes a projecting fin on one side that in use is held between the teeth. According to this second definition, the bitewing, or bitewing holder, thus extends perpendicular to the plane of an x-ray film or sensor such that a dental patient may bite down on the bitewing while the film or sensor is inside of his or her mouth, opposite the x-ray source.
[0002] Historically, bitewings or bitewing tabs were simple cardboard devices which were attached to an x-ray film holder, used once and then thrown away. Many dentists no longer use x-ray film. On the contrary, x-ray images are often now acquired with digital electronic x-ray sensors.
[0003] Unlike a traditional x-ray film, a digital x-ray sensor (referred to herein as a sensor) is a reusable device. Typical sensors are provided in a substantially flattened package with a data cable extending from one end. In use the sensor will typically be associated with a bitewing type device to take bitewing images. Thus, in use a modern sensor is positioned in the same manner as a traditional film for a bitewing image, with the patient biting down on a projecting fin attached to the sensor.
[0004] Unlike conventional x-ray film, a sensor must be used multiple times. Therefore, sensors are typically placed within sterile disposable sheaths before use to avoid the transfer of germs or other substances from one patient to another. Various bitewing type holders have been developed which tightly wrap around the sensor or sensor sheaths or alternatively are bonded with adhesives to a sensor and sheath and which further provide a bitewing fin. Known sensor holders can be somewhat problematic to use because they can be uncomfortable for the patient, or difficult to install and remove from the sensor. For example, sensors may be easily damaged by pulling on the data cable during sheath or holder removal. A conventional holder applied loosely to facilitate removal may not adequately secure the sensor during the x-ray imaging process.
[0005] The embodiments disclosed herein are directed toward overcoming one or more of the above problems set forth above.
SUMMARY OF THE EMBODIMENTS
[0006] One embodiment is a dental sensor holder including or fabricated with a strip of pliable, longitudinally elastic material having two ends. The holder is constructed by permanently bonding the two ends of the strip to form a somewhat elastic loop. In addition, the sensor holder includes an adjustable bond portion on the inside of the loop which may selectively be engaged to join adjacent portions of the strip into a functional bitewing.
[0007] The dental sensor holder may also include a fold line transverse the width of the strip at a point corresponding to the midpoint of the loop opposite the permanent bond. The adjustable bond may be a “hook and hook” or a “hook and loop” type adjustable fastener. For example, the adjustable bond may include a first attachment surface associated with a strip at an inner surface of the loop near the permanent bond and a second attachment surface associated with the inner surface of the looped strip on the opposite side of the permanent bond from the first attachment surface.
[0008] The length of the strip between the first and second attachment surfaces away from the permanent bond will typically be selected to be less than the circumference of a desired dental imaging sensor. Accordingly, in use, the sensor and a sheath may be placed loosely into the loop over the central fold line and away from the permanent bond. Then, the adjustable bond may be engaged by pressing the first and second attachment surfaces together thereby accomplishing two tasks: first, the first and second attachment surface and the portion of the looped strip associated with the first and second attachment surfaces will engage to form a bitewing tab. Second, the portion of the loop opposite the bitewing tab will properly and generally securely support the sensor for use taking a bitewing image. Since the strip used to form the loop is slightly elastic in the longitudinal direction and typically slightly less in length than the circumference of the selected sensor, the loop opposite the bitewing tab will gently, but firmly support the sensor.
[0009] Selective articulation of the adjustable bond may be used to accommodate reasonable variations in the size of a sensor. For example, the user may engage all or only a portion of the first and second attachment surfaces which allows a user to accommodate sensors having different circumferences. In addition, the adjustable bond allows the user to easily open the loop after use for the safe and convenient removal of the sensor or sheath.
[0010] An alternative embodiment disclosed herein is a method of fabricating a dental sensor holder as described above. Another alternative embodiment is a method of holding a dental sensor for a bitewing image, using a dental sensor holder as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a plan view of a disclosed dental sensor holder prior to the formation of the dental sensor holder into a loop.
[0012] FIG. 2 is a front elevation view of the dental sensor holder of FIG. 1 , after the holder has been formed into a loop and trimmed.
[0013] FIG. 3 is a side elevation view of a dental sensor holder after the holder has been formed into a loop but before the dental sensor holder is trimmed.
[0014] FIG. 4 is a side elevation view of a dental sensor holder after the holder has been formed into a loop and trimmed.
[0015] FIG. 5 is a perspective view of a dental sensor holder with an adjustable bond unattached.
[0016] FIG. 6 is a perspective view of a dental sensor holder in use with the adjustable bond attached.
DETAILED DESCRIPTION
[0017] One embodiment is a dental sensor holder 10 as shown in FIGS. 1-6 . FIG. 1 is a plan view of the dental sensor holder 10 before the dental sensor holder 10 is formed into a loop and before a permanent bond is made or trimming occurs as described below. The dental sensor holder 10 includes a strip 12 of a pliable longitudinally elastic material. The strip 12 may be fabricated from any material which is pliable and longitudinally elastic. The most suitable materials will however be substantially water resistant, soft and inherently clean since the dental sensor holder 10 will be placed within a dental patient's mouth. 30 mm thick polyethylene foam has been determined to be a well suited material for the strip element. Other functionally similar foams, plastics, or similar materials would be suitable for the fabrication of the strip element as well.
[0018] As also shown in FIG. 1 , the strip 12 has a length L and a width W and two ends 14 and 16 respectively. The two ends 14 and 16 will be joined in a permanent bond 18 as shown in FIGS. 2-4 as a manufacturing step prior to delivery of the dental sensor holder 10 to a dentist for use. Connection of the two ends 16 and 14 with a permanent bond causes the strip 12 to form a loop 20 . The permanent bond may be made with an adhesive, a heat generated weld or any other bonding process that is suitable for bonding the strip material.
[0019] Referring back to FIG. 1 , the dental sensor holder 10 also includes an adjustable bond 22 which provides for the selective and adjustable joining or connection of selected portions of the strip extending on each side of the strip 12 from the region of the permanent bond 18 toward opposite, open, portions of the loop. In the embodiment depicted in FIG. 1 the adjustable bond includes a first attachment surface 24 and a second attachment surface 26 which may selectively be attached or bonded together and then separated.
[0020] The first and second attachment surfaces 22 , 24 may be fabricated of any suitable material; however, hook and loop fasteners or hook and hook or similar fasteners may be utilized to implement the adjustable bond. Any material which is well suited for the first or second attachment surface will be easily joined together and easily separated while maintaining a stable connection or bond prior to separation. Ideally the adjustable bond will be of similar thickness when compared to known bitewing tabs, comfortable in the mouth and resistant to shear stress. The ULTRA-MATE® PS731 Product of the Velcro® companies is particularly well suited for the implementation of the first and second attachment surfaces. ULTRA-MATE® PS731 and similar fasteners which may be developed in the future includes scale-like extrusions which interlock and grip one another and have substantially greater shear strength than conventional hook and loop fasteners.
[0021] It may be advantageous to form the permanent bond 18 with multiple thickness of the strip material bonded together. For example, as shown in FIG. 1 and the side view of FIGS. 3-4 each end of the strip, 14 and 16 may be folded over along a perforated fold line 27 and bonded together at each adjacent surface to fabricate a permanent bond having a total of four thicknesses of strip material. In use, multiple thicknesses of the strip material at the location of the permanent bond provides for a consistent overall bitewing tab thickness along with the adjacent adjustable bond structure when the adjustable bond is engaged.
[0022] It may also be noted that the permanent bond greatly facilitates the accurate but quick and easy alignment of the first and second attachment surfaces 24 and 26 respectively. It is important that the attachment surfaces 24 , 26 be accurately aligned such that all portions of the attachment surface are covered by the relatively soft strip material in use. Thus, accurate alignment helps avoid irritation of a patient's mouth tissue by the first and second attachment surfaces or other adjustable bond structure in use.
[0023] The dental sensor holder 10 may include an optional perforated fold line 28 at the midpoint of the strip as shown in FIG. 1 . This fold line assists in the fabrication of a loop from the strip and further defines the center point of the sensor receiving portion of the loop.
[0024] The looped over strip portions of the dental sensor holder dental at the top of the permanent bond as shown in FIG. 3 may be trimmed along a trim line 30 as shown in FIG. 4 . Typically, any trimming step will be part of the manufacturing process, performed after the permanent bond is created but before the dental sensor holder is delivered to a dentist for use. In addition, the top edges of the permanent bond region may be rounded as shown in FIG. 2 and FIGS. 5-6 to enhance patient comfort through the elimination of potentially irritating corners.
[0025] The dental sensor holder 10 is provided to a dentist or dental technician in the substantially flattened and pre-looped configuration of FIGS. 2 and 4 . In use, as shown in the FIGS. 5-6 , the sensor holder is first opened into a loop away from the adjustable bond. Typically the sensor will have previously been placed into a sterile sleeve. The sensor and sleeve may then be inserted into the loop over the perforated fold line 28 if the dental sensor holder includes a perforated fold line. The adjustable bond 22 may be centered on the sensor body as shown in FIG. 6 . The operator may than firmly pinch across the adjustable bond joining the portions of the adjustable bond into a bitewing and simultaneously securing the sensor.
[0026] As described above, the dental sensor holder is fabricated in part from a longitudinally elastic material. Thus, when the bitewing tab is formed as shown on FIG. 6 , the loop may be made to stretch slightly around the sensor thus gently but securely holding the sensor.
[0027] The dental sensor holder and sensor included therein may then be placed into a patient's mouth in the conventional manner, the patient may be asked to bite down on the bitewing tab portion of the holder and a dental image may be obtained. As described above, the relatively soft strip material which covers all portions of the adjustable bond, in conjunction with the doubled strip thickness at the permanent bond provides an extremely smooth and comfortable biting surface for the patient which will not irritate adjacent cheek or tongue tissue.
[0028] After an image is obtained, the technician may safely remove the sensor by separating the adjustable bond at the base of the bitewing. In this manner the sensor may be removed without pulling on the data cable or otherwise applying undesirable stress to the delectate sensor apparatus.
[0029] As described above, a particular size of dental sensor holder 10 may accommodate various sensors having slightly different circumferences through the elasticity of the strip material and the ability to selectively engage some or the entire adjustable bond. The dental sensor holder may be provided in various sizes however, which correspond to categories of sizes of standardized digital sensor or phosphor x-ray plates.
[0030] Various embodiments of the disclosure could also include permutations of the various elements recited in the claims as if each dependent claim was a multiple dependent claim incorporating the limitations of each of the preceding dependent claims as well as the independent claims. Such permutations are expressly within the scope of this disclosure.
[0031] While the embodiments have been particularly shown and described with reference to a number of embodiments, it would be understood by those skilled in the art that changes in the form and details may be made to the various embodiments disclosed herein without departing from the spirit and scope of the invention and that the various embodiments disclosed herein are not intended to act as limitations on the scope of the claims. All references cited herein are incorporated in their entirety by reference.
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A dental sensor holder including a strip of pliable, longitudinally elastic material having two ends. The holder is constructed by permanently bonding the two ends of the strip to form a somewhat elastic loop. In addition, the sensor holder includes an adjustable bond portion on the inside of the loop which may selectively be engaged to join adjacent portions of the strip into a functional bitewing.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a motor drive control device, and more particularly to a motor drive control device in which a motor is driven in accordance with a designation to raise and lower a raised/lowered member so that the raised/lowered member is raised and lowered.
2. Description of the Related Art
Conventionally, a motor drive control device is applied to, for example, a power window control device provided at the door of a vehicle. If the motor drive control device is applied to the power window control device in this way, a motor is used, and in accordance with the operations of a switch which designates raising and lowering of a door glass, the motor is driven so as to raise and lower the door glass. Further, in order to detect catching of a foreign object between the door glass and a window frame or the like, a pulse encoder, which synchronizes with the rotation of the motor and generates a pulse signal, is provided at the power window control device.
By calculating the amount of variation in the cycle of the pulse signal generated by the pulse encoder and by determining whether the calculated amount of variation is greater than a threshold value, a determination is made as to whether a foreign object has been caught between the door glass and the window frame. If it is determined that the foreign object has been caught therebetween, the motor is driven reversely (the door glass is lowered) by a certain amount and then stopped.
Incidentally, in order to be able to determine precisely whether the catching of a foreign object has occurred, it is assumed that a pulse signal synchronized with the rotation of the motor is generated by the pulse encoder. In the power window control device, it is not determined whether failure of the pulse encoder has occurred.
As a result, in a case in which the pulse encoder has failed and a pulse signal which is not synchronized with the rotation of the motor is generated, or in a case in which the pulse signal is not generated even if the motor rotates, a user cannot tell whether these cases are caused by the failure of the pulse encoder or by the catching of the foreign object.
Accordingly, even if the failure of the pulse encoder has occurred and a designation to raise the door glass is made, since it is not determined that the pulse encoder has failed, the operation of the door glass cannot be differentiated from the ordinary raising operation thereof.
SUMMARY OF THE INVENTION
With the aforementioned in view, an object of the present invention is to provide a motor drive control device in which when a designation to raise a raised/lowered member is made in a state in which generating means, which generates a pulse signal synchronized with the rotation of a motor, has failed, the raised/lowered member does not carry out an ordinary rising operation.
In order to achieve the above-described purpose, the first aspect is a motor drive control device, comprising: a motor which raises and lowers a raised/lowered member; designating means which designates that said raised/lowered member is raised and lowered by said motor; generating means which synchronizes with the rotation of said motor and generates a pulse signal; determining means which, in a case in which there is a predetermined difference between said pulse signal and a normal pulse signal which is generated by synchronizing with the rotation of said motor, determines that said generating means is failed; and control means which, in a case in which said determining means determines that said generating means is failed and said designating means designates that said raised/lowered member is raised, controls said motor so that the operation of said raised/lowered member is different from an ordinary raising and lowering operation.
The second aspect is a motor drive control device according to the first aspect, wherein in at least one of a case in which the pulse signal generated by said generating means is not synchronized with said normal pulse signal and a case in which the pulse signal is not generated by said generating means, said determining means is structured so as to determine that said predetermined difference exists.
The third aspect is a motor drive control device according to the second aspect, wherein in a case in which the state of the pulse signal generated by said generating means is not reversed when the state of said normal pulse signal is reversed, said determining means is structured so as to determine that said pulse signal is not synchronized with said normal pulse signal.
The fourth aspect is a motor drive control device according to the third aspect, wherein in a case in which the pulse width of the pulse signal generated by said generating means is longer than the pulse width of said normal pulse signal, said determining means is structured so as to determine that the state of the pulse signal generated by said generating means is not reversed when the state of said normal pulse signal is reversed.
The fifth aspect is a motor drive control device according to the second aspect, wherein in a case in which the pulse width of the pulse signal generated by said generating means is shorter than the pulse width of said normal pulse signal, said determining means is structured so as to determine that said pulse signal is not synchronized with said normal pulse signal.
The sixth aspect is a motor drive control device according to the fifth aspect, wherein said determining means obtains said pulse width by calculating time determined on the basis of at least one of raising and lowering of said pulse signal, and said determining means obtains said pulse width by eliminating said time which is shorter than a predetermined time, and thereafter, said determining means is structured so as to determine whether the pulse width of the pulse signal generated by said generating means is shorter the pulse width of said normal pulse signal.
The seventh aspect is a motor drive control device according to the second aspect, wherein said determining means controls said motor so that the motor which has been driven in accordance with said designation is driven reciprocally to said designation, and in a case in which the state of said pulse signal at the time of control is not changed from the state of the pulse signal before the time of control, said determining means is structured so as to determine that the pulse signal generated by said generating means is not synchronized with said normal pulse signal.
The eighth aspect is a motor drive control device according to the second aspect, wherein when said motor is driven, said determining means is structured so as to determine whether said pulse signal is generated.
The ninth aspect is a motor drive control device according to any one of the first through eighth aspects, wherein said generating means is structured by a plurality of pulse signal generating means which generate pulse signals which are synchronized with the rotation of said motor and have the same cycles and deviated phases.
The tenth aspect is a motor drive control device according to the ninth aspect, wherein in a case in which, among the plurality of pulse signals generated by said plurality of pulse signal generating means, the cycle of a pulse signal is different from the cycle of said normal pulse signal, said determining means is structured so as to determine that said predetermined difference exists.
The eleventh aspect is a motor drive control device according to the ninth aspect, wherein in a case in which a pulse signal is not generated by at least one of said plurality of pulse signal generating means, said determining means is structured so as to determine that said predetermined difference exists.
The twelfth aspect is a motor drive control device according to any one of the first through eleventh aspects, wherein said control means is structured so as to control said motor, so that raising of said raised/lowered member is stopped in a time shorter than the time in which said raised/lowered member is designated to raise by said designating means.
Here, the motor relating to the above-described first aspect raises and lowers the raised/lowered member. A designation is made by the designating means so that the raised/lowered member is raised and lowered by the motor. The pulse signal which synchronizes with the rotation of the motor is generated by the generating means.
In a case in which there is a predetermined difference between the pulse signal and the normal pulse signal which is generated by synchronizing with the rotation of the motor, the determining means determines that the generating means is failed.
In a case in which the determining means determines that the generating means is not failed, the control means controls the motor so that the raised/lowered member effects the normal raising and lowering operation in accordance with the above-described designation made by the designating means. In the ordinary raising and lowering operation, for example, in a case in which a designation to raise the raised/lowered member is made by the designating means, the motor is controlled so that the raised/lowered member is raised until a designation to stop the raised/lowered member is made. In a case in which a designation to lower the raised/lowered member is made by the designating means, the motor is controlled so that the raised/lowered member is lowered until the designation to stop the raised/lowered member is made. When the raised/lowered member is placed at a predetermined position and a designation is not made by the designating means, the designation to stop the raised/lowered member is made. Raising and lowering of the raised/lowered member is thereby stopped.
On the other hand, in a case in which it is determined by the determining means that the generating means is failed and the designation to raise the raised/lowered member is made by the designating means, the control means controls the motor so that the operation of the raised/lowered member is different from the ordinary raising and lowering operation thereof.
As an operation of the raised/lowered member which is different from the ordinary raising and lowering operation, for example, as described in the twelfth aspect, raising of the raised/lowered member may be stopped in a time shorter than the time in which a designation to raise the raised/lowered member is made by the designating means. In this way, in a case in which it is determined by the determining means that the generating means is failed and a designation to raise the raised/lowered member is made by the designating means, if raising of the raised/lowered member is stopped in a time shorter than the time in which a designation to raise the raised/lowered member is made by the designating means, the motor is not continuously driven. Accordingly, even if catching of a foreign object occurs, the load cannot be continuously imparted at the foreign object. In addition, in the operation of the raised/lowered member which is different from the ordinary raising and lowering operation, even if a designation to raise the raised/lowered member is made by the designating means, it is possible that the raised/lowered member is not raised. Also, by intermittently raising the raised/lowered member, the raised/lowered member may be raised at a speed smaller than the normal raising speed.
In a case in which there is a predetermined difference between the pulse signal and the normal pulse signal which is generated by synchronizing with the rotation of the motor, it is determined that the generating means is failed. Accordingly, in a case in which it is determined that the generating means is failed and the designation to raise the raised/lowered member is made by the designating means, the operation of the raised/lowered member can be differentiated from the ordinary raising and lowering operation thereof
For example, as described in the second aspect, in at least one of the case in which the pulse signal generated by the generating means is not synchronized with the normal pulse signal (a first state) and the case in which the pulse signal is not generated by the generating means (a second state), the determining means determines that the above-described predetermined difference exists.
When the first state occurs, for example, the state of the pulse signal generated by the generating means may not be reversed when the state of the normal pulse signal is reversed. As described in the above-described third aspect, if the state of the pulse signal generated by the generating means is not reversed when the state of the normal pulse signal is reversed, i.e., so-called lack of pulse occurs, it may be determined that the pulse signal generated by the generating means is not synchronized with the normal pulse signal.
Further, if the state of the pulse signal generated by the generating means is not reversed when the state of the normal pulse signal is reversed, the pulse width of the pulse signal generated by the generating means is longer than the pulse width of the normal pulse signal. Consequently, as described in the fourth aspect, in a case in which it is determined that the pulse width of the pulse signal generated by the generating means is longer than the pulse width of the normal pulse signal, it may be determined that the state of the pulse signal generated by the generating means is not reversed when the state of the normal pulse signal is reversed.
In a case in which the first state occurs, for example, the pulse width of the pulse signal generated by the generating means may be shorter than the pulse width of the normal pulse signal. As described in the fifth aspect, in a case in which the pulse width of the pulse signal generated by the generating means is shorter than the pulse width of the normal pulse signal, i.e., so-called chattering occurs, it may be determined that the pulse signal is not synchronized with the normal pulse signal.
The above-described pulse width can be obtained by calculating the time determined on the basis of at least one of raising and lowering of the pulse signal. The time determined on the basis of raising or lowering of the pulse signal is one cycle of the pulse signal, and the time determined on the basis of raising and lowering of the pulse signal is a half cycle of the pulse signal.
In this way, when the above-described pulse width is obtained by calculating the time determined on the basis of at least one of raising and lowering of the pulse signal, for example, due to the vibrations or the like of the motor drive control device, raising and lowering of the pulse signal may occur even if the generating means is not failed. As a result, it may be mistakenly determined that the generating means is failed. Therefore, as described in the sixth aspect, the pulse width is obtained by eliminating the time which is shorter than the predetermined time, i.e., the time corresponding to the pulse width in which, even if raising and lowering occurs, it can be determined that the generating means is not failed. Thereafter, it may be determined as to whether the pulse width of the pulse signal generated by the generating means is shorter than the pulse width of the normal pulse signal.
Further, when the first state occurs, in a case in which the motor which has been driven in accordance with the above-described designation of the designating means is driven reciprocally to the designation, the state of the pulse signal is not changed from the state of the pulse signal when the motor has been driven in accordance with the above-described designation, i.e., so-called non-change in the state of the pulse signal may occur. Accordingly, as described in the seventh aspect, the motor is controlled so that the motor, which has been driven in accordance with the above-described designation of the designating means, is driven reciprocally to the designation. At the same time, in a case in which the state of the pulse signal at the time of control is not changed from the state thereof before the time of control, it may be determined that the pulse signal generated by the generating means is not synchronized with the normal pulse signal.
On the other hand, when the second state occurs, the pulse signal may not occur at the time of driving of the motor, i.e., non-generation of the pulse signal may occur. Thus, as described in the eighth aspect, when the motor is driven, a determination may be made as to whether the pulse signal is generated. In a case in which motor current flows and motor voltage is greater than or equal to the voltage at which the motor is driven regardless of the environmental condition (e.g., the state of -30° C.), it may be determined that the motor is driven, i.e., the time at which the motor is driven.
The generating means relating to the invention described above may be structured by one pulse signal generating means which synchronizes with the rotation of the motor and generates a pulse signal. As described in the ninth aspect, the generating means may be structured by a plurality of pulse signal generating means which generate pulse signals which are synchronized with the rotation of the motor and have the same cycles and deviated phases.
In a case in which the generating means is structured by the plurality of pulse signal generating means in this way, on the basis of the pulse signal from at least one of the plurality of pulse signal generating means, one of the aforementioned lack of pulse, chattering, non-change in the state of pulse signal and non-generation of the pulse signal may be determined.
As described in the tenth aspect, in a case in which, among the plurality of pulse signals generated by the plurality of pulse signal generating means, the cycle of a pulse signal is different from the cycle of the normal pulse signal, i.e., lack of pulse occurs, the determining means may determine that a predetermined difference exists. Further, as described in the eleventh aspect, in a case in which the pulse signal is not generated by at least one of the plurality of pulse signal generating means, i.e., non-generation of the pulse signal occurs, the determining means may determine that a predetermined difference exists.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view which shows the inner structure of a driver's side door relating to a first embodiment of the present invention.
FIG. 2 is a circuit diagram of a motor drive control device relating to the first embodiment.
FIG. 3 is a flowchart which illustrates a failure detection processing routine relating to the first embodiment.
FIG. 4 is a flowchart which illustrates a count up processing routine for a count value T.
FIG. 5 is a flowchart which illustrates a main routine.
FIG. 6 is a circuit diagram of a motor drive control device relating to a second embodiment.
FIG. 7 is a flowchart which illustrates a failure detection processing routine relating to the second embodiment.
FIG. 8 is a circuit diagram of a motor drive control device relating to a third embodiment.
FIG. 9 is a flowchart which illustrates a failure detection processing routine relating to the third embodiment.
FIG. 10 is a flowchart which illustrates a failure detection processing routine relating to the fourth embodiment.
FIG. 11 is a flowchart which illustrates a portion of a failure detection processing routine relating to the fifth embodiment.
FIG. 12 is a flowchart which illustrates a remaining portion of a failure detection processing routine relating to the fifth embodiment.
FIG. 13 is a flowchart which illustrates a failure detection processing routine relating to the sixth embodiment.
FIG. 14A is a diagram which shows a difference between a pulse signal of the first embodiment and a normal pulse signal.
FIG. 14B is a diagram which shows a difference between a pulse signal of the third embodiment and a normal pulse signal.
FIG. 15A is a diagram which shows, in a case in which a designation to raise a door glass is made, the state of a pulse signal outputted from a two-pulsed pulse encoder.
FIG. 15B is a diagram which shows, in a case in which a designation to lower the door glass is made, the state of a pulse signal outputted from the two-pulsed pulse encoder.
FIG. 16 is a diagram which shows a relationship between a time in which a switch, which raises the door glass, is turned on and a time in which a motor is raised(operated).
FIG. 17A is a plan view which shows the structure of the pulse encoder.
FIG. 17B is a cross sectional view, taken along line I--I, of the pulse encoder shown in FIG. 17A.
FIG. 18 is a diagram which shows the structure of another pulse encoder.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be described hereinafter in detail with reference to the drawings. As illustrated in FIG. 1, a motor drive control device of the first embodiment includes a motor 22. A window regulator portion 16 is connected to the motor 22. In the first embodiment, the window regulator portion 16 is a so-called wire type and a wire is trained around a rotating plate 22A which is mounted to a driving shaft of the motor 22. The end portion of the wire is connected to a retaining channel member 24 which supports the lower end portion of a door glass 20. Further, the retaining channel member 24 is mounted to a main guide 26 so that the retaining channel member 24 is able to move vertically. As a result, when the motor 22 rotates in the reciprocal direction, the rotational driving force thereof is transmitted to the retaining channel member 24 and the door glass 20 vertically moves along a glass guide 18. The structure of the window regulator portion 16 is not limited to such wire type, and an X-arm type or a so-called motor mobile type in which the motor itself moves along a rack may be used.
When the door glass 20 is raised by the motor 22, the peripheral end portion of the door glass 20 is fit with a rubber-made weather strip (unillustrated) within a frame 12A of a door 12 so as to close the opening of the door frame 12A. Moreover, since the motor 22 is driven to rotate, when the door glass 20 is lowered, the opening of the frame 12A of the door 12 is opened.
On the other hand, the motor 22 is operated by an auto/manual switch 34. For example, an auto/manual switch in which two stage operations are possible in both directions can be applied to the auto/manual switch 34. At one-stage operation, the motor 22 of the door 12 is driven only during the operation (manual operation). At two-stage operation, even if a user releases his/her hand from the switch, the motor 22 is driven until the door glass 20 reaches a predetermined position (until a raising or lowering lock stop occurs) (automatic operation). Moreover, the motor 22 rotates the rotating plate 22A in any of the reciprocal directions so as to be able to raise or lower the door glass 20.
As shown in FIG. 2, the motor drive control device 10 includes a power window control portion 50 for controlling the driving of the motor 22 due to the operation of the auto/manual switch 34. The power window control portion 50 is formed by one chip of microcomputer. The microcomputer is formed by including an unillustrated CPU, ROM, RAM, input/output port, analog-digital (A/D) converter and E 2 P ROM, and these are connected to each other by buses. A moving average, which will be described later, is stored in the E 2 P ROM.
The motor drive control device 10 is connected to a plus terminal of a battery 60. A minus terminal of the battery 60 is grounded.
Signal lines 52 from switches of the auto/manual switch 34 are connected to the power window control portion 50.
The ends of a first relay coil 110 and a second relay coil 112 for opening and closing the door glass are connected to the power window control portion 50. In accordance with the operations of the auto/manual switch 34, the power window control portion 50 energizes any of the relay coils 110, 112.
A first relay switch 108 is disposed at the position corresponding to the first relay coil 110. A common terminal 108A of the first relay switch 108 is connected to one end of the motor 22. Further, a first contact point 108B is connected to the plus side terminal of the battery 60, and a second contact point 108C is grounded. In a case in which the first relay coil 110 is not energized, the first relay switch 108 switches the first contact point 108B to the second contact point 108C.
On the other hand, a second relay switch 109 is disposed at the position corresponding to the second relay coil 112. A common terminal 109A of the second relay switch 109 is connected to the other end of the motor 22. Further, a first contact point 109B is connected to the plus side terminal of the battery 60, and a second contact point 109C is grounded. In a case in which the second relay coil 112 is not energized, the second relay switch 109 switches the first contact point 109B to the second contact point 109C.
When the first relay coil 110 is energized, the first relay switch 108 switches the second contact point 108C to the first contact point 108B and electric current flows from one end of the motor 22 to the other end thereof. Then, the motor 22 rotates normally and the door glass moves in the closing direction. When the second relay coil 112 is energized, the second relay switch 109 switches the second contact point 109C to the first contact point 109B and electric current flows from the other end of the motor 22 to one end thereof. Then, the motor 22 rotates reversely and the door glass moves in the opening direction.
Further, a pulse encoder 62 is mounted to the motor 22. As illustrated in FIG. 17A, the pulse encoder 62 includes a rotating plate 62A which rotates around a shaft 62G in accordance with the rotation of a motor shaft 22G of the motor 22. A plurality of magnets are disposed on a concentric circle 62NS 1 (shown by a solid line) which centers around the shaft 62G so that a plurality of south poles 62S and north poles 62N are arranged alternately. As illustrated in FIG. 17B which shows the cross sectional view, taken along line I--I, of the pulse encoder in FIG. 17A, a sensor 62K 1 (shown by a solid line), which is connected to the power window control portion 50 and detects a line of magnetic force formed by a Hall element or the like, is disposed at the position corresponding to the concentric circle 62NS 1 . Accordingly, when the sensor 62K 1 detects the line of magnetic force, the detection signal is inputted to the power window control device 50 via a signal line 64. As a result, in the power window control portion 50, the rotational speed of the motor 22 can be obtained on the basis of the pulse signal outputted from the pulse encoder 62. Additionally, by counting the pulse signal from the pulse encoder 62, the approximate position of the door glass 20 can be determined.
Next, the failure detection processing routine of the pulse encoder 62 will be explained with reference to FIG. 3. In the first embodiment, if there is a difference between the pulse signal outputted from the pulse encoder 62 and the normal pulse signal due to the occurrence of lack of pulse, it is determined that the pulse encoder 62 fails. In a state in which a designation to lower the door glass 20 is made due to the operation of the auto/manual switch 34, and when the pulse signal generated by the pulse encoder 62 is raised and lowered, the present routine starts by interrupting a main routine (see FIG. 5), which will be described later. In step 36, a determination is made as to whether a timer count value T, which has been counted as described hereinafter, is greater than or equal to 2·t 0 .
Wherein, t 0 is a moving average of pulse widths (a pulse width is the time in which the pulse signal is raised and lowered). In the first embodiment, the moving average t 0 of the pulse widths is calculated by a routine which is different from the present routine. Namely, the pulse widths are calculated and the moving average of 16 pulse widths (the number of pulse width is not limited to 16) is stored as t 0 .
Unless T≧2·t 0 , in step 38, the timer count value T and a flag F are reset. If T≧2·t 0 , in step 40, the flag F is set to 1 and the timer count value T is reset.
As shown in FIG. 14A, in a case in which the pulse encoder 62 is not failed, pulse signals (normal pulse signals) P 1 , P 2' , P 3' , P 4 . . . which are synchronized with the rotation of the motor 22 are outputted. In this case, t 0 is a moving average of a time between raising P 1U and lowering P 1D , a time between lowering P 1D and raising P 2U , a time between raising P 2U and lowering P 2D' , a time between lowering P 2D' , and raising P 3U' , . . . . In this way, if the pulse signal (normal pulse signal) is synchronized with the rotation of the motor 22 and generated correctly, the timer count value T corresponds to the pulse width. Thus, the timer count value T is not more than or equal to 2·t 0 .
However, in a case in which dust or the like is attached to a magnetic pole such as a north pole 62N or a south pole 62S, the sensor 62K 1 cannot detect a line of magnetic force from the magnetic pole to which the dust or the like is attached. When the states of pulse signals (normal pulse signals) P 2' , P 3' , which are expected to generate, are reversed, the states of pulse signals are not reversed, i.e., so-called lack of pulse occurs. Namely, the pulse signal P 2' is not lowered and the pulse signal P 3' is not raised. If the state of the pulse signal is not reversed, the present routine does not start, and count-up continues without resetting the timer count value T to 0. As a result, the timer count value T is substantially 3·t 0 .
Consequently, by judging whether the timer count value T is greater than or equal 2·t 0 , it can be determined as to whether the states of the pulse signals P 2' , P 3' , which are expected to generate, are reversed.
Next, a count up processing routine of the timer count value T will be explained with reference to FIG. 4. In a state in which a designation to lower the door glass 20 is made due to the operation of the auto/manual switch 34, the present routine starts every time an unillustrated pulse, which is oscillated every predetermined time, is inputted. In step 42, the timer count value T is incremented by one, and then the present routine ends.
The failure detection processing routine of the pulse encoder (FIG. 3) and the count up processing routine of the timer count value T (FIG. 4) start when the designation to lower the door glass 20 is made. If these routines are carried out while the door glass 20 is raised, in a case in which there is catching of a foreign object, the pulse width of the pulse signal becomes longer and the timer count value T is greater than or equal to 2·t 0 . Therefore, a user cannot tell whether it is caused by the failure of the pulse encoder 62 or catching of the foreign object.
Next, a door glass raising/lowering routine (main routine) which is effected when the auto/manual switch 34 is turned on will be explained with reference to FIG. 5. In the first embodiment, catching of a foreign object is detected only when the door glass 20 is automatically raised by the auto/manual switch 34.
In step 66, on the basis of the signal from the auto/manual switch 34, a determination is made as to whether a designation to raise the door glass 20 (wherein, automatic operation) is inputted. If the designation to raise the door glass 20 is inputted, in step 68, a determination is made as to whether the flag F is reset. Accordingly, it is determined whether the failure has occurred to the pulse encoder 62. If the answer to the determination in step 68 is "No", i.e., if the designation to lower the door glass 20 is made or if the designation to raise the door glass is made due to the manual operation, in step 76, the other processings, i.e., ordinary lowering process of the door glass 20 based on the signal from the auto/manual switch 34, and raising process of the door glass (wherein, manual operation) are effected.
In a case in which the flag F is reset, the failure has not occurred to the pulse encoder 62. Thus, in step 70, the door glass 20 is raised. In step 72, the process waits until a designation to stop raising of the door glass 20 is made. Namely, if the manual operation is effected and the present routine has started, the process waits until the operation of the auto/manual switch 34 is finished. On the other hand, if the automatic operation is effected and the present routine has started, the process waits until the raising lock stop occurs. If the designation to stop the raising of the door glass 20 is made in this way, in step 74, the raising of the door glass 20 is stopped. Then, the present routine ends.
On the other hand, if the flag F is set to 1, the failure has occurred to the pulse encoder 62. Accordingly, the present routine ends. As a result, if the designation to raise the door glass 20 is inputted in a state in which the failure has occurred to the pulse encoder 62, the door glass 20 is not raised, i.e., the operation which is different from the ordinary operation can be effected.
Thus, if the timer count value T is greater than twice the value of the moving average to of the pulse widths, the flag F is set to 1 as the failure has occurred to the pulse encoder 62. In this state, if the designation to raise the door glass 20 is inputted, the door glass 20 is not raised. Accordingly, even if the designation to lower the door glass 20 is not inputted, the motor cannot be driven continuously. As a result, even if the foreign object is positioned between the door glass 20 and the door frame 12A, the door glass 20 is not raised. Therefore, load is not continuously imparted at the foreign object.
Next, a second embodiment of the present invention will be explained. Because the structure of the second embodiment is substantially similar to that of the aforementioned first embodiment, members which are the same are denoted by the same reference numerals, and descriptions thereof are omitted. Only members which are different from those of the first embodiment are explained.
As illustrated in FIG. 6, means for detecting motor current is connected to a power window control portion 50 of the second embodiment. Namely, a second contact point 108C of a relay switch 108 and a second contact point 109C of a relay switch 109 are grounded via a shunt resistor 120 having a minute value of resistance (approximately 10 mΩ).
A signal line 122 is branched off from the high electric potential side of the shunt resistor 120. The signal line 122 is connected to a non-reversal input terminal 130A of an operational amplifier 132 via resistors 124, 128. One end of an electrolytic capacitor 126 is grounded, and the other end thereof is connected to a line between the resistors 124 and 128 so as to form a filter. A reversal input terminal 130B of the operational amplifier 132 is grounded via a resistor 134. An output terminal 130C of the operational amplifier 132 is connected to the reversal input terminal 130B via a feedback resistor 136 so as to form an amplifying circuit.
Further, the output terminal 130C of the operational amplifier 132 is connected to an A/D converter of the power window control portion 50, such that the power window control portion 50 can detect a motor current value.
Also, means for detecting motor voltage is connected to the power window control portion 50 of the second embodiment. Namely, one end of a line 30 is connected to the line between a first contact point 108B and a plus side terminal of a battery 60, and the other end thereof is connected to the aforementioned analog digital (A/D) converter of the power window control portion 50. Accordingly, the power window control portion 50 can detect voltage (so-called motor voltage) applied to the motor 22.
Further, a limit switch 54, which outputs a signal to the power window control portion 50 when the door glass 20 is placed in the vicinity of a fully-closed position, is connected to the power window control portion 50 of the second embodiment.
Next, the operation of the second embodiment will be explained. In the second embodiment, because a failure detection processing routine of a pulse encoder 62 is different from that of the first embodiment, the failure detection processing routine will be explained hereinafter with reference to FIG. 7. In the second embodiment, in a case there is a difference between a pulse signal from the pulse encoder 62 and a normal pulse signal due to the occurrence of non-generation of the pulse signal, it is determined that the pulse encoder 62 is failed.
The present routine starts at every predetermined time and when the auto/manual switch 34 to lower the door glass 20 is turned on. In step 78, a determination is made as to whether a signal is outputted from the limit switch 54, i.e., whether the door glass 20 is in the vicinity of a fully-closed position. As a result, when the switch to lower the door glass 20 is turned on after the raising lock stop of the door glass 20 occurs, it can be determined as to whether the present routine has started. If the answer to the determination in step 78 is "No", the present routine ends. If the answer to the determination in step 78 is "Yes", in step 80, a determination is made as to whether motor current is flowing. If the answer to the determination in step 80 is "No", the present routine ends. If the answer to the determination in step 80 is "Yes", in step 82, a determination is made as to whether the motor voltage V m is greater than or equal to V 0 . Wherein, V 0 is a motor voltage at which the motor 22 drives in a case of, for example, -30° C. If the answer to the determination in step 82 is "No", the present routine ends. If the answer to the determination in step 82 is "Yes", the process proceeds to step 84.
If the process goes to step 84 in this way, the motor 22 is driven, i.e., it can be determined correctly as to whether the pulse encoder 62 is failed. Namely, if the motor current flows, it can be determined that the motor 22 is connected to the battery 60. Moreover, if the motor voltage V m is greater than or equal to V 0 , it can be determined that the motor 22 is reliably driven regardless of the environmental condition.
In step 84, a determination is made as to whether the pulse signal has not been detected within a predetermined time in which raising and lowering of the pulse signal can be detected. If the answer to the determination in step 84 is "Yes", it can be determined that, even though the motor 22 is driven, the pulse signal is not outputted from the pulse encoder 62 (non-generation of the pulse signal). Namely, because it can be determined that the failure has occurred to the pulse encoder 62, in step 86, a flag F is set to 1. Thereafter, the present routine ends.
As mentioned before, in order to determine the failure of the pulse encoder 62, it is assumed that the door glass 20 is in the vicinity of the fully-closed position. The present routine starts when the switch to lower the door glass 20 is turned on, and as previously mentioned, it is determined as to whether the pulse signal is not detected. Therefore, it is necessary to differentiate the case in which the door glass 20 is lowered, the lowering lock stop occurs and the pulse signal is not outputted from the pulse encoder 62 from the case in which a failure has occurred to the pulse encoder 62 and the pulse signal is not outputted. The present invention is not limited to this. Instead of step 78, it may be determined as to whether the door glass 20 is lowered further than the position at which the lowering lock stop does not occur during the performance of the present routine.
Further, since the present routine starts when the switch to lower the door glass 20 is turned on, it is necessary to differentiate the case in which the switch to raise the door glass 20 is turned on, the door glass 20 is raised, a foreign object is caught and the pulse signal is not outputted from the pulse encoder 62 from the case in which the failure has occurred to the pulse encoder 62 and the pulse signal is not outputted therefrom.
Next, the third embodiment of the present invention will be explained. Because the structure of the third embodiment is substantially similar to that of the aforementioned first embodiment, members which are the same are denoted by the same reference numerals, and descriptions thereof are omitted. Only members which are different from those of the first embodiment are explained.
As illustrated in FIG. 8, one end of a capacitor 46 is connected to the line between a pulse encoder 62 and a power window control portion 50, and the other end thereof is grounded. Due to the capacitor 46, high frequency component, which will be described later, of the pulse signal outputted from the pulse encoder 62 is removed.
Next, the operation of the third embodiment will be explained. In the third embodiment, since a failure detection processing routine of the pulse encoder 62 is different from that of the first embodiment, the failure detection processing routine will be explained hereinafter with reference to FIG. 9. Because the failure detection processing routine (see FIG. 9) of the third embodiment is partially the same as the failure detection processing routine (see FIG. 3) of the first embodiment, portions which are the same are denoted by the same reference numerals and descriptions thereof are omitted. Only the portions which are different from those of the first embodiment are explained. In the third embodiment, in a case in which there is a difference between the pulse signal from the pulse encoder 62 and the normal pulse signal due to the occurrence of chattering, it is determined that the pulse encoder 62 has failed.
In a state in which a designation to lower a door glass 20 is made by an auto/manual switch 34, the present routine (see FIG. 9) starts at every predetermined time and every time raising and lowering of the pulse signal outputted from the pulse encoder 62 is detected. In step 88, a determination is made as to whether a count value T is smaller than t 0 /2.
As shown in FIG. 14B, in a case in which the pulse encoder 62 is not failed, pulse signals (normal pulse signals) P 5 , P 6' , P 7 , P 8 . . . which are synchronized with the rotation of the motor 22 are outputted. If the pulse signal (normal pulse signal) is generated so as to be properly synchronized with the rotation of the motor 22 in this way, the timer count value T is not smaller than t 0 /2.
However, in a case in which dust or the like is attached to a magnetic pole such as a north pole 62N or a south pole 62S, the sensor 62K 1 cannot detect a line of magnetic force from the magnetic pole to which the dust or the like is attached. For example, while the pulse signal P 6' , which is to expected to generate, is high, lowering P 6D' and raising P 6U' , occur, such that so-called chattering generates. When the so-called chattering generates in this way, there is a case in which raising and lowering of the pulse signal is detected, the present routine starts, and the timer count value T determined in step 88 is smaller than t 0 /2. Consequently, by determining as to whether the timer count value T is smaller than t 0 /2, it can be determined that the chattering has occurred.
In a case in which chattering has occurred in this way, it can be determined that the pulse encoder 62 is failed, and the process proceeds to step 40. In a case in which chattering has not occurred, it can be determined that the pulse encoder 62 is not failed, and the process proceeds to step 38.
As shown in the state of the pulse signal P 5 in FIG. 14B, there is a case in which minute chattering occurs due to vibrations or the like of the motor drive control device 10 and lowering P 5D' and raising P 5U' are outputted at high frequency. However, the high frequency component is removed by the aforementioned capacitor 46. The capacitor 46 may be omitted by ignoring the pulse width in which the timer count value T is permitted (e.g., time between the lowering P 5D' and raising P 5U' ) and by counting the pulse width (e.g., time between raising and lowering of the pulse signal P 5 ).
Next, the fourth embodiment of the present invention will be explained. Because the structure of the fourth embodiment is similar to that of the aforementioned first embodiment, members which are the same are denoted by the same reference numerals, and descriptions thereof are omitted.
Next, the operation of the fourth embodiment will be explained. In the fourth embodiment, since a failure detection processing routine of a pulse encoder 62 is different from that of the first embodiment, the failure detection processing routine will be explained hereinafter with reference to FIG. 10. In the fourth embodiment, in a case in which there is a difference between the pulse signal from the pulse encoder 62 and the normal pulse signal due to non-change in the pulse signals, it is determined that the pulse encoder 62 has failed.
The present routine starts when the lowering lock stop occurs. In step 186, a door glass is raised. In step 188, a determination is made as to whether the state of the pulse signal has changed from the state in which the door glass is lowered. At this time, if the failure has not occurred to the pulse encoder 62, the state of the pulse signal has changed from the state in which the door glass is lowered. In this case, it can be determined that the failure has not occurred to the pulse encoder 62. In step 192, raising of the door glass is stopped, and thereafter, the present routine ends. On the other hand, when the lowering lock stop occurs and then the door glass is raised, if the failure has occurred to the pulse encoder 62, the state of the pulse signal has not changed from the state in which the door glass is lowered. In this case (non-change in the state of pulse signal), in step 190, a flag F is set to 1. The process proceeds to step 192.
In the fourth embodiment, when the lowering lock stop occurs and then the door glass is raised, it is determined as to whether non-change in the pulse signal occurs. However, the present invention is not limited to this. Non-change in the pulse signal may be determined when the raising lock stop occurs and then the door glass is lowered. Alternatively, non-change in the pulse signal may be determined when the lowering lock stop occurs and then the door glass is raised and when the raising lock stop occurs and then the door glass is lowered.
Next, the fifth embodiment of the present invention will be explained. The structure of the fifth embodiment is substantially the same as that of the first embodiment. However, it is different in that a pulse encoder 62 is a two-pulsed encoder. Namely, a plurality of magnets are disposed on two concentric circles 62NS 1 and 62NS 2 , which center around a shaft 62G and have different radii, so that north poles 62N and south poles 62S are arranged alternately. As illustrated in FIG. 17B, sensors 62K 1 and 62K 2 , which are connected to a power window control portion 50 and detects a pole (north pole or south pole) formed by a Hall element or the like, are disposed at the positions corresponding to the north pole N and the south pole 62S of the concentric circle 62NS 1 and 62NS 2 .
As illustrated in FIG. 17A, the north poles 62N and the south poles 62S, which are arranged on the concentric circles 62NS 1 , 62NS 2 , deviate by a predetermined angle. As a result, the pulse signals, which are synchronized with the rotation of the motor 22 and have the same cycles and deviated phases, are outputted from the sensors 62K 1 and 62K 2 . As a result, in a case in which a designation to raise the door glass 20 is made by the auto/manual switch 34, a pulse signal A is outputted from the sensor 62K 1 and a pulse signal B is outputted from the sensor 62K 2 as shown in FIG. 15A. On the other hand, in a case in which a designation to lower the door glass 20 is made, the pulse signals A, B are outputted as shown in FIG. 15B. In a case in which the failure has not occurred to the pulse encoder 62, Table 1 shows states of the pulse signal B (normal pulse signal) at the time of raising and lowering of the door glass 20 when the pulse signal (normal pulse signal) A is raised and lowered. Table 2 shows states of the pulse signal A (normal pulse signal) at the time of raising and lowering of the door glass 20 when the pulse signal (normal pulse signal) B is raised and lowered. In Tables 1 and 2, "L" indicates that the pulse signal is low and "H" indicates that the pulse signal is high.
TABLE 1______________________________________ At the Time of At the Time Raising of the of Lowering of Pulse Signal A the Pulse Signal A______________________________________At the Time of Raising of L Hthe Door GlassAt the Time of Lowering H Lof the Door Glass______________________________________
TABLE 2______________________________________ At the Time of At the Time Raising of the of Lowering of Pulse Signal B the Pulse Signal B______________________________________At the Time of Raising of H Lthe Door GlassAt the time of Lowering L Hof the Door Glass______________________________________
Next, the operation of the fifth embodiment will be explained. In the fifth embodiment, since a failure detection processing routine of the pulse encoder 62 is different from that of the first embodiment, the failure detection processing routine will be explained hereinafter with reference to FIGS. 11 and 12. In the fifth embodiment, in a case in which there is a difference between a pulse signal from the pulse encoder 62 and a normal pulse signal due to the occurrence of lack of pulse, it is determined that the pulse encoder 62 fails.
When an auto/manual switch 34 is turned on, the present routine (see FIG. 11) starts every time the signal from the auto/manual switch 34 is inputted and at every predetermined time. In step 140, a determination is made as to whether the door glass is rising on the basis of the signal inputted from the auto/manual switch 34. When it is determined that the door glass is rising, in step 142, a determination is made as to whether the edge of the pulse signal A (rising or lowering of the pulse signal) is detected. When the edge of the pulse signal A is not detected, in step 144, a determination is made as to whether the edge of a pulse signal B is detected. When the edge of the pulse signal B is not detected, the present routine ends. Accordingly, the edge of the pulse signal A or B is detected.
When the edge of the pulse signal A has been detected (step 142; Y), in step 146, a determination is made as to whether the raising of the pulse signal A is detected. When the raising of the pulse signal A is detected, in step 148, a determination is made as to whether the pulse signal B is low ("L").
As illustrated in FIG. 15A and Table 1, when the raising of the pulse signal A has been detected during the raising of the door glass 20, unless the pulse encoder 62 has failed, the pulse signal B is low ("L"). In this case, the present routine ends. On the other hand, as illustrated by a dotted line in FIG. 15A, in a case in which so-called lack of pulse has occurred, when the raising of the pulse signal A is detected, the pulse signal B is high ("H"). In this case, it can be determined that the pulse encoder 62 has failed. The process proceeds to step 158 where the flag F is set to 1, and then the present routine ends.
Contrary to this, as illustrated in FIG. 15A and Table 1, when the lowering of the pulse signal A has been detected during the raising of the door glass 20 (step 146; N), unless the pulse encoder 62 has failed, the pulse signal B is high ("H"). In this case (step 150; Y), the present routine ends. On the other hand, in a case in which so-called lack of pulse has occurred, the lowering of the pulse signal A is detected and the pulse signal B is low ("L"), it can be determined that the failure has occurred to the pulse encoder 62. In this case, the process proceeds to step 158 where the flag F is set to 1, and then the present routine ends.
Further, when the edge of the pulse signal B has been detected (step 142; N), steps 144 through 156 are carried out. Steps 144 through 156 are processed in the same way as the aforementioned steps 146 through 150. Namely, in a case in which so-called lack of pulse has occurred, when the pulse signal A is low ("L") (step 154, N) at the time of raising of the pulse signal B, and as illustrated by a dotted line in FIG. 15A, when the pulse signal A is high ("H") (step 156; N) at the time of lowering of the pulse signal B, the process proceeds to step 158 where the flag F is set to 1. Thereafter, the present routine ends.
Moreover, in step 140, when it is determined that the door glass 20 is not rising and that the door glass 20 is lowering (step 160; Y), steps 162 through 176 shown in FIG. 12 are carried out. Steps 162 through 176 are substantially the same as the steps 142 through 156. Instead of the pulse signal A in steps 142 through 156, the pulse signal B is used to effect steps 162 through 176. Instead of the pulse signal B in steps 142 through 156, the pulse signal A is used to effect steps 162 through 176.
Next, the sixth embodiment of the present invention will be explained. The structure of the sixth embodiment is substantially the same as that of the aforementioned second embodiment, and the structure of the pulse encoder 62 is the same as that of the aforementioned fourth embodiment.
Next, the operation of the sixth embodiment will be explained. The operation of the sixth embodiment is substantially the same as that of the aforementioned second embodiment. Namely, since the portion of the failure detection processing routine of the sixth embodiment (see FIG. 13) is different from the failure detection processing routine shown in FIG. 7, members which are the same are denoted by the same reference numerals, and descriptions thereof are omitted. Only the portions which are different from the second embodiment are explained. In the sixth embodiment, in a case in which there is a difference between the pulse signal from the pulse encoder 62 and the normal pulse signal due to the occurrence of the non-generation of the pulse signal, it is determined that the pulse encoder 62 has failed.
Similarly to the failure detection processing routine in FIG. 7, the present routine (see FIG. 13) starts at every predetermined time and when the switch to lower the door glass 20 of auto/manual switches 34 is turned on. Then, steps 84, 78, 80, 82 are carried out in succession. In step 84, in a case in which the pulse signals A, B have not been detected within a predetermined time, the process proceeds to step 180 where a determination is made as to whether any one of pulse signals A, B has been detected. When any one of pulse signals A, B has been detected, it can be determined that the failure has occurred to the pulse encoder 62. In this case, the process goes to step 86. When the answer to the determination in step 180 is "No", it can be determined that the failure has not occurred to the pulse encoder 62. In this case, the present routine ends.
In the above-described first through sixth embodiments, the failure detection processing routine in accordance with each embodiment is effected. However, the present invention is not limited to the same. It may be determined that the pulse encoder is failed in a case in which at least one of lack of pulse, non-generation of the pulse signal, chattering, and non-change in the state of the pulse signal has occurred.
Namely, the motor drive control device 10 is structured as described in the aforementioned second embodiment (see FIG. 6), and includes the capacitor 46 (see FIG. 8) of the third embodiment. In a case in which at least one of lack of pulse (see FIG. 3), non-generation of the pulse signal (see FIG. 7), chattering (see FIG. 9) and non-change in the state of pulse signal (see FIG. 10) has occurred, it may be determined that the pulse encoder is failed. Moreover, the two-pulsed pulse encoder is formed, and in a case in which at least one of lack of pulse (see FIGS. 11 and 12) and non-generation of the pulse signal (see FIG. 13) has occurred, it may be determined that the pulse encoder is failed. Also, in a case in which at least one of the lack of pulse (see FIGS. 3, 11, 12), non-generation of the pulse signal (see FIGS. 7, 13), chattering (see FIG. 9) and non-change in the state of pulse signal (see FIG. 10) has occurred, it may be determined that the pulse encoder is failed.
Further, in the aforementioned first through sixth embodiments and a variant example, even if it is determined that the pulse encoder 62 is failed and a designation to raise the door glass 20 is inputted, the door glass 20 is not raised. However, the present invention is not limited to the same. When the door glass 20 is raised due to the auto operation and manual operation, catching of a foreign object is detected. At the same time, if the answer to the determination in step 68 is "No", as illustrated in FIG. 16, the door glass 20 may be raised during a time j which is shorter than the time J in which the automatic operation and manual operation to raise the door glass 20 are effected. Alternatively, the speed of raising the door glass 20 is slowed down during the time J in which the automatic operation and manual operation are effected.
Further, in the aforementioned first through sixth embodiments, the pulse encoder for detecting a pole is used. However, the present invention is not limited to this. A sliding type pulse encoder may be used which rotates in accordance with the rotation of a motor shaft and whose contact points abut a conductor and a non-conductor which are arranged alternately. Namely, as shown in FIG. 18, a rotating portion 210, which rotates so as to synchronize with the rotation of a motor shaft 22G, is included at the motor shaft 22G of the pulse encoder 62. A conductor portion 202 is formed at a half of the peripheral portion of the rotating portion 210 and a non-conductor portion 204 is formed at the other half of the peripheral portion thereof. A first pulse electrode terminal (sliding contact point) 206 and a second pulse electrode terminal (sliding contact point) 208 are provided at the rotating portion 210 so as to contact the conductor portion 202 and the non-conductor portion 204. A battery 60 is connected to the first pulse electrode terminal 206, and a power window control portion 50 is connected to the second pulse electrode terminal 208. Two first pulse electrode terminals 206 and two second pulse electrode terminals 208 may be provided to form a two-pulsed system. In this case, the conductor portion 202 and the non-conductor portion 204 which contact one of the first pulse electrode terminal 206 and of the second pulse electrode terminal 208, and the conductor portion 202 and the non-conductor portion 204 which contact the other of the first pulse electrode terminal 206 and of the second pulse electrode terminal 208 are arranged, so that both of them center around the motor shaft 22G and are deviated by a predetermined angle.
As described hereinbefore, in a case in which there is a predetermined difference between the pulse signal from the generating means and the normal pulse signal generated by synchronizing with the rotation of the motor, it is determined that the failure has occurred to the generating means. Therefore, in a case in which it is determined that the generating means is failed and a designation to raise the raised/lowered member is effected by the designating means, the present invention achieves a superior effect in that the operation of the raised/lowered member can be differentiated from the ordinary raising/lowering operation.
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A motor drive control device, comprises: a switch which operates a motor; a motor which raises and lowers a door glass; a pulse signal generating device which synchronizes with the rotation of the motor and generates a pulse signal; and a determining device which, in a case in which there is a predetermined difference between this pulse signal and a normal pulse signal which is generated by synchronizing with the rotation of said motor, determines that the pulse signal generating device is failed. Therefore, in a case in which it is determined that the pulse signal generating device is failed and the switch is operated so that the motor raises the door glass, raising of the door glass can be stopped.
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BACKGROUND OF THE INVENTION
Amine molybdates may be produced by reacting an amine with a molybdenum compound such as molybdenum trioxide (MoO 3 ), molybdic acid or a molybdenum salt in an acidic aqueous medium made acidic through the addition of a suitable acid such as an organic acid containing 1 to 12 carbon atoms (exemplified by acetic acid, propionic acid, benzoic acid, and the like) or an inorganic acid (exemplified by hydrochloric acid, nitric acid or sulfuric acid). The acidic mixture is refluxed, preferably while being stirred continuously, until the reaction is complete, usually for about 1/4 to 4 hours.
Amine molybdates also may be produced, as described in my copending allowed application Ser. No. 016,583, filed Mar. 1, 1979 and entitled "Process For Making Amine Molybdates" by reacting essentially stoichiometric quantities of molybdenum trioxide with an amine in an aqueous medium essentially free of acid and in which a water-soluble ammonium or monovalent metal or divalent metal or trivalent rare earth metal salt of an inorganic or organic acid is dissolved.
The particular amine molybdate formed may depend upon which process is used to form the amine molybdate and the quantity of reactants present in the reaction mixture, as well as the reaction conditions.
SUMMARY OF THE INVENTION
The present invention pertains to a novel amine molybdate, namely, dicyclohexylammonium alpha-octamolybdate, [H(C 6 H 11 ) 2 NH] 4 Mo 8 O 26 , which exhibits major x-ray diffraction peaks at "d" spacings of 12.8 A, 9.68 A and 9.15 A. Like many other amine molybdates, dicyclohexylammonium alpha-octamolybdate functions as an effective smoke retardant additive for vinyl chloride and vinylidene chloride polymers.
DETAILED DESCRIPTION OF THE INVENTION
Dicyclohexylammonium alpha-octamolybdate may be produced by reacting ammonium dimolybdate and dicyclohexylamine in essentially a 2/1 molybdenum/dicyclohexylamine molar ratio in an acidic aqueous medium. Suitable acids include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and the like, or mixtures thereof. The amount of acid used may be varied widely from about 1/2 to 10 or more molar equivalents of acid per molar equivalent of ammonium dimolybdate. However, about a 1/1 molar equivalent ratio is preferred. Sufficient water is included in the reaction mixture to insure a reaction medium that has a consistency that enables it to be easily stirred. Desirably, the ammonium dimolybdate is dissolved in water and is added to an acidic solution of the dicyclohexylamine. If preferred, the ammonium dimolybdate, dicyclohexylamine, acid and water can be charged essentially simultaneously to the reaction vessel. The The reaction materials desirably are refluxed while being stirred continuously for 0.25 to 16 hours. Although the reaction can occur at room temperature (25° C.), desirably the reaction mixture is heated to between 75° to 110° C. in order to reduce the time for the reaction to be completed. After the reaction is completed, the white crystalline dicyclohexylammonium alpha-octamolybdate formed can be separated from the liquid phase by filtration, centrifugation or other suitable separation means, washed with water, alcohol or a mixture of water and alcohol, and then dried. The reaction mixture may be cooled to room temperature (about 25° C.) before the separation of the solid dicyclohexylammonium alpha-octamolybdate from the liquid phase, although cooling the mixture before separation of the solid product from the liquid phase is not necessary. The recovered dicyclohexylammonium alpha-octamolybdate may be air dried, preferably at about 100° to 200° C., or may be vacuum dried, preferably at temperatures up to 150° C. and higher. The dicyclohexylammonium alpha-octamolybdate is readily identifiable by elemental, infrared or x-ray diffraction analysis.
Alternatively, the dicyclohexylammonium alpha-octamolybdate can be prepared by reacting together essentially stoichiometric quantities of molybdenum trioxide with dicyclohexylamine in an aqueous medium essentially free of acid and in which a water-soluble ammonium or monovalent metal or divalent metal or trivalent rare earth metal salt of an inorganic or organic acid is dissolved. Sufficient water is included in the reaction mixture to insure a reaction medium that has a consistency that enables it to be easily stirred. The water-soluble ammonium or monovalent metal or divalent metal or trivalent rare earth metal salt may be a salt of a strong acid (HCl, HNO 3 and H 3 SO 4 ) or of a weak acid (such as carbonic acid, acetic acid, formic acid, benzoic acid, salicyclic acid, oxalic acid, sebacic acid and adipic acid). A combination of one or more of the water-soluble salts can be used. The water-soluble salt desirably is present in the reaction mixture in an amount to form at least a 1:1 mole ratio with the molybdenum trioxide. The reaction time for obtaining the highest yield of dicyclohexylammonium alpha-octamolybdate will vary depending in part upon the temperature at which the reaction is occuring and the amount of excess water-soluble salt present in the reaction mixture. The reaction usually is completed within 4 hours and, when the water-soluble salt is present in about a 50 percent excess, may be completed in 1/4 to 2 hours or even less. The reaction mixture desirably is stirred continuously while being refluxed during the time the reaction is occurring. Desirably, the reaction mixture is heated to between 75° to 110° C. during the reaction, although the reaction can take place at room temperature (25 C.). After the reaction is completed, the crystalline dicyclohexylammonium alpha-octamolybdate can be separated from the liquid phase, washed and dried in the manner described above.
The following examples illustrate the preparation of dicyclohexylammonium alpha-octamolybdate more fully:
EXAMPLE 1
10.00 grams of dicyclohexylamine, 10.87 grams of a 37 percent hydrochloric acid solution and 250 milliliters of water were added to a 500 milliliter round-bottom flask equipped with a water-cooled condenser and was brought to reflux. 18.75 grams of ammonium dimolybdate were added to 50 milliliters of water and the mixture was heated until the ammonium dimolybdate dissolved. The hot ammonium dimolybdate solution was added to the flask and the reaction mixture was refluxed while being stirred continuously for one hour. The contents of the flask was cooled to room temperature (about 25° C.) and was filtered. A white crystalline solid was recovered. The recovered solid was washed with water and vacuum dried at 100° C. for approximately 16 hours. 24.62 grams of the crystalline product were recovered. Elemental and infrared analyses identified the solid to be dicyclohexylammonium alpha-octamolybdate.
EXAMPLE 2
10.00 grams of dicyclohexylamine, 15.88 grams of molybdenum trioxide, 10.94 grams of ammonium sulfate and 300 milliliters of water were charged into a 500 milliliter round-bottom flask equipped with a water-cooled condenser. The reaction mixture was refluxed for 2 hours while being stirred continuously and then was filtered. A crystalline solid was recovered. The solid was washed with water and was vacuum dried for 3 hours at 100° C. Infrared and x-ray diffraction analyses identified the recovered solid to be dicyclohexylammonium alpha-octamolybdate. 22.55 grams of the solid product was recovered.
Dicyclohexylammonium alpha-octamolybdate has been found to be a smoke additive for vinyl chloride and vinylidene chloride polymer compositions. When used as a smoke retardant additive, the dicyclohexylammonium alpha-octamolybdate desirably has an average particle size from about 0.1 to about 100 microns, and is present in an amount from about 0.1 to about 20 parts by weight per 100 parts by weight of the vinyl chloride or vinylidene chloride polymer.
Vinyl chloride and vinylidene chloride polymers with which the dicyclohexylammonium alpha-octamolybdate can be used as a smoke retardant additive include homopolymers, copolymers and blends of homopolymers and/or copolymers. The vinyl chloride and vinylidene chloride polymers may contain from 0 to 50 percent by weight of at least one other olefinically unsaturated monomer. Suitable monomers include 1-olefins containing from 2 to 12 carbon atoms such as ethylene, propylene, 1-butene, isobutylene, 1-hexene, 4-methyl-1-pentene, and the like; dienes containing from 4 to 10 carbon atoms, including conjugated dienes such as butadiene, isoprene, piperylene, and the like; ethylidene norbornene and dicyclopentadiene; vinyl esters and allyl esters such as vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl laurate, alkyl acetate, and the like; vinyl aromatics such as styrene, α-methyl styrene, chlorostyrene, vinyl toluene, vinyl naphthalene, and the like; vinyl and allyl ethers and ketones such as vinyl methyl ether, allyl methyl ether, vinyl isobutyl ether, vinyl n-butyl ether, vinyl chloroethyl ether, methylvinyl ketone, and the like; vinyl nitriles such as acrylonitrile, methacrylonitrile, and the like; cyanoalkyl acrylates such as α-cyanomethyl acrylate, the α-, β- and γ-cyanopropyl acrylate, and the like, olefinically unsaturated carboxylic acids and esters thereof, including α,β-olefinically unsaturated acids and esters thereof such as methyl acrylate, ethyl acrylate, chloropropyl acrylate, butyl acrylate, hexyl acrylate, 2-ethyl-hexyl acrylate, dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, glycidyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, hexylthioethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, and the like; and including esters of maleic and fumaric acid, and the like; amides of the α,β-olefinically unsaturated carboxylic acids such as acrylamide, and the like, divinyls, diacrylates and other polyfunctional monomers such as divinyl benzene, divinyl ether, diethylene glycol diacrylate, ethylene glycol dimethacrylate, methylene-bis-acrylamide, allyl pentaerythritol, and the like; and bis(β-chloroethyl)vinyl phosphonate, and the like.
The vinyl chloride and vinylidene chloride polymer, in addition to the dicyclohexylammonium alpha-octamolybdate additive, may contain the usual compounding ingredients known to the art such as fillers, stabilizers, opacifiers, lubricants, processing aids, impact modifiers, plasticizers, antioxidants, and the like.
Smoke retardancy may be measured using an NBS Smoke Chamber according to procedures described in ASTM E662-79 "Test For Specific Optical Density Of Smoke Generated By Solid Materials". Maximum smoke density (DM) is a dimensionless number and has the advantage of representing a smoke density independent of chamber volume, specimen size for photometer path length, provided a consistent dimensional system is used. Percent smoke reduction is calculated using the equation: ##EQU1##
The term "Dm/g" means maximum smoke density per gram of sample. Dm and other aspects of the physical optics of light transmission through smoke are discussed fully in the ASTM publication.
The smoke retardant property of dicyclohexylammonium alpha-octamolybdate is illustrated by the following examples:
EXAMPLES 3-5
The following recipe was used:
______________________________________Material Parts by Weight______________________________________Polyvinyl Chloride Resin* 100.00Lubricant** 2.0Tin Stabilizer*** 2.0Dicyclohexylammonium alpha-octamolybdate Varied______________________________________ *Homopolymer of vinyl chloride having an inherent viscosity of about 0.98-1.04; ASTM Classification GP5-15443. **A commercial polyethylene powder lubricant (Microthene 510). ***Tin thioglycolate.
The ingredients of the recipe were dry-mixed and bonded on a two-roll mill for about 5 minutes at a roll temperature of about 165° C. The milled compositions were pressed into 6×6×0.025 inch sheets. Pressing was done at about 160° C. for 5 minutes using 40,000 pounds (about 14,900 Kg) of force applied to a 4-inch ram. The sample received a 2 minute preheat before being pressed.
The molded samples were cut into 27/8×27/8×0.050 inch sections. Testing was performed using the flaming mode of the NBS Smoke Chamber Test (ASTM E662-79 described heretofore. Test results are given in Table I.
TABLE I______________________________________ Dicyclohexylammonium Smoke Alpha-octamolybdate ReductionExample Parts By Weight Dm/g %______________________________________3 (control) 0 68.40 --4 2.0 38.51 445 5.0 35.16 49______________________________________ *Dm/g maximum smoke density per gram of sample.
The improved smoke retardant vinyl chloride and vinylidene chloride polymer compositions obtained by the addition of dicyclohexylammonium alpha-octamolybdate to the compositions are useful wherever smoke resistance is desirable, such as in carpets, house siding, plastic components for airplane and passenger car interiors, and the like.
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Dicyclohexylammonium alpha-octamolybdate is disclosed as a novel amine molybdate and as a smoke retardant additive for vinyl chloride and vinylidene chloride polymer compositions.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a circuit and more particularly to a differential-input circuit for providing differential logic signals.
2. Description of the Related Art
Due to the increasing demand for high speed data transmission and RF (radio frequency) wireless communications, the differential-input circuit such as an ECL (emitter coupled logic) is widely used for providing differential logic signals because of its application in high speed operations. To implement the digital control of the high speed circuit, an interface circuit, such as a MOS (metal oxide semiconductor) circuit, is employed because it provides high density, low cost, and low power consumption. To fulfill the high speed operation, a differential ECL generally includes bipolar transistors which require a differential reduced-swing input voltage, e.g., a differential input of voltages with a swing less than a swing from ground voltage to supply voltage. However, a MOS circuit usually provides a single-ended rail-to-rail output, e.g., a single output of voltage with a full swing from ground voltage to supply voltage, but not a differential reduced-swing signal. Hence, it is desirable to provide a MOS interface circuit which can provide a differential reduced-swing voltage signal to a differential ECL circuit for outputting a differential logic signal.
Further, as the functions of the high speed communication circuits become complicated, the size of the MOS control logic grows accordingly larger. A larger area interface circuit creates disadvantages, such as more power consumption. Hence, the demand to maintain small area for MOS logic to ECL interface is also desirable. Furthermore, the MOS control logic consumes more power not only when it has a larger area, but by its nature, this kind of circuit consumes static power. To generate an intermediate voltage level in an interface to the ECL circuit, static power consumption through the resistors and transistors is unavoidable unless an external reference voltage is supplied. For example, a cellular phone can draw power from the battery when its power is on even though it does not transmit or receive signal yet. Hence, the demand to maintain low power consumption for interfacing to an ECL circuit is also desirable.
SUMMARY OF THE INVENTION
The present invention provides a differential reduced-swing input voltage to a differential-input circuit for outputting a differential logic signal. The present invention further provides a differential-input circuit which maintains area efficiency and low power consumption.
In one aspect of the present invention, there is provided a circuit for providing a differential logic signal. The circuit includes a differential-input circuit having a first differential input and a second differential input. A first unit receives an input voltage signal and a supply voltage for providing a first voltage to the first differential input via a first node. A second unit receives the supply voltage for providing a second voltage to the second differential input via a second node, wherein the differential-input circuit outputs a signal in accordance with the first and second voltages.
In another aspect of the present invention, there is provided a circuit for providing differential logic signal. The circuit includes a differential-input circuit having a first differential input and a second differential input. A first unit receives an input voltage signal and a supply voltage for providing a first voltage to the first differential input via a first node. A second unit receives the input voltage signal and the supply voltage for providing a second voltage to the second differential input via a second node, wherein the differential-input circuit outputs a signal in accordance with the first and second voltage.
In another aspect of the present invention, the circuit may include a logic device to provide an enable signal to the circuit for providing a low power consumption operation. In another aspect of the present invention, the circuit may include the same type transistors for providing small area. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will become more apparent by describing in detail embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a schematic diagram of a circuit for providing a differential reduced-swing input voltage and outputting a differential logic signal according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a circuit for providing a differential reduced-swing input voltage and outputting a differential logic signal according to another embodiment of the present invention;
FIG. 3 is a schematic diagram of a circuit for illustrating the selection of appropriate bias input voltage of another embodiment of the circuit in FIG. 1;
FIG. 4 is a schematic diagram of a circuit for illustrating the selection of appropriate bias input voltage of another embodiment of the circuit in FIG. 2;
FIG. 5 is a schematic diagram of a circuit with the advantage of low power consumption of another embodiment of the circuit in FIG. 3;
FIG. 6 is a schematic diagram of a circuit with the advantage of low power consumption of another embodiment of the circuit in FIG. 4;
FIG. 7 is a schematic diagram of a circuit comprising n-type transistors of yet another embodiment of the circuit in FIG. 3;
FIG. 8 is a schematic diagram of a circuit comprising n-type transistors of yet another embodiment of the circuit in FIG. 4;
FIG. 9 is a schematic diagram of a circuit with the advantage of low power consumption of yet another embodiment of the circuit in FIG. 7;
FIG. 10 is a schematic diagram of a circuit with the advantage of low power consumption of yet another embodiment of the circuit in FIG. 8;
FIG. 11 is a schematic diagram of a circuit where the transistors in the interface circuit are all n-type transistors according to yet another embodiment of the present invention;
FIG. 12 is a schematic diagram of a circuit where the transistors in the interface circuit are all p-type transistors according to another embodiment of the circuit in FIG. 11;
FIG. 13 is a schematic diagram of a circuit with the advantage of small area according to yet another embodiment of the circuit in FIG. 11;
FIG. 14 is a schematic diagram of a circuit with advantages of small area and low power consumption according to another embodiment of the circuit in FIG. 13;
FIG. 15 is a schematic diagram of a circuit where certain transistors are independent of the input voltage, and transistor sizes are ratioed according to yet another embodiment of the present invention;
FIG. 16 is a schematic diagram of a circuit where resistors are replaced with MOS transistors according to yet another embodiment of the circuit in FIG. 15; and
FIG. 17 is a schematic diagram of a circuit with the advantage of low power-consumption according to yet another embodiment of the circuit in FIG. 16 .
DESCRIPTION OF EMBODIMENTS
The present invention will be described in terms of illustrative circuits. It is to be understood that these circuits are described with particular values for parameters, such as voltage, current, resistance, component sizes, etc. These values are illustrative and should not be construed as limiting the present invention.
Referring now in detail to the drawing in which like reference numerals identify similar or identical elements throughout the drawings.
FIG. 1 shows an embodiment of the present invention where an interface circuit 102 provides a differential reduced-swing voltage signal to a circuit 100 . Note the interface circuit 102 represents the circuit other than circuit 100 in all FIGs of the specification.
In FIG. 1, reference numeral 102 illustratively represents a CMOS (complementary metal oxide semiconductor) interface circuit. Reference numeral 100 illustratively represents a bipolar PECL (positive emitter coupled logic) circuit which needs a differential input with reduced swing for noise-immune operation at high operating speed. It is to be understood that circuit 102 is an interface circuit including different types of MOS circuits, such as CMOS, pMOS, or nMOS. Circuit 100 may include other or different circuits which can benefit from an interface circuit of the present invention.
A CMOS, as well as other types of MOS, logic circuit inputs and outputs single-ended signal, e.g., the logic signal is inputted/outputted via a single line. Also, a CMOS logic signal swings from ground voltage for logic “LOW” to the supply voltage for logic “HIGH” or so-called a “rail-to-rail” full swing. The single-ended, rail-to-rail signal in a CMOS standard logic circuit does not meet the input requirement for a differential logic circuit, such as a PECL circuit, because a PECL circuit needs differential reduced-swing input voltage.
A differential input is a pair of signals, e.g., a main signal and a complementary signal, to represent logic information, wherein the complementary signal is an inverted version of the main signal. The differential logic circuit, such as a PECL circuit, takes the difference of the differential signals and performs the logic function. The differential logic circuit, such as a PECL circuit, is particularly useful in high-speed operation due to its noise-immune capabilities. For example, the noise coupled to the signal lines affects each line signal in the PECL circuit. The difference of line signals remains unaffected since, according to the invention, the noise on each line signal is about the same amount. This results in the difference between the line signals being unchanged. Further, a reduced-swing input is an input voltage centering around a supply voltage with a smaller magnitude than a rail-to-rail full swing, which consumes more time during a high-speed operation. A reduced-swing input voltage is thus advantageous for a differential logic circuit, such as PECL circuit, because the high-speed operation will not be slowed down by a rail-to-rail full swing.
Referring to FIG. 1, in one embodiment of the present invention, a CMOS interface circuit 102 provides differential reduced-swing voltages as the inputting voltages via node 1 and node 2 , respectively, to a PECL circuit 100 . The reduced-swing inputs (e.g., between about 300 mV and about 700 mV) centered around the middle of a supply voltage (e.g., 1 V) are provided to bias input differential stage of the bipolar transistors Q 1 and Q 2 in bipolar PECL 100 .
Resistors R 1 and R 2 in the CMOS interface circuit 102 are designed such that they provide appropriate bias voltage at node 1 . Resistors R 3 and R 4 are also designed to provide the same voltage at node 2 as that of node 1 . For example, R 1 /R 2 =R 3 /R 4 , while R 1 =R 3 and R 2 =R 4 .
Transistor M 5 is a pMOS, and transistor M 6 is an nMOS. When an input voltage signal Vin is logic “HIGH” (in this case, VDD in CMOS logic level), the transistor M 6 turns on and transistor M 5 turns off. As the transistor M 6 turns on, transistor M 6 adds parallel resistance between node 1 and the ground (GND), so the resistance between transistor M 6 and resistor R 2 will be lower than resistor R 4 . Hence, the voltage at node 1 will go lower than that in node 2 . For example, if resistors R 1 , R 2 , R 3 and R 4 are all, e.g., 1 kΩ, VDD and VCC are, e.g., 3 V, and the on-resistance of transistor M 6 is designed to be, e.g., 1 kΩ, then the voltage at node 2 is, e.g., 1.5 V (3 V×1.0 kΩ/2.0 kΩ), and node 1 becomes, e.g., 1 V (3 V×0.5 kΩ/1.5 kΩ). In this example, the PECL 100 input node 1 is 500 mV lower than the other input node 2 , and in turn the base of transistor Q 1 is lower than the base of transistor Q 2 . As a result, transistor Q 1 turns off and transistor Q 2 turns on allowing the tail current, It, flowing through the transistor Q 2 to provide a voltage drop across load resistor RL 2 , e.g., (It)(RL 2 ). Hence, the output Y becomes “HIGH” and Yb becomes “LOW” in PECL 100 level in FIG. 1 .
On the other hand, when the input voltage signal Vin is logic “LOW” (0 V), transistor M 5 turns on and transistor M 6 turns off. As transistor M 5 turns on, transistor M 5 adds parallel resistance between node 1 and VDD, so the resistance between transistor M 5 and resistor R 1 will be lower than resistor R 3 . Hence, the voltage at node 1 will go higher than that in node 2 . If the on-resistance of transistor M 5 is designed to be, e.g., 1 kΩ, the voltage at node 2 is still, e.g., 1.5 V (3 V×1.0 kΩ/2.0 kΩ), and node 1 is now, e.g., 2 V (3 V×1.0 kΩ/1.5 kΩ). In this example, the PECL 100 input node 1 is 500 mV higher than the other input node voltage at node 2 , and the output Y is “LOW” and Yb is “HIGH.”
According to this structure of the present invention as shown in FIG. 1, the CMOS interface circuit 102 provides differential reduced-swing input voltages to a PECL circuit.
FIG. 2 shows another embodiment of the present invention where an interface circuit 102 provides differential reduced-swing voltage signal to a PECL circuit 100 . FIG. 2 is substantially the same as FIG. 1 except for the location of transistor M 6 in the interface circuit 102 . In FIG. 2, the nMOS M 6 has been moved to between node 2 and VDD, from being between node 1 and GND in FIG. 1 . Transistors M 5 and M 6 are designed to have on-resistance of, e.g., 1 kΩwhen transistors M 5 and M 6 are on. In FIG. 2, the same parts as those shown in FIG. 1 are represented with like reference numbers to avoid redundant description, accordingly, their explanation will be omitted.
When input voltage signal Vin is “HIGH,” transistor M 6 is turned on, and transistor M 5 turns off. The voltage at node 1 is set by the resistive divider R 3 and R 4 , which is, e.g., 1.5 V (3 V×1.0 kΩ/2.0 kΩ). Transistor M 6 reduces the resistance between VDD and node 2 , so the voltage at node 2 will go up to, e.g., 2 V (3 V×1.0 kΩ/1.5 kΩ). In this example, the PECL 100 input node 1 is 500 mV lower than the other input node 2 . As a result, transistor Q 1 turns off and transistor Q 2 turns on allowing the tail current flowing through the transistor Q 2 to provide a voltage drop across load resistor RL 2 . Hence, the output Y becomes “HIGH” and Yb becomes “LOW” in PECL 100 level in FIG. 2 .
When input voltage signal Vin is “LOW,” transistor M 5 turns on and transistor M 6 turns off, and the voltage at node 2 is, e.g., 1.5 V (3 V×1.0 kΩ/2.0 kΩ, same as in FIG. 1 ). As transistor M 5 is on, M 5 reduces the resistance between VDD and node 1 . Hence, the voltage at node 1 will go up to, e.g., 2V (3V×1.0 kΩ/1.5 kΩ). In this example, the PECL 100 input node 1 is 500 mV higher than the other input node voltage at node 2 , and the output Y is “LOW” and Yb is “HIGH.” Accordingly, the embodiment of FIG. 2, the CMOS interface circuit 102 also provides differential reduced-swing input voltages to a PECL circuit 100 .
FIG. 3 is another embodiment of the present invention which illustrates the selection of appropriate bias input voltage for PECL 100 . FIG. 3 is substantially the same as FIG. 1 except that the resistors R 1 , R 2 , R 3 , and R 4 (FIG. 1) are replaced with CMOS transistors M 1 , M 2 , M 3 , and M 4 , respectively. In FIG. 3, the appropriate bias voltage at the input of the PECL 100 circuit can be provided by choosing the size W/L (Width/Length ratio) of transistors M 1 , M 2 , M 3 , and M 4 . In light of FIG. 1, the on-resistance of transistors M 1 , M 2 , M 3 , and M 4 can be designed to be, e.g., about 1 kΩ, respectively, in this example.
FIG. 4 shows another embodiment of the present invention which illustrates the selection of appropriate bias input voltage for PECL 100 . FIG. 4 is substantially the same as FIG. 2 except that the resistors R 1 , R 2 , R 3 , and R 4 (FIG. 2) are replaced with CMOS transistors M 1 , M 2 , M 3 , and M 4 , respectively. In FIG. 4, the appropriate bias voltage at the input of the PECL 100 circuit can be provided by choosing the size W/L of transistors M 1 , M 2 , M 3 , and M 4 . In light of FIG. 1, the on-resistance of transistors M 1 , M 2 , M 3 , and M 4 can be designed to be, e.g., about 1 kΩ, respectively, in this example.
FIG. 5 shows another embodiment of the present invention with the advantage of low power consumption. The embodiment in FIG. 5 is made by adding an ENABLE signal to the circuit in FIG. 3 . The gate nodes of transistors M 1 through M 4 in interface circuit 102 are digitally controlled by connecting to an ENABLE signal, so that they can be enabled or disabled. When the logic signal in ENABLE is “HIGH,” the transistors M 1 through M 4 are turned on. When the logic signal in ENABLE is “LOW,” the transistors M 1 through M 4 are turned off to be in a standby mode. Thus, static power consumption through the transistors M 1 through M 4 can be reduced during the standby mode.
FIG. 6 shows another embodiment of the present invention with the advantage of low power consumption. The embodiment in FIG. 6 is made by adding an ENABLE signal to the circuit in FIG. 4 . In FIG. 6, the gate nodes of transistors M 1 through M 4 in interface circuit 102 are digitally controlled by connecting to an ENABLE signal, so that they can be enabled or disabled. When the logic signal in ENABLE is “HIGH,” the transistors M 1 through M 4 are turned on. When the logic signal in ENABLE is “LOW,” the transistors M 1 through M 4 are turned off to be in a standby mode to reduce the power consumption.
FIG. 7 shows another embodiment of the present invention. The circuit of FIG. 7 is the same as FIG. 3 except that the CMOS transistors M 1 through M 4 in interface circuit 102 are replaced with nMOS, and the gate nodes of nMOS transistor M 1 and M 3 are tied to VDD to turn M 1 and M 3 on in the operating mode.
FIG. 8 shows another embodiment of the present invention. The circuit of FIG. 8 is substantially the same as FIG. 4 except that the CMOS transistors M 1 through M 4 in interface circuit 102 are replaced with nMOS, and the gate nodes of NMOS transistor M 1 and M 3 are tied to VDD to turn M 1 and M 3 on in the operating mode.
FIG. 9 shows another embodiment of the present invention with the advantage of low power consumption. The circuit of FIG. 9 is substantially the same as FIG. 7 except that gates of transistors M 1 , M 2 , M 3 and M 4 in interface circuit 102 are connected to an ENABLE signal. The transistors M 1 , M 2 , M 3 , and M 4 can be turned off by the ENABLE signal to be in a standby mode to reduce the power consumption.
FIG. 10 shows another embodiment of the present invention with the advantage of low power consumption. The circuit of FIG. 10 is substantially the same as FIG. 8 except that gates of transistors M 1 , M 2 , M 3 and M 4 in interface circuit 102 are connected to an ENABLE signal. The transistors M 1 , M 2 , M 3 , and M 4 can be turned off by the ENABLE signal to be in a standby mode to reduce the power consumption.
FIG. 11 shows another embodiment of the present invention. In FIG. 11, the transistors in the interface circuit 102 are all nMOS transistors. Transistors M 5 and M 6 have the same size. Resistors R 1 , R 2 , R 3 and R 4 are designed as, for example, R 1 /R 2 ×R 3 /R 4 , in one embodiment, for example, R 1 =R 3 and R 2 =R 4 . When input voltage Vin is “LOW,” transistor M 6 and M 7 are turned off. As transistor M 5 is always on, the voltage at node 2 is lower than that of node 1 . Hence, the outputs in PECL 100 are Y=“HIGH” and Yb=“LOW.”
FIG. 12 shows another embodiment of the present invention. The configuration in FIG. 12 is substantially the same as the one in FIG. 11 except that pMOS transistors are employed instead of NMOS transistors in interface circuit 102 .
FIG. 13 shows another embodiment of the present invention with the advantage of small area. The configuration of FIG. 13 is substantially the same as FIG. 11 except that the resistors R 1 , R 2 , R 3 , and R 4 in interface circuit 102 are replaced with NMOS transistors M 1 , M 2 , M 3 , and M 4 , respectively. In some technologies, nMOS transistors need to be formed in diffusion “wells,” while pMOS transistors do not need “wells.” In common process technology, however, pMOS transistors need an additional layer of wells in the fabrication, while the nMOS transistors do not need wells. When the pMOS transistors need wells, if only the pMOS transistors are used in the circuit, the pMOS transistors can share the wells, and the area can be reduced. However, if nMOS and pMOS transistors are mixed, then the necessary area is larger. Since the interface circuit 102 in FIG. 13 is composed of nMOS transistors only, so the physical size of this circuit is small because it does not need n-wells for pMOS transistors.
FIG. 14 shows another embodiment of the present invention with advantages of small area and low power consumption. The embodiment in FIG. 14 is made by adding an ENABLE signal to the circuit in FIG. 13 .
FIG. 15 shows another embodiment of the present invention. In FIG. 15, transistors M 5 and M 6 in interface circuit 102 are independent of the input voltage Vin, and their sizes are ratioed n:1, were n>1, preferably. When Vin=“LOW,” transistor M 5 reduces more resistance than M 6 , so the voltage at node 2 is lower than that of node 1 , resulting in Y=“LOW,” and Yb=“HIGH.” The size of transistor M 7 is set as m(W/L) such that size of M+M 6 , or (m+1)W/L, is larger than size of M 5 , or n(W/L). For example, n is 2, and m is 3. When input voltage Vin=“HIGH,” transistors M 7 and M 6 provide more conductance than M 5 , so the voltage at node 1 becomes lower than the voltage at node 2 , resulting in Y=“HIGH,” and Yb=“LOW.” The transistors M 5 , M 6 , and M 7 can be also replaced with pMOS transistors.
FIG. 16 shows another embodiment of the present invention. The circuit of FIG. 16 is substantially the same as FIG. 15 except that the resistors R 1 , R 2 , R 3 , and R 4 in interface circuit 102 are replaced with MOS transistors M 1 , M 2 , M 3 , and M 4 , respectively. The gate nodes of transistors M 1 , M 2 , M 3 , and M 4 are connected to VDD so that M 1 , M 2 , M 3 , and M 4 are on all the time. As transistors M 2 and M 6 have the same terminal connections (drain, gate, and source connections are common), transistors M 2 and M 6 can be merged into a wider transistor. For the same reason, transistors M 4 and M 5 can be merged too.
FIG. 17 shows another embodiment of the present invention with the advantage of low power-consumption. The embodiment in FIG. 17 is made by connecting gates of transistors M 1 , M 2 , M 3 , and M 4 in circuit of FIG. 16 to an ENABLE signal. The ENABLE signal is “LOW” when the circuit is not used, and the transistors M 1 , M 2 , M 3 , M 4 , M 5 , and M 6 are turned off.
The embodiments of the present invention may include other components in addition to or instead of the components shown in the FIGS. For example, other types of transistors may be employed, or transistors with different polarity types and connections may be employed as one skilled in the art would understand.
Having described preferred embodiments of a differential-input circuit for providing differential logic signal (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be make in the particular embodiments of the invention disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described the invention with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
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A circuit provides differential logic signals and includes a differential-input circuit having a first differential input and a second differential input. A first unit receives an input voltage signal and a supply voltage for providing a first voltage to the first differential input via a first node. A second unit receives the supply voltage for providing a second voltage to the second differential input via a second node. The differential-input circuit outputs a signal in accordance with the first and second voltages.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority with U.S. Provisional Ser. No. 61/955,163, filed Mar. 18, 2014, titled “MODAL ANTENNA BASED COMMUNICATION SYSTEM”; the contents of which are hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to the field of wireless communication; and more particularly, to communication networks and improvements afforded to these networks when beam steering techniques via modal antenna systems are used on both communication nodes and wireless subscribers to increase system capacity and mitigate interference therebetween.
[0004] 2. Description of the Related Art
[0005] In the field of wireless communications, a recent technological advancement includes the advent of multi-mode active antennas, or “modal antennas”. A modal antenna is a single port antenna capable of being actively reconfigured between a plurality of antenna modes, wherein the modal antenna is characterized with a distinct radiation pattern in each of the plurality of antenna modes. By using the modal antenna capable of generating different radiation patterns, it is possible to exploit a priori knowledge of antenna nulls and lobes in the different modes for steering the beam to have nulls in dominant interference directions while keeping gain in desired directions. Examples of structures and implementations of the modal antennas are provided in U.S. Pat. No. 7,911,402, entitled “ANTENNA AND METHOD FOR STEERING ANTENNA BEAM DIRECTION,” issued on Mar. 22, 2011; the contents of the which are hereby incorporated by reference and are summarized as follows:
[0006] FIG. 1 illustrates an example of a modal antenna 100 , which includes an Isolated Magnetic Dipole™ (IMD) element 104 placed on a ground plane 108 , a first parasitic element 112 coupled to an first active element 113 , and a second parasitic element 116 coupled to a second active element 117 . The active elements 113 and 117 may include switches that either electrically connect (short) or disconnect (open) the parasitic elements 112 and 116 to the ground plane 108 . This structure allows for two different modes of operation with a common frequency corresponding to a first state where the parasitic elements 112 and 116 are shorted to the ground and a second state where the parasitic elements 112 and 116 are open.
[0007] FIG. 2( a ) illustrates a radiation pattern 204 associated with the antenna 100 in the first state; and FIG. 2( b ) illustrates a radiation pattern 208 in the second state, which shows a ninety-degree shift in direction as compared to the radiation pattern 204 . Thus, by controlling the active elements 113 and 117 of the modal antenna 100 , the operation of two modes can be obtained at the same frequency. The control scheme can be extended for three or more multi-mode operations by incorporating, for example, tunable elements in the active elements for variable control and additional active elements for matching. Further, while a parasitic element coupled to a switch will exhibit two tuning states as the switch is (i) shorted or (ii) opened, another parasitic element being coupled to a variable control active element, such as a tunable capacitor or similar tunable element, will be capable of three or more discrete tuning states, and the resulting antenna will be capable of tuning across a plurality of corresponding antenna modes. Examples of these active elements include switches, tunable capacitors, tunable phase shifters, diodes, micro-electro-mechanical system (MEMS) switches, MEMS tunable capacitors, and transistors including a metal oxide semiconductor field effect transistor (MOSFET), a metal semiconductor field effect transistor (MESFET), a pseudomorphic high electron mobility transistor (pHEMT), a heterojunction bipolar transistor (HBT) or of other suitable technologies.
[0008] Although certain examples are provided above, it shall be recognized that the term “modal antenna” is intended to include any single-port antenna system configured to produce a plurality of distinct radiation patterns with each radiation pattern thereof corresponding to a unique mode of a plurality of possible antenna modes. Note that the modal antenna will be characterized with a first antenna radiation pattern when in the first mode, and will be further characterized with a second and distinct antenna radiation pattern when in the second mode. Also note that the modal antenna will produce only a single mode and corresponding radiation pattern at any given time, but that the modal antenna can vary the antenna mode in time to vary the antenna's radiation pattern.
[0009] For purposes herein, the term “antenna radiation pattern” is defined as: the variation of the power radiated by the antenna as a function of the direction away from the antenna.
[0010] Now, with the above understanding of the modal antenna, we describe the state of the art of communication networks.
[0011] For purposes herein, a “communication network” includes: one or more sub-networks of communication nodes, and wireless communication devices configured to communicate with the communication nodes. A communication system may include a subpopulation of communication nodes and wireless devices within a single room, a building, a city block, or other space.
[0012] The term “sub-network” is defined as: a group of interconnected communication nodes and wireless communication devices.
[0013] The term “communication node” is defined as a central connecting point through which one or more wireless communication devices communicate to form a network. A communication node may include, for example, a WiFi access point (AP) or cellular base station transceiver (BST), including a miniature cellular base station transceiver (mBST) also referred to as a “small cell site” or “personal base station”.
[0014] The term “wireless communication device”, is defined as any device configured to communicate with one or more other devices through a wireless network connection. A wireless communication device may include a “mobile device”, such as, for example, a cell phone, tablet, or lap top computer, which is portable. Another example of wireless communication devices includes a wireless computer tower, which is non-portable or “fixed”. The terms “mobile user device” and “mobile device” are a subset of the group of wireless communication devices including those devices which are mobile or portable.
[0015] Cellular networks and wireless local area networks (WLANs) are now prevalent in society and have evolved to a level that moderate to high data rate transmissions along with voice communications are stable and reliable over large regions and throughout urban areas. Mobile user devices have progressed to the point of providing not only voice communications and low data rate text and email service, but also high data rate internet connectivity. Continued adoption of mobile devices, and introduction of new uses of cellular networks, such as machine to machine (M2M) applications, have put a strain on the cellular systems in regard to providing consistent service and improved service in terms of higher data rates and less service interruptions from one year to the next. Similar congestion can be found on WLAN networks were large number of users are putting strain on the systems. Continued improvements are sought after to improve communication system reliability as well as better command and control of communication nodes and the mobile devices utilizing these nodes.
SUMMARY OF THE INVENTION
[0016] It is therefore one aspect of the invention to provide an improved communication system, with improved management of the communication nodes that make up the communication system, and increased flexibility of synchronizing multiple mobile device users of these networks.
[0017] In the instant disclosure, a communication network is optimized using modal antenna techniques, wherein a plurality of communication nodes are synchronized with each other along with mobile and fixed wireless communication devices which comprise the user base. With one or more of the communication nodes and wireless communication devices including at least one respective modal antenna, the network is adapted for dynamic optimization of communication links amongst the wireless users. Node to user throughput, node to node throughput, as well as interference characteristics among the nodes and wireless users are each optimized as a network system to increase communication system network capacity and reliability. The multiple radiation patterns provided by the modal antennas provide a parametric for network-level synchronization to improve communication system performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows an example of a modal antenna.
[0019] FIG. 2( a ) illustrates a radiation pattern associated with the antenna of FIG. 1 in the first state.
[0020] FIG. 2( b ) illustrates a radiation pattern associated with the antenna of FIG. 1 when in the second state, which shows a ninety-degree shift in direction as compared to the radiation pattern of the first state.
[0021] FIG. 3 illustrates a communication network having three nodes and four communication devices; at least one of the nodes includes a modal antenna and algorithm which is used to optimize communication links with the multiple communication devices.
[0022] FIG. 4 shows an example of a signal data matrix (matrix of data) wherein signal level data is populated for various nodes and devices among a plurality of modes of the modal antenna.
[0023] FIG. 5 shows a method for optimizing link quality and reducing interferers among devices and nodes within a modal antenna communication network.
[0024] FIG. 6 illustrates a communication network having three communication nodes and four wireless communication devices; multiple of the nodes and devices each contain a modal antenna.
[0025] FIG. 7 shows multiple signal data matrices with data propagated from multiple nodes and devices.
[0026] FIG. 8 shows another method for optimizing link quality and reducing interferers among devices and nodes within a modal antenna communication network.
[0027] FIG. 9A illustrates a communication node which is positioned close to a wall or obstruction; an external antenna is used to transmit and/or receive for the access point or base terminal; the antenna position in relation to the obstruction or wall will affect the performance of the antenna.
[0028] FIG. 9B is a plot of antenna gain as a function of antenna position from obstruction with respect to the communication node of FIG. 9A .
[0029] FIG. 10 illustrates a communication which contains a modal antenna capable of generating multiple radiation patterns; the four radiation patterns (modes) are shown.
[0030] FIG. 11 shows a two dimensional plot of the corresponding antenna radiation patterns associated with the four modes of the modal antenna of FIG. 10 .
[0031] FIG. 12 illustrates a communication network operating in a building; wherein one node of the communication network connects to a base terminal external to the building and relays information to and from other nodes positioned in-building.
[0032] FIG. 13 illustrates a communication network operating in an apartment, wherein a communication node is installed on the floor of a building and coupled with five communication devices labeled E 1 through E 5 .
[0033] FIG. 14 shows an attenuation profile for the communication links shown in FIG. 13 as a function of time.
[0034] FIG. 15A illustrates the frequency response of a signal used in a communication network that occupies a set bandwidth.
[0035] FIG. 15B shows the time domain response of this frequency domain signal of FIG. 15A .
[0036] FIG. 15C shows a time domain plot of the propagation channel characteristics for four radiation modes.
DESCRIPTION OF EMBODIMENTS
[0037] In the following description, for purposes of explanation and not limitation, details and descriptions are set forth in order to provide a thorough understanding of the present invention in accordance with an illustrated embodiment. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these details and descriptions without departing from the spirit and scope of the invention. An illustrated embodiment will be described below with reference to the drawings wherein illustrative features are denoted by reference numerals.
[0038] Herein described is a communication network where beam steering antenna techniques are implemented in the form of modal antenna techniques at both the communication nodes and the mobile and fixed devices. A modal antenna is generally a single port antenna system capable of generating multiple radiation modes, wherein the radiation modes are de-correlated when compared to each other. The propagation link characteristics are measured for each mobile and fixed device on the communication network, with the link characteristics per radiation mode for each device transmitted to one or several nodes in the network. The network determines the optimal radiation modes for each mobile and fixed device on the network to provide optimal data transfer between mobile and fixed devices and the nodes as well as data transfer between mobile and fixed devices with other mobile and fixed devices. Interference characteristics for devices on the network are taken into consideration and accounted for during the radiation mode selection process for the mobile and fixed devices.
[0039] One embodiment includes a modal communication network comprised of a plurality of communication nodes, with a plurality of the nodes possessing modal antennas capable of generating multiple radiation modes. A plurality of mobile and fixed communication devices using this modal communication network are further configured with modal antennas capable of generating multiple radiation modes. Each node surveys communication devices in the vicinity, or within range, and determines the radiation mode for the modal antenna at the node and the modal antenna at the communication device for optimal communication link performance therebetween. Each communication device using the modal communication network that possesses a modal antenna conducts a survey of nodes and communication devices comprising and using the modal communication network. Communication link quality between communication devices and nodes and interfering signals from one communication device to other communication devices is noted and logged, and this information is transmitted as signal data from each communication device to one or multiple nodes. A modal communication control unit contains a processor with algorithm which collects and analyzes information on link quality related to radiation modes of modal antennas at the nodes and communication devices using the network. The algorithm makes decisions based on system metrics such as capacity, throughput, received signal strength indicator (RSSI), channel quality indicator (CQI), and other parameters to provide optimal system performance. Modal antenna mode selection is made by the algorithm and this information is transmitted to the nodes on the network as well as the communication devices. Each node and device then configures the respective modal antennas in a preferred mode (also called an “operating mode”).
[0040] In another embodiment, one node is selected as a master node that interfaces with the modal communication control unit. The master node is used to send modal antenna mode selection to the other nodes in the communication system as well as the communication devices on the network.
[0041] In another embodiment, a fixed location communication device is connected to the modal communication system and the radiation modes of the integrated modal antenna system in the fixed location device are tested to determine the optimum mode to use when communicating with a node. The use of multiple radiation modes in the fixed location device provides the capability of choosing the best mode for the propagation environment in the vicinity of the fixed location device and the nodes that it can communicate with. The best radiation mode is selected and used for communication per node. Periodic sampling of the other modes is performed to verify that the best mode is used. The periodic sampling of the other available modes provides the capability of compensating the antenna system characteristics for changes in the propagation channel.
[0042] In another embodiment, a modal communication network can interface with another communication network such as a cellular network operating at 3 G or 4 G protocol. The modal communication network can be a dedicated in-building link where multiple communication devices and nodes are dispersed within the building. This dedicated in-building link can be operating on the WLAN protocol or can be operating on a private secure communication system. One or multiple nodes can operate at the frequency band and protocol that the cellular network operates at, and can provide a communication link between the cellular network and the modal communication network. The nodes that are assigned to communicate with the cellular network contain modal antennas that are dual or multi-frequency such that the node can communicate with the cellular system and relay data to communication devices on the modal communication network. A modal antenna can select the radiation mode that best interfaces with the cellular network, and then communicates to in-building devices on the modal communication network by selecting the modal communication network radiation mode that best interfaces with the in-building device. This type of communication network can provide improved transmission performance for in-building applications.
[0043] In another embodiment, a communication network comprises: one or multiple communication nodes, where a node is comprised of a communication circuit capable of transmitting and receiving data; one or multiple communication devices, wherein a communication device comprising a communication circuit capable of transmitting or receiving data; and a communication control unit; wherein one or more of the nodes comprise a modal antenna, wherein the modal antenna is capable of generating a plurality of radiation modes each having a distinct radiation pattern at each mode. The communication control unit contains an algorithm which implements a radiation mode selection process to optimize the communication link between nodes and communication devices by selecting radiation modes for the nodes with modal antennas.
[0044] The communication system may include one of the nodes containing a modal antenna being assigned a master control status (termed master node), wherein the master node is responsible for control of the other nodes and communication devices. The master node will monitor the communication link performance between node to node, communication device to node, and/or communication device to communication device.
[0045] In certain embodiments, the master node establishes a connection with a second communication network, with this second communication network operating at a different frequency, modulation scheme, and/or protocol compared to the first communication network. The master node receives and transmits data from the second communication network and sends the data to, or receives data from, nodes and/or communication devices that are associated with the first communication network.
[0046] In another embodiment, the master node receives data from a node associated with the second communication network and transmits this data using the first communication network to a communication device or node associated with the first communication network. The node or communication device that receives the data from the master node transmits the data using the first communication network to another node or communication device on the first communication network.
[0047] In another embodiment, the master node contains a first modal antenna associated with the first communication network and a second modal antenna associated with the second communication network.
[0048] In another embodiment, one or multiple communication devices each contain a modal antenna, wherein a modal antenna system is capable of generating a plurality of radiation modes. The modal antenna of the communication device measures communication link performance between the communication device and one or multiple nodes for the plurality of radiation modes of the modal antenna system of the communication device. The communication link performance for the radiation modes is transmitted to one or multiple nodes, which relays the information to the communication control unit. The communication control unit contains an algorithm which implements a radiation mode selection process to optimize the communication link between nodes and communication devices by proper selection of radiation modes for the modal antennas at the communication device and the nodes.
[0049] In another embodiment, a communication network comprises: multiple communication nodes, and a communication control unit; wherein one or more of the nodes comprise a modal antenna, wherein the modal antenna is capable of generating a plurality of radiation modes each having a distinct radiation pattern at each mode. The communication control unit contains an algorithm which implements a radiation mode selection process to optimize the communication link between nodes and communication devices by selecting radiation modes for the nodes with modal antennas.
[0050] Now turning to the drawings:
[0051] FIG. 3 illustrates a communication network 100 having three access points or nodes 101 a ; 101 b ; 101 c and four communication devices 102 a ; 102 b ; 102 c ; 102 n . One or more of the nodes each contain a modal antenna which is used to establish communication links with the multiple communication devices. Communication link quality data is measured and stored for modal antennas in both the nodes and communication devices. An algorithm 103 hosted in one of the nodes is used to compare signal level achieved between nodes and devices for determining a potential link quality improvement. If an improvement is obtainable, the algorithm will select the preferred mode prior to communicating instructions to the devices and nodes containing modal antennas for configuring the modal antennas in their preferred mode for optimizing link performance and minimizing interferers within the communication network.
[0052] FIG. 4 shows an example of a signal data matrix (matrix of data) wherein signal level data is populated for various nodes and devices among a plurality of modes of the modal antenna. Here, the nodes are labeled as AP 1 to APn, and the devices are labeled as Device 1 to Device n.
[0053] FIG. 5 shows a method for optimizing link quality and reducing interferers among devices and nodes within a modal antenna communication network.
[0054] FIG. 6 illustrates a communication network 100 having three nodes 101 a ; 101 b ; 101 c and four communication devices 102 a ; 102 b ; 102 c ; 102 n . The nodes contain modal antennas which are used to establish communication links with the multiple communication devices. Communication link quality data is measured and stored for modal antennas for links between communication device to communication device, as well as communication device to node, and node to node. This data is used to populate a signal data matrix, and a plurality of data matrices can be combined for the various nodes and devices as shown in FIG. 7 .
[0055] FIG. 8 shows another method for optimizing link quality and reducing interferers among devices and nodes within a modal antenna communication network.
[0056] FIG. 9A illustrates a communication node such as an access point or base terminal which is positioned close to a wall or obstruction. An external antenna is used to transmit and/or receive for the access point or base terminal. Distances between antenna and the wall or obstruction (D 1 ); the node and the wall or obstruction (D 2 ); the bent external antenna (D 3 ) are each shown. The antenna position in relation to the obstruction or wall will affect the performance of the antenna.
[0057] FIG. 9B shows a plot of antenna gain as a function of antenna position from obstruction.
[0058] FIG. 10 illustrates a communication node which contains a modal antenna. The modal antenna is a single port antenna capable of generating a distinct radiation patterns for each of the multiple modes of the modal antenna. Four radiation pattern modes M 1 ; M 2 ; M 3 ; and M 4 of the modal antenna embedded in the base terminal or access point are each shown. A modal antenna where multiple radiation modes can be generated can be integrated internal to an access point or terminal and radiation modes can be selected to optimize the corresponding radiation pattern for the environment.
[0059] FIG. 11 shows a two-dimensional plot of the radiation patterns corresponding to modes M 1 thru M 4 of the modal antenna of FIG. 10 . Note that the gain maxima and nulls can be steered in a desired direction by configuring the antenna in one of the four illustrated modes.
[0060] FIG. 12 illustrates a communication network operating in a building. The cellular network is capable of monitoring building communications in addition to communications with external devices such as the cell phone as shown. One node of the communication network connects to a cellular base station transceiver that is external to the building and relays information to and from other nodes positioned in-building. Node E 1 is connected to the cellular network. Because E 1 is the node gateway to the network, node E 1 is regularly synchronized with the network. E 2 could be implemented as a sub-node; optimizing links L 1 or L 3 depending on the request from E 1 .
[0061] FIG. 13 illustrates an access point installed on the floor of a building (apartment) and coupled with five communication devices labeled E 1 through E 5 . FIG. 14 shows an attenuation profile for the communication links as a function of time.
[0062] FIG. 15A illustrates the frequency response of a signal used in a communication network that occupies a set bandwidth.
[0063] FIG. 15B shows the time domain response of this frequency domain signal of FIG. 15A .
[0064] FIG. 15C shows a time domain plot of the propagation channel characteristics for four radiation modes.
[0065] While this document contains many specifics, these should not be construed as limitations on the scope of an invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be exercised from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.
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A communication network is optimized using modal antenna techniques, wherein a plurality of communication nodes are synchronized with each other along with mobile and fixed wireless communication devices which comprise the user base. With one or more of the communication nodes and wireless communication devices including at least one respective modal antenna, the network is adapted for dynamic optimization of communication links amongst the wireless users. Node to user throughput, node to node throughput, as well as interference characteristics among the nodes and wireless users are each optimized as a network system to increase communication system network capacity and reliability. The multiple radiation patterns provided by the modal antennas provide a parametric for network-level synchronization to improve communication system performance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 61/334,451 filed on May 13, 2010, which is hereby incorporated by reference in its entirety.
STATEMENT OF U.S. GOVERNMENT INTEREST
[0002] This invention was made with U.S. government support under grant number NAG9: 1258 awarded by the National Aeronautics and Space Administration, and grant number EB003849 awarded by the National Institutes of Health. The government has certain rights in the invention.
BACKGROUND
[0003] Ultrasonography is used for imaging patients for diagnosis or for guiding interventions. During a typical ultrasound procedure, an ultrasound transducer is manipulated over or within the body of the patient to acquire images of the patient's tissues. Performing ultrasonography requires technical skill in positioning and orienting the transducer so that a two-dimensional tomographic view in the desired anatomic location is obtained, as well as cognitive skill or knowledge to interpret the images and make the correct diagnosis.
[0004] To acquire these skills, trainees typically practice on live patients at a medical institution. However, this approach has a number of drawbacks. First, recent cut-backs in physician working hours render it difficult for residents to receive the required training Second, the shortening of hospital stays further reduces opportunities for training physicians as the patients in the hospital are more ill and require more care, leaving faculty with less time available for teaching. Third, not all trainees learn at the same rate. Greater teaching efficiency may be achieved by a proficiency-based approach; this, however, would require a method for measuring competence.
[0005] The current medical educational system for competency testing in ultrasound trains and certifies physicians based on the duration of patient exposure and the number of procedures performed, but does not measure competence in procedural performance for certification or re-certification. Skill competency has always been difficult to assess in a manner that is objective and reproducible between instructors. Unlike knowledge, judgment, and process thinking, which are assessed by written and oral examinations, there is no standardized assessment method for technical skills such as competency with ultrasounds. Some studies report success using the Objective Structured Assessment of Technical Skills which uses direct instructor observation accompanied by a checklist detailing the component skills; however its reliance on instructor observation renders this approach subjective.
[0006] Without competency testing, agencies are continuing their tradition of certifying ultrasound practitioners based on experience using guidelines developed by consensus. Trainees are not tested to determine whether they are performing the procedure correctly. This contrasts with the benefits of simulator-based systems for performance-based training, objective testing, and continuing practice to maintain skills.
[0007] The problem is not limited to the training period. Assurance of competence is equally important for practicing physicians seeking to refresh skills following deployment to the battlefield or other absences such as family leave, and for those wishing to continue their education. A review of malpractice claims due to medical error found that the most complications were caused by experienced physicians, underlining the need for both continuing education and better assessment techniques.
[0008] The use of ultrasound in clinical medicine now is widespread and likely to grow as systems become smaller and less expensive, and as the range of clinical situations and locations where this approach is useful grows. Physicians in fields other than radiology and cardiology, and who are therefore not certified in ultrasound are performing diagnostic and interventional ultrasound procedures following short training courses. Examples of the diagnostic use of ultrasound include evaluation of acute chest or abdominal pain by emergency room physicians, preoperative risk assessment by anesthesiologists, evaluation of cardiac function in hypotensive patients by intensivists, and evaluation of a murmur by internists. Examples of the interventional use of ultrasound include guidance of central line catheterization, fluid drainage from the chest or abdominal cavity, and suprapubic bladder catheter placement. There is controversy but no consensus concerning the amount of training that should be required before non-certified physicians perform ultrasound in applications such as these. The lack of competency testing in ultrasound also complicates the study of skills retention following a short course, and the benefit of continuing medical education on mitigating skills erosion. In the meantime, while academics ponder the training requirements, sales in hand-carried ultrasound units are growing rapidly. Thus there is an increasing need for methods to provide efficient training and for competency testing.
[0009] Ultrasound simulators have been developed to address the training need. An ultrasound simulator typically comprises a mannequin, a simulated transducer, and a computer. The trainee manipulates a simulated transducer on a mannequin as if imaging a live patient, and the computer displays previously acquired images in a view corresponding to the position and orientation of the simulated transducer on the mannequin. The advantages of training on a simulator include compensation for the lack of patient availability, possibility of skills practice at any time, reduction in exposure and embarrassment for the live patient, clinical cost savings from allocation of patient exam rooms and facilities to teaching, and standardization of training programs across the country. Organizations involved in the certification of training programs for medical professionals are moving toward recommendation and even requirement of ultrasound simulation in some fields.
[0010] However, the ultrasound simulators currently in the marketplace have several limitations that reduce their effectiveness. The first major limitation of currently marketed ultrasound simulators is the lack of a method for competency testing. Specifically there is a lack objective and quantitative metrics for assessing physician competence in the acquisition and interpretation of ultrasound images. Simulation is particularly effective for this task. The development of competency test metrics on an ultrasound simulator would have many benefits. For example it would a) enable standardization of certification testing across the country to remove variability in test difficulty; b) remove dependency of testing and training on availability of live patients; c) enable measurement of ultrasound skill retention over time following training; d) enable assessment of the benefit of interventions such as continuing medical education to prevent or mitigate skill erosion; e) save health care costs by deferring training and testing on live patients until the trainee has mastered basic skills so that use of valuable clinic resources is minimized; and f) improve training efficiency by focusing remedial training on the areas of inadequacy while allowing faster learners to advance.
[0011] Another major limitation of currently marketed ultrasound simulators is the paucity of tools for training The fundamental reason why ultrasonography is difficult to learn is because the only clue to the location and orientation of the image plane relative to anatomy is the appearance of the target organ on the image. That is, trainees have difficulty learning to interpret three-dimensional anatomy from two-dimensional images that slice through the target organ in random planes. The training is further confounded by the necessity of practicing on live patients who have abnormal anatomic findings, whose hearts are all beating at different heart rates, and whose images vary widely in quality. Current simulators have addressed some of these by providing excellent quality images, and three-dimensional reconstructions of the anatomy showing the location of the image plane corresponding to the position of the simulated transducer on the mannequin. However to learn how to diagnose pathology requires the trainee to first acquire an image in the same anatomic view as illustrated in a textbook example of that pathology. The trainee must also consider multiple possible diagnoses by comparing the image that she obtained with views in textbooks; however the comparison studies may be illustrated in different anatomic views; in this case the trainee must acquire images in the views that match those in the textbook in order to perform the comparison. Thus the necessity of obtaining images in the same anatomic view plane makes the process of learning slow and tedious. The trainee must also consider multiple severities of each diagnosis, which also presents different appearances in the images. The learning process could be facilitated by having the simulator present the comparison studies in the same anatomic view as the image that the trainee has acquired on the simulator. Another way to facilitate learning is to present the comparison study with the heart beat synchronized to the study being imaged on the mannequin. Yet another method is to enable the trainee to scroll through multiple comparison studies to visually match the appearance of the current study with that of the comparison studies. Similarly, it would be helpful if the trainee could visually match the current study with comparison studies with the same diagnosis but different severities of that medical condition. It would also be helpful if the trainee could visually compare the current study with other studies having diagnoses that may appear similar but are incorrect, to learn how to avoid diagnostic errors.
[0012] Yet another major limitation of currently marketed ultrasound simulators is that they are expensive. The cost of a simulator places a burden on medical training programs, which have traditionally provided training in return for reduced remuneration for patient care service, and which therefore lack any budget for educational expenses. A large part of the cost of the simulator is the system employed to track the position and orientation of the simulated transducer. There are several modalities for tracking an object in three-dimensional space: magnetic, optical, acoustic, and inertial. When utilized alone, magnetic, optical, and acoustic tracking systems each can provide highly accurate six degree-of-freedom tracking, called such because three coordinates of position (x, y, and z) and three angles of orientation (azimuth, elevation, roll) are tracked. All of these modalities of tracking are expensive. Inertial systems sense motion using accelerometers and rotation using gyroscopes. Inertial systems are not accurate at measuring position because they suffer from drift when the tracked object ceases to move. However inertial systems are so inexpensive that remote control devices for computer games combine an inertial device to track orientation together with either a) a magnetometer to sense position by referencing the direction of the earth's magnetic field, or b) an infrared sensor to sense position by referencing infrared signals from emitters placed around the television screen. These game remote control devices lack the tracking accuracy required for an ultrasound simulator.
[0013] There is a need for a method for a six degree-of-freedom tracking device that meets the accuracy requirements of an ultrasound simulator and is inexpensive.
SUMMARY
[0014] In accordance with the present invention, an apparatus and a method are defined for simulating a diagnostic or interventional ultrasound procedure. In one embodiment, the method may comprise receiving a position of a simulated ultrasound transducer relative to a part of a simulated body, generating an image data set from image data stored in data storage to the received position, selecting and displaying the generated image on a display, and displaying at least one of: a three-dimensional reconstruction of anatomy shown in the selected image data set, a three-dimensional reconstruction of a plane of the correlated image, a three-dimensional reconstruction of an anatomically defined image plane for a specified view of the body part displayed in the image, and an image of a variation of the anatomy shown in the selected image data set.
[0015] In another embodiment, a physical computer-readable storage medium having stored thereon instructions executable by a device to cause the device to perform functions is provided. The instructions comprise receiving a position of a simulated ultrasound transducer relative to a part of a simulated body, generating an image data set from image data stored in data storage to the received position, selecting and displaying the generated image on a display, and displaying a three-dimensional reconstruction of anatomy shown in the selected image data set, a three-dimensional reconstruction of a plane of the generated image, and a three-dimensional reconstruction of an anatomically defined image plane for a specified view of the body part displayed in the image.
[0016] In yet another embodiment, a device is provided. The device comprises a first interface configured to couple to a simulated ultrasound transducer, a processor, data storage, and program instructions stored in data storage and executable by the processor to cause the computing device to receive a position of a simulated ultrasound transducer relative to a part of a simulated body, generate an image data set from image data stored in data storage to the received position, select and display the generated image on a display, and display at least one of: a three-dimensional reconstruction of anatomy shown in the selected image data set, a three-dimensional reconstruction of a plane of the generated image, a three-dimensional reconstruction of an anatomically defined image plane for a specified view of the body part displayed in the image, and an image of a variation of the anatomy shown for the selected image data set.
[0017] The apparatus and method provide real-time reproduction of a diagnostic or interventional ultrasound procedure. The apparatus simulates the hardware of an ultrasound machine, with a transducer, a display unit, and requisite controls. The technical and the cognitive stages of an actual diagnostic ultrasound procedure are reproduced, including image acquisition by scanning (manipulating the transducer over the simulated body or body part), viewing the reproduced images on the display unit, utilizing information from the images to optimize the transducer position and orientation for image acquisition, and diagnosis. The technical and cognitive stages of utilizing ultrasound are also reproduced to guide an actual interventional procedure including image acquisition, viewing the reproduced images on the display unit, utilizing information from the images to optimize the transducer position, and orientation for visualizing the anatomy of the targeted body part, the interventional device, and performing the intervention. This allows the operator to practice the procedure as if performing on a live patient, as well as to practice the hand-eye coordination required of the procedure, and to recognize key anatomic landmarks on the images when viewed in various perspectives.
[0018] The stored image data may comprise ultrasound images previously acquired by scanning live patients. The stored image data may also comprise synthetic ultrasound images.
[0019] Real-time reproduction of ultrasound imaging may be provided. As the operator manipulates the simulated transducer over the simulated body or body part, the processor displays two-dimensional images prepared from stored image data. The two-dimensional images are prepared such that the images provide a view that is anatomically appropriate to the position and orientation of the transducer on the simulated body or body part.
[0020] A second window of the display unit for display of the three-dimensional anatomy of the body part being scanned with the simulated transducer may be provided. The location and orientation of the image plane being acquired relative to the anatomy can be presented. The location and orientation of the anatomically defined image plane for specified views can also be presented relative to the anatomy.
[0021] Alternatively, the second window of the display may contain images of variations on the anatomy shown in the selected image data set. A plurality of variations can be presented that are all in the same anatomical view. If the anatomy includes an organ that exhibits motion, the variations can be presented with motion at the same velocity and direction or orientation.
[0022] In one embodiment, the invention enables competency testing that is quantitative and objective, and that may encompass skill as well as knowledge. For each type of ultrasound procedure, a set of learning objectives defined by experts in ultrasound and in medical education is employed to define the test metrics. Testing of competency is performed according to achievement of learning objectives specific for each ultrasound application and for the level of the operator. For example, learning objectives for a medical student are less rigorous than those for a fellow in cardiology. The types of test metrics for competency testing may include but are not restricted to: error in the position and orientation of an image plane acquired from the simulator calculated relative to the anatomically defined image plane, error in measurements made by the operator from one or more acquired images calculated relative to measurements made from the stored image data, and error in diagnosis. Preferably the curriculum directs operators to advance to more difficult objectives as testing documents the mastery of primary skills.
[0023] The tracking device may perform six degree-of-freedom tracking of the position and orientation of an object using one or more tracking modalities. One embodiment may include employing an infrared sensor to enable accurate position and orientation tracking of the simulated transducer.
[0024] These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0025] FIG. 1 depicts an exemplary ultrasound simulator system, in accordance with at least one embodiment;
[0026] FIG. 2 a depicts an exemplary simulated transducer and simulated body part for the example ultrasound simulator system, in accordance with at least one embodiment;
[0027] FIG. 2 b depicts the exemplary simulated transducer and simulated body part of FIG. 2 a in operation;
[0028] FIG. 2 c depicts a top view of a plurality of emitter clusters that may reside within the exemplary simulated body part of FIG. 2 a;
[0029] FIG. 3 a depicts a visualization of an exemplary organ from a single pyramidal volume of image data using a three-dimensional ultrasound machine;
[0030] FIG. 3 b depicts a visualization of an exemplary organ from a plurality of images from an image storage using a three-dimensional ultrasound machine;
[0031] FIG. 4 depicts the exemplary ultrasound simulator system of FIG. 1 , in accordance with at least one embodiment;
[0032] FIG. 5 depicts a simplified flow diagram of an example method that may be carried out by the example ultrasound simulator system, in accordance with at least one embodiment; and
[0033] FIG. 6 depicts a simplified flow diagram of an example method that may be carried out by the example ultrasound simulator system, in accordance with at least one embodiment.
DETAILED DESCRIPTION
[0034] In the following detailed description, reference is made to the accompanying figures, which form a part thereof. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, figures, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
[0035] FIG. 1 depicts an exemplary ultrasound simulator system in accordance with at least one embodiment of the present application. In one system 100 , a device with a user interface 110 may contain hardware to enable a wired or wireless communication link. The device with user interface 110 is coupled to a simulated ultrasound transducer 120 with a communication link, and may be coupled to communicate with other devices as well. The communication link may also be used to transfer image or textual data to the user interface 110 from other sources, or may be used to transfer unprocessed data, for example.
[0036] The communication link connecting the device with user interface 110 with the simulated ultrasound transducer 120 may be one of many communication technologies. For example, the communication link may be a wired link via a serial bus such as USB, or a parallel bus. A wired connection may be a proprietary connection as well. The communication link may also be a wireless connection using, e.g., Bluetooth® radio technology, communication protocols described in IEEE 802.11 (including any IEEE 802.11 revisions), Cellular technology (such as GSM, CDMA, UMTS, EV-DO, WiMAX, or LTE), or Zigbee® technology, among other possibilities.
[0037] The device with user interface 110 comprises a display 112 . The device with user interface 110 may also comprise a processor 114 , and data storage storing image data and logic 116 . These elements may be coupled by a system bus or other mechanism. The processor 114 may be or may include one or more general-purpose processors and/or dedicated processors, and may be configured to compute displayed images based on received data. The processor 114 may be configured to perform an analysis on the orientation, position, or movement determined by the simulated ultrasound transducer 120 so as to produce an output. An output interface may be configured to transmit the output to the display 112 . The device with user interface 110 may include elements instead of and/or in addition to those described.
[0038] The system 100 also comprises a simulated body part 130 , and an operator 140 . In the present embodiment, the operator 140 may manipulate the simulated ultrasound transducer 120 and view the display 112 .
[0039] Display 112 comprises a first window 113 and a second window 115 . In the first window 113 , a two-dimensional image is displayed. In the second window 115 , a three-dimensional reconstruction of the anatomy 117 shown in the first window 113 is displayed, including a reconstruction of an anatomically defined image plane 118 and a reconstruction of a plane of the image generated by the operator 119 .
[0040] The anatomically defined image plane may be an anatomically correct image plane. The anatomically defined image plane is identified analytically from the three-dimensional reconstruction. For example, the four-chamber view of the heart is the two-dimensional image obtained in a plane defined by the centroids of the mitral and tricuspid valve annuli and the apex of the heart. The coordinates of analytically defined image planes are in the same space as the acquired image. A graphic of such a plane may be displayed with the three-dimensional reconstruction for comparison with the acquired image plane.
[0041] For some organs, the anatomically defined image plane may be the plane that visualizes the organ in its maximum dimension such as length or cross sectional area. For other organs, such as the heart, the anatomically defined image plane may be the plane that visualizes specific anatomic landmarks. For example, the apical four chamber view of the heart may be defined as taught by King D L, et al., Ultrasound Beam Orientation During Standard Two - Dimensional Imaging: Assessment by Three - Dimensional Echocardiography , 5 J. Am. Soc. of Echocardiography 569-576 (1992) incorporated herein by reference, as a plane passing through the center of the left ventricle of the heart and parallel to the left ventricular central long axis, and further refined by C. M. Otto, Textbook of Clinical Echocardiography, 4th ed. (2009), incorporated herein by reference, as also passing through the mitral valve at its largest diameter. It will be noted that the definition of the anatomically defined plane for a specified view may vary between experts. For example, M. N. Allen, Echocardiography, 2d ed. (1999), incorporated herein by reference, teaches that the apex of the left ventricle should appear at the center of the sector where the septum and lateral wall meet and should almost come to a point, the mitral and tricuspid valves should swing open widely in the absence of pathology, the walls of the left and right atria should be clearly seen, pulmonary veins should be seen entering the left atrium, and the right ventricle should appear as a triangular shape in the absence of pathology. However this definition should not be taken as a disagreement with the definition of the references King D L et al. and Otto because the Allen reference describes the desired result rather than prescribing the view.
[0042] FIG. 2 a depicts an exemplary simulated ultrasound transducer and simulated body part for an example ultrasound simulator system such as the example system 100 , in accordance with at least one embodiment. The simulated ultrasound transducer 120 comprises an infrared sensor 122 at one end. The simulated body part 130 comprises a plurality of infrared emitters 132 .
[0043] The plurality of infrared emitters 132 may be a cluster of emitters. FIG. 2 a depicts one such cluster of four infrared emitters 132 . Each infrared emitter comprises a pedestal 134 , and may be any standard infrared emitter known in the art. In the present example, each of the plurality of infrared emitters 132 is the same emitter with the exception of the height of their respective pedestals 134 . The varying heights of the pedestals (resulting in a varying height of the emitters on top of the pedestals) may comprise a distinct spatial pattern that is detectable by the simulated ultrasound transducer 120 .
[0044] The infrared emitters 132 are configured in such spatial patterns that permit recognition of each cluster's identity, to enable calculation of the infrared sensor's position in three-dimensional space. The spatial pattern may be nonplanar (tetrahedral) to provide orientation angle discrimination; specifically, an inverse viewing transformation is performed on data from the infrared sensor 122 and the infrared emitter 132 geometry to determine the viewing angle of the simulated transducer relative to the known three-dimensional target geometry. An iterative algorithm for determining best fit of the transformed data, thereby yielding accurate relative angle and distance is commonly known in the art as the POSIT (Pose from Orthographic and Scaling with Iterations) Algorithm.
[0045] The infrared emitters 132 may also fluctuate in intensity over time at frequencies that aid in identifying specific emitter groups, as needed to enable accurate calculation of the infrared sensor's spatial position. The infrared sensing of spatial position is combined with the simulated ultrasound tracking device's measurement of orientation to provide six degree-of-freedom tracking of the simulated ultrasound transducer 120 .
[0046] In operation, the end of the simulated ultrasound transducer 120 with the infrared sensor 122 is positioned on the simulated body part 130 . As an operator moves the simulated ultrasound transducer 120 to a different position and/or orientation (as illustrated by the dashed lines), the coordinates of the new position and orientation are computed, at least in part, from the pattern detected from the presence of the plurality of infrared emitters 132 .
[0047] The coordinates of position and orientation may be measured using a six degree-of-freedom tracking device. One application of the six degree-of-freedom tracking device is to register the image data sets in the memory unit to the position and orientation of the simulated body or body part at the beginning of each use.
[0048] Another application of the six degree-of-freedom tracking device is to measure the position and orientation of the simulated ultrasound transducer 120 in real time as the operator 130 is manipulating the transducer 120 over the simulated body part 130 . The tracking data are used to compute the location of the two-dimensional ultrasound image plane that corresponds spatially to the location of the simulated ultrasound transducer 120 on the simulated body or body part 130 .
[0049] In an alternative embodiment, inertial guidance may be utilized in combination with infrared sensing to improve accuracy and precision of tracking The tracking data from such other modalities will be fused with infrared sensor data using methods such as Kalman filtering.
[0050] FIG. 2 b depicts the exemplary simulated ultrasound transducer 120 and simulated body part 130 of FIG. 2 a in operation. In FIG. 2 b , a first cluster of infrared emitters 136 and a second cluster of infrared emitters 138 are shown. As the simulated ultrasound transducer 120 is changed in position and/or angulation by the operator over the simulated body part 130 , the infrared sensor 122 may detect one of or both the first cluster of infrared emitters 136 and the second cluster of infrared emitters 138 . A detection field 124 for each of the plurality of positions and/or orientations of the simulated ultrasound transducer 120 is shown.
[0051] FIG. 2 c depicts a top view of a plurality of emitter clusters, such as the emitter cluster 132 , which may reside within the exemplary simulated body part 130 of FIG. 2 a . Each of the plurality of emitter clusters 132 may be disposed within the simulated body part 130 in positions corresponding to the expected location of certain organs within a human body. Alternatively or in combination, the emitter clusters 132 may be disposed within the simulated body part 130 in positions that facilitate the computation of the position and orientation of the sensor.
[0052] FIG. 3 a depicts a visualization of a single volume of image data using a 3-dimensional ultrasound machine. In the example shown in FIG. 3 a , the visualization 200 comprises a single pyramidal volume of image data comprising a portion of a heart 210 . Visualization 200 illustrates the difficulty of visualizing an organ such as the heart 210 within a single pyramidal volume of image data as may be acquired using a three-dimensional ultrasound machine. The entire heart 210 is not able to be captured in the visualization 200 . Although FIG. 3 a depicts a human heart as the example organ, it will be understood that the organ can be any anatomic structure within a living vertebrate.
[0053] FIG. 3 b depicts a visualization of the exemplary organ of FIG. 3 a taken from a plurality of images from an image storage using a three-dimensional ultrasound machine. In FIG. 3 b , a plurality of three-dimensional image data sets 220 from an image library are used to provide an operator with a complete visualization of the human heart 210 and any surrounding tissue.
[0054] FIG. 4 depicts an exemplary ultrasound transducer system 400 in accordance with at least one embodiment. FIG. 4 shows computing an imaging plane 410 over an organ 411 and surrounding tissue 409 in a body 405 taken by an ultrasound transducer 420 using the six degree-of-freedom coordinates of the transducer 420 position and orientation. The imaging plane 410 can then be used to create a subset of a case image set, which can be presented as a two-dimensional image 412 on a display 430 , such as the display 110 described with reference to FIG. 1 . The case image set creation will be described in further detail with respect to FIG. 5 . The image plane location 413 and a three-dimensional reconstruction of the anatomy shown in the selected image 414 may also be shown on display 430 .
[0055] FIG. 5 depicts a simplified flow diagram of an example method that may be carried out to create a plurality of case image sets to install in the example ultrasound simulator system, in accordance with at least one embodiment. Method 500 shown in FIG. 5 presents an embodiment of a method that, for example, could be used with system 100 .
[0056] In addition, for the method 500 and other processes and methods disclosed herein, the flowchart shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive. The computer readable medium may include a physical and/or non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, a tangible storage device, or other article of manufacture, for example. Alternatively, program code, instructions, and/or data structures may be transmitted via a communications network via a propagated signal on a propagation medium (e.g., electromagnetic wave(s), sound wave(s), etc.).
[0057] Initially, the method 500 includes acquiring multiple overlapping three-dimensional ultrasound image data sets of a live patient while recording ultrasound transducer position and orientation, at block 510 . In the preferred embodiment, a commercial three-dimensional ultrasound machine and transducer are used in conjunction with a tracking device to record the six degree-of-freedom position and orientation of the transducer during imaging.
[0058] The image data is linked in computer files to the tracking data and is used to compute the coordinates of each voxel in three-dimensional space. The volumes of image data may be partially overlapping as needed to obtain visualization of the target organ and the tissue immediately surrounding the target organ without gaps. The volumes of image data are then assembled into a single volume of image data using a spatial compounding method that assigns a gray scale value to each voxel in the image volume after consideration of gray values in adjacent voxels.
[0059] The method 500 then includes acquiring coordinates of three fiducial anatomic landmarks, at block 520 .
[0060] The method 500 includes combining the image data sets and fiducial landmarks into a single volume of image data, at block 530 .
[0061] The method includes tracing the target organ borders from images, at block 540 .
[0062] The method includes using the borders to reconstruct target anatomy in three dimensions, at block 550 .
[0063] The method includes using the reconstructed anatomy to compute anatomically defined views, at block 560 .
[0064] The method includes providing a case image set, at block 570 . The case image set comprises the combined image data set, reconstructed target anatomy, and anatomically defined views.
[0065] The method includes linking the case image set with acquired clinical data, at block 580 . A trainer may gather clinical data from the live patient and prepare the patient's medical history, comprising patient symptoms and other various pertinent test results, as well as records of surgery and other treatments. The trainer can prepare test questions from this clinical data, and send the data to be linked with the case image set for that particular patient. The linked clinical data with the case image set comprises a case study. Alternatively, the trainer may modify the clinical data from the live patient, for example to enhance its instructional capacity, before sending the data to be linked to the case image set.
[0066] An image library may be prepared from a plurality of such case studies, which may be representative of a field of medical practice or knowledge.
[0067] The case image sets may be positioned computationally within the simulated body or body part using a registration procedure. The registration procedure enables preparation of image data for presentation on the display that is appropriate for the position and orientation of the simulated transducer on the simulated body or body part. Specifically, as each live patient is scanned to create a case study for an image library, the coordinates of three anatomic landmarks will be measured from tracking data recorded when the ultrasound transducer is touched briefly to each landmark. At the beginning of each session on the simulator, the simulated transducer is touched to the same anatomic landmarks on the simulated body or body part to define the coordinates of these landmarks. The case image set is then registered to the simulated body or body part by translating, rotating, and scaling to match, using these landmark coordinates as fiducial markers. To save time in opening case studies, all case image sets in a library may be translated, rotated, and scaled to register them together. Each of the case image sets may be linked with its associated acquired clinical data.
[0068] The two-dimensional imaging plane of the transducer is calculated from the six degree-of-freedom coordinates of transducer position and orientation. The imaging plane is intersected with the case image set to identify a subset of image data that is presented on the display as a two-dimensional ultrasound image.
[0069] The location(s) of one or more image planes acquired from the case image set may be displayed with the three-dimensional reconstruction when the simulator is used for teaching. The three-dimensional reconstruction may be prepared by entering at least three anatomic points on the image data using an interface for image review and feature tracing. Three-dimensional reconstruction of the target organ from such sparse input data is enabled by a database that embodies knowledge of the expected shape of the target organ. For example, a piecewise smooth subdivision surface is computed as a weighted sum of surfaces in the database. The weights are determined by shape similarity to the entered points using an optimization routine that minimizes the distance from the entered points to the surface. If the target organ is a heart, the process is repeated for every time point in the cardiac cycle to enable a beating heart graphic display.
[0070] One embodiment may include a display of image data from one or more stored image data sets for visual comparison with the image data from the data currently being scanned, called image matching. Image matching is a tool for assisting the operator in learning to interpret medical ultrasound images by identifying similarities and differences between the image data set being scanned and other patients' image data sets stored in the memory unit having, for example, a similar diagnosis but different severity of disease. The comparison data set or sets may be displayed in the same anatomic view as the image data acquired on the simulated body or body part. The comparison data set or sets may be displayed with the heart beating synchronously with the image data acquired on the simulated body or body part. These options allow adjustment of the training to be easier or more difficult as needed or desire according to the ability of the operator.
[0071] Preferably, an extensive number of image data sets illustrating a wide range of pathologies and of the severities of these pathologies will be available. The image data sets may be accompanied by clinical data to enhance the realism of the training and testing. A curriculum may be established by experts in the field of ultrasound and in medical education to direct the operator of the transducer.
[0072] The image matching display may be prepared by selecting a plurality of case studies in the image library and presenting image data from them in the second window, after conversion from three-dimension to two-dimension, for side-by-side comparison with image data from the case study being scanned in the two-dimensional ultrasound window. The selected case studies are registered by three anatomic landmarks for presentation in the same anatomic view as the case study being scanned. The anatomic landmarks utilized are appropriate for the diagnosis. For example, studies illustrating coronary artery disease would be registered by the centroids of the aortic and mitral valves and the apex of the left ventricle.
[0073] The case studies in the image library may be synchronized in time by adjusting the playing time for one cardiac cycle or heart beat to equal that of the case study being scanned in the simulated body or body part. If not synchronized, then the case studies may be played at the heart rate of the live patient at the time of image acquisition.
[0074] Testing of competency in the technical skill of ultrasound acquisition measures proficiency in manipulating the transducer, identifying the anatomy of the target organ and surrounding tissues, and acquiring images in the anatomically defined image plane. In the preferred embodiment, proficiency in manipulating the transducer is assessed by measuring how well the operator maintains the target organ in the center of the image while rotating or angulating the transducer; the error is computed as the distance between the centroid of the target organ in the image plane and the centroid of the portion of the image plane that contains the image at time intervals during the test. However it will be understood that there may be other examples of proficiency testing. Error in acquiring an image in the anatomically defined image plane is computed in terms of distance and angle. The distance between the anatomically defined plane and plane acquired by the operator will be computed as the distance between a specified anatomic landmark such as the centroid of the mitral annulus in the two planes. The error in orientation will be computed as the angle between the two planes. Error in measurements of organ dimension, volume, shape, and/or function made by the operator from one or more acquired images is calculated relative to measurements made from the anatomically defined images. Error in diagnosis is assessed by comparison with the true diagnosis as defined by experts and the medical records of the patient whose image data are stored in the memory unit.
[0075] Testing of competency in ultrasound guided intervention measures proficiency in manipulating the transducer to obtain views of both the anatomical target and the needle or catheter or other device that is to be inserted into the target. For example, the Learning Objectives for ultrasound guided jugular vein catheterization (JVC) are ability to a) visualize both the jugular vein and the needle in a cross sectional view, b) position the needle over the vein using ultrasound guidance, and c) insert the needle into the vein in a safe manner. When JVC is performed safely, a) the needle does not enter the carotid artery, b) the needle stays within the jugular vein, c) the angle of needle entry is 45±10°, and d) JVC is completed in no more than 3 attempts. Error in needle position is measured directly from the tracking coordinates of the needle's tip and the coordinates of the three-dimensional reconstructions of the carotid artery and jugular vein in the case study.
[0076] FIG. 6 depicts a simplified flow diagram of an example method that may be carried out by the example ultrasound simulator system, in accordance with at least one embodiment. Method 600 shown in FIG. 6 presents an embodiment of a method that, for example, could be used with system 100 .
[0077] Initially, the method 600 includes receiving a position of a simulated ultrasound transducer relative to a part of a simulated body, at block 610 .
[0078] Then, the method 600 includes generating a two-dimensional image from three-dimensional image data stored in data storage for the received position, at block 620 .
[0079] The method 600 includes selecting and displaying the generated image on a display, at block 630 .
[0080] The method 600 includes displaying at least one of a three-dimensional reconstruction of anatomy shown in the selected image data set, a three-dimensional reconstruction of a plane of the generated image, a three-dimensional reconstruction of an anatomically defined image plane for a specified view of the body part displayed in the image, and an image of a variation of the anatomy shown in the selected image data set, at block 640 .
[0081] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
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An apparatus and a method reproduce a diagnostic or interventional procedure that is performed by medical personnel using ultrasound imaging. A simulator of ultrasound imaging is used for purposes such as training medical professionals, evaluating their competence in performing ultrasound-related procedures, and maintaining, refreshing, or updating those skills over time.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a mobile communication service, and more particularly to a method of reporting a service option re-negotiation to a mobile switching center.
[0003] 2. Background of the Related Art
[0004] Generally, when an call (i. e. , originating/terminating call) is established in a related art CDMA mobile communication system, the service option negotiated between a mobile station (MS) and a base station is reported to a mobile switching center.
[0005] Specifically, if a mobile station wants to receive a specific service, it requests the base station a service option corresponding to that service in an initial call setup procedure. Then the base station and the mobile switching center assign the required resources to provide the specified service to the mobile station according to the service option negotiated with the mobile station.
[0006] In the call (i. e. , originating/terminating call) setup procedure between the mobile station and the base station, the mobile station and the base station perform a service option negotiation procedure. Then the base station reports negotiated service option to the mobile switching center. The mobile switching center makes accounting information or creates a call detailed record(CDR) based on the service option information.
[0007] If the service option needs to be changed by the base station, for example due to base station's resource management, or by the mobile station during the conversation, a service option re-negotiation procedure can be performed. The service option re-negotiation is carried out in accordance with the communication standard for the signal process between the mobile station and the base station TIA/EIA IS-2000.5.
[0008] [0008]FIG. 1 illustrates a mobile communication system. Referring to FIG. 1, the mobile communication system comprises a mobile station (MS) 1 , a base transceiver station (BTS) 21 and a base station controller (BSC) 22 , namely base station, and a mobile switching center (MSC) 3 . Communication between the mobile station 1 and the base station ( 21 , 22 ) is performed according to the IS-2000 standard. Communication between the base station 21 , 22 and the mobile switching center 3 is performed according to the 3G-IOS standard.
[0009] [0009]FIG. 2 illustrates the call set-up procedure of a CDMA mobile communication system. The procedure in the FIG. 2 focuses on the originating call setup procedure including service option negotiation process. Here, the service option negotiation procedure in FIG. 2 is also applied to the terminating call set-up procedure.
[0010] [0010]FIG. 3 illustrates the structure of a 3G-IOS Assignment Complete message including the service option determined through the call set-up procedure of FIG. 2. This message is transmitted from the base station to the mobile switching center. The message structure comprises a one (1) byte message type field, 301 for message discrimination, a channel number field 302 , representing the channel number allocated, encryption information 303 , representing encoding information of transmitted data, and a service option 304 representing service. The service option includes a service option information element identifier (IEI) 304 ′, and service option information 304 ″, representing value of the service option.
[0011] A related art originating call setup procedure will be described with reference to FIG. 2. First, when a user attempts to initiate a call, the mobile station transmits a TIA/EIA IS-2000 Origination message, including a service option so_A identifying the service required by the user. The origination message is transmitted to the base station on an access channel (step 201 ).
[0012] The base station, having received the IS-2000 Origination message, transmits an IS-2000 Acknowledgement Order to the mobile station (step 202 ). The base station then assigns a service option connection identifier (SOCI) (expressed by 1 byte to discriminate respective services) to the corresponding service. The SOCI is an identifier element for identifying the service provided between the base station and the mobile switching center. The base station transmits a 3G-IOS connection management (CM) service request message, including the service option so_A requested by the mobile station and corresponding SOCI to that service so_A, to the mobile switching center using a 3G-IOS complete layer 3 information message (step 203 ). The sending of this message drives a timer T 303 for awaiting a 3G-IOS assignment request message from the mobile switching center (step 203 ).
[0013] Then the mobile switching center transmits a 3G-IOS Assignment Request message to the base station to request the assignment procedure for the radio resources (step 204 ). The sending of this message drives a timer T 10 for a awaiting a 3G-IOS Assignment Completion message. The Assignment Request message terminates the timer T 303 . The base station and the mobile station then exchange a channel assignment message for the radio resource assignment process (i. e. , traffic channel assignment process), a traffic preamble signal for matching the traffic channel synchronization, the base station sends Acknowledgment Order to acknowledge the traffic channel preamble, and the mobile station sends Acknowledgment Order (step 205 ).
[0014] After completion of the radio resources assignment procedure, the base station newly assigns a connection reference (CON_REF) defined in the TIA/EIAIS-2000.5 specification as an identifier for identifying the service between the mobile station and the base station. The base station then sends a Service Connection message to the mobile station, and the mobile station sends a Service Connection Completion message to the base station. These messages are used for determining a service configuration including the CON_REF Let's call it as CON_REF #1) and the corresponding service option so_A (step 206 ). And the service option could include “13k voice”, “8k enhanced voice rate control (EVRC)” in case of voice call to identify the kind of service and the quality of service.
[0015] According to the assignment request at step 204 , the base station transmits to the mobile switching center the 3G-IOS Assignment Completion message, including the service option so_A determined through steps 205 and 206 (step 207 ). The mobile switching center, upon receiving this message, terminates the timer T 10 .
[0016] After the above described processes, the mobile station, base station, and mobile switching center enter into in a conversation state, and the mobile switching center uses the service option included in the 3G_IOS Assignment Completion message received from the base station for creation of the billing information or the CDR.
[0017] Subsequently, if the base station requires a change of the service option due to, for example, resource management of the system or a request of the mobile station during the conversation, a service option re-negotiation procedure can be performed according to the communication standard TIA/EIA IS-2000.5 between the mobile station and the base station (step 208 ).
[0018] When setting up the call, as described above, the service option negotiated between the mobile station 1 and the base station 21 and 22 is reported to the mobile switching center 3 using the 3GIOS Assignment Completion message as shown in FIG. 3. There ported information is used for reasons such as billing information.
[0019] When the service option of the call is changed through the service option re-negotiation procedure during the conversation, however, there is no way to report the change to the mobile switching center 3 currently. Instead, the mobile switching center can create the billing information or the CDR using only the service option negotiated during the call setup. Thus, the initially created information becomes inaccurate if service option re-negotiation procedure occurs during the conversation.
[0020] For example, if service option is changed from a 13k voice to a new value of 8k EVRC through service re-negotiation, there is no way for the base station to report the change of service option to the mobile switching center. Consequently, the data created based on only the service option negotiated during the call setup is incorrect.
[0021] The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
SUMMARY OF THE INVENTION
[0022] An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
[0023] Another object of the present invention is to provide a method of reporting a service option changed according to a re-negotiation between a mobile station and base station during conversation to a mobile switching center.
[0024] Another object of the present invention is to provide a method of using a changed service option.
[0025] Another object of the present invention is to provide a method of reporting the result of the service option re-negotiation procedure performed when at least two services are simultaneously provided with respect to one mobile station to a mobile switching center.
[0026] In order to achieve the above objects, in whole or in parts, a new method provided is that the base station reports a changed service option using an Assignment Completion message to a mobile switching center, comprising a message type, a channel number representing a communication path being used, transmitting encoded information, and the changed service option.
[0027] In order to achieve the above objects, in whole or in parts, the other new method provided that the base station reports a changed service option using a Service Option Report message, comprising a message type and the changed service option.
[0028] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:
[0030] [0030]FIG. 1 is a drawing illustrating a mobile communication system;
[0031] [0031]FIG. 2 is a flowchart illustrating a call setup procedure of a related art CDMA mobile communication system;
[0032] [0032]FIG. 3 is a drawing illustrating a structure of a related art 3G-IOS Assignment Complete message;
[0033] [0033]FIG. 4 is a flowchart illustrating a method of reporting a changed service option through a service option re-negotiation between a mobile station and base station using 3G-IOS Assignment Complete message;
[0034] [0034]FIG. 5 is a drawing illustrating the structure of a 3G-IOS Assignment Complete message of FIG. 4;
[0035] [0035]FIG. 6 is a drawing illustrating a structure of a service option list in the message structure of FIG. 5;
[0036] [0036]FIG. 7 is a flowchart illustrating a method of reporting a changed service option through a service option re-negotiation using Service Option Report message;
[0037] [0037]FIG. 8 is a drawing illustrating the structure of a Service Option Report message of FIG. 7;
[0038] [0038]FIG. 9 is a flowchart illustrating a reporting method when one or more service options are changed while all other services are maintained according to the preferred embodiment of the present invention as a result of service option re-negotiation procedure;
[0039] [0039]FIG. 10 is a flowchart illustrating a procedure and process in case that one or more services are released and one or more service options are changed according to the present invention as a result of service option re-negotiation procedure;
[0040] [0040]FIG. 11 is a flowchart illustrating a procedure when any service options are not changed and one or more services are released according to the preferred embodiment of the present intention as a result of service option re-negotiation; and
[0041] [0041]FIG. 12 is a flowchart illustrating a procedure when all the services are released according to the preferred embodiment of the present invention as result of service option re-negotiation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] A method of reporting a mobile switching center 3 the service option changed by a service re-negotiation procedure between the mobile station 1 and the base station 21 , 22 after the completion of call set-up is described below. Additionally, the message structure and a procedure between the base station 21 , 22 and the mobile switching center used for reporting service option changed as a result of re-negotiation will also be described.
[0043] [0043]FIG. 4 illustrates one method of reporting the changed service optionthrough the service option re-negotiation between the mobile station and the base station. This method uses Assignment Complete message to report the changed service option to the MSC.
[0044] [0044]FIG. 5 illustrates the structure of the Assignment Complete message in the FIG. 4. As shown in FIG. 5, changed service option information is added to a conventional Assignment Complete message, which is defined in the 3G-IOS A1 I/F. This redefined Assignment Complete message is used to report to the mobile switching center. The redefined message modify a conventional 3G-IOS A1 message structure (as shown in FIG. 3) which is used to report the completion of the call set up to the mobile switching center by adding a new field, service option list. The service option list is an information element that can contain the result of service re-negotiation between the mobile station and the base station.
[0045] [0045]FIG. 6 illustrates the structure of the service option list in the message structure of FIG. 5. To support one or more services (for example, a voice call and a data call) simultaneously, the service option list structure preferably comprises a one (1) byte service option list IEI 601 to identify respective provided services, a length field 602 to indicate a length of transmitted information, and a number of service options field 603 to indicate the number of service options changed as a result of negotiation. Also, a SOCI field (# 1 ,# 2 ) 604 is included to identify the changed service, and a service option (i) field 605 is provided to indicate the corresponding service information (i. e. , option) (for example, so_A and so_B are identified by two bytes). The SOCI(# 1 ,# 2 ) 604 and the service option (i) 605 information are repeated as many as the number of service options 603 .
[0046] [0046]FIG. 7 illustrates the other method of reporting a new service option that has changed through the service option re-negotiation between the mobile station and the base station. This method is accomplished by using a Service Option Report message that is a new message not defined in the conventional 3G-JOS A1I/F.
[0047] [0047]FIG. 8 illustrates a preferred structure of the service option report message in the FIG. 7. The service option report message preferably comprises a one (1) byte message type to identify respective messages, and a service option list. The service option list information is the same as that of FIG. 5.
[0048] [0048]FIGS. 9, 10, 11 , and 12 illustrate useable methods of reporting to the mobile switching center the result of service option renegotiation between the mobile station and the base station in various cases according to the present invention.
[0049] With respect to FIG. 9, a procedure of reporting the change is shown, where one or more service options are changed while all other services are maintained. In this procedure, the result of the service option re-negotiation between the mobile station and the base station can be reported to the mobile switching center using either of the Assignment Complete message or the Service Option Report message(step 901 ).
[0050] With respect to FIG. 10, a procedure is shown, where one or more services are released and one or more service options are changed. In this procedure, the result of the service re-negotiation between the mobile station and the base station can be reported to the mobile switching center using either of the Assignment Complete message and the Service Option Report (step 1001 ). The service options which are to be released are cleared using a Service Release message and a Service Release Complete message (step 1002 ).
[0051] Referring to FIG. 11, a procedure is shown where one or more services are released and tie remaining service option is maintained, i. e. , the existing service options are not changed. In this procedure, since the service option is not changed, no reporting procedure is required from the base station to the mobile switching center. However, the Service Release/Service Release Complete message including the SOCI information that indicates the released service is transmitted/received between the base station and the mobile switching center to clear the service. (step 1101 ).
[0052] With respect to FIG. 12, a procedure is shown, where all the services are to be released as a result of service option re-negotiation. In this procedure, a 3G-IOS Clear Request message, Clear Command message, and Clear Complete message are transmitted/received between the base station and the mobile switching center as the call clearing procedure defined in the 3G-IOS.
[0053] Next, a preferred method of reporting the changed service option to the mobile switching center after the service option re-negotiation and the method when one or more services are changed, and/or a portion of the service options is released will be described.
[0054] According to the method of reporting the changed service option to the mobile switching center after the service option re-negotiation, as shown in FIGS. 4 and 5, only new information elements are added to the existing message, Assignment Complete defined in the 3G-IOS A1 I/F. The new added information element contains information that has changed as a result of the service option re-negotiation.
[0055] That is, according to this reporting method, the Assignment Complete message structure (of FIG. 3) defined in the 3G-IOS A1 I/F is modified to include the changed service option in the message structure. Since service re-negotiation may occur during the conversation as well as the call set-up time, the mobile switching center should make the Assignment Complete message processed during both the call setup time and conversation.
[0056] In this method, in order to identify and support two or more services (for example, a voice call and a data call) simultaneously, the changed service option is reported to the mobile switching center using the service option list information elements (FIGS. 5 and 6). These elements include the service option connection identifier (SOCI) corresponding to the service option of the Assignment Complete message structure of FIG. 3.
[0057] Specifically, when the call is first setup, the completion of the call set-up is reported to the mobile switching center using the service option of the assignment completion message structure. When the service option is then changed through the service option re-negotiation procedure, this event is reported to the mobile switching center along with the service option list information elements of the changed Assignment Complete message structure. The structure and effect of the changed Assignment Complete message are the same as that of FIG. 3 except for the service option portion. Accordingly, the newly added service option list represents the change resulting from the service option re-negotiation.
[0058] After being changed, the Assignment Complete message structure includes the service option list information element in order to support the voice call and the data call simultaneously. This information element preferably comprises a service option list IEI, a length for indicating the length of transmitted information, the number of service options for indicating the number of services changed as a result of negotiation, SOCI(# 1 ,# 2 ) for identifying the changed service information, and a service option (i) for indicating the changed service information (i. e. , option). The SOCI(# 1 ,# 2 ) and the service option (i) information are repeated as many as the number of service options.
[0059] Referring next to FIGS. 7 and 8, in a second embodiment of the present invention, the result of the service option re-negotiation is reported to the mobile switching center in tie form of a new message not previously defined in the 3G-IOS A1 I/F. The new message is a communication I/F between the base station and the mobile switching center.
[0060] The Assignment Complete message, as shown in FIG. 4, is the message used for the resource assignment procedure to mate with the assignment request. Thus, according to the second embodiment, a new message, named a Service Option Report, is used to report the changed contents due to the service option re-negotiation. The Service Option Report message structure of FIG. 8 includes a message type, and information in the form of a service option list of FIG. 6.
[0061] The service option list is the same as the service option list of FIGS. 5 and 6. Specifically, in order to support two or more services (for example, a voice call and a data call) simultaneously, the service option list comprises a service option list IEI 601 , a length 602 for indicating the length of transmitted information, the number of service options 603 for indicating the number of services changed as a result of negotiation, a SOCI(# 1 ,# 2 ) 604 for identifying the changed service, and a service option (i) 605 for indicating the changed service information. The SOCI(# 1 ,# 2 ) and the service option (i) are repeated as many as the number of service options.
[0062] In a reporting method according to another embodiment of the present invention, the contents of one or more services may be changed, and/or a portion of the service options may be released as a result of the service re-negotiation.
[0063] First, referring to FIG. 9, when a portion or all of the services are changed while all of the services in progress are maintained, the base station reports the changed service option to the mobile switching center in accordance with the method and structure of FIGS. 4 and 5, or FIGS. 7 and 8, respectively.
[0064] Second, referring to FIG. 10, when a portion of the services in progress is released and one or more the non-released service options are changed, the base station reports the changed service options to the mobile switching center in accordance with the method and structure of FIGS. 4 and 5, or FIGS. 7 and 8, respectively, and performs a service release procedure with respect to the released service. The service release is performed using the Service Release and Service Release Complete messages defined in the 3G-IOS v4.1.
[0065] Referring next to FIG. 11, when a portion of the services in progress is released and other services, which are not the released service, are not changed, the base station is not required to report to the mobile switching center since the contents of service option are not changed. The base station, however, must perform a service release procedure with respect to the released service using the Service Release and Service Release Complete messages defined in the 3G-IOS v4.1.
[0066] Finally, referring to FIG. 12, when all of the services in progress are released as a result of the service option re-negotiation between the mobile station and the base station, the base station performs a call release procedure using a Clear Request, Clear Command, and Clear Complete messages defined in the 3G-IOS v4.1.
[0067] As described above, the embodiments of the present invention have many advantages. For example, a method of reporting a result of service option re-negotiation to a mobile switching center is provided by adding a service option list to the existing Assignment Complete message. Additionally, a method of reporting the result of a service option re-negotiation using a service option report message, having a new message structure, is provided when the service option re-negotiation procedure is performed with respect to a call made in the mobile communication system.
[0068] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other tipes of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.
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A method of reporting a result of service option re-negotiation to a mobile switching center of a CDMA communication services is disclosed. An assignment completion message structure or a service option report message structure is used to report the changed service option. The method using the assignment completion message structure includes transmitting a message type, a channel number representing a communication path being used, encoded information, and contents of the changed service option. Also, the method using the service option report message structure includes transmitting a message type and the contents of the changed service option.
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BRIEF DESCRIPTION OF THE INVENTION
This invention relates to glob top ball-grid array (“BGA”) electronic packages that are thermally enhanced to accommodate higher powered integrated circuit (“IC”) devices, a.k.a. chips.
BACKGROUND OF THE INVENTION
Among the variety of electronic packages used in the electronics industry, glob top BGA packages are one of the popular packages for low-end performance applications. Glob top BGA packages are part of a large family of wirebond BGA packages. These wirebond BGA packages utilize low-cost organic material based substrates (a.k.a. laminates) such as Bismaleimide triazine epoxy (“BT”), polyimide, and polytetrafluoroethylene, and are well-suited for the low-end performance applications because of their relatively low cost.
FIG. 1 illustrates a cross-sectional view of such a prior art glob top BGA package. The package consists of a laminate substrate 10 having on one side BGA solder balls 20 and on the opposite side a die attach pad (“DAP”) 14 for receiving an IC device (a.k.a. a die) 30 . DAP 14 is typically surrounded by metallized wirebond pads 12 on laminate substrate 10 to which wirebond wires 34 can be bonded.
An IC device 30 is attached to DAP 14 using thermally conductive epoxy 32 with its active side facing away from laminate substrate 10 . Wirebond wires 34 make the electrical interconnection between IC device 30 and metallized pads 12 on laminate substrate 10 . One end of each wirebond wire 34 is bonded to a wirebond pad (not shown) on the IC device and the other end of the wire is bonded to a pad 12 . The side of laminate substrate 10 where IC device 30 is attached is then encapsulated with glob top epoxy 40 which is dispensed in sufficient amount to cover IC device 30 and wirebond wires 34 . Glob top epoxy 40 is dispensed in a liquid state and then cured. Glob top epoxy 40 protects IC device 30 and wirebond wires 34 against corrosion and mechanical damage.
Although these prior art wirebond BGA packages have relatively poor cooling capability, they have been adequate because IC devices used in low-end performance applications have been relatively low powered. Typical power dissipation of IC devices used in this performance segment up to now has been about 3 Watts.
With ever-increasing integration of the IC devices driven by the demand for higher performance, IC devices at all levels of application have been incorporating more circuits per unit area. With every new generation of IC devices, this development has resulted in increases in both the performance and the power output of each device. This trend has also resulted in the utilization of higher performing and higher powered IC devices in the low-cost application segment where glob top BGA packages are commonly used. Therefore, there is a need for low-cost wirebond BGA packages with improved cooling capabilities that can accommodate IC devices with greater than 3 Watts of power dissipation.
SUMMARY OF THE INVENTION
The present invention provides a thermally enhanced wirebond BGA package. A substrate having two sides is provided on which an IC device is attached to one side. A metal cap having a side wall portion and a top portion is attached to the substrate along peripheral portion of substrate so that the cap forms an internal cavity enclosing the IC device. The cap has one or more holes in the top portion. The internal cavity is filled with an epoxy encapsulant material filling a substantial portion of the internal cavity, wherein the epoxy encapsulant material is in contact with both said IC device and the top portion of the metal cap.
The epoxy encapsulant material provides a thermal conduction path between the IC device and the metal cap to improve the package's ability to cool the IC device. Also in a preferred embodiment, the thermal conductivity of the epoxy encapsulant material is enhanced by dispersing high thermal conductivity particles in the epoxy encapsulant material. The high thermal conductivity particles are preferably also electrical insulators so that a separate electrical insulation between the IC device and the metal cap is not required.
Another embodiment of the present invention may incorporate a metal heat slug that is provided between the IC device and the laminate substrate to further enhance the thermal performance of the wirebond BGA package. The metal heat slug has a DAP portion, preferably at least one wirebond pad window portion, and a peripheral rim portion. The metal heat slug is bonded to the top surface of the laminate substrate and the IC device is attached to the DAP portion of the metal heat slug. The metal heat slug may extend out to the peripheral edge portion of the laminate substrate so that the metal cap is attached to the peripheral rim portion of the metal heat slug. In this configuration, the metal heat slug functions as a heat spreader for the IC device and further enhances the thermal performance of the wirebond BGA package by providing a second thermal conduction path between the IC device and the metal cap through the metal heat slug. The metal heat slug is preferably made of a metal or metal alloy having relatively high thermal conductivity such as copper, aluminum or alloys thereof. The metal heat slug may be made of a material with sufficient stiffness so that substrate warping problem sometimes observed after the epoxy encapsulant cure process is minimized.
The present invention also includes a method of forming a wirebond BGA package whose structures are disclosed herein. The involved process steps may include: providing a substrate having two sides; attaching a metal heat slug to one of the two sides where the metal heat slug is provided with a die attach pad portion, at least one wirebond pad window portion, and peripheral rim portions; attaching an integrated circuit device to the die attach pad portion; attaching a metal cap to the metal heat slug along the peripheral rim portions forming an internal cavity between the metal cap and the substrate; and filling a substantial portion of the internal cavity with an epoxy encapsulant material.
DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic cross-section of a prior art glob top BGA package;
FIG. 2 is a cross-sectional view of a metal cap according to the present invention;
FIG. 3 is a top view of the metal cap of FIG. 2 ;
FIG. 4 is an illustration of a metal heat slug that may be used in conjunction with the metal cap of FIG. 2 to further enhance the thermal performance of a BGA electronic package according to the present invention; and
FIG. 5 is a schematic cross-section of an embodiment of a wirebond BGA package according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 illustrates a cross-sectional view of a metal cap 100 according to the present invention. Metal cap 100 has a sidewall portion 104 and a top portion 102 that form an internal cavity 106 . Metal cap 100 also has a plurality of holes 110 in top portion 102 . Metal cap 100 may be made from metal or metal alloys having relatively high thermal conductivity such as copper, aluminum, or alloys thereof.
FIG. 3 illustrates a top view of metal cap 100 showing a plurality of holes 110 . Metal cap 100 is shown as having a square outline. This particular shape is for illustrative purposes only and the particular outline shape and dimension of a given metal cap would be determined by the particular shape of the laminate substrate to which the given metal cap will be attached.
FIG. 4 illustrates a top view of a metal heat slug 200 according to an embodiment of the present invention. Metal heat slug 200 has a DAP portion 202 where an IC device would be attached. Along the edge of metal heat slug 200 are peripheral rim portions 207 . Between DAP portion 202 and peripheral rim portions 207 is at least one wirebond pad window portion 205 that provides clearance for wirebond pads 312 (see FIG. 3 ) when metal heat slug 200 is attached to the top surface of a laminate substrate. Metal heat slug 200 may be made of metal or metal alloy sheets having relatively high thermal conductivity such as copper, aluminum, or alloys thereof.
An embodiment of a wirebond BGA package fully assembled according to an embodiment of the present invention is illustrated in FIG. 5. A laminate substrate 310 is illustrated as having BGA solder balls 320 on its bottom side. A metal heat slug 200 is bonded to the top surface of the laminate substrate. An epoxy adhesive may be used to bond the metal heat slug to the laminate substrate. As illustrated, wirebond pads 312 sit within wirebond finger window 205 (see FIG. 4 ) without interfering with metal heat slug 200 . An IC device 330 is attached to DAP portion 202 (see FIG. 4 ) of metal heat slug 200 . The IC device is typically and preferably attached to DAP portion 202 using a thermally conductive epoxy 332 . Wirebond wires 334 provide the electrical interconnection between the IC device and wirebond pads 312 .
Metal cap 100 having a side wall portion 104 and a top portion 102 is then attached to metal heat slug 200 along peripheral rim portions 207 . The resulting internal cavity formed between metal cap 100 and laminate substrate 310 is then filled with epoxy encapsulant material 340 . Epoxy encapsulant material 340 may be dispensed into the internal cavity through one or more holes 110 provided in top portion 102 of metal cap 100 . Epoxy encapsulant material 340 is dispensed in an uncured liquid form and then cured by heating the whole package assembly to a cure temperature of about 150-175 deg. C. Other holes 110 provide escape paths for gases produced by outgassing of epoxy encapsulant material 340 during the curing process. Epoxy encapsulant material 340 may be the same material as glob top epoxy 40 (see FIG. 1 ) typically used in prior art % wirebond BGA packages. After the epoxy encapsulant is cured, warping of the laminate substrate may be observed in some BGA packages but this problem may be minimized by selecting a metal heat slug 200 having a sufficient stiffness. In another embodiment of the invention, metal heat slug 200 may not be included and metal cap 100 is attached directly onto the laminate substrate 310 .
In another embodiment, the thermal conductivity of epoxy encapsulant material 340 may be enhanced by dispersing high thermal conductivity particles in the epoxy encapsulant material. A preferred material for the high thermal conductivity particles is diamond powder, cubic boron nitride, oxides such as alumina, or other materials having high thermal conductivity. Preferably, these high thermal conductivity particles are also electrical insulators so that a separate electrical insulation is not required between the IC device and the metal cap. An example of such thermally enhanced epoxy encapsulant material is Hysol FP4450 encapsulant marketed by Dexter Corporation of Industry, California Hysol FP4450 is enhanced with diamond powder (15% by weight). The thermal conductivity of this enhanced encapsulant is about 2.8 W/MK. In comparison, the thermal conductivity of a conventional glob top epoxy found in prior art wirebond BGA packages is about 0.8−0.7 W/MK.
In this configuration of the wirebond BGA package, at least two primary thermal conduction paths are established between IC device 330 and metal cap 100 . A first thermal conduction path is established through epoxy encapsulant material 340 and a second thermal conduction path is established through metal heat slug 200 . In this configuration, metal cap 100 functions as a heat sink that dissipates the heat from IC device 330 that has been conducted to metal cap 100 via the thermal conduction paths described above.
Additionally, FIG. 5 also illustrates a feature of another embodiment of the invention, where a retaining ring 400 may be attached to metal heat slug 200 along peripheral rim portion of the metal heat slug. In this embodiment, retainer ring 400 is attached to metal heat slug 200 before the metal cap attachment. Retainer ring 400 may be attached to metal heat slug 200 using a suitable adhesive such as an epoxy adhesive or other adhesive materials or means. Next, a first dose of an epoxy encapsulant material 340 is dispensed into the center of retainer ring 400 covering IC device 300 until the encapsulant material reaches the top edge of the retainer ring. After epoxy encapsulant material 340 is cured, a metal cap 100 is attached to laminate substrate 310 . Retainer ring 400 acts as a darn around IC device 300 to control the height of the first dose of epoxy encapsulant material 340 so that when metal cap 100 is attached, the top surface of the epoxy encapsulant material 340 comes in close proximity to the inside surface of metal cap 100 forming a small gap between the metal cap and the first dose of the epoxy encapsulant material.
Next, a second dose of epoxy encapsulant material 340 is applied through the one or more holes 110 in the top portion of metal cap 100 to fill the gap between the metal cap and the first dose of, now cured, epoxy encapsulant material 340 . The BGA package then goes through a second epoxy cure process to cure the second dose of epoxy encapsulant material 340 . The result is that the space between IC device 330 and metal cap 100 is substantially filled with epoxy encapsulant material 340 providing a thermal conduction path between IC device 330 and metal cap 100 .
A wirebond BGA package configured as illustrated in FIG. 5 , and discussed above, is able to accommodate IC devices dissipating greater than 3 Watts of power. The applicants have successfully assembled a wirebond BGA package according to an embodiment of the invention and demonstrated that a 5 Watt IC device can be maintained at a maximum IC device junction temperature of 125 deg. C in a natural convection environment having maximum ambient temperature of 70 deg. C. These are the same thermal performance parameters met by the prior art glob top BGA package of FIG. 1 , carrying a 3 Watt IC device. In this embodiment of the invention, the wirebond BGA package was provided with a laminate substrate having X-Y dimensions of 23 mm×23 mm and a thickness of 0.56 mm. The metal cap was made of anodized aluminum having a thickness of 0.25 mm and its dimensions were 23 mm×23 mm×0.9 mm. The metal heat slug was made of a copper sheet having a thickness of 0.25 mm and had X-Y dimensions of 23 mm×23 mm. The IC device had X-Y dimensions of 1.0 cm×1.0 cm.
It will be appreciated to one skilled in the art that the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
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A thermally enhanced wirebond BGA package having a laminate substrate, an IC device mounted on the substrate, and a metal cap defining a cavity inside the package between the IC device and the metal cap. A substantial portion of the cavity is filled with a thermally enhanced epoxy encapsulant establishing a thermal conduction path between the IC device and the metal cap. The BGA package may be further enhanced by bonding a metal heat slug on the laminate substrate and mounting the IC device on the slug.
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This application is a continuation, of application Ser. No. 849,446, filed 4/8,86 now abandoned.
The present invention relates to a skin reflectance measuring apparatus.
BACKGROUND OF THE INVENTION
The measurement of skin reflectance finds a particular application in pathology and in cosmetology. In particular, skin reflectance may be associated to other parameters such as the rate of secretion of sebum. The measurement of reflectance then becomes useful in the study of seborrhea. It may also present an advantage for studying other skin diseases such as lichen, SSM. . . . In cosmetology, the invention finds an application in measuring the effect of products known as "anti-reflectance" products for greasy skins, particularly for making efficiency-aimed tests. Another application of the present invention could be the grading of different types of skins.
Various methods and devices already exist for measuring surface reflectance, for example in the industry of paints and varnishes, in order to determine the characteristics of reflection of coated surfaces. It has also been proposed to use reflectance measurement to determine a surface finish.
All said known methods and processes which are used in industry are not applicable to the measurement of skin reflectance.
A first problem to be solved with this particular application is the problem of influence of color. Indeed, with the known devices which can only measure the specular reflection, the results obtained for different surfaces are only comparable if the surfaces are all of the same color.
To overcome the effect of color, it has been proposed to substitute to the specular reflection absolute measurement, a relative measurement between specular reflection and diffuse reflection. However, the known devices using such relative measurement remain inappropriate for measuring skin reflectance.
Indeed, the apparatuses used in industry, generally comprise optical systems with focusing lenses which require an accurate positioning of the measuring apparatus with respect to the surface of which the reflectance is being measured. It is then necessary for said surface to be flat and for the measuring area to be, in general, of relatively large dimensions.
Yet, in the case of the skin, the measuring area has to be relatively small in order to keep the characteristics of the skin uniform in that area and to make the measurement on as flat a surface as possible, without changing the characteristics to be measured by a flattening of the skin.
It is also important to have a measuring apparatus which is easy to handle and requires no higher accurate positioning with respect to the skin.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to propose a reflectance measurement apparatus which is specifically adapted for measuring the reflectance of the skin.
This object is reached with an apparatus which, according to the invention, comprises:
a probe comprising a casing of which one face, which will be in contact with the skin, is provided with an aperture,
a flexible connection in fiber optics, comprising at least three optical conductors which, at a first end, are secured in the casing of the probe such as to face the aperture thereof, the first and second conductors having their first end portions directed respectively in a first and a second directions which are symmetrical to each other with respect to an axis extending normally through the aperture, while the third conductor has its first end portion directed in another direction than said second direction,
a measuring device comprising: light emitting means optically coupled to a second end of said first conductor; light receiving means optically coupled to a second end of said second conductor to produce a first signal representing the specular reflection, and to a second end of said third conductor to produce a second signal representing part of the non-specular or diffuse reflection; and processing means connected to said light emitting and receiving means, and provided with correcting means to compensate for variations in the emitted light and for the influence of ambient light, said correcting means producing a relative reflectance signal from the measured values of specular reflection and diffuse reflection, and
a display device receiving the reflectance signal to indicate the amplitude of said signal.
The structure of the measuring apparatus according to the invention, such as defined hereinabove, with a probe connected to a measuring device via a flexible connection in fiber optics, presents many advantages.
The use of fiber optics having their end secured inside the casing of the probe in a relatively fixed configuration, permits the miniaturization of the probe. It becomes, as a result, possible to carry out measurements on reduced surfaces and, in particular, on surfaces less than 1 cm2, for example surfaces between 10 and 50 mm2. This also makes the apparatus readily usable since the probe is of reduced dimensions and is connected to the rest of the apparatus by way of a flexible connection. Such readiness of use is further increased due to the fact that, contrary to the systems using optical means with beam focusing lenses and requiring an extremely accurate positioning of the apparatus on a flat surface, the apparatus according to the invention can tolerate a few degrees of deviation of relative position between the probe and the skin surface.
The correction of variations in the intensity of the emitted light and in the effect of the ambient light makes it possible to obtain a very accurate measurement without very strict operational conditions.
The means for correcting variations in light intensity can be in the form of a circuit for regulating a source of light of the emitting means, using servo-control means.
As a variant, means may be provided for measuring the intensity of the light produced by the emitting means in order to compensate for any variations occurring in that intensity, directly at the level of the signals produced by the reflected light receiving means.
The compensation for the effect of ambient light is advantageously achieved by conducting measurements according to the "synchronous detection" principle, namely by carrying out cycles of measurements during which the specular reflection and the diffuse reflection are measured when the light-emitting means is operative and when the light-emitting means is inoperative. To control the course of said measurements and to process the results, the measuring device advantageously uses digital processing means such as a micro-computer.
It will be further noted that the display of the reflectance not only enables the operator to view immediately the value that he is seeking, but also helps in correctly positioning the probe.
The resulting reflectance is a relative value worked out from measurements of the specular reflection and of the diffuse reflection, for example the difference or the quotient between the measured values of specular and diffuse reflection. The difference is preferred to the quotient insofar as it introduces less scale distortion with respect to the judgement of the skin reflectance made by eye. A scale of reflectance may be defined from a measurement of a matt surface of reference (unit 1) and of a calibrated mirror (unit 10 n , n being an integer above 0).
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which:
FIG. 1 is a general diagram of one embodiment of a reflectance measuring apparatus according to the invention.
FIG. 2 is a more detailed cross-section of the probe of the apparatus shown in FIG. 1.
FIG. 3 illustrates in more detail the structure of the emitter of the light emitting means of the apparatus shown in FIG. 1.
FIG. 4 is a diagram of the circuits of emitting and receiving means and of the interface circuit of the apparatus shown in FIG. 1.
FIG. 5 illustrates the variation in time of the output voltage of the receiving means during a measuring cycle.
FIGS. 6 and 7 are flow charts of the operations carried out under the control of the digital processing means for, respectively measuring and calibrating.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus illustrated very diagrammatically in FIG. 1. comprises a probe 10, a measuring device 30 and a flexible connection 20 in fiber optics connecting the measuring device to the probe 10.
The probe 10 is designed to be placed in contact with the skin P in order to light up the part of the skin surface requiring to be examined.
The connection 20 comprises three optical channels 21, 22, channel 21 conveys to the probe the light produced from a light-emitting device 31 in order to illuminate the skin surface to be examined. Channel 22 transmits to a receiving device 32 the light reflected specularly (normally) by the examined part of surface whereas channel 23 transmits to the receiving device part of the light reflected in non-specular or diffuse manner. In the illustrated example, the diffuse reflection is measured in the direction opposite to the direction of incidence of the light on the surface to be examined. Channels 21 and 23 can therefore be re-grouped, at least at their end portions connected to the probe, into a bi-directional optical cable.
The emitting 31 and receiving 32 devices are connected to a control and processing device 33 via an interface circuit 34.
Said device 31 comprises means of regulating the intensity of the emitted light and is operated by control signals issued by the processing device 33.
The receiving device 32 comprises photo-electrical transducers working out electrical signals representing the normal reflection and the diffuse reflection. Said signals are transmitted to processing device 33 through the interface circuit 34, this transmission being achieved under the control of signals produced by the processing device.
In conventional manner, said processing device 33 comprises memory circuits 35, an arithmetical and logical unit 36 and interface circuits 37 permitting the connection with a display device 38, such as a cathod ray tube, with a keyboard 39 and with a printer 40. The processing device may be constituted by any of the existing micro-computers, therefore it will not be described any further herein.
Supply of the different circuits of the apparatus is ensured by supply circuits (not shown).
FIG. 2 is a diagrammatical cross-section showing the probe 10 in more details.
Said probe 10 comprises a casing 11 of which the front face 12 is provided in its center with an opening 13 such as of circular shape. The casing also presents two connecting parts 14, 15 in which are respectively secured the ends of channels 21 and 23 and the end of channel 22. Channels 21, 23 are re-grouped at their ends into a bidirectional optical cable 24 provided with an end socket 25 screwed into the connecting part 14, whereas optical cable 26 forming the channel 22 is provided with a ring 27 and is inserted in a tubular guide 17 housed in the connecting part 15.
The axis of optical cable 24, namely the axis of connecting part 14, traverses the center of aperture 13 and is inclined with respect to the perpendicular N to the front face 12 of an angle i, said angle i corresponding to the angle selected for the incidence under which the part of skin surface to be examined is illuminated. In the illustrated example, the angle of incidence i is equal to about 45°, but another value could also be selected. The axis of optical cable 26, namely the axis of connecting part 15 is symmetrical to the axis of cable 24 with respect to the perpendicular N traversing the center of aperture 13 since channel 22 is designed to pick up the normally reflected light.
Cables 24 and 26 are secured to the casing 11 in such a way that the ends of the fiber optics composing them are at predetermined distances d1 and d2 from the center of aperture 13. Adjustment of the position of the end of cable 24 is achieved by interposition of wedges 16 between the socket 25 and the connecting part 14 whereas the end of cable 26 is fixed in the required position in the guide 17 by a locking screw 18 traversing the connecting part 15 and resting against the ring 37. By way of example, distances d1 and d2 are about 20 mm.
The use of a flexible connection composed of fiber optics of which the ends are secured to the probe, presents several advantages. For example, the probe may be small, its overall dimensions being determined by the connecting means of the optical cables. Moreover, the probe has no optical elements such as lenses which require high positioning accuracy.
The measuring area, determined by the size of aperture 13 may then be small enough to allow significant measurements over a surface with as little rigidity and uniformity as the skin. For example, the surface of the measuring area may be between 10 and 50 mm2, such as about 25 mm2. The miniaturization of the probe and its flexible connection with the rest of the apparatus, also allow ready handling for taking measurements over different areas of the skin surface.
FIG. 3 diagrammatically illustrates the structure of the emitter of the light emitting device 31.
Said emitter comprises a casing 311 to which is connected the starting end of optical channel 21. Said casing 311 is provided with walls 312 used as support for the different elements housed in the casing. The light source is a lamp 314 with tungsten filament. The beam produced by the lamp is focussed by means of a lens 315 in order to obtain an adequate light intensity at the input 21a to optical channel 21. An infrared filter 316 may be interposed between the lamp 314 and the input to optical channel 21 in order to carry out measurements within the field of the infrared-free visible light. Two photodiodes 317, 318 are placed on both sides of the input to optical channel 21 so as to supply signals representing the light intensity at that input. Photodiodes 317 and 318 are connected to a circuit 319 for regulating the light intensity produced by lamp 314.
Regulation circuit 319 (FIG. 4) comprises a source of voltage consisting of a transistor T1 of which the collector is at potential +V of a supply source and the emitter is connected to a terminal at the reference potential (earth) via the lamp 314. Photodiodes 317, 318 are connected to an amplifier circuit AMP which delivers a voltage V MES representing the real intensity of the light beam applied to the input of channel 21. Voltage V MES is compared to a reference voltage V REF , supplied by a voltage-adjustable generator SV; the comparison is carried out by means of a differential circuit CP which delivers a voltage V COM which is function of the difference between V REF and V MES . The voltage V COM is applied to the base of T1 and determines the voltage in the lamp 314 so as to return towards zero the difference between voltages V REF and V MES .
The circuit 319 receives a start control signal SCA applied via a resistor R1 to the base of a transistor T2. The emitter thereof is connected to earth whereas its collector is connected, on the one hand, to the voltage source +V via a resistor R2 and, on the other hand, to the base of a transistor T3 via a resistor R3. Transistor T3 has its emitter-collector circuit connected between the base of T1 and the earth. When the start control signal is at a level between the triggering signal of transistor T2 (SCA=0, or low logic level), transistor 2 is in the OFF state, but transistor T3 is in the ON state, bringing the base of T1 to the earth potential; lamp 314 is switched off. When the ON control signal exceeds the triggering threshold of T2 (SCA=1, or high logic level), transistor T2 is turned to the ON state, this keeping T3 in the OFF state and lamp 314 is switched on, the intensity of the current through the lamp being determined by V COM .
FIG. 4 also shows the circuit of receiving device 32.
Two photodiodes 322, 323 receive light beams transmitted respectively by optical channels 22, 23. Diodes 322, 323 are silicon diodes connected in reverse. The cathodes of diodes 322, 323 are connected to the middle point of a voltage divider formed by two resistors R4, R5 connected in series between the earth and a terminal of potential V. Diodes 322, 323 thus produce a voltage substantially proportional to the intensity of the picked up light beams. The anodes of diodes 322, 323 are connected to two input contacts of an analog switch 324 of which the output contact is connected to the input of a logarithmic amplifier APL producing an analog signal S RFX representative of the specular reflection or of the diffuse reflection, depending on the position of switch 324. The use of a logarithmic amplifier procures greater dynamics. Moreover, the human eye constituting a logarithmic type receiver, the measuring apparatus makes it possible to come closer to the visual judgement which it is required to quantify.
The receiving device receives a switch control signal SCM controlling the position of the switch. For example, when signal SCM has a high logic level (SCM=1), switch 324 connects photodiode 232 with amplifier APL to measure the specular reflection, whereas when signal SCM has a low logical level (SCM=0) switch 234 connects photodiode 233 to amplifier APL to measure the diffuse reflection.
Interface circuit 34 comprises an analog-to-digital converter CAN which receives the signal S RFX to convert it in the form of a digit word N RFX of n bits. A connection circuit PIA ("parallel interface adapter") is interposed between the converter CAN and the micro-computer 33. Said circuit PIA also transmits signals SCA and SCM as well as the control signals of converter CAN. Circuit PIA is controlled in known manner by control signals produced by the micro-computer.
The emitting and receiving devices are controlled to produce a reflectance measurement from the specular and diffuse reflection values; in the illustrated case, the worked out value represents the difference between the specular reflection intensity and the diffuse reflection intensity. Moreover, in order to take into account the influence of ambient light, the reflection is measured according to a principle of "synchronous detection" namely by alternately controlling the switching on and off of the light source.
The light flux ΦS carried by channel 22 (specular reflection is composed of flux ΦSp effectively reflected by the skin, of flux ΦSa coming from the outside (ambient light) and from leaks from the detectors, and of flux ΦSs sent back by the casing of the probe. Likewise, the light flux ΦD carried by channel 23 (diffuse reflection) comprises components ΦDp, ΦDa and ΦDs.
During a measuring cycle, the flux ΦDa, ΦSa are successively measured by actuating switch 324, the lamp being switched off, then after switching the lamp on, the flux ΦS and ΦD are measured successively by actuating the switch 324.
The desired reflectance Re is equal to:
Re=ΦSp-ΦDP=(ΦS-ΦSa-ΦSs)-(ΦD-ΦDa-ΦDs)/K,
K being a corrective factor taking into account the geometry of the probe and of the optical channels 22, 23 since the reflectance is assessed by differences between intensities of the specular and diffuse reflections, and not by differences between flux.
The quantities ΦSs, ΦDs and K are determined by calibration. By placing the probe before a light trap (instead of the skin) ΦSa+ΦSs and ΦDa+ΦDs are measured, when the lamp is switched on, and ΦSa and ΦDa are measured when the lamp is switched off, wherefrom ΦSs and ΦDs are deduced. The value of K is thereafter determined by placing the probe before a matt surface used as a reference of nil reflectance (Re=0) by measuring φD, ΦS, ΦDa and ΦSs, and by calculating:
K=(ΦD-ΦDa-ΦDs)/(ΦS-ΦSa-ΦSs).
A scale coefficient SC is also determined by placing the probe before a reflecting surface of reference such as a calibrated mirror at 80% reflection, the reflectance being then arbitrarily fixed to a predetermined value ReM (for Example 1000). After measuring φD, ΦS, and ΦSs, the coefficient SC is determined by dividing ReM by the quantity:
(ΦS-ΦSa-ΦSs)-(ΦD-ΦDa-ΦDs)/K.
The values of ΦSs, ΦDs, K and SC, determined by calibration, are stored in the memory circuits 34 of the micro-computer.
FIG. 5 shows the variation in time of voltage S RFX in output of logarithmic amplifier APL. The times t.sub.ΦSa, t.sub.ΦDa, t.sub.ΦD, t.sub.ΦS correspond to the times of measurement of quantities ΦSa, ΦDa, ΦD and ΦS. The times t A and t E correspond to the switching on and switching off of the lamp, whereas times t S and t D correspond to the times of actuation of switch 234, respectively, towards photodiode 232 (specular reflection) and towards photodiode 233 (diffuse reflection).
The successive measuring cycles are performed under the control of the micro-computer. The duration of one cycle may be less than 1 sec., for example around 0.7 sec., said duration being for example function of the times necessary for the stabilization of the lamp when this is switched on and off. The values of reflectance Re calculated during successive measurement cycles are displayed as successive positions of a cursor on the screen of tube 38. The operator can thus correct any incorrect positioning of the probe by observing the position variations in y-axis of the cursor when moving the probe slightly. Instantaneous display of the reflectance calculated value thus contributes to positioning the probe. The reflectance value finally retained may be a mean value worked out from the results of a predetermined number of measurement cycles. Said final value may be edited on the printer 40 and is displayed on the screen. The resulting reflectance value is recorded in a computer file which may contain other information concerning the patient whose skin is being examined, the date of examination and any special conditions of examination. The recorded information may be edited on paper via the printer, at the operator's request.
The main programme including the operations of initialization of the system and the subroutines of recording on file and file readout are not specific phases of the proposed application; therefore they are not explained hereinafter in details.
The measuring and calibrating operations use programmes such as per flow-charts illustrated in FIGS. 6 and 7.
The measuring operation consists in the following phases:
initialization of the graph, and tracing of the outline of the screen with a view to displaying the measurement results as a curve representing the variation of the reflectance (phase 400);
positioning of the cursor in abscissa L=1 on the screen (phase 401);
scanning of the keyboard (phase 402);
if the operator, by actuating the keyboard, requests the exit of the subroutine (test 403), return to the main programme;
if the operator, by actuating the keyboard, requests an integration on the reflectance values obtained during the successive cycles of measurement (test 404), a subroutine (420) is called during which a test is carried out on the positioning of an averaging indicator (E=-1!), so as, in the affirmative, to arrive at end of averaging, to return indicator E to zero, and to return to the programme, and, in the negative, to bring sum S and parameter N to zero, to position E to -1 and to return to the programme;
measurement of the flux ΦDa, the signals SCA and SCM being in zero position, and readout of the corresponding digital value (phase 405);
switching from channel 23 to channel 22 by placing SCM in position 1, measurement of flux ΦSa and readout of the corresponding digital value (phase 406);
switching on of the lamp by bringing SCA to position 1, measurement of the flux ΦS and readout of the corresponding digital value (phase 407);
switching from channel 22 to channel 23 by bringing SCM to position 0; measurement of ΦD and readout of the corresponding digital value (phase 408);
calculation of Re from the readout values of ΦDa, ΦSa, ΦS and ΦD, and of the pre-recorded values of ΦSs, ΦDs, K and FE (phase 409)
if an integration is called (test 410) calling of a summation subroutine 430 including updating of sum S (S=S+Re), incrementing of N (N=N+1), calculation of an "instant mean value" of reflectance M i (Re)=S/N, control of the display on the screen of the digital value of M i (Re) and return to the programme;
editing of the digital values of Re or, optionally, of M i (Re)(phase 411);
graphic display of the digital value of Re by control of the ordinate of the cursor on the screen (phase 412);
incrementing of the abscissa of the cursor on the screen: L=L+1 (phase 413);
if the value of L is equal to the maximum abscissa possible L MAX (test 414), clearing of the screen (phase 415) and return to initialization of the graph, if not, return to phase 402;
The calibration operation consists in the following phases:
recall of existing constant values (phase 5 1)
passage to first constant value (phase 502);
display on the screen of a message (phase 503) for placing the probe before the surface corresponding to the constant value to be determined (light trap, matt surface of reference, reference mirror);
scanning of the keyboard (phase 504);
if the operator, by actuating the keyboard, requests the exit of the subroutine (test 505), return to the main programme without changing the calibration;
for every constant to be determined K1 to K4 (K1=ΦSs, K2=ΦDs, K3=K and K4=SC), performance of M successive cycles of measurement, for example 10 cycles, (phase 506) each one including:
measurements of flux ΦDa, ΦSa, ΦS and ΦD (phases 405 to 408 of the aforesaid measuring programme):
the calculation of quantities R1=ΦS-ΦSa,
R2=ΦD-∠Da, R3=(R2-K2)/(R1-K1), R'4=(R1-K1)-(R2-K2)/K3
and
R4=ReM/R'4;
updating of sum Si by:
Se=Si+Ri (i=1, 2, 3 or 4);
and updating of sum ΣI by
Σi=Σi+R.sup.2 (i=1, 2, 3 or 4);
calculations of mean value and standard deviation for every constant (phase 507), namely mean value Xi=Si/M, standard deviation Vi=Σi/m-Xi 2 and reduced standard deviation
Zi=⃡Vi/Xi: (i=1, 2, 3 or 4);
display of calculated mean value X (phase 508);
if the reduced standard deviation is greater than a predetermined threshold (test 509), it is displayed on the screen, if not, then direct passage to the next phase;
consultation by the operator (phase 510)
scanning of the keyboard (phase 511)
if the operator, by actuating the keyboard, requests a new assessment of the same constant (test 512), return to phase 503;
if the operator, by actuating the keyboard, requests that the new constant be kept (test 513), then Ki=Xi (phase 514) and passage to the next constant (phase 515);
if the operator, by actuating the keyboard, refuses the value Xi (test 516), then the actual value of the constant is kept (phase 517) with passage to the next constant (phase 515);
if the operator, by actuating the keyboard, requests the exit (test 518), then return to the main programme without modifying the calibration;
when passing to the next constant (phase 515) and if the four constants have not yet been calculated (test 519), return to phase 503;
if all the constants have been calculated, exit with modification of the calibration and return to the main programme.
Tests have been conducted with a mesuring apparatus suc as described hereinabove by using a scale of reflectance Re ranging from 0 for the matt surface of reference to 1000 for the reflecting surface of reference (mirror with 80% reflection).
The measurements taken on 34 people have given reflectance values within a range of 8 to 12.5 for the fore-arm and from 6 to 13.9 for the forehead.
In the case of people (7 cases) whose skin appears to be greasy to the eye, the mean reflectance value measure on the forehead has been 11.7, to be compared with the general means value of 9.56 obtained from measurements taken in 32 random cases. Moreover, measurements taken on five subjects have shown a deviation of 5.4 between the mean reflectance values obtained before and after application of "Vaselin" on the fore-arm.
These results show the effective correlation between the visual aspect of reflectance and the measurements taken, thereby justifying the use of the measuring apparatus according to the invention as an "objective"means of quantifying the reflectance of the skin.
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A probe comprising a casing of which one face which will be in contact with the skin is providied with an aperture, is connected to a measuring device by means of a flexible connection in fiber optics comprising at least three optical conductors which, at a first end, are secured in the casing of the probe such as to face the aperture thereof, the first and second conductors having their first end portions directed respectively in a first and a second directions which are symmetrical to each other with respect to an axis extending normally through the aperture, while the third conductor has its first end portion directed in another direction than said second direction.
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FIELD OF THE INVENTION
The present invention relates in general to a technique for allowing computer users to diagnose CPU and memory boards through high level commands, in order to maintain accurate data retention and performance of computers and I/O processors.
BACKGROUND OF THE INVENTION
Present day computer systems generally require intricate, low-level, time consuming operations to test hardware for proper operation. Computers employ registers which perform operations on strings of bits and these registers are used during testing procedures. Most computers group interconnected shift registers into scan rings, to aid in the testing. Generally, when a user needs to make a correction to a string of bits stored on a memory chip or the like, the entire string of bits needs to be analyzed, i.e., thousands of bits need to be dumped into a scan ring and individually analyzed.
It is desirable to have a system that employs a less cumbersome manner of identifying and correcting defective bits retrieved from hardware elements.
With most present day computer systems, in order for a user to check memory and CPU board operation, a low-level machine code program would have to be written. This entails listing every shift register and other hardware command individually and storing it in a file to subsequently be carried out by the computer. Not only does this require an exhaustive effort on the part of the user to write the code, but the computer system would be utilized for only this purpose during operation of this routine.
It is desirable to both have a powerful high level language which enables users to create hardware testing procedures simply, as well as one that operates from a command line, performing commands individually as typed next to a prompt. This would both save time and aggravation on the part of the user.
With most present day hardware testing procedures, strings of bits are loaded into scan ring registers and viewed serially. To return to a bit just previously viewed, the scan ring would have to be rotated a complete 360 degrees. This delay could become problematic if the step had to be repeated numerous times, which is not unlikely.
It is further desirable to reduce the amount of time used to scan bits in a scan ring.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to allow users to test CPU and memory boards without having to view every bit in a scan ring in order to make a single correction.
It is a further object of the present invention to allow users to be able to view small portions of scan rings if they are only interested in checking certain items.
It is a further object of the present invention to allow users to test the state of CPU and memory boards through use of a high level language without having to write out machine level code.
It is a further object of the present invention to create a new mode of computer operation, easily accessible, which could carry out a hardware testing routine and return to normal operation upon command.
It is a further object of the present invention to be able to scan bits from a scan ring in a parallel fashion.
According to the present invention, these and other objects and advantages are achieved in a method for allowing the user to create testing subroutines with a high level powerful computer language. The present invention includes a high level assembly language allowing users to manipulate desired portions of scan rings, referred to as scan paths, in a time saving manner.
In brief, in accordance with the present invention there is provided a method for testing memory and other CPU hardware elements in response to high-level commands generated by a user. The method broadly comprises the steps of translating the user generated high level commands into low-level machine code, accessing the appropriate hardware element, loading bits into and retrieving bits from the scan ring in size, content, and location as requested by a user, and performing additional operations in accordance with the user generated high-level commands.
One feature of the present invention is a Scan Path Diagnostic Language (SPDL), which allows a user to work on a complete scan ring or on a specific portion of the scan ring, denoted as the scan path, depending upon the nature of the diagnostic. This invention accomplishes the objective of viewing portions of scan rings by transparently partitioning the scan rings into subsections. Each subsection, including a group of bits or an individual bit can then be tagged for future identification through use of certain commands available in the SPDL.
Another feature of the present invention allows a user to run a diagnostic test either from a command file or from the command line of the processor being used. Because the language can be run from the command line of a maintenance processor, the user can work in an interactive environment which allows direct communication between the keyboard and the scan ring.
According to another feature of the present invention, it is possible to test non-adjacent elements on a scan path in parallel. Due to this, scan path delay timing is reduced significantly.
According to another feature of the present invention, all testing operations are performed in an exclusive mode of operation called the SCAN mode. This mode of operation is accessible through use of a simple command. When the SCAN mode is entered the CPU is frozen and only SPDL operations may follow. Thus, a user may be working in an area outside of the scan mode and interrupt this work to test hardware by entering the SCAN mode. Subsequently, the user may return to continue the previous work by exiting the SCAN mode.
According to another feature of the present invention there is provided a method which comprises the step of appropriately responding to user generated debugging commands to allow a user to remedy faulty programs.
According to another feature of the present invention all debugging commands are exclusively carried out in a debugging mode of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a general block diagram illustrating the broad concepts of the invention;
FIG. 1A shows a portion of the block diagram of FIG. 1 in greater detail;
FIG. 1B shows another portion of the block diagram of FIG. 1 in greater detail;
FIG. 2 is a diagram illustrating the SCAN mode of operation which accepts input from both the command line and command files;
FIG. 3 is a flow chart of entering and exiting the SCAN mode of operation;
FIG. 4 is a flow chart of a sample diagnostic test program; and
FIG. 5 is a flow chart of the SPCC compiler operation.
DETAILED DESCRIPTION OF THE INVENTION
A computer system incorporating the present invention is shown in block diagram form in FIG. 1. The system includes a Maintenance Processor (MP) 10 which receives testing commands and interacts with the appropriate hardware during execution. As shown in FIG. 1A, Maintenance Processor 10 includes a test pattern register 10A, an address register 10B, and a compare register 10C. During testing, data is transferred from memory boards 12 or CPU boards 14 to scan rings 16 and is subsequently viewed. As shown in FIG. 1B, scan rings 16 include a plurality of scan rings, including scan ring 16-1, scan ring 16-2, scan ring 16-3 , . . . scan-ring 16-N. A scan path 19 can, if and as desired, be defined on a portion of a scan ring, such as (but not necessarily) scan ring 16-1. A printer 17 and a plurality of terminals 18 may communicate with and utilize the MP. Prime 50-series architecture, produced by Prime Computer, Inc., is preferred, but not required, nor is the present invention limited thereto.
The present invention includes a high level assembly language (referred to hereafter as Scan Path Diagnostic Language or SPDL) which is designed to enable a user to quickly and easily diagnose memory and CPU boards. As indicated previously, in the past, in order to diagnose memory and CPU boards, strings of data from these hardware elements would have to be loaded into scan rings and individually viewed for correctness. The SPDL provides a means by which defective bits within a scan ring can be tagged, easily identified and viewed individually.
The SPDL provides a means for diagnosing the CPU through the scan path with a relatively high level of coding. The language is interpreted through a new MP mode, SCAN mode, and the code can either be entered directly on the command line through a terminal, or invoked with a filename of a file containing the code.
SPDL allows a user to concentrate on a specific portion of the scan ring. SPDL accomplishes this by requiring data to be entered into the scan path from the scan ring before viewing. The details of the scan path are transparent to the MP. Therefore, the string of bits within the scan path has no significant meaning or relationship to the software. Because of this the coder can work on the complete scan ring or on a specific portion of the scan ring, by only entering that portion into the scan path, depending on the nature of the diagnostic.
A useful tool is thus provided to the user who might only want to concentrate on a single bit or bit string in the scan ring. It also provides a quick and simple method to test small areas. Thus individual VLSI chips can be tested separately. It is common to have different designers for different VLSI chips who are only familiar with their own design. Employing the present invention, each designer can concentrate on his/her own portion of the scan ring for his/her own debug.
As indicated in FIG. 2, the MP 10 accepts input from both the command line 20 and command files 22. The code can either be entered on the command line 20, through a terminal, or invoked with a filename of a file 22 containing the code. Basic testing can thus be done on the MP system console without the need of a file. If a short test, including only a few commands, needs to be performed, a user can do so directly from the command line 20 by typing in commands after a prompt on the terminal while in the SCAN mode.
By use of the SPDL another mode of operation is added to current M/P modes of operation. This new mode is designated SCAN mode. FIG. 3 is a flow diagram illustrating the routine for entering and exiting the SCAN mode of operation. As shown, a user may invoke the SCAN path mode 26 to invoke a hardware test procedure 28 while in the middle of other MP work such as a regular mode of operation 24. The scan mode may be simply accessed at the MP by entering MO SCAN on the system console. Once in SCAN mode, the machine processor expects to receive a diagnostic test through either a file or a direct command. The user can invoke a diagnostic test by entering the filename of a previously created file which includes an SPDL test procedure. This file may be stored on one of the MP storage media and the MP would retrieve this file upon execution.
Alternatively the user can enter the commands directly from the command line 20. Once in SCAN mode, the user may invoke commands allowed in an SPDL file. This allows the user to create short tests in the SCAN mode while working previously in another mode of operation. Upon completion of the hardware test the user may return to the regular MP mode and continue work.
SPDL allows for the diagnosing of a CPU through the scan path with a relatively high level of coding. Data may be entered as binary, octal, hexadecimal, or decimal.
In the SPDL, comments are allowed at the end of a command line or on a line by itself. Putting a comment after a command requires no delimeters in the comment field. The parser will ignore any test after the semicolon. Putting a comment on a line by itself requires the comment be processed by a semicolon.
When manipulating data in registers the first argument in a command is usually the destination register. The results of the operation are usually placed in the register corresponding to the first argument and the original contents of that register are altered.
Each SPDL command file program must begin with a BEGIN statement and end with an ENDS statement.
Outlined below is a partial list of available commands to a user working with SPDL.
I. ARITHMETIC
A. ADDR
ADDR is used to add a number to a specified register or to add two registers. The sum is always placed in the first argument, which must be a register.
B. SUBR
SUBR is used to subtract a number from a specified register, or to subtract one register from another register. The result if placed in the second register.
C. INC
INC is used to increment a specified register by 1.
D. DECR
DECR is used to decrement a specified register by 1.
II. BINARY LOGIC
A. AND
AND is used to perform a bitwise AND operation on two 80 bit registers or on a register and a number. The two are ANDed together and the result is placed in the first register.
B. OR
OR is very similar to AND except that it performs a bitwise OR operation on the specified registers. The contents of the first register are ORed with the contents of the second and the result is placed in the second register. An immediate value can also be ORed with a register to obtain a result.
C. XOR
XOR performs a logical XOR on the specified registers and places the result in the second register XOR can also be used with an immediate operand.
III. DOWN LOADING FILES
A. DLOAD
DLOAD downloads a test procedure file from an outside operating system it was created on, such as PRIMOS, through the MP to the scan ring The file will be a string of hex digits which will be put into the scan ring. The file will end with a "$". The load will be terminated when either a "$" is encountered or the appropriate number of bits have been put into the scan ring. The bits in the file will only be loaded. The bits will not be interpreted.
B. LOADF
LOADF loads a file from one of the MP storage media to the scan ring. It is very similar to DLOAD except that the file is an MP storage media instead of an outside operating system like PRIMOS The file attributes are the same as that for DLOAD.
IV. UP LOADING FILES
A. ULOAD
ULOAD is used to upload a file from the scan ring to PRIMOS. The file produced takes on the same format as discussed under the LOADF command.
B. STOREF
STOREF is used to store a complete scan ring to a specified MP file. The file will be the hex equivalent of the scan ring terminated by a "$". This is the same format as for the LOADF and DLOAD commands.
V. LOOPING
A. CONTINUE/COUNTL
COUNTL sets up the counter register for looping within a command file. Every COUNTL command must be followed by a CONTINUE command. COUNTL marks the beginning of the loop and is followed by a number specifying how many loops, and CONTINUE marks the end of the loop.
VI. COMPARING
A. CMPS
CMPS is used to compare the values of two specified registers. If the values are equivalent, the next statement is skipped. If the values differ, the next statement is executed. The next statement will typically be an ECHO command to print out an error message.
VII. PRINTING
A. ECHO
ECHO is used to print text messages to the screen. This can be used to make the command file output more readable. The text must be delimited by double quotes ("), similar to print in standard "C" language.
B. PRINT
PRINT is used to print a register value to the screen.
VIII. SCAN RING REGISTER COMMUNICATION
A. PUTR
PUTR is used to put the value of a register into the scan path starting at the current position. For many applications there might not be a need for all 80 bits of a register, so the number field is used to specify how many of the bits are to be scanned in. This is done so the user can get at smaller fields and not have to duplicate the existing scan path in the unused portion of the scan ring.
B. GET
GET is very similar to PUTR except that it gets the value of the scan ring and puts it into the specified register. The number field on the command specifies the number of bits to access from the scan ring to be stored in the specified register.
IX. READ/WRITE
A. READST
READST is used to perform the read strobe to parts of the scan ring that need a separate read signal.
B. WRITEST
WRITEST is used to perform the write strobe to parts of the scan ring that need a separate write signal.
X. REGISTER MOVEMENT
A. MOVR
MOVR moves the contents from the source register to the destination register. The original contents of the destination register are destroyed.
XI. SHIFTING
A. SHFTL
SHFTL performs a logical shift left on a specified register. The contents of the register are shifted left a specified number of positions and zeros are shifted into the least significant bits of the register.
B. SHFTR
SHFTR performs a logical shift right operation on a specified register. The contents of the register are shifted right a specified number of bits and zeros are inserted in the most significant bits of the register.
XII. SCAN PATH POSITION
A. POSCAN
POSCAN is used to position the scan path so the 16-bit piece of the scan ring needed is aligned within the scan register. This allows the scan register to be read from and written to. An internal pointer is used to keep track of where the scan path is currently aligned so all POSCANs are relative from point O. If a POSCAN 128 is done, then for a POSCAN 129, the scan path will only be shifted 1 bit.
B. REALIGN
REALIGN re-aligns the scan path back to position O. This has the same effect as doing a POSCAN O.
XIII. CHANGE SCAN PATH
A. CCSP
CCSP is used to re-direct the scan commands to a specific scan path. The current scan path may be changed at any point in a command file. CCSP will change the current board, the current CPU, or both. The following boards are available: E board, PS board, OI board, IOPO board, IOPl board, and BCU/ACU/SCU scan path. The following CPUs are available: CPU0, CPU1, CPU2, CPU3.
XIV. INITIALIZE REGISTER
A. SET
SET allows the user to fill one of the available registers with a specified value. Each register is 80 bits wide. When SETting a register with less than 80 bits, the upper bits of the register will be filled with 0.
XV. CLOCK ALIGNMENT
A. SHDCLK
SHDCLK strobes the shadow register clock on the scan path. This allows the data in the shadow register to be clocked to its appropriate data register.
XVI. DEBUG
A. STEPP
STEPP allows the user to step the processor through a specified number of commands.
FIG. 4 illustrates a flow diagram of a SPDL program for testing a memory element in a CPU. The memory element could be a RAM module with an array of bits, which is chosen as the scan path location. The program includes writing a test pattern to all locations on the scan path, and subsequently reading from these locations and comparing the data to the test pattern that was written, If a discrepancy is revealed in the comparison, the program will print out an error message.
As can be seen in FIG. 4, the program includes two subroutines 30,50. Subroutine 30 entails writing a test pattern to all locations on the scan path. Subroutine 50 entails reading from all of said locations on the scan path and comparing to the test pattern.
As displayed in FIG. 4, the first step 32 in subroutine 30 is to select a scan path, which includes a memory board or element and corresponding CPU, to test. The second step 34 requires initializing the address register with the initial scan path address to be accessed. The third step 36 comprises initializing the test pattern register to an initial value. The fourth 38 and fifth 40 steps, respectively, are entering the address register contents and entering the test pattern register contents into the scan ring. The sixth step 42 consists of writing the test pattern to the scan path at the appropriate address location. The seventh 44 and eighth 46 steps consist of, respectively, incrementing the address register contents and the test pattern register contents. These eight steps are then repeated through the use of a loop until every memory bit in the scan path has been written to. For example, if the memory element being tested is a 4K×72 bit RAM module, then the test pattern register would be 72 bits long and steps 38-46 would be repeated 4K times. The loop command 48 is shown as the ninth step in subroutine 30.
Subroutine 50, which includes reading from the scan path and comparing to the test pattern, begins when all memory element locations on the scan path have been written to. As shown, the tenth 52 and eleventh 54 steps which begin subroutine 50, consist of, respectively, re initializing the address register and the test pattern register to the same values initialized during steps 2 and 3 in subroutine 30. The twelfth step 56 requires entering the address register contents to the scan ring. The address denotes the appropriate location on the scan path to be read from, which is the location written to in subroutine 30. The thirteenth step 58 calls for reading from the scan path to the scan ring. The fourteenth step 60 consists of getting the data from the scan ring into the compare register. The fifteenth step 62 requires comparing the contents of the test pattern register to the contents of the compare register. The sixteenth step 64 will be executed only if a discrepancy is revealed during the comparison conducted by the fifteenth step. In the event of a discrepancy, an error message will be printed. The seventeenth 66 and eighteenth 68 steps respectively will accomplish incrementing the contents of the address register and test pattern register. Steps 56-68 are repeated as many times as steps 38-46 were repeated during subroutine 30. The loop 70 occurs so that every location that was written to during subroutine 30 will be read from and compared during subroutine 50.
Because SPDL is a high level powerful language, a user can implement this program easily with the user-friendly commands described above. The flow diagram of the program, shown in FIG. 4, can be used to test most memory and other hardware storage elements. Specific scan paths, initial addresses, and test patterns will have to be chosen in accordance with the hardware element being tested. Any size hardware element can be tested as the scan path can be shortened or lengthened as needed, and the loop can be increased or decreased accordingly.
The following is an example of an SPDL program for testing a RAM module that is on the scan ring. The routine tests a 4K×72 bit RAM module located on the scan path from bits 128-200. The modules require that a read and a write strobe be used to access/modify data:
______________________________________BEGIN ECHO "Start RAM Module Diagnostic" CCSP 0,0 ; select PS board and CPU0 SET r0,0 ; initialize the r0 register SET r1,0 ; initialize the r1 register COUNTL #4096 ; set the loop count to be 4K POSCAN #302 ; align to address field PUTR r1, #12 ; enter address POSCAN #128 ; point to beginning of RAM module PUTR r0, #72 ; put r0 into scan ring REALIGN ; re-position the scan ring WRITEST ; perform the write strobe INC r1 ; increment the address field INC r0 ; increment the test pattern CONTINUE ; go to the top of the loop SET r0,0 ; re-initialize the r0 register SET r1,0 ; re-initialize the address field COUNT #4096 ; reset the count POSCAN #302 ; align with address field PUTR r1, #12 ; enter address REALIGN ; re-position scan ring POSCAN #128 ; align with RAM module GET r2, #72 ; get all 72 bits of data CMPS r0, r2 ; compare w/ expected results ECHO "Data ; print error message Miscompare Error" INC r0 ; increment test pattern INC r1 ; increment the address CONTINUE ; loop till done ECHO "End of RMD"ENDS;______________________________________
In order to speed the execution time of a SPDL command file, the invention includes a compiler which is called the SPCC compiler. The SPCC compiler translates the high level language commands into low level machine language commands, which the computer can understand. This eliminates the need to parse each command as the file is run.
Fie. 5 illustrates the compiling procedure. As shown, a high level language program (SPDL) is entered and the SPCC compiler 74, when invoked, translates this into machine language code 76 which the computer can interpret.
The SPCC compiler is run under an outside operating system such as PRIMOS. The maintenance processor produces machine language code in binary form which can be run through SPDL. The compiler is stored in a directory within said outside operating system.
To invoke the compiler, the SPCC program compiler is run with the .spdl file as a command line input. The .spdl file is a test file created with the above-described SPDL commands. The compiler will produce an .exe and an .out file. The machine language code is put into the .exe file (the executable file for SPDL), and the output of the compile (including any error messages) is put in the .out file.
An example of how to run the SPCC compiler and the files that are outputted is as follows: Ict.spdl is a cache test program. It could be any .spdl test file. After a prompt from the operating system, the user should type in the command, "RUN SPCC ICT.SPDL". This accesses the SPCC compiler and tells it to compile the test file ict.spdl. The operating system will then return with the display SPCC REV. 1.0 showing the SPCC compiler REV. 1.0 has been accessed. Upon completion of the compiling, error messages, if any, will be listed. If compiling is accomplished without any errors, this will also be listed, as well as the number of lines compiled.
Ict.exe would be the executable file outputted from the compiler and ict.out would be the output file which contains the result of the compiling, and any errors there might be.
The error messages outputted from running SPDL command files and running the SPCC compiler are the same messages. They define all the errors A message tells the user what is incorrect with the command and what line number the error occurred on.
The following is a list of the error messages that will occur and the proper action that should be taken by the user thereafter in running the SPCC compiler.
NO INPUT FILE
This message tells the user that no input file was entered for the SPCC compiler. The user should run the compiler again with an input file.
UNABLE TO OPEN FILE
This tells the user that the computer was unable to open the spdl input file specified for the compiler. The user should make sure that the input file has the correct file name and exists in memory.
NO BEGIN STATEMENT FOUND
This message tells the user that no BEGIN statement was found at the beginning of the .spdl file. The user should make sure that the first executable line in the .spdl file is the BEGIN command.
INVALID COMMAND
This tells the user that an invalid command was entered in either the command file or the input line (while in scan mode). In this case the user should re type the command using correct syntax, if in Command mode.
INVALID REGISTER NAME
This tells the user that an invalid register mnemonic was entered in the command file or on the input line. The user should check the command for valid register names (r0-r9) and retry the operation.
INVALID IMMEDIATE OPERAND
This tells the user that an invalid number was inputted while using the immediate operand instructions. The user should check the current default radix and use radix prefix characters where necessary.
INVALID SCAN PATH NAME
This tells the user that an invalid scan path name was inputted while using the CCSP command. The user should check the list of valid scan path names in the SPDL spec and retry the operation.
INVALID CPU NAME
This tells the user that an invalid CPU name was entered while using the CCSP command. The user should check the list of valid CPU names in the SPDL spec and retry the operation.
WARNING: NUMBER TOO LARGE, TRUNCATED TO 16 BITS
This warns the user that a number was inputted that was larger than the 16 bit quantity the SPCC compiler is looking for. The number is truncated to take the least significant 16 bits. In this case, if the least significant 16 bits is ok with the user, then the user may ignore the warning. Otherwise, the user should re-enter an adequate number that is not greater than 16 bits long.
NO BEGINNING QUOTE IN ECHO COMMAND
This tells the user that no beginning quote was found in the ECHO command, which is one of the print commands. In this case, the user should add a beginning quote to the ECHO command.
UNDEFINED SCAN COMMAND
This tells the user that an undefined scan command was entered. The user should check the syntax of the command, correct the form and try again.
INVALID NUMBER
This tells the user that an invalid number was entered. Usually, the number is inputted incorrectly or is in the wrong radix. In this case the user should check the current default radix or use radix prefix characters where necessary.
The invention further provides a set of debug commands within SPDL. This allows users to do some rudimentary debugging on their SPDL programs. The debug commands can be used on either command language .spdl files or compiled .exe files. The debug commands are not available for use in the command line (non-file) mode of operation.
For example, the DEBUG mode is entered by adding "-DEBUG" to the SPDL command. When the DEBUG mode is entered, a ">>" is added to the end of the scan prompt. The prompt includes a label describing which CPU and memory board or element is being accessed with the present scan path, as well as the current position. Once in the DEBUG mode, the user can perform any valid SPDL command from the command line.
The following are examples of the DEBUG commands that are available within SPDL.
BRK
BRK is the command used to set a breakpoint. This command allows the user to define locations in his/her program where he/she wishes the program to suspend execution so that he/she may examine the data and registers to ensure that the code is executing as designed. These locations, where program execution is suspended, are called breakpoints. During execution, when the program reaches a breakpoint location, control is passed to the monitor, and the user has access to all the standard functions. Breakpoints can be set at an valid SPDL command file line number. Execution will be stopped after the command at which the breakpoint was set. After the breakpoint has been executed, it is cleared. To continue the same breakpoint again (e.g. while in a loop), the breakpoint must be set again. Only one breakpoint is allowed at one time. If the breakpoint command is done twice, before a CONT or RST command, the second of the two breakpoints will be the breakpoint address.
CLR
CLR allows the user to clear the current breakpoint. This will reset the current state so that there are no breakpoints in the code.
CONT
CONT allows the user to continue execution from the breakpoint forward into the program. This will continue the program execution from where it broke until another breakpoint is encountered or the program has finished execution.
PC
The PC command allows the user to set the current program counter to the specified line in the SPDL program. This will, in effect, let the user re-start the program from a different entry point. A subsequent CONT command will begin execution at the line number specified after the PC command.
RST
The RST command allows the user to re start the command file again. The execution will always begin from the beginning of the file.
SNGLSTEP
The SNGLSTEP command allows the user to step a specified number of SPDL commands in a command file.
Testing and running SPDL programs can be done on an outside operating system such as PRIMOS. The scan paths are simulated using memory arrays. Any command file (.spdl or .exe) can be executed and debugged on a machine which employs an outside operating system. This will considerably speed the execution and debugging of .spdl files and also alleviate the problem of finding an MP to test .spdl files on.
When considering timing for SPDL, two areas must be looked at. One is the time it takes for the CPU to perform the scan. The other is the time it takes for the SPDL instruction to be executed. Some instructions are dependent upon the speed of the CPU scanning operation (i.e., POSCAN). For this reason, all instruction timings are calculated separately from scan path delay
It takes a considerable amount of time to rotate the scan path a complete cycle. To load a bit into the scan ring, the ring must be rotated a complete 360 degrees. During a read/write operation, the ring must be rotated first to read/write a bit., and then rotated back to re-align the ring. If the scan ring is 1000 bits, this operation could take 36 μsecs for example, regardless of the time necessary for the MP to read/write the bit. If this operation was to take place 4K times (like in the RAM module test described above), the scan path delay time would be 4K×36 μsecs, or 0.15 secs. If a read/write test were being performed, this number becomes doubled to 0.3 secs. This time does not include MP overhead to load the data and compare results.
In order to reduce the amount of time spent scanning, the invention provides for testing certain elements on the scan path in parallel. This increases the MP overhead but reduces the scan path delay timing considerably. This method can be used when multiple RAM modules reside on one scan ring.
There are three basic types of instructions in the SPDL. These include register instructions, non-register instructions, and file specific instructions. The fastest instructions are the non register instructions, and the slowest instructions are the file specific instructions. The following discussion describes the general timing involved in each of the types of instructions and estimates the total timing involved in an example program.
Non-register instructions are all those instructions that require little or no involvement with the 80-bit registers. The non register instructions are as follows: COUNTL, DECR, INC, POSCAN, PRINT, READST, REALIGN, SHFTL, SHFTR, STEP, TOP, WRITEST, and ECHO.
A typical example of a non-register instruction is the REALIGN instruction. This instruction realigns the scan path back to its original position. The 80186 machine code necessary to perform this instruction is as follows:
______________________________________ push si push di push bp mov bp, sp ; save the important stuff lds di, ; point to scan count register PDA.sub.-- SCAN.sub.-- COUNT mov bx, SCANSIZE ; put scan size into bx register sub CURPOINT, bx ; get scan number back to original not bx ; complement number inc bx ; make 2's comparison mov ds:[di], bx ; put it in the count register lds di, PDA.sub.-- CMDREG ; point to cmd reister mov ds:[di], SCAN.sub.-- GO ; kick off scan lds di, PDA.sub.-- STATUS ; point to status registertest again: test ds:[di], ; test for scan doneSCAN.sub.-- DONE jz test again mov sp, bp ; clean-up after scandone pop bp pop di pop si ret______________________________________
If these instructions alone, not including the scan path delay, take 30 μsecs to execute, it is possible that the scan path delay could take a maximum time of 36 μsecs. Therefore, in this example the worst case timing for a REALIGN instruction would be 66 μsecs. On the average, however, instructions of this type take about 20 μsecs to execute.
Register instructions are those which involve the 80-bit wide data word. These 80-bit registers are preferably blocks of memory in maintenance processor 10. The following are examples of register instructions: ADDR, AND, CMPS, OR, SET, SUBR, PUTR, GET, and XOR.
A typical register instruction is the ADD instruction. This instruction takes two 80-bit registers, adds their values, and places the result in a destination register. The 80186 machine code necessary to perform this instruction is as follows:
______________________________________ push si push di push bp mov bp, sp ; save all the good stuff clc ; clear the carry bit mov ds, [bp + 0ah] mov di, [bp + 0ch] ; put first reg. addr. in ds:di mov es, [bp + 0eh] mov si, [bp + 10h] ; put 2nd reg. addr. in es:si mov bx, 0 ; clear count registertop: mov cx, ds: [di] ; put 16 bits in cx adc cx, es:[si] ; perform an add w/ carry inc di inc si ; inc. reg. pointers inc bx ; increment count cmp bx, 05h ; test for done j1 top mov sp, bp pop bp pop di pop si ; restore all the good stuff ret______________________________________
If the execution of the machine code set forth above takes 56 μsecs and since there is not scan path delay associated with the instruction, the worst case timing would be 56 μsecs.
File-specific instructions include those instructions which require file-specific operations. Examples of such instructions include: DLOAD, LOADF, STOREF, ULOAD. LOAD and STOREF are local file instructions and interface with the MPOS and its disk storage facilities. ULOAD and DLOAD require communication with an outside operating system such as PRIMOS through the MP outside operating system load facility (i.e. MP-PRIMOS). Since this communication takes place over a serial line, these two instructions will be slower than the MP specific instructions.
As an example of the time saved by employing the test program of the invention the execution time for the SPDL sample program discussed previously for the 4K×72 bit RAM module test required 2.4 seconds to perform a full read/write test. This time does not include the time required to parse the instructions. It only includes the time necessary to perform each instruction. Since SPDL is an interpretive language, each instruction must be parsed each time through the loop.
While the present invention has been described by reference to a preferred embodiment thereof, numerous variations and modifications could be made thereto by those skilled in the art without departing from the spirit and scope of the invention.
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A method of diagnosing memory and CPU boards by using scan rings which are composed of interconnected shift registers. A maintenance processor (MP) down-loads vector files to the scan rings. The scan rings are transparently partitioned into subsections and each subsection and individual bits are then tagged using a high level language, i.e., a scan path diagnostic language (SPDL). The user of SPDL writes a program in SPDL language addressing a portion of the scan ring. Next, the high level commands are translated into low level machine code and run on the MP. Bits are then loaded into the scan ring and subjected to a test routine. Additional commands are given to correct any errors uncovered and the bits are then reloaded through the MP to the hardware element being tested.
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RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/321,551, titled “SPLINTS AND RELATED METHODS OF USE,” filed Apr. 12, 2016, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] This application relates generally to splints or other devices for immobilizing and/or supporting a portion of a body of a patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The written disclosure herein describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to certain of such illustrative embodiments that are depicted in the figures, in which:
[0004] FIG. 1A is a view of a splint, according to one embodiment of the present disclosure, in an expanded configuration.
[0005] FIG. 1B is a view of the splint of FIG. 1A where the splint has been rotated 180 degrees about an axis of symmetry of the splint relative to the configuration depicted in FIG. 1A .
[0006] FIG. 1C is a cross sectional view of the splint of FIG. 1A .
[0007] FIG. 2A is a side view of a leg that is supported by the splint of FIG. 1A in an expanded configuration and with an ankle/elbow/knee device.
[0008] FIG. 2B is a side view of a leg that is supported by the splint of FIG. 1A in an expanded configuration and without the ankle/elbow/knee device.
[0009] FIG. 2C is a side view of a leg that is supported by the ankle/elbow/knee device of FIG. 2A .
[0010] FIG. 2D is a side view of an arm that is supported by the splint of FIG. 1A in a partially expanded configuration.
[0011] FIG. 2E is a side view of an arm that is supported by the splint of FIG. 1A in an unexpanded configuration.
[0012] FIG. 2F is a side view of an arm that is supported by the ankle/elbow/knee device of FIG. 2A .
[0013] FIG. 2G is a side view of a leg bent at the knee supported by the ankle/elbow/knee device of FIG. 2A .
DETAILED DESCRIPTION
[0014] It will be readily understood that the components of the embodiments as generally described and illustrated in the figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
[0015] The phrase “coupled to” is used in its ordinary sense, and is broad enough to refer to any suitable coupling or other form of interaction between two or more entities, including mechanical, fluid, and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. The phrases “attached to” or “attached directly to” refer to interaction between two or more entities which are in direct contact with each other and/or are separated from each other only by a fastener of any suitable variety (e.g., a hook-and-loop element).
[0016] The terms proximal and distal are generally used in their ordinary sense. For example, the term proximal, when used with reference to a splint or limb, may refer to a portion of the splint or limb that is near or nearer to the point of limb attachment. When used in connection with a splint or splint component, the term proximal may be used to refer to the end or region of the splint or component nearest or nearer to the torso of the patient when the splint is in normal use. The term “hook-and-loop” is broad enough to refer to arrangements comprising not only hooks and loops, but also fasteners that include hooks on both faces of material to be fastened together.
[0017] Splints or other related appliances may be used to immobilize or support a body portion. For example, splints or other immobilization devices may be used to immobilize or support an injured (e.g., broken) arm or leg. The need for splints may be particularly acute in remote locations (e.g., mountains, wilderness, ski slopes, military expeditions, etc.), where the injured individual must be transported to receive further medical assistance.
[0018] In some embodiments, a splint may include a first side to be oriented toward the injured limb when splinting a leg (e.g., a leg orientation) and a second side to be oriented toward the injured limb when splinting an arm (e.g., an arm orientation). In some embodiments, a splint may be configured for use with other accessories to immobilize a joint, such as a wrist or ankle.
[0019] In some embodiments, a splint or splint assembly may be configured for compact storage. For example, in some embodiments, the splint may be rolled, folded, or otherwise compacted to reduce the space occupied by the splint. This compact configuration may facilitate portability and storage of the splint, thereby enabling use of the splint in remote or otherwise difficult-to-access locations. In some embodiments, components of the splint may be used to support an arm in a sling configuration.
[0020] In some circumstances, it is desirable to immobilize the joints above and below the site of an injury to prevent further damage from rotation or movement about the joint. For example, for a fracture of a radius and/or ulna, it may be advantageous to immobilize the elbow and the wrist.
[0021] FIGS. 1A and 1B provide views of a splint 300 , according to another embodiment of the present disclosure. FIG. 1A is a view of a splint 300 in an expanded configuration. FIG. 1B is a view the splint 300 where the splint 300 has been rotated 180 degrees about an axis of symmetry of the splint 300 relative to the configuration depicted in FIG. 1A , showing the rear or underside of the splint 300 . FIG. 1C is cross sectional view of the splint 300 of FIG. 1A .
[0022] Referring to FIGS. 1A and 1B generally and collectively, the splint 300 includes an expandable support structure 310 formed by a proximal portion 330 and a distal portion 340 . The distal portion 340 of the support structure 310 may be slidably coupled to the proximal portion 330 by an integrated track system 307 . The track system 307 may be disposed along the lateral edges of the distal portion 340 and along the rear or back surface of the proximal portion 330 . The track system 307 may include rails and/or grooves on the proximal and distal portions 330 , 340 . The rails may pair with the grooves such that the track system 307 secures the distal portion 340 to the proximal portion 330 , while allowing the distal portion 340 to slide relative to the proximal portion 330 to transition the support structure 310 between an expanded configuration and an unexpanded configuration. The rails and/or grooves may be configured by their size, shape, length, orientation, and/or any other suitable feature, to slidably couple the distal portion 340 to the proximal portion 330 . For example, the track system 307 may allow the distal portion 340 to slide in continuous motion between a fully expanded configuration (see FIGS. 1A & 1B ), with the splint 300 configured with the greatest possible length, and an unexpanded configuration (see FIG. 2E ), with the splint 300 configured with a majority of the distal portion 340 disposed adjacent to the proximal portion 330 .
[0023] Some embodiments may allow the distal portion 340 to separate from the proximal portion 330 . For example, with the splint 300 in a fully expanded configuration, the track system 307 may allow the distal portion 340 to slide away from the proximal portion 330 until the proximal and distal portions 330 , 340 separate. In some circumstances, it may be advantageous to employ both the distal portion 340 and the proximal portion 330 to splint a limb (e.g., when splinting an adult limb), while in other circumstances (e.g., when splinting the limb of a child or infant) it may be advantageous to separate the distal portion 340 from the proximal portion 330 and use only the distal portion 340 or the proximal portion 330 to splint the limb. Stated differently, embodiments where the distal portion 340 and proximal portion 330 may be detached from one another may allow a responder to better adjust the length of the splint to the dimensions of the injured individual. Additionally, in some embodiments, it may be advantageous to employ only the proximal portion 330 of the splint 300 .
[0024] A stop 350 located at a distal end of the proximal portion 330 may be configured to limit the distal portion 340 from sliding out of engagement with the proximal portion 330 . The stop 350 may be a protrusion disposed toward a proximal end of the distal portion 340 and may be configured to engage a protrusion or other structural element at structural element disposed toward a distal end of the proximal portion 330 .
[0025] In alternative embodiments, the track system 307 may be configured with a locking mechanism to substantially prevent or restrict separation of the proximal and distal portions 330 , 340 . For example, when the splint 300 is in a fully expanded configuration, the track system 307 may prevent movement of the distal portion 340 away from the proximal portion 330 . Stated differently, the track system 307 may be configured to prevent the proximal and distal portions 330 , 340 from separating.
[0026] The support structure 310 of the splint 300 may be made from any suitable material. For example, the support structure 310 may be formed from or comprise metal (e.g., aluminum), plastic, acrylic, carbon fiber, or any other suitable rigid material. In some embodiments, the slidable support structure may be radiolucent to facilitate observation of the relevant limb via x-ray. Further, the support structure 310 of the splint may be more rigid in a first direction, parallel to an axis extending from the distal portion 330 to the proximal portion 340 , than a second direction transverse to the first direction. Said another way, the second direction of the support structure 310 is more flexible than the first direction to allow the support structure 310 to wrap around the limb of the patient, while maintaining a support surface for the limb. This allows the edges with the rails 302 to wrap around a limb of a patient, while maintaining support of the limb in the first direction. For example, the rails 302 on each of transverse sides of the support structure 310 are a first distance apart when the support structure is in a flat configuration and the rails 302 are a second distance apart when in the support structure 310 is in a wrapped configuration around a limb, such that the second distance is less than the first distance.
[0027] As indicated above, some splints 300 may include one or more handles 308 that are configured to facilitate lifting of splint 300 and the appendage supported by the splint 300 and/or may also facilitate configuring the splint 300 in an expanded configuration. For example, the handles 308 may allow a user to grasp each of the proximal and distal portions 330 , 340 and may enable the user to pull the portions 330 , 340 in opposite directions, expanding the splint. For example, each handle 308 may be disposed at or along edges of each of the proximal and distal portions 330 , 340 and may include a space, an opening, an indent, and/or a groove formed in the slidable support structure 310 .
[0028] The slidable support structure 310 may include a plurality of slidable securing bands/straps 305 and corresponding slidable fasteners 304 (e.g., a plurality of hook-and-loop fasteners and/or fastener elements) to adjust the configuration of the slidable support structure 310 and/or facilitate securing and/or splinting a limb with the splint 300 . For example, the slidable securing straps 305 and the corresponding slidable fasteners 304 may be disposed along the lateral edges of each of the proximal and distal portions 330 , 340 of the support structure 310 . Further, the slidable straps 305 and corresponding slidable fasteners 304 may be slidably coupled to the proximal or distal portions 330 , 340 by a slidable base 303 coupled to a rail or track 302 . As shown in FIGS. 1B and 1C , the rail 302 may include a raised portion 360 of the support structure 310 configured to form an extended ridge, lip, or cavity 309 . The extended ridge 309 may allow a hooked portion of each of the sliding bases 303 to couple to the rail 302 and to slide along the length of the portion 330 , 340 to which each sliding base 303 is coupled. When splinting a limb (e.g., leg) it may be advantageous to wrap one or more securing straps 305 around the limb and secure the straps 305 at a length based on the girth of the limb, utilizing the slidable fasteners 304 . The fasteners 304 may be buckles, hook-and-loop, or any suitable fastener to secure the strap 305 around the leg.
[0029] In some embodiments, the slidable support structure 310 may be used as a support panel of a back pack or other carrying case. The slidable support structure 310 may be removed from the back pack or other carrying case as needed. When not in use, however, the slidable support structure 310 functions as the support panel for the back pack or other carrying case for transport. That is, the slidable support structure 310 has a dual function as a splint and as a support panel of a back pack or other carrying case for ease of transport.
[0030] FIG. 2A is a side view of a leg that is supported by the splint 300 of FIG. 1A in a flat configuration and an ankle/elbow/knee device 301 . FIG. 2B is a side view of a leg that is supported by the splint 300 of FIG. 1A , without the ankle/elbow/knee device 301 . FIG. 2C is a side view of a leg that is supported by the ankle/elbow/knee device 301 of FIG. 1A . FIG. 2D is a side view of an arm that is supported by the splint 300 of FIG. 1A in an expanded configuration. FIG. 2E is a side view of an arm that is supported by the splint 300 of FIG. 1A in an unexpanded configuration. FIG. 2F is a side view of an arm that is supported by the ankle/elbow/knee device 301 . FIG. 2G is a side view of a leg bent at the knee supported by the ankle/elbow/knee device 301 .
[0031] As depicted in FIGS. 2A-2G , the splint 300 may be used to splint and/or secure the limb of an injured individual to provide support to the limb. When the limb of the injured individual has been splinted, the proximal portion 330 of the splint 300 may be disposed around an upper portion of the patient's limb, while the distal portion 340 of the splint 300 is disposed around a lower portion of the patient's limb. The splint 300 may be attached to the limb of the patient in any suitable manner (e.g., via cravats or one or more slidable securing bands 305 and corresponding fasteners 304 ). The slidable securing straps 305 may be of a variety of sizes (e.g., longer bands for securing the splint 300 around the upper portion of the limb and shorter bands for securing the splint around a lower portion of the limb).
[0032] The ankle/elbow/knee device 301 may be used in connection with the splint 300 to support an ankle, an elbow, or a knee of the patient. For example, the ankle/elbow/knee device 301 , as shown in FIGS. 2A and 2C , may be configured (e.g., bent) in an L-shaped or substantially L-shaped configuration to cradle the ankle of the injured individual. When disposed in this manner in relation to the lower portion of the injured individual's leg, the ankle/elbow/knee 301 device may be slidably fastened to the splint 300 . For example, a portion of the ankle/elbow/knee device 301 may abut the lowermost portion of the splinted leg, and may be slidably coupled to the track system 307 disposed in the distal portion 340 of the slidable support structure 310 . Further, when splinting the leg of a relatively short-legged individual, the ankle/elbow/knee device 301 together with the proximal and distal portions 330 , 340 of the slidable support structure 310 may adjust to decrease the overall length of the splint 300 and facilitate securing and splinting the leg. Similarly, when splinting the leg of a relatively long-legged individual, the slidable support structure 310 of the splint 300 may extend increasing the length of the splint 300 and the ankle/elbow/knee device 301 may be positioned to support the ankle region of the patient. Stated otherwise, the ankle/elbow/knee device 301 may be slidably coupled to the distal portion 340 to allow the proximal and distal portions 330 , 340 and the ankle/elbow/knee device 301 to each slide along rails of the track system 307 and configure the length of the splint 300 based on the length of the limb to be secured and/or splinted. A coupling member 342 may be configured to slidably engage the track system 307 on the distal portion 340 and slidably engage a similar track system or rail on the ankle/elbow/knee device 301 .
[0033] The ankle/elbow/knee device 301 may include one or more slidable securing strap 306 and corresponding slidable fasteners similar to the securing straps 305 and slidable fastener elements 304 of the splint 300 . The at least one slidable securing strap 306 may include a slidable base 303 to slide along a track. The at least one slidable securing strap 306 may be configured to wrap around the patient's ankle or foot to secure the ankle/elbow/knee device 301 to the foot or leg of the patient. When disposed around the ankle and attached to the distal portion 340 of the slidable support structure 310 , the ankle/elbow/knee device 301 may restrict motion of the lower portion of the injured individual's leg and/or foot. A padded angle brace 344 may be positioned at a front side of the ankle between the limb and the slidable securing strap 305 . The padded angle brace 344 may enhance bracing of the ankle/elbow/knee device 301 .
[0034] As can be appreciated, the same slidable configurations may be utilized to secure and/or splint an elbow in a manner substantially similar to that described above. FIG. 2F shows the ankle/elbow/knee device 301 being used to support an elbow. The elbow is supported in a bent position with the padded angle brace 344 positioned within the inner surface of the elbow. The at least one slidable securing strap 306 may be configured to wrap around the patient's elbow or arm to secure the ankle/elbow/knee device 301 to the arm of the patient. When disposed around the elbow, the ankle/elbow/knee device 301 may restrict motion of the lower portion of the injured individual's arm and the injured elbow. The padded angle brace 344 may be positioned at a front side of the elbow and may enhance bracing of the ankle/elbow/knee device 301 .
[0035] FIG. 2G shows the ankle/elbow/knee device 301 being utilized to secure and/or splint a knee in a manner substantially similar to that described above. The knee is supported in a bent position with the padded angle brace 344 positioned at the posterior knee. The at least one slidable securing strap 306 may be configured to wrap around the patient's knee or leg to secure the ankle/elbow/knee device 301 to the leg of the patient at the knee. When disposed around the knee, the ankle/elbow/knee device 301 may restrict motion of the lower portion of the injured individual's leg and/or knee.
[0036] Any methods disclosed herein include one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified. Moreover, sub routines or only a portion of a method described herein may be a separate method within the scope of this disclosure. Stated otherwise, some methods may include only a portion of the steps described in a more detailed method.
[0037] Reference throughout this specification to “an embodiment” or “the embodiment” means that a particular feature, structure or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.
[0038] The following are examples of further embodiments of the disclosed technology.
[0039] Example 1 is a splint for supporting or immobilizing a limb of a patient, the splint comprising a proximal portion formed of material that is more flexible in a first direction than a second direction transverse to the first direction, the proximal portion to bend around the limb along the first direction and to support and stabilize at least a portion of the limb along the second direction; and a distal portion formed of material that is more flexible in the first direction than the second direction, the distal portion to bend around the limb along the first direction and to support and stabilize at least another portion of the limb along the second direction. The distal portion slidably couples to the proximal portion, such that the splint can transition from an unexpanded state to an expanded state.
[0040] Example 2 is the splint of example 1, wherein the distal portion slidably couples to the proximal portion via a track system. The track system includes a first set of rails disposed on the proximal portion of the splint, and a second set of rails disposed on the distal portion of the splint to pair with the first set of rails such that the track system slidably couples the distal portion to the proximal portion.
[0041] Example 3 is the splint of examples 1 and 2, wherein the track system further includes a stop to prevent the distal portion from disengaging from the proximal portion.
[0042] Example 4 is the splint of example 3, wherein the stop includes a protrusion disposed toward a distal end of the proximal portion that engages with a protrusion disposed toward a proximal end of the distal portion to prevent the distal portion from disengaging with the proximal portion.
[0043] Example 5 is the splint of any one of examples 1-4, wherein the track system further includes a locking mechanism to prevent the distal portion from separating from the proximal portion.
[0044] Example 6 is the splint of any one of examples 1-5, wherein the proximal portion and the distal portion are detachably coupled.
[0045] Example 7 is the splint of any one of examples 1-6, further comprising a plurality of securing straps to secure the proximal portion and the distal portion to the limb of the patient.
[0046] Example 8 is a splint system including the splint of any one of examples 1-7 and an L-shaped device for immobilizing one of an ankle, an elbow, and a knee on a limb that is supported by the splint.
[0047] Example 9 is the splint system of example 8, wherein the L-shaped device is slidably couplable to the distal portion of the splint.
[0048] Example 10 is a splint for supporting or immobilizing a limb of a patient, the splint comprising a proximal portion, having a distal end, a proximal end, and two transverse sides perpendicular to the distal end and the proximal end, the proximal portion transitionable from a flat configuration to a wrapped configuration to support the limb of the patient. The flat configuration of the proximal portion includes the transverse sides spaced a first distance apart and the wrapped configuration of the proximal portion includes the transverse sides spaced a second distance apart. The second distance is less than the first distance. The splint also comprises a distal portion, having a distal end, a proximal end, and two transverse sides perpendicular to the distal end and the proximal end, the distal portion transitionable from a flat configuration to a wrapped configuration to support the limb of the patient. The flat configuration of the distal portion includes the transverse sides of the distal portion space a third distance apart and the wrapped configuration of the distal portion includes the transverse sides spaced a fourth distance apart. The third distance is less than the fourth distance. A track system is also included in the splint to slidably couple the distal portion to the proximal portion such that the splint can transition from an unexpanded state to an expanded state.
[0049] Example 11 is the splint of example 10, wherein the track system includes a first set of rails mounted to the proximal portion parallel to the transverse sides and a second set of rails mounted to the distal portion parallel to the transverse sides to pair with the first set of rails such that the track system slidably couples the distal portion to the proximal portion.
[0050] Example 12 is the splint of either example 10 or 11, wherein the track system further includes a stop to prevent the distal portion from disengaging with the proximal portion.
[0051] Example 13 is the splint of any one of examples 10-12, wherein the track system further includes a lock mechanism to prevent the distal portion from disengaging with the proximal portion.
[0052] Example 14 is the splint of any one of examples 10-13, further comprising a plurality of securing straps to secure the proximal portion and the distal portion to a limb of a patient.
[0053] Example 15 is the splint of example 14, wherein each of the plurality of securing straps is slidably coupled to one of the proximal portion and the distal portion.
[0054] Example 16 is a splint for supporting or immobilizing a limb of a patient, the splint including a proximal portion formed of a material that is bendable in a first direction to wrap the proximal portion around the limb and to configure the proximal portion to be rigid in a second direction transverse to the first direction to support and stabilize at least a portion of the limb, and a track system to slidably couple a distal portion to the proximal portion such that the splint is transitionable from an unexpanded state to an expanded state.
[0055] Example 17 is the splint of example 16, further comprising a plurality of securing straps to secure the proximal portion to the limb of the patient.
[0056] Example 18 is the splint of example 17, wherein each of the plurality of securing straps is slidably coupled to the proximal portion.
[0057] Example 19 is the splint of example 18, wherein each of the plurality of securing straps is slidably coupled about a rail on a surface opposite the track system.
[0058] Example 20 is the splint of example 19, wherein the rail includes a raised portion defining a ridge, lip, or cavity to receive each of the plurality of securing straps.
[0059] Example 21 is a splint for supporting or immobilizing a limb. The splint includes a proximal portion formed of a material that is more flexible in a first direction to wrap the proximal portion around the limb than a second direction transverse to the first direction to support and stabilize at least a portion of the limb. The splint also includes a first rail mounted on a surface of the splint and extending parallel to the second direction. The splint also includes a first strap securable to the first rail to secure the proximal portion to the limb of the patient.
[0060] Example 22 is the splint of example 21, wherein the first rail includes an extended portion to define an extended ridge to receive an end portion of the first strap.
[0061] Example 23 is the splint of example 22, wherein the end portion of the first strap includes a hooked portion to engage with the extended ridge and slide along a length of the first rail.
[0062] Example 24 is the splint of example 21, wherein the splint further includes a second rail mounted on a surface of the splint parallel to the second direction.
[0063] Example 25 is the splint of example 24, wherein the splint further includes a second strap securable to the second rail to secure the proximal portion to the limb of the patient.
[0064] Example 26 is the splint of example 25, wherein the second rail includes an extended portion to define an extended ridge to receive an end portion of the second strap.
[0065] Example 27 is the splint of example 26, wherein the end portion of the second strap includes a hooked portion to engage with the extended ridge and slide along a length of the second rail.
[0066] Example 28 is the splint of any one of examples 25-27, wherein the second strap removably couples to the first strap to secure the proximal portion to the limb of the patient.
[0067] Similarly, it should be appreciated by one of skill in the art with the benefit of this disclosure, that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim require more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. Thus, the claims following this Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims.
[0068] Recitation in the claims of the term “first” with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the present disclosure.
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A splint may be used to support or immobilize a body portion of a patient. Some splints may include one or more features to facilitate transport, placement, and/or manipulation of a splint. For example, some splints may be relatively lightweight, rugged, and in a compact configuration prior to use. Some splints may use radiolucent materials to permit x-ray examination of the relevant appendage without removal of the splint. Some splints may be used with other accessories or devices to facilitate immobilization of a limb and/or transport of the injured individual.
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[0001] This application claims priority to Korean Patent Application No. 10-2008-0029892, filed on Mar. 31, 2008, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a radio-immunoconjugate for diagnosis and treatment of cancer or metastasis, and to development of metastasis inhibitory formulations using the same. More particularly, the present invention provides a radio-immunoconjugate as material for indicating a metastatic cancer that has antibody marked with any lanthanum radionuclide and/or gamma, beta or alpha ray emitting radioisotopes targeting a vascular endothelial growth factor receptor (VEGFR). The present invention also provides a composition for detection of pre-metastatic sites and cancer metastasis inhibitory formulations containing the radio-immunoconjugate.
[0004] 2. Description of the Related Art
[0005] Radioisotope marking techniques applied to physiologically active materials are generally employed for treatment of diseases such as cancers. The radioisotopes fundamentally have weak transmission but emit beta rays with strong destructive force and (optionally) emit gamma rays. The primary isotopic elements used for internal irradiation treatment using seal-less radioisotopes are 89 Sr, 32 P, 90 Y, 188 re, 153 Sm, 166 Ho and so forth. A method of using these elements includes introducing a marking compound to emit beta energy suitable to treat a cancer so that the marking compound accumulates only in the cancer cells, thereby treating the same. Also, since specific nuclides with a short half-life sufficient to decay the nuclides in a relatively short time are used. These elements have substantially less effect on organs or other portions of a human body that do not suffer from the cancer. In addition, the nuclide is concentrated at only one site during the treatment, thus minimizing metastasis of the cancer to other internal organs. Among the above isotopic elements, 166 Ho is a beta ray emitting radionuclide, emitting energy at 1.77 MeV (48%) and 1.85 MeV (51%), which is well known for treatment of cancers.
[0006] Diagnostic methods using radioisotopes may include positron emission tomography (PET), photon emission computed tomography (SPECT), use of a gamma camera, and so forth. PET refers to a process comprising: combining a metabolite such as glucose with a positron emitting radioisotope; administering the combined material to a human body; observing biochemical changes that occur in the body; and forming CT images. Based on a principle wherein a cancerous tissue consumes glucose much more than other tissues, and, when the cancerous cells absorb a relatively large amount of glucose compared to other tissues, only the cancerous tissues emit radioisotopes. The PET detects emission signals and generate an image from the detected signals.
[0007] SPECT refers to a process comprising: intravenous (IV) administering a gamma ray-emitting radioactive compound to a patient; taking pictures of blood flow distribution in organs such as heart, brain, liver, bone, etc. when the radioactive compound is entirely and homogeneously distributed throughout the organs; observing changes of the distribution caused by a disease; and forming CT images based on the observed results. The gamma camera measures gamma rays emitted from a radioactive compound, which was administered to a body for the purpose of diagnosis, using a detector fixed to a test subject; records internal distribution of the compound or distribution of the compound in organs; and then forms images based on the recorded results.
[0008] Growth of a new vascular network connected to cancer tissues is considered to be a significant condition for cancer metastasis. Such a vascular cell growth is necessary for primary cancers and/or metastatic tumors, and a cancer tissue cannot grow to a size of more than 1 to 2 mm unless nutrients and oxygen are supplied by the vascular cell growth (see Judah Folkman, The Role of Angiogenesis in Tumor Growth, Seminars in Cancer Biology, Vol. 3, pp. 65-71 (1992)). During the vascular cell growth, a primary cancer cell flows into a blood vessel, moves to other sites and generates a metastatic tumor. That is, conventional treatment agents targeting vascular cell growth factors may be commonly used in all solid tumors.
[0009] Recently, the most well known vascular cell growth factor has been a vascular endothelial growth factor (VEGF). Studies for identifying a cancer metastasis mechanism using the VEGF have recently taken place and have reported that a bone marrow-derived cell having a vascular endothelial growth factor receptor 1 (VEGFR 1), which is the first determinant to select a pre-metastatic site and promotes metastasis, moves to a specific site where a cancer cell inducible environment is formed (see Rosandra N. Kaplan et al., VEGFR 1- positive haematopoietic bone marrow progenitors initiate the pre - metastatic niche, Nature, Vol. 438, pp. 820-827, December 2005). In addition, it was disclosed that when antibody targeting a VEGFR 1 is administered to an experimental animal model to which lung cancer or melanoma cells were xenografted, the antibody combines with VEGFR 1 existing in the mouse so as to inhibit metastasis thereof (see Rosandra Kaplan et al., Nature, 2005).
[0010] Accordingly, it is expected that using such VEGFR 1 in immunotherapy and/or radioimmunotherapy will simultaneously achieve detection and inhibit metastasis of pre-metastatic sites.
[0011] Under the circumstances described above, the present inventors found that a radio-immunoconjugate prepared by stably marking a VEGFR with a radioisotope for diagnosis and medical treatment is efficiently adsorbed to the surface of vascular endothelial cells without alteration in immune activity and/or structure of protein. It also exhibits excellent accumulation in cancer tissues in the body of an animal model used in a cancer development experiment. The inventors therefore, have identified that the radio-immunoconjugate may be used for marking, diagnosis and medical treatment of cancer, as well as for detection and inhibition of pre-metastasis, thereby completing the present invention.
BRIEF SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention has been proposed to solve problems of conventional techniques, and an object of the present invention is to provide a composition for detection of pre-metastatic sites and inhibition of metastasis, containing a radio-immunoconjugate that has an antibody marked with a radioisotope targeting a vascular endothelial growth factor receptor (VEGFR).
[0013] In one aspect, there is provided a composition for detection of pre-metastatic sites, containing a radio-immunoconjugate that has antibody marked with a radioisotope targeting a vascular endothelial growth factor receptor (VEGFR).
[0014] In another aspect, there is provided a method for detection of pre-metastatic sites, comprising: (1) administering the composition for detecting pre-metastatic sites described above to an individual with a cancer; and (2) detecting signals emitted from tissues of the individual by the composition in step (1) then imaging the detected signals.
[0015] In another aspect, there is provided a method for diagnosis of cancer or metastasis, comprising: (1) administering a composition containing the radio-immunoconjugate described above to an individual; (2) detecting signals emitted from tissues of the individual by the composition in step (1) then imaging the detected signals to determine an accumulation rate thereof; and (3) comparing the determined accumulation rate in step (2) to that of a normal individual (a reference level) and selecting individuals with relatively high accumulation rates.
[0016] In another aspect, there is provided a kit for diagnosis of cancer or metastasis, containing the radio-immunoconjugate described above.
[0017] In another aspect, there is provided a composition for inhibition of metastasis, containing the radio-immunoconjugate described above.
[0018] In another aspect, there is provided a method for inhibition of metastasis, comprising administration of a therapeutically effective amount of the composition for inhibition of metastasis described above to an individual with a cancer. The composition for detection of pre-metastatic sites that contains a radio-immunoconjugate using antibody targeting a VEGRF, according to the one embodiment of the present invention, may be used for preliminary diagnosis and treatment of pre-metastatic sites, as well as treatment of a primary cancer or a metastatic tumor, so that the composition may be used as a detection factor. Alternatively, the composition for inhibition of metastasis that contains a radio-immunoconjugate may primarily block metastasis so as to eliminate the possibility of metastasis or recurrence thereof, thereby effectively inhibiting metastasis in its early stages.
[0019] Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0020] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0021] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
[0022] FIG. 1 illustrates cell transformation of a normal cell through an inter-cellular network, when the normal cell as well as a cancer cell were co-cultured; here, a) is a schematic view of an experiment, and b) is an electron microscope picture (at 40× magnification);
[0023] FIG. 2 is a schematic view illustrating carcinogenesis observed from reduced expression of tumor suppressor proteins (p53, p21) in modified cells while increasing apoptosis inhibitory proteins (cancer cell indicating factor, Bcl2);
[0024] FIG. 3 is a schematic view illustrating over-expression of FLT-1 as a VEGFR after carcinogenesis of normal cells;
[0025] FIG. 4 illustrates a stable radio-immunoconjugation after antibody marked with Lu-177 targeting a VEGFR; here a) is a graphical representation illustrating an instant thin-layer chromatography (TLC) profile, b) is an electrophoresis image, and c) is a radiographic picture;
[0026] FIG. 5 is a graphical representation illustrating degrees of targeting vascular endothelial cells (surface adsorption rates) by antibody marked with Lu-177 targeting the VEGFR; and
[0027] FIG. 6 is a graphical representation illustrating variation in distribution of antibody marked with Lu-177 targeting the VEGFR in an animal model used in a cancer development experiment.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0029] In an aspect of the present invention, there is provided composition for detection of pre-metastatic sites, containing a radio-immunoconjugate that has antibody marked with a radioisotope targeting a vascular endothelial growth factor receptor (VEGFR).
[0030] Such a VEGFR may include at least one selected from KDR, flk-1 and flt-1, however, is not particularly limited thereto. An antibody may include a humanized antibody, a chimeric antibody, a modified antibody that was conjugated with polyethylene glycol (PEG), or a fragment thereof, however, the antibody is not particularly limited thereto.
[0031] The radioisotope used herein for marking the antibody may include at least one selected from a group of Sc-47, Cu-64, Cu-67, Ga-68, Br-76, Y-86, Y-90, Tc-99m, In-111, Sm-153, Dy-165, Ho-166, Er-169, Yb-169, Lu-177, Re-186 and Re-188 and, preferably, Lu-177, however, it is not particularly limited thereto.
[0032] As for proving that the VEGFR can be used as a metastasis detector, the present inventors found that when a brain cancer cell and a human umbilical vein endothelial cell (HUVEC) were extracted and incubated in a same chamber, the HUVEC was transformed through an inter-cellular network (as shown in FIG. 1 ).
[0033] In order to discover a reason for cell transformation caused by a hybrid culture, transformed cells were recovered and used to monitor an increase in protein levels in view of p53, p21 and Bcl 2 through a Western Blot analysis. As a result, the most representative cancer inhibitory gene, P53, as well as another protein p21 (which prevents cell growth when the cell is damaged, thus inhibiting cell transformation), were decreasingly expressed. On the other hand, expression of Bcl 2 protein, which is well known to inhibit apoptosis and to be excessively expressed in different tumor cells, was observed to increase. From these observations, it can be seen that normal cells have been transformed into cancer cells (as shown in FIG. 2 ).
[0034] The present inventors also investigated an expression degree of a specific VEGFR, Flt 1, known as the first determinant, to determine pre-metastatic sites in metastasis derived cells so as verify whether the VEGFR can be utilized as a metastasis detector. As a result, it can be seen that the metastasis derived cells exhibited over-expression of Flt 1 more than that in the normal cells (as shown in FIG. 3 ).
[0035] As far as using the VEGFR as a metastasis detector, structural stability of a protein and immune activity were investigated. After immuno-conjugation of antibody targeting the VEGFR with a bi-functional complexing agent, the immuno-conjugated product was marked using the radioisotope Lu-177 to synthesize a radio-immunoconjugate. The radio-immunoconjugate was subjected to protein staining and a radiographic process to verify its structural stability. Consequently, it can be seen that the radio-immunoconjugate maintained favorable structural stability and immune activity (as shown in FIG. 4 ).
[0036] As to another condition for using the VEGFR as a metastasis detector, specific adsorption to cancer cells was investigated. After a control substance having only a bi-functional complexing agent marked with Lu-177 and the radio-immunoconjugate of the present invention which has the marked antibody targeting the VEGFR, respectively, were administered to each culture solution containing vascular endothelial cells, adsorption to the surface of cancer cells was determined for each case. As a result, the control having only a bi-functional complexing agent marked with Lu-177 exhibited an adsorption rate of at most 0.5%, while the inventive radio-immunoconjugate having the marked antibody targeting the VEGFR had an adsorption rate of 16.35%, thus demonstrating high target attraction to cancer cells (as shown in FIG. 5 ). Accordingly, it can be seen that the inventive radio-immunoconjugate exhibits excellent specific bonding to external VEG factors out of the vascular endothelial cells, thereby achieving detection of pre-metastatic sites.
[0037] As to yet another condition for using the radio-immunoconjugate as a metastasis detector, an accumulation rate of the radio-immunoconjugate in cancer cells was investigated. After introducing the inventive radio-immunoconjugate, with the antibody targeting the VEGFR, into a blood vessel of an animal model used in a cancer development experiment, each organ and cancer cells were subjected to radiation measurement. As a result, it was found that the cancer cells had an accumulation rate of the radio-immunoconjugate 4.75 times that of the radio-immunoconjugate residue in blood (as shown in FIG. 6 ). Accordingly, it can be seen that the inventive radio-immunoconjugate may use the antibody targeting the VEGFR to target solid cancers.
[0038] The inventive radio-immunoconjugate can have an adsorption rate of 5 to 30%, preferably, 10 to 20% to the surface of the vascular endothelial cells, however, is not particularly limited thereto.
[0039] If the radio-immunoconjugate of the present invention is administered to an individual with cancer, the conjugate in the cancer cells may have an accumulation rate of 2 to 10 times, preferably, 3 to 5 times higher compared to that in normal tissues, however, it is not particularly limited thereto.
[0040] In another aspect of the present invention, there is provided a method for detection of pre-metastatic sites, comprising: (1) administering the composition for detecting pre-metastatic sites as set forth in claim 1 to an individual with a cancer; and (2) detecting signals emitted from tissues of the individual by the composition of step (1) then imaging the detected signals.
[0041] According to the detection method described above, the cancer in step (1) may be selected from any of liver cancer, gastric cancer, breast cancer, colon cancer, bone cancer, pancreatic cancer, head or neck cancer, uterine cancer, ovarian cancer, rectal cancer, esophageal cancer, small intestine cancer, perianal cancer, fallopian tube cancer, endometrial cancer, cervical cancer, vaginal cancer, vulvar cancer, Hodgkin's disease, prostate cancer, bladder cancer, renal cancer, urethral cancer, renal cytoma, renal pelvis cancer and tumors of the central nervous system and the like, however, it is not particularly limited thereto.
[0042] As to the detection method described above, the imaging in step (2) may be performed by, e.g., PET, SPECT and a gamma camera, however, the imaging process is not particularly limited thereto.
[0043] In another aspect of the present invention, there is provided a method for diagnosis of cancer or metastasis, comprising: (1) administering a composition containing radio-immunoconjugate having antibody marked with a radioisotope targeting a VEGFR to an individual; (2) detecting signals emitted from tissues of the individual by the composition in step (1), and then imaging the detected signals to determine an accumulation rate thereof; and (3) comparing the determined accumulation rate in step (2) to that of a normal individual (a reference level) and selecting individuals with relatively high accumulation rates.
[0044] As to the diagnosis method described above, the imaging in step (2) may be performed by, e.g., PET, SPECT and a gamma camera, however, the imaging process is not particularly limited thereto.
[0045] As to the diagnosis method described above, the accumulation rate in step (3) may be 2 to 10 times, preferably 3 to 5 times compared to that in tissues of a normal individual (without cancer), however the accumulation rate is not particularly limited thereto.
[0046] As to the diagnosis method describe above, the cancer in step (3) may be any of liver cancer, gastric cancer, breast cancer, colon cancer, bone cancer, pancreatic cancer, head or neck cancer, uterine cancer, ovarian cancer, rectal cancer, esophageal cancer, small intestine cancer, perianal cancer, fallopian tube cancer, endometrial cancer, cervical cancer, vaginal cancer, vulvar cancer, Hodgkin's disease, prostate cancer, bladder cancer, renal cancer, urethral cancer, renal cytoma, renal pelvis cancer and tumors of the central nervous system and the like, however, is not particularly limited thereto.
[0047] In an yet aspect of the present invention, there is provided a kit for diagnosis of cancer or metastasis, containing a radio-immunoconjugate that has an antibody marked with a radioisotope targeting a VEGFR.
[0048] In addition, the present invention provides a composition for inhibiting metastasis, containing a radio-immunoconjugate that has antibody marked with a radioisotope targeting a VEGFR.
[0049] The radio-immunoconjugate of the present invention has excellent specific bonding to VEGF out of vascular endothelial cells and high accumulation rate in cancer cells so as to mark solid cancers, thereby inhibiting metastasis thereof.
[0050] The metastasis inhibitory composition of the present invention may further contain pharmaceutically available salts in addition to the radio-immunoconjugate. Such a pharmaceutically available salt may include additive salts obtained from free acid. Preferred examples of the free acid may be organic acid or inorganic acid. The inorganic acid may be hydrochloric acid, bromic acid, sulfuric acid, phosphoric acid and so forth. The organic acid may be citric acid, acetic acid, lactic acid, tartaric acid, maleic acid, fumaric acid, formic acid, propionic acid, oxalic acid, trifluoroacetic acid, benzoic acid, gluconic acid, methanesulfonic acid, glycolic acid, succinic acid, 4-toluenesulfonic acid, galacturonic acid, embonic acid, glutamic acid, aspartic acid, and so forth. Additionally, the pharmaceutically available salt may include all the salts that may be prepared by conventional methods, hydrides and solvates.
[0051] The metastasis inhibitory composition of the present invention may be orally or parenterally administered and used in the form of medical formulations. In order to prepare the formulation, any additive such as a filler, extending agent, binder, wetting agent, diluents, such as surfactant and disintegrating agent, excipient may be added to the composition. A solid formulation for oral administration may include tablets, pills, powders, granulates, capsules and the like. Such a solid formulation may be prepared by adding for example, starch, calcium carbonate, sucrose, lactose, gelatin, etc. to a metastasis inhibitory composition of the present invention. Other than general excipients, lubricants such as magnesium, stearate, talc and the like may also be used.
[0052] A liquid formulation for oral administration may include a suspension, anti-solution agent, emulsifier, syrup and the like. In addition to typical diluents such as water, liquid paraffin, etc., a variety of excipients, such as a wetting agent, sweetener, aromatic agent, preservative and the like, may also be used. Meanwhile, parenteral formulations may include a sterile aqueous solution, non-aqueous solvent, suspension, emulsifier, lyophilizing agent, suppository and the like. The non-aqueous solvent and suspension may include vegetable oil such as propylene glycol, polyethylene glycol, olive oil, etc. and an injective ester such as ethyl oleate. The suppository may be prepared using a base material such as witepsol, macrogol, tween 61, cacao butter, laurin butter, glycerol, gelatin, and so forth. The cancer inhibitory composition of the present invention may be parenterally administered by subcutaneous, intravenous and/or intramuscular injection.
[0053] Administration unit may include, for example, 1, 2, 3 or 4 times each dosage, or otherwise, ½, ⅓ or ¼ times each dosage. Such dosage preferably refers to an amount of an active drug per time and commonly corresponds to 1, ½, ⅓ or ¼ times of a dose per day. An effective amount of the cancer inhibitory composition may range from 0.0001 to 10 g/kg, preferably 0.0001 to 5 g/kg and be administered 1 to 6 times per day.
[0054] Moreover, the present invention provides a method for inhibition of metastasis, comprising administration of the metastasis inhibitory composition to an individual with a cancer.
[0055] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the following examples, which are only given for the purpose of illustration and are not to be construed as limiting the scope of the invention.
EXAMPLE 1
Identification of Inter-Cellular Relation Between Cancer Cells and Normal Cells
[0056] Cancer cells, glioblastoma (T98 G; Korean cell line bank No. 21690) were inoculated in Transwell plates (purchased from Millipore Co.) at 1×10 6 per well located above a polycarbonate film having a 0.4 μm pore size, while the same amount of human umbilical vein endothelial cells (HUVEC) (purchased from Lonza Co.) were inoculated into wells located below the polycarbonate film. Subsequently, the inoculated samples were cultured at 37° C. in 5% CO 2 atmosphere for 48 hours under constant temperature and humidity conditions, followed by observing cell modification caused by a film separation culture through an electron microscope (40×) (Leica, USA).
[0057] As a result, it was identified that the normal cells, vascular endothelial cells were transformed (see FIG. 1 ).
EXAMPLE 2
Western Blot Analysis
[0058] In order to examine the cell transformation caused by the film separation culturing as described in Example 1, the transformed cells were separated from the polycarbonate film after the culturing and added to 100 μl of a buffer solution (0.5M Tris-Cl, 0.01 MEGTA, Triton X-100; 0.4M PMSF), followed by crushing the cells at 4° C. for 30 minutes. Loading the treated cells into an acrylamide gel, the mixture was subjected to electrophoresis then moved into a nitrocellulose film. Using p53, p21, Bcl 2 and Flt 1 antibodies as first antibodies (Santa Cruz Biotechnology, USA), as well as a goat anti-mouse IgG-HRP (Santa Cruz Biotechnology, USA) as a second antibody, the cells were treated so as to monitor a band thereof.
[0059] As a result, it can be seen that expression of p53 and p21 proteins was reduced while expression of Bcl 2 protein was increased, and therefore, the normal cells were connected with cancer cells through inter-cellular network, leading to carcinogenesis (see FIG. 2 ). It was also found that expression of Flt 1 protein increased, thus demonstrating that VEGFR is applicable as a metastasis detector (see FIG. 3 ).
EXAMPLE 3
Synthesis of Radio-Immunoconjugate Marked with Lanthanum Radionuclide (Lu-177)
[0060] The VEGFR, Flt 1, which was identified as a pre-metastatic site determinant in Example 2 was stably marked with Lu-177 which is well known as a lanthanum radionuclide that emit both beta rays and gamma rays. The marking process was performed by dissolving an anti-Flt 1 antibody (Santa Cruz, Biotechnology Co., USA) targeting the VEGFR in a PBS buffer solution (pH 7.4) to prepare 0.1 mM diluted solution, adding DTPA-NCS (DTPA isothiocyanate) as a bi-functional complexing agent for radio-immunoconjugation to the solution in a ratio by moles of 1:1, to produce an immunoconjugate, and purifying the obtained mixture through a ultra-filtration film (purchased from Millipore Co., Centricon filter 50 kDa). Reacting the purified immunoconjugate with 0.1 mCi Lu-177 solution (manufactured by HANARO, Korea Atomic Energy Research Institute) at room temperature for 5 minutes, the reaction product was treated using an instant TLC (EG&G Berthold linear analyzer) and a cyclone storage phosphor system (Perkin Elmer, USA) so as to determine a mark yield. After protein electrophoresis in a polyacrylamide gel, the resultant product was subjected to a coomassie blue staining using coomassie brilliant blue R-250 (BioRad, SIGMA, USA) and, at the same time, a radiography analysis using the cyclone storage phosphor system (Perkin Elmer, USA), so as to identify structural stability of the radio-immunoconjugate.
[0061] From the identification, neither degradation of the antibody nor generation of other side products were observed whereas Lu-177 marked bands were observed. It can be seen that the synthesized radio-immunoconjugate favorably maintained structural stability and immune activity (see FIG. 4 ).
EXAMPLE 4
Determination of Cell Surface Adsorption of Radio-Immunoconjugate
[0062] Antibody marked with Lu-177 targeting the VEGFR ( 177 Lu-DTPA-NCS-anti Flt 1 mAb) resulted from Example 3 was used to determine surface adsorption of the HUVEC (Lonza Co.). Administering the radio-immunoconjugate (5 μCi Lu-177, containing 1 μg of antibody) to a culture solution containing HUVEC, the mixture was left at 37° C. for 1 hour under a constant temperature condition. Washing the mixture with the PBS solution (pH 7.4), cells were recovered. Comparison and analysis of amount of the radio-immunoconjugate to be adsorbed to the surface of the cells was performed using a gamma counter (Perkin Elmer, USA).
[0063] As a result, if the bi-functional complexing agent was only marked with Lu-177, the radio-immunoconjugate exhibited an adsorption rate of at most 0.5%. On the other hand, when the antibody targeting the VEGFR was marked, the adsorption rate of the radio-immunoconjugate reached 16.35%. In addition, the radio-immunoconjugate exhibited excellent target attraction to human brain cancer cells. Therefore, it can be seen that the radio-immunoconjugate has excellent target attraction to any VEGFR that exists in pre-metastatic sites (see FIG. 5 ).
EXAMPLE 5
Observation of Internal Distribution of Radio-Immunoconjugate in Cancer-Induced Animal Model
[0064] Radio-immunoconjugate marked with Lu-177 targeting the VEGFR ( 177 Lu-DTPA-NCS-anti Flt 1 mAb) resulting from Example 3 was used to identify internal distribution of the antibody in an experimental animal. A female nude mouse weighting 21 to 23 g that was xenografted with human lung cancer cells (obtained from Orientbio Inc., KOREA) was used as the experimental animal. 5 μCi of the radio-immunoconjugate (containing 1 μg of antibody) was injected into a tail vein of the mouse. After 24 hours, organs (including blood, heart, lung, liver, spleen, stomach, small intestine, large intestine, kidney) and cancer tissues were excised and weighed, followed by measuring radioactivity in each organ using a gamma counter. The measured results were applied to calculation of injected dose per g weight of the organ, that is, percent of injected dose/g (% ID/g).
[0065] As a result, compared to the injected dose remaining in blood of 0.32% ID/g, the injected dose remaining in cancer tissues was 1.56% ID/g, thus verifying relatively high accumulation rate. Therefore, it can be seen that the synthesized radio-immunoconjugate of the present invention is useful for diagnosis and treatment of cancer or metastasis as well as diagnosis of pre-metastatic sites.
[0066] Although the present invention has been described in detail reference to its presently preferred embodiment, it will be understood by those skilled in the art that various modifications and equivalents can be made without departing from the spirit and scope of the present invention, as set forth in the appended claims.
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A radio-immunoconjugate for diagnosis and treatment of cancer or metastasis and development of metastasis inhibitory formulations using the same is provided. Also, a radio-immunoconjugate is used as a material indicating a metastatic cancer that has antibody marked with any lanthanum radionuclide and/or gamma, beta or alpha ray emitting radioisotopes targeting a vascular endothelial growth factor receptor (VEGFR) is provided. Such a radio-immunoconjugate is advantageous in that it maintains structural stability of a protein and immune activity thereof and is effectively adsorbed to the surface of vascular endothelial cells. This makes it useful as a pre-metastatic site detection factor. When the radio-immunoconjugate is administered to an animal model with cancer, the radio-immunoconjugate is accumulated in cancerous tissues. Therefore, it is useful for development of radioactive metastasis inhibitory formulations.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims benefit of U.S. Provisional Application No. 60/718,145, filed Sep. 15, 2005, the disclosure of which is hereby incorporated by reference herein; and the present application is related to concurrently filed commonly owned U.S. Patent Application for SELECTIVE SOUND SOURCE LISTENING IN CONJUNCTION WITH COMPUTER INTERACTIVE PROCESSING, Attorney Docket No. SCEA04005JUMBOUS, which is hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to controlling devices through the use of air pressure waves, and more particularly, to interacting with a video game through the use of air pressure waves.
BACKGROUND OF THE INVENTION
[0003] An important consideration in the design of video game systems is providing a way for users to interact with the system. Typically, a handheld controller having a number of buttons and/or a joystick is provided and a user interacts with the game by manipulating the buttons and/or joystick. For example, if the user is playing a game in which the user controls a displayed character, the user will press a “jump” button on a handheld controller to make the character jump.
[0004] FIG. 1 is a plan view of a person 5 playing a video game in accordance with the prior art. The FIG. 1 configuration includes a console 10 that is coupled to a television set 15 and a handheld controller 20 . The television set includes a display screen 15 ′ on which video game graphics generated by console 10 are displayed. The player's input to the game is conveyed through the manipulation of buttons or other control interfaces on the handheld controller 20 . More specifically, the player's manipulations of the control interfaces on the handheld controller are converted to electrical signals that are relayed to the console 10 . Through the received electrical signals the console can determine the player's desired action.
[0005] As depicted in FIG. 1 , prior art video game systems require a coupling suitable for the transmission of electrical signals between the handheld controller and the console. In FIG. 1 , such coupling is illustrated by a hardwired coupling 25 . However, the coupling need not be a hardwired coupling. It could be, for example, an infra-red or wireless radio coupling. In any event, a coupling for transmitting electrical signals between the controller and console is necessary.
[0006] The requirement of an electrical coupling between the game controller and console has many drawbacks. In the case of hardwired connections, the wires are cumbersome and prone to tangling. Further, the wires can become disconnected if a player moves the handheld controller too far from the console. In the case of wireless connections, the corresponding handheld controllers generally require batteries and are therefore subject to battery failure. Moreover, the controllers used with electrical couplings, whether wired or wireless, are prone to liquid spills which can damage their circuitry. Still further, the controllers used with electrical couplings are expensive, thereby adding to the initial cost of the game system and making the controllers costly to replace.
[0007] In view of the drawbacks associated with prior video game controllers, the inventor of the present system and method has recognized that it is desirable to provide a video game controller that does not require an electrical coupling between the controller and the video game console.
SUMMARY OF THE INVENTION
[0008] A system and method is provided for controlling a device through air pressure waves. The system and method involve receiving an air pressure wave signal and analyzing the signal to determine whether or not it has one or more predetermined characteristics. If it is determined that the signal does have one or more predetermined characteristics, at least one control signal is generated for the purpose of controlling at least one aspect of the device.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0009] The following detailed description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may best be understood in conjunction with the accompanying drawings wherein like reference numerals denote like elements and parts, in which:
[0010] FIG. 1 is a plan view of a prior art video game system.
[0011] FIG. 2A is a plan view of a first embodiment including a microphone as a distinct element.
[0012] FIG. 2B is a plan view of a second embodiment in which a microphone is provided as part of a game console.
[0013] FIG. 3A is a block diagram useful in describing the operation of the FIG. 2A embodiment.
[0014] FIG. 3B is a block diagram useful in describing the operation of the FIG. 2B embodiment.
[0015] FIG. 4 is a flow chart showing the steps included in an audio data analysis scheme of a preferred embodiment.
DETAILED DESCRIPTION
[0016] Prior to describing the present system and method in detail, it is noted that the term “sound” is used in the description and claims to refer to air pressure waves in general and is not limited to audible air pressure waves.
[0017] FIG. 2A is a plan view of a first embodiment including a microphone 30 as a distinct element. The microphone is coupled to a game console 35 which is, in turn, coupled to a television set 40 . The television set includes a display screen 40 ′ for displaying video game graphics generated by the game console.
[0018] The microphone of FIG. 2A is used to pick up sounds 45 generated by a sound-generating element 50 operated by a person 55 playing the video game. The sound-generating element is preferably a handheld controller that produces sounds of various frequencies, each sound being produced in response to the activation of a respective interface on the controller. For example, the controller may include three buttons, one for “jump,” one for “move left,” and one for “move right,” each button generating an audible “click” of respective frequency “f 1 ,” “f 2 ,” or “f 3 ” when pressed. In another example, the controller may include a joystick that produces an audible click having a frequency dependent on the position to which the joystick is moved. For instance, moving the joystick to the 0 degree (12 o'clock) position produces a click of a first frequency “f 1 ,” to the 90 degree (3 o'clock) position produces a click of a second frequency “f 2 ,” to the 180 degree (6 o'clock) position produces a click of a third frequency. “f 3 ,” and so on.
[0019] In any event, sounds generated by controller 50 are picked up by microphone 30 and converted to electrical signals. The electrical signals are passed to the console 35 and based on the characteristics of the electrical signals received the game console controls one or more aspects of the video game. Thus, in the example of a “jump” button that generates a sound of frequency “f 1 ” when pressed, when the console determines that a sound of frequency “f 1 ” has been picked up by the microphone, the console will cause a video game character to jump in response to the determination. In this manner, interaction between a person and a video game is achieved without the need for an electrical coupling between the controller and game console. Rather, the controller and game console are coupled through sound.
[0020] In a preferred embodiment, the microphone is positioned in close proximity to the display screen so that a person playing the video game will be facing the microphone and the sounds generated by the handheld controller will be directed toward the microphone.
[0021] It should be noted that the coupling between the microphone and console is not limited to a hardwired coupling, or to a hardwired coupling of any particular type. Indeed, the coupling can be in the form of twisted-shielded-pair wiring, coaxial cable, fiber optic cable, wireless link, and the like. Similarly, the coupling between the console and television is not limited to any one particular type of coupling.
[0022] Further, it should be noted that the controller is not limited to a handheld controller with hand operated interfaces. In a preferred alternative embodiment, the controller is air activated such that by blowing into the controller a person produces a sound that causes the game to react accordingly. For example, a whistle is provided that produces a sound of frequency “fw.” When a person is within range of the game microphone and blows into the whistle, the console takes action commensurate with the detection of a sound having frequency “fw.” It is envisioned that such a whistle could be given away as a promotional item such as the small toys that are included in cereal boxes or the toys given away at fast-food restaurants. A customer could then use the whistle they obtain as part of a promotion to gain an advantage in a video game such as obtaining a secret weapon or opening a hidden door.
[0023] Moreover, it should be noted that the amplitude of sound produced by a controller may be used as a control parameter. For example, the controller may be a whistle that produces sound of amplitude proportional to the force with which a user blows into the whistle. The whistle could be used to control a displayed video game character such that the character's speed of movement is proportional to the sound amplitude, the character moving faster when the amplitude is high and slower when the amplitude is low.
[0024] FIG. 2B is a plan view of a second embodiment in which a microphone 60 is provided as part of a game console 65 . Since the microphone is integral with the game console, there is no need for an external coupling between the microphone and console. In all other respects, the embodiment of FIG. 2B is implemented in the same manner as the embodiment of FIG. 2A .
[0025] In both the FIG. 2A and FIG. 2B embodiments, the microphone is not limited to a single microphone element. For example, the microphone may be made up of an array of microphone elements.
[0026] FIG. 3A is a block diagram useful in describing the operation of the FIG. 2A embodiment. As can from FIG. 3A , the microphone 30 includes a transducer 70 , an Analog-to-Digital (A/D) converter 75 , and a data buffer 80 . Sounds picked up by the transducer are converted to analog electrical signals. The analog electrical signals are passed to the A/D converter where they are converted into digital electrical signals.
[0027] The digital electrical signals are made up of a multiple of sequential temporal samples, each sample being quantized and represented by a binary number. In a preferred embodiment, the samples of the analog signal are taken at a rate of≧40 KHz such that analog signals of 20 KHz—the commonly accepted upper frequency limit of human hearing—can be represented by the samples without aliasing. Nevertheless, the sampling rate is not limited to being≧40 KHz. For instance, if no sound of frequency>15 KHz is to be used as a control sound, then samples of the analog signal can be taken at a rate of 30 KHz (the Nyquist rate) without aliasing.
[0028] In any case, the samples generated by the A/D converter are stored in the data buffer prior to being passed to a RAM 85 within the game console. Once the samples have been passed to RAM 85 , they can be analyzed by a processor 90 within the console. In a preferred embodiment, the processor operates on subsets of the samples to determine for each subset whether or not the subset includes one or more predetermined control tones. More specifically, the processor performs a frequency transformation on a subset of samples, and if it is determined that the subset includes a tone corresponding to an action, the processor generates a control signal 95 to implement the action. In the example of a “jump” action being denoted by a frequency “f 1 ,” if the processor detects a tone of frequency “f 1 ” within the spectral content of a given subset, the processor determines that the sound corresponding to the “jump” command was detected during the time period of that subset and consequently generates a control signal that causes an on-screen character to jump.
[0029] More than one predetermined control tone may be present in a subset. In such event, the processor issues the control signals necessary to implement the actions associated with all the detected tones. For example, if predetermined tones of “f 1 ” and “f 2 ” are detected for a given subset, and “f 1 ” is associated with “jump” while “f 2 ” is associated with “move left,” the processor will issue control signals to cause an on-screen character to jump to the left.
[0030] FIG. 3B is a block diagram useful in describing the operation of the FIG. 2B embodiment. The data handling operations of FIG. 3B are the same as those discussed in connection with FIG. 3A . The only difference between FIGS. 3A and 3B is the inclusion of transducer 100 , A/D converter 105 and audio data buffer 110 within the console rather than outside the console.
[0031] FIG. 4 is a flow chart showing the steps included in a data analysis scheme of a preferred embodiment. As a first step, “t” seconds worth of digital data samples captured by the microphone are read from the data buffer to the RAM (step 115 ). Thus, for a sampling rate of 40 KHz and a value of “t=0.25 seconds,” 10,000 samples are read from the buffer into the RAM. Next, a frequency domain transformation is performed on the samples read into the RAM (step 120 ), and the resulting spectral content is analyzed to determine if one or more control tones are present in the content (step 125 ). If the analyzed data contains control tones, the processor generates one or more control signals directing the system to take action commensurate with the detected control tones (step 130 ). Once any necessary control signals have been generated, or a determination has been made that no control tones are present in the data, the process checks to see if “t” seconds have elapsed since the last data read (step 135 ). If “t” seconds have elapsed, the process reads the next “t” seconds worth of data into the RAM (step 115 ). If “t” seconds have not elapsed, the process waits until “t” seconds have elapsed before conducting the next read. In this manner, it is assured that “t” seconds of data is always available for reading from the buffer to the RAM.
[0032] As these and other variations and combinations of the features discussed above can be utilized without departing from the present invention as defined by the claims, the foregoing description of the preferred embodiments should be taken by way of illustration rather than by way of limitation of the invention as defined by the claims. For example, the present system and method is not limited to a data analysis scheme that includes a frequency domain transformation, and is not limited to a data analysis scheme that includes the detection of one or more control tones. Indeed, the analysis could be performed exclusively in the time domain or can make use of both domains. Moreover, the data analysis is not limited to detecting predetermined control tones. For instance, the analysis may include the detection of time domain or frequency domain patterns that are not distinguishable solely on the presence or absence of one or more predetermined tones.
[0033] Further, it is noted that the present invention may be used as presented herein or in combination with other user input mechanisms and notwithstanding mechanisms that track the angular direction of the sound and/or mechanisms that track the position of the object actively or passively, mechanisms using machine vision, combinations thereof and where the object tracked may include ancillary controls or buttons that manipulate feedback to the system and where such feedback may include but is not limited to light emission from light sources, sound distortion means, or other suitable transmitters and modulators as well as buttons, pressure pads, etc. that may influence the transmission or modulation of the same, encode state, and/or transmit commands from or to the device being tracked.
[0034] Still further, it is noted that in the video game embodiment of the invention the console is not a necessary element. For example, the elements that are included within the console may be alternatively integrated within the television set, integrated within the handheld controller, or integrated within both the television set and handheld controller.
[0035] In addition, the present system and method is not limited to video games, but rather, is applicable to device control in general. For example, a sound-based controller can be use to remotely control a television set.
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A system and method is provided for controlling a device through air pressure waves, or “sound”. The system and method involve receiving a sound and analyzing the sound to determine whether or not it has one or more predetermined characteristics. If it is determined that the sound does have one or more predetermined characteristics, at least one control signal is generated for the purpose of controlling at least one aspect of the device.
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FIELD OF THE INVENTION
This invention relates to apparatuses for agitating and aerating bodies of water, specifically to an improved vessel for use in agitating the surface of a body of water and aerating the entire body of water, and to a method of aerating a body of water.
BACKGROUND OF THE INVENTION
Facultative waste stabilization lagoons are currently the predominant tool for the treatment of wastewater by sanitation and public health professionals. Facultative refers to the ability of the bacteria typically used in sewage treatment/waste stabilization to live under more than one set of environmental conditions. Facultative bacteria are useful as they can tolerate the varying physical and chemical conditions resulting from changes in the bodies of water over time, such as when animal waste or plant matter degrades.
Commercial catfish ponds, constructed for the breeding and production of catfish, and other man-made bodies of water typically follow a design similar to facultative waste stabilization lagoons and thus experience many common problems.
Facultative waste stabilization lagoons utilize aerobic and facultative bacteria to stabilize organic waste materials. An adequate on-going supply of oxygen to the body of water is essential in order for the bacteria to perform the stabilization function. Originally, the designers of facultative waste stabilization lagoons, commercial catfish ponds, and other bodies of water relied on the natural process of algal photosynthesis on and below the surface of the water to supply this essential oxygen.
However, repeated experience has shown that various climatic conditions and other external and internal factors may sometimes inhibit the process of algal photosynthesis to the point that the ongoing supply of oxygen to the body of water is inadequate.
Most commonly, this occurs during the warmer months of the year when an overgrowth of algae can occur on the water surface, resulting in filamentous algae mats on the surface which block the radiation of sunlight into the water. In the absence of such sunlight, photosynthesis cannot take place and thus the production of oxygen below the surface is inhibited.
In severe cases, this set of factors causes a septic condition in the body of water in which the biological system within the body of water becomes anaerobic. This phenomenon can eventually result in the release of offensive odors from the lagoon and in the lagoon's failure to meet regulatory effluent limits on the organic discharge from these facilities.
These septic conditions can also occur during cooler months when limited intervals of sunlight result in an inadequate rate of algal photosynthesis. In the context of commercial catfish ponds, these septic conditions can quickly result in the death of the entire fish population.
In response to these problems, inventors previously have created several types of devices to mechanically and/or chemically aerate facultative waste stabilization lagoons, commercial catfish ponds, and similar bodies of water.
U.S. Pat. No. 4,409,107 to Busch discloses a fixed position aerating device which uses a paddlewheel with rotatable paddles to agitate the water near the surface to mix oxygen-rich surface water with oxygen-deficient deep water; however, this device must be moored to the bank of the body of water and hence can only aerate the small area within a narrow radius of the aerator's fixed position. It also does not break up algae masses on the surface.
U.S. Pat. No. 4,680,148 to Arbisi et al. shows an unmanned mobile pond aerating vessel whose movement and position are controlled by a complex microprocessor and beam transmitting/receiving system. The Arbisi device is powered by an electric motor which necessitates the expense and availability of a three-phase power line or other suitable electric power source in close proximity to the pond. Moreover, the unmanned Arbisi vessel cannot be utilized in a pond until trained personnel have programmed the microprocessor in a manner suitable for the particular pond in question; and the complexity of the electronic circuitry and microprocessor render construction and use of the device expensive. These features likely render actual use of the Arbisi vessel overly complicated and time-consuming. Furthermore, Arbisi discloses no mechanism for dispensing chemical agents into the water which, under certain circumstances, is a necessary complementary means of aeration.
U.S. Pat. No. 5,089,120 to Eberhardt broadly discloses a vessel with laterally adjustable pontoons adapted for dispensing into the water a treatment agent, such as lime, for neutralizing acid rain; however, this device fails to recognize the importance of mechanical aeration and surface agitation in combatting the problems outlined earlier. Specifically, the Eberhardt vessel lacks a paddlewheel or any similar device designed for breaking up algae mats in a manner sufficient to cause the submersion and decomposition of such mats. Eberhardt is also relatively large, complex, and expensive.
U.S. Pat. No. 4,268,398 to Shuck et al. discloses a sludge-agitating vessel mounted on pontoons. The Shuck device is designed for operation within a defined radius of a separate pumping station and is dependent on controlled air distribution and compression for carrying out its sludge treatment method. The Shuck device is intended specifically for agitating sludge toward a previously constructed pumping station and is unsuitable for portable use in aerating algae-infested lagoons or ponds absent such a pumping station at each required location.
U.S. Pat. No. 4,441,452 to Strain, Jr. shows a pumping apparatus to be attached to a tractor and backed into a pond to aerate the shallow areas at the edge of the pond. The Strain device is capable of mechanically aerating and destroying algae mats only within a small area radiating from the bank of the body of water.
U.S. Pat. No. 4,190,619 to Cherne discloses a liquid aerating rotor assembly which has a front scoop for preventing solid debris located in the surface layer of liquid form coming in contact with an aerating rotor.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an aerating apparatus and method which overcome the problems of conventional devices.
It is a further object of the invention to provide an aerating apparatus which can be freely navigated throughout a lagoon or body of water without any restrictive mooring or fixed position constraints.
It is another object of the invention to provide an aerating apparatus which can be simply and manually navigated.
It is a still further object of the invention to provide an aerating apparatus which can be powered with a simple power plant.
It is another object of the invention to provide an aerating apparatus in which both the amount and degree of aeration can be accurately and precisely adjusted by both mechanical and chemical aeration means.
It is yet another object of the invention to provide an aeration apparatus which can destroy aquatic vegetation.
It is yet a still further object of the invention to provide an aeration apparatus capable of disbanding and dislodging filamentous algae mats and other accumulated masses of organic material on the surface of a body of water so that such masses will sink and decompose.
It is another object of the invention to provide an aeration apparatus which is portable, mobile, and adaptable for use in any body of water without the need for previously constructed auxiliary equipment or devices.
It is a further object of the invention to provide an aeration apparatus which is suited for equalizing the amount of dissolved oxygen throughout a body of water.
It is another object of the invention to provide a method of aerating water that overcomes the drawbacks of conventional water aeration methods.
It is a still further object of the invention to provide a method of aerating water that combines the best of both mechanical and chemical aeration procedures in a highly flexible manner.
It is a still further object of the invention to provide a novel method of destroying aquatic plant life so that the quality of a body of water is enhanced.
In summary, therefore, the invention provides for a self-propelled mobile apparatus for aerating water. The apparatus is comprised of a vessel configured for movement across a body of water, a means disposed on said vessel for propelling said vessel across a body of water, the said propelling means being contained entirely on said vessel and, a first means disposed on said vessel for aerating water as said vessel is propelled across a body of water.
The invention likewise provides a mobile apparatus for destroying aquatic vegetation and for aerating water which includes a vessel configured for movement across a body of water, a means disposed on said vessel for propelling said vessel across a body of water, a first means disposed on said vessel for destroying aquatic vegetation as said vessel is propelled across a body of water containing aquatic vegetation, and a first means disposed on said vessel for aerating water as said vessel is propelled across a body of water.
The invention further provides a method of aerating a body of water by placing an entirely self-propelled vessel on a body of water to be aerated, propelling the self-propelled vessel across the body of water, and activating an aeration device disposed on the vessel for aerating the body of water as the self-propelled vessel moves across the body of water.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of a mobile water agitating and aerating apparatus according to the invention, as viewed from above;
FIG. 2 is a perspective view of the preferred embodiment of FIG. 1, as viewed from below;
FIG. 3 illustrates a side elevational view of the preferred embodiment of the invention;
FIG. 4 is a side elevational view of a rotor blade assembly according to the invention;
FIG. 5 is a perspective view of the rotor blade assembly of FIG. 4; and
FIG. 6 is a fragmentary, perspective view of one of the preferred embodiments of an aquatic vegetation guiding device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of an aeration vessel 10 according to the present invention is illustrated in FIGS. 1-3.
Aeration vessel 10 is supported on left and right pontoons and 14, respectively. An aquatic vegetation guide member 16 is disposed on a forward part of both left pontoon 12 and right pontoon 14, in this embodiment resembling a slightly upwardly offset, blunted cone.
A work platform 20 is mounted on left and right pontoons 12 and 14. Conveniently, a railing 22 circumscribes work platform 20.
A substantially V-shaped dry chemical hopper 30 having a variable feed control 32 is mounted on work platform 20, preferably near the forward endof aeration vessel 10.
An aeration chemical compound 34 is shown in FIG. 3.
An engine/gear box 40 is placed near the rear of aeration vessel 10. A conventional air filter/muffler 42 is attached to engine/gear box 40. Conveniently, the engine drives a V-belt 44 by means of a drive pulley 46 mounted on a horizontal drive shaft powered by an engine/gear box 40. A driven pulley 48 is connected to drive pulley 46 by V-belt 44.
A rear rotor assembly 60 mounted on a driven shaft 62 is powered by driven pulley 48 likewise being mounted on driven shaft 62. Conventional bearings64 support rear rotor assembly 60. Preferably, rear rotor assembly 60 includes a torque tube 66 and a plurality of rear rotor blades 70. Rear rotor assembly 60 is mounted conveniently between left pontoon 12 and right pontoon 14.
In a preferred construction of rear rotor assembly 60, rear rotor blades 70include a first semicircular plate 72 from which a plurality of first blades 74 extend outwardly in a radiating fashion. In order to provide a complete array of blades spaced apart and extending from torque tube 66 and surrounding the circumference thereof, a second semicircular plate 76 to which a second plurality of blades 78 are attached, mates with first semicircular plate 74.
A preferred construction of rear rotor assembly 60 is best understood from reference to FIGS. 4 and 5. A nut and bolt attachment 82 detachably secures an extension 84 of first semicircular plate 72 to an extension 86 of second semicircular plate 76. Accordingly, the rear rotor assembly can be inexpensively constructed, and selected ones of the rotor blades can bereplaced, as necessary.
Preferably, rear rotor blades 70 are staggered relative to the rotor bladesof an adjacent pair of first and second pluralities of blades 74 and 76, soas to achieve better aeration, destruction of aquatic vegetation, and decreased power requirements, when aeration vessel 10 according to the invention is in use.
Conveniently, a rear splash guard 90 extends over rear rotor assembly 60.
A front rotor assembly 100 is similar to rear rotor assembly 60, and, preferably has a smaller nominal diameter.
A plurality of water aerating/aquatic plant destroying blades 102 radiates outwardly from front rotor assembly 100; blades 102 can be constructed in a manner similar to the construction of the blades of rear rotor assembly 60, as will be readily appreciated by a person having ordinary skill in the art. A shaft 104 supports front rotor assembly 100. A plurality of blades 106 is staggered relative to a plurality of blades 108, and a frontsplash guard 110 extends over a portion of front rotor assembly 100.
A height adjust/locking mechanism 112 is disposed between vessel 10 and shaft 104, so that the height of front rotor assembly 100 relative to pontoons 12 and 14, and hence, the water, is adjustable. Height adjusting/locking mechanism 112 also is adapted to lock and prevent shaft 104 from rotating.
A steering rudder 120 mounted at the rear of aeration vessel 110 controls the movement of vessel 10 by use of a steering linkage 122 operatively connected to a single stick steering mechanism 124.
An operator's seat 130 is conveniently placed on work platform 20 near the rear of aeration vessel 10, thereby defining an operator's station, and a hinged horizontal seat portion 132 provides access to storage space, as required.
A representative water level 140 on which a mass 142 of aquatic vegetation floats, shows a typical depth at which aeration vessel 10 operates.
An alternative embodiment of a pontoon 212 is shown in FIG. 6. Pontoon 212 has a forward part 216 configured for guiding aquatic vegetation to front rotor assembly 100, the configuration being akin to the prow of an ocean-going ship or to a hemisphere having opposed, left and right dimpledportions.
OPERATION
In use, mobile aeration vessel 10 will be brought to the body of water to be treated in an assembled or disassembled state.
After aeration vessel 10 is placed on a body of water, the engine is started, and the operator engages engine/gear box 40 so that power is transmitted from drive pulley 46 through V-belt 44 to driven pulley 48. Inthis manner, rear rotor assembly 60 is rotated relative to left and right pontoons 12 and 14, whereby aeration vessel 10 is moved over the body of water. Engine/gear box 40 includes forward and reverse gears whereby even in an embodiment where only rear rotor 60 is powered, rear rotor 60 will be either the leading or the trailing rotor, depending on the physical requirements of the body of water and/or the aquatic vegetation therein.
Typically, rear rotor assembly 60 will be driven in a counter-clockwise fashion as viewed FIG. 3, so that aeration vessel 10 moves from right to left as viewed in FIG. 3. Front rotor assembly 100 is, hence, driven counter-clockwise owing to the movement of the water relative to blades 102.
An appropriate forward speed of aeration vessel 10 is selected by the operator so that the water is sufficiently aerated by the blades of both front rotor assembly 100 and rear rotor assembly 60. The speed of vessel 10 is likewise selected so that aquatic vegetation 142 is sufficiently chopped up and destroyed by blades 102, as well as blades 70, so that the vegetation 142 will sink and decompose.
Concurrently, the operator determines whether chemical aeration compound 34should be applied based on the dissolved oxygen content of the water, and on the amount of aquatic vegetation 142 present. Accordingly, the operatordetermines the application rate of aeration chemical 34 by manipulation of feed mechanism 32.
As aeration vessel 10 traverses the body of water, aquatic plant vegetationguides 16 and 216, respectively, guide plant life, such as mats of algae and other scum toward front rotor assembly 100 to ensure that the vegetable matter encounters blades 102.
The placement of left and right pontoons 12 and 14 close to front rotor assembly 100, as well as to rear rotor assembly 60, ensures that aquatic vegetation 142 is trapped between pontoons 12 and 14 so that the front andrear rotor assemblies can adequately break up the vegetation and cause it to sink. The rotor blades chop up vegetation, such as algae mats which form on the surface of catfish ponds and facultative wastewater stabilization lagoons by breaking or chopping up the algae mats into smaller particles which will then settle to the bottom of the body of water and decay.
Rear rotor 60 provides the bulk of the aeration, and continues the break upof the plant matter broken up by front rotor assembly 100.
Under certain conditions, such as the presence of "duck weed" which tends to sufficiently cover the water surface so as to block sunlight and cause anaerobic conditions in the water, front rotor assembly 100 can be locked by use of height adjust/locking mechanism 112 and used as a pusher or water plow. In this manner, aeration vessel 10 could be used to push the offending duck weed towards the banks of the body of water where it could be removed.
In a preferred embodiment of the invention, the pontoons are constructed of0.080 inch aluminum sheeting. The work platform is constructed of 3/8-inch aluminum non-skid checker plate supported by 2-inch aluminum channel stock, although various other materials are suitable. The railing is suitably constructed of two-inch aluminum and extend around the work platform at a height of 30 to 36 inches in accordance with Occupational Safety and Health Administration (OSHA) standards.
The dry chemical hopper is preferably 2 feet deep, 4 feet wide, and having a capacity of about 4.5 cubic feet.
The self-contained power plant/engine is preferably a horizontal drive gasoline engine mounted on the starboard (right) side of the vessel, and having a rating of about 5 horsepower. Lesser or greater power engines would be suitable depending on the circumstances.
The rear rotor assembly/paddle wheel may have a 30 inch diameter, the rear torque tube having a diameter of about 18 inches, and each of the blades extending outwardly therefrom by about 6 inches. The front rotor assembly may have an overall diameter of about 18 inches, the front torque tube having a diameter of 12 inches, and the blades extending about 3 inches outwardly therefrom. The rear blades may have overall measurement of 6 by 3 inches, and 14 sets of blades may be placed along the length of the torque tube.
The front rotor assembly may likewise have 14 sets of blades extending lengthwise thereof, each of the blades having nominal dimensions of 3 inches by 3 inches.
It is further contemplated that front rotor assembly may be driven, and powered by the same engine or a separate engine, as required. The preferred embodiment would not require a drive mechanism for the front rotor. The front rotor will freewheel due to resistance force of the wateras the vessel moves through the water.
The metals used in the construction of the invention are preferably stainless steel and aluminum, although other suitable materials within theskills of a person having ordinary skill in the art are contemplated.
While the invention has been disclosed as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptations of the invention following in general the principle of the invention and including such departures from the present disclosure as onewithin known or customary practice in the art of which the invention pertains, and as may be applied to the central features hereinbefore set forth, and fall within the scope of the invention of the limits of the appended claims.
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Self-propelled mobile apparatus for aerating water includes a vessel configured for movement across a body of water, and a mechanism contained entirely on the vessel for propelling the vessel across a body of water. A water aerating device is disposed on the vessel for aerating water as the vessel is propelled across a body of water.
A method of aerating a body of water includes placing an entirely self-propelled vessel on a body of water to be aerated, propelling the self-propelled vessel across the body of water, and activating an aeration device disposed on the vessel.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present regular United States Patent Application claims the benefits of U.S. Provisional Application Ser. No. 60/735,074, filed on Nov. 9, 2005.
FIELD OF THE INVENTION
The present invention relates generally to fastener devices or retention clips used for holding an item for attachment to a mating structure, and, more particularly, the invention pertains to a holding clip used for retaining a magnet and anchoring the magnet in a panel.
BACKGROUND OF THE INVENTION
Office furniture manufacturers provide various types of panel systems for use in office cubicles and other commercial or business environments. Individual panels are connected one to another to define separate work spaces. Work areas defined by panel systems are moved easily, allowing efficient office reconfiguration as changes are desired. Work areas can be defined, expanded and reconfigured without expensive remodeling or reconstruction by relocating the various panels, or by using more panels or fewer panels as required. Panel systems have achieved wide acceptance and use.
It is known to use various types of assembly constructions for the panels used in office environments. The panels can be secured in place in many different ways. Various materials with sound absorption and flame retardant properties have been used and are under consideration, as well as materials providing direct office utility such as for pinups and postings. One such material is a pressed fiberglass panel that is cut to a desired size and wrapped in fabric to provide an aesthetically pleasing surface. Due to the low structural strength of pressed fiberglass panels, various methods have been investigated for mounting the pressed fiberglass panels to various frame designs, some having achieved greater success than others. The fibrous, irregular fiber network of pressed fiberglass panels can present challenges in achieving the desired attachment. Physical fasteners can distort the layers of pressed fiberglass panels, reducing the integrity of the panel
One solution has been to provide the wall panel with a metal frame and to hang the top portion of the pressed fiberglass panel from the frame, or to securely attach the panel to the frame to take up most of the weight of the panel. A magnet is attached to the fiberglass panels for connecting the bottom of the panel to the metal frame by magnetic attraction. The panels are then wrapped in fabric to provide the desired color, appearance or other cosmetic surface.
One known manner of securing a magnet to a fiberglass panel on the bottom portion of the panel assembly is through the use of adhesives. However, adhesives present some problems and difficulties. The magnets may not always be securely fastened, and the application of glue adds undesirable assembly costs. The use of glue is messy and labor intensive. The use of glue can delay final assembly, in that an appropriate cure time must be available before the panel is handled in a manner that could loosen the adhesive attachment. Accordingly, the panels can be only partly assembled, then held for the adhesive to cure.
SUMMARY OF THE INVENTION
The present invention provides a molded plastic part that has a cavity to accept and retain a magnet while being configured for anchoring in the fibrous panel.
In one aspect thereof, the present invention provides a magnet retention clip with a magnet holder defining a cavity configured for receiving and holding a magnet therein. The cavity has an exposure opening and an assembly opening. At least one deflectable retention arm at least partly obstructs the assembly opening. A probe extends from the magnet holder, and first and second stabilizers are at opposite sides of the magnet holder, substantially normal to the probe.
In another aspect thereof, the present invention provides a magnet and retention clip assembly with a magnet holder defining a cavity having an exposure opening in a face of the holder and an assembly opening for receiving a magnet. At least one deflectable retention arm at least partly obstructs the assembly opening. A probe extends outwardly from the magnet holder. First and second stabilizers at opposite sides of the magnet holder are substantially normal to the probe. A stepped magnet is disposed in the cavity and has a base and a projection from the base. The projection is narrower than the base, leaving an exposed surface of the base outwardly of the projection. The projection is exposed in the exposure opening.
In a still further aspect thereof, the present invention provides a wall panel assembly with a panel frame having at least a metal component, a panel of fibrous material and a magnet retention clip including a magnet holder defining a cavity having an exposure opening. A probe extends from the magnet holder and is embedded in the fibrous material. First and second stabilizers are at opposite sides of the magnet holder, substantially normal to the probe. The stabilizers are in contact with the fibrous material. A magnet is disposed in the cavity and has a portion exposed in the exposure opening. The magnet is assembled to the metal component.
An advantage of the present invention is providing a low cost component that secures a magnet and engages compressed fibrous panels, such as compressed fiberglass panels.
Another advantage of the present invention is providing an anchoring device that seats easily into a fiberglass panel.
Still another advantage of the present invention is providing a magnet clip for anchoring in fibrous panels that is easy to assemble both manually and robotically.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an assembled magnet and magnet retention clip in accordance with the present invention;
FIG. 2 is a cross-sectional view of the magnet retention clip shown in FIG. 1 , the cross-section having been taken along line 2 - 2 of FIG. 1 ;
FIG. 3 is a perspective view of the magnet retention clip shown in FIG. 1 , but without a magnet installed therein;
FIG. 4 is a perspective view of a magnet used in the magnetic retention clip shown in FIGS. 1-3 ;
FIG. 5 is a perspective view of another embodiment for a magnet retention clip of the present invention;
FIG. 6 is a perspective view of the clip shown in FIG. 5 , but illustrating the side opposite the side shown in FIG. 5 ;
FIG. 7 is a perspective view of yet another embodiment for a magnet retention clip of the present invention;
FIG. 8 is a plan view of the clip shown in FIG. 7 , but illustrating the side opposite the side shown in FIG. 7 ;
FIG. 9 is a perspective view of a magnet for the retention clip shown in FIGS. 7 and 8 ; and
FIG. 10 is a fragmentary perspective view of a wall panel assembly having a magnetic retention clip in accordance with the present invention.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and 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 or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more specifically to the drawings and to FIGS. 1-3 in particular, a magnet retention clip 20 of the present invention is shown. Magnet retention clip 20 includes a magnet holder 22 , probes 24 and 26 , and stabilizers 28 and 30 . Magnet retention clip 20 , including magnet holder 22 , probes 24 , 26 and stabilizers 28 , 30 can be a monolithic body of plastic, such as nylon, formed by injection molding or the like.
Magnet holder 22 forms a rectangular slot or cavity 32 having an assembly opening 34 and a closed end 36 . Channels 38 , 40 are formed along opposite sides of cavity 32 , extending from assembly opening 34 to closed end 36 . Accordingly, channels 38 and 40 are open at assembly opening 34 and closed at closed end 36 . Assembly opening 34 provides assembly access to cavity 32 and channels 38 , 40 . Cavity 32 is open or exposed also at an exposure opening 42 in a face of holder 22 . Cavity 32 has a bottom 44 opposite to exposure opening 42 . A deflectable arm 46 is provided in bottom 44 and includes a lip 48 projecting above the surface of bottom 44 and into cavity 32 , thereby obstructing assembly opening 34 . Magnet holder 22 is configured to receive and retain a magnet 50 therein.
Magnet 50 has a stepped configuration, with a larger base 52 and a smaller projection 54 . The peripheral edge of base 52 , as best seen in FIG. 4 , extends outwardly beyond projection 54 , and portions thereof on opposite sides of projection 54 are received in channels 38 , 40 in the completed assembly. Projection 54 extends to and is exposed at exposure opening 42 .
Probes 24 , 26 are rod-shaped projections from magnet holder 22 . Distal ends 56 , 58 respectively thereof are tapered or pointed to facilitate insertion into a fiberglass mat, such as the aforementioned pressed fiberglass panels.
Stabilizers 28 , 30 comprise outwardly projecting wings from magnet holder 22 . Stabilizers 28 , 30 inhibit rotation of the installed holder 20 .
Magnet 50 is inserted into magnet holder 22 by deflecting arm 46 downwardly and sliding base 52 into channels 38 , 40 . As base 52 passes beyond lip 48 , arm 46 rebounds to its non-deflected position, and lip 48 overlies the outer end edge portion of base 52 , to hold magnet 50 in cavity 32 . The assembly of magnet retention clip 20 and magnet 50 can then be embedded in a compressed fiberglass panel 60 to secure the fiberglass panel 60 relative to a metal frame 62 for a wall panel assembly 64 . As seen in the drawings, magnet holder 22 and stabilizers 28 , 30 present a flat edge on a side of retention clip 20 opposite to probes 24 , 26 for fitting against frame 62 .
FIGS. 5 and 6 illustrate another embodiment of the present invention. A magnetic retention clip 120 includes a magnet holder 122 , probes 124 , 126 and stabilizers 128 , 130 . Again, clip 120 can be manufactured by injection molding of various plastics such as nylon, or formed in any other convenient and efficient manner. Probes 124 , 126 are similar to probes 24 and 26 described previously, and stabilizers 128 , 130 are similar to stabilizers 28 , 30 described previously herein.
Holder 122 defines a rectangular cavity 132 having an assembly opening 134 at an assembly face of holder 122 and an exposure opening 136 at an exposure face of holder 122 . At exposure opening 136 a flange 138 is formed in cavity 132 whereby exposure opening 136 is smaller than assembly opening 134 . At assembly opening 134 , deflectable retention arms 140 , 142 are provided. Arms 140 , 142 are outwardly deflectable to allow magnet 50 to be inserted therebetween. To facilitate the outward deflection, distal ends 144 , 146 of arms 140 , 142 are smoothly curved with inwardly directed faces 148 , 150 thereof being angled to facilitate spreading as magnet 50 is forced therebetween. Inwardly directed 152 154 are provided at faces 148 , 150
Magnet 50 is installed in retention clip 120 by inserting magnet 50 through assembly opening 134 , leading with projection 54 . Arms 140 , 142 are deflected outwardly as magnet 50 engages angular distal end faces 148 , 150 and is pushed there between. As base 52 of magnet 50 passes lips 152 , 154 , arms 140 , 142 rebound inwardly. Lips 152 , 154 overlap the then exposed bottom surface of base 52 and hold magnet 50 in cavity 132 . Projection 54 of magnet 50 extends into exposure opening 42 , with the peripheral edge portion of base 52 outwardly of projection 54 engaged against an inner surface of flange 138 .
FIGS. 7 , 8 and 9 illustrate yet another embodiment of the present invention that has advantages for both manual and robotic assembly. As with clips 20 and 120 , a magnet retention clip 220 can be manufactured by injection molding of various plastics such as nylon, or formed in any other convenient and efficient manner. Magnet retention clip 220 includes a magnet holder 222 , probes 224 and 226 and stabilizers 228 and 230 . Probes 224 , 226 are similar to probes 24 , 26 and 124 , 126 described previously herein. So also, stabilizers 228 and 230 are similar to stabilizers 28 , 30 and 128 , 130 described previously herein.
Magnet holder 222 is similar to magnet holder 122 , defining a cavity 232 having an assembly opening 234 at an assembly face of holder 222 and an exposure opening 236 at an exposure face of holder 222 . A flange 238 is formed in cavity 232 whereby exposure opening 236 is smaller than assembly opening 234 . Magnet holder 222 differs from magnet holder 122 in that cavity 232 is round, whereas cavity 132 is rectangular. Arms 240 , 242 similar to arms 140 , 142 are provided at opposite sides of assembly opening 234 and are similarly shaped at distal ends 244 , 246 having inwardly directed angular faces 248 , 250 to facilitate deflection upon insertion of a suitable magnet 252 .
A round magnet 252 is used for clip 220 . Magnet 252 has a stepped configuration, with a larger base 254 and a smaller projection 256 . The peripheral edge of base 254 , as best seen in FIG. 9 , extends outwardly beyond projection 256 , and is received against the inner surface of flange 238 in the completed assembly. Projection 256 extends to and is exposed at first open face 234 . Magnet 252 is inserted into cavity 232 by deflecting arms 240 , 242 outwardly as magnet 252 is inserted into cavity 232 through assembly opening 234 , and a manner similar to that described above for the insertion of magnet 50 into cavity 132 of magnet holder 122 . However, the embodiment illustrated with respect to clip 220 facilitates assembly in that the insertion of magnet 252 having a round periphery into a round cavity 232 does not require the same orientation adjustment as does the insertion of magnet 50 having a rectangular periphery into a rectangular cavity 32 or 132 . Accordingly, assembly manually and robotically is facilitated.
Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
Various features of the invention are set forth in the following claims.
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A magnet retention clip for assembling modular wall panels includes a magnet holder, prongs insertable into the wall panel and stabilizers outwardly of the magnet holder.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cryogenic system for radiation detector comprising:
a finger cooled to a low temperature and adapted for supporting and cooling said detector,
a wall surrounding said finger having, opposite said detector, a window transparent to the radiation to be detected
and in which the enclosure defined by said finger and said wall is closed and filled with at least a gas.
2. Description of the Prior Art
The present invention applies to all sorts of radiation detectors having to operate at very low temperatures, in particular infra red radiation detectors.
A cryogenic system of the above type is already known and described in patent FR-A-1 529 857. In this device, the gas filling the enclosure, as well as its pressure, are chosen so that its liquefaction temperature is smaller than that reached by the cooling finger.
Compared with conventional systems, in which the thermal insulation is provided by evacuating the enclosure defined by the finger and the wall, the present system has the main advantage of not requiring a fastidious pumping operation whenever the detector is to be changed.
To provide a certain thermal insulation, the wall defining the enclosure is a double wall under a sealed vacuum, which increases the cost of the apparatus and, despite this precaution, taking into account the fact that the thermal conductivity of the gas filling the enclosure is not zero, the time of self-supporting operation of the system, that is the time during which the temperature of the detector remains less than a certain value, for a given cooling time, is less than that of a conventional vacuum system of the same dimension.
The present invention overcomes these drawbacks.
SUMMARY OF THE INVENTION
To this end, it provides a cryogenic system of the above defined type in which said gas, as well as its pressure in the enclosure, are chosen so that said gas has low thermal conductivity and so that its liquefaction or solidification temperature is greater than the temperature reached by said finger.
In the device of the invention, the latent vaporization or sublimation heat of the filling gas considerably increase its time of self-supporting operation.
Moreover, since the double wall under sealed vacuum is no longer necessary, the cost of the apparatus is considerably reduced and its reliability increased.
Advantageously, said gas is chosen from the following: xenon, krypton, argon, nitrogen, carbon dioxide, nitrogen protoxide and a mixture of these gases.
These gases, transparent to the wavelength of the radiation to be detected, are in fact inert under the conditions of use of the radiation detectors.
Again advantageously, the refrigerating fluid used for cooling said finger is recovered at the output of said finger for application in a jacket surrounding said wall.
The time of self-supporting operation of the device is further increased because of the reduction of the external temperature of the wall.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following description of the preferred embodiment of the cryogenic system of the invention, with reference to the accompanying drawings in which:
FIG. 1 shows a cryogenic system according to the invention,
FIG. 2 shows a conventional thermo-dynamic diagram concerning the changes between the solid S, liquid L and vapor V phases of a pure substance, as a function of its temperature T and its pressure P.
FIG. 3 is a diagram of the evolution, during the time θ, of the temperature T of the device of FIG. 1, shown with a continuous line, compared with that of a prior art system shown with a broken line, and
FIG. 4 shows experimental recordings of the evolution, during the time θ of the temperature T of the system in accordance with the invention, shown with a continuous line, and of a prior art device shown with a broken line.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a radiation detector, here a photodetector 3 is supported by the end piece 2 of a finger 1 surrounded by a wall 4 forming a sealed and closed enclosure 6 with this finger. Wall 4 is provided with a window 7 facing the detector 3 so as to let the radiation to be detected pass.
After the photodetector 3 has been mounted, brief degasification of the enclosure surrounding finger 1 is carried out in the interwall enclosure 6 through a nipple 8, then a low thermal conductivity gas under a suitable pressure is introduced into this space 6.
The refrigerant supply for finger 1, of a known type and here a Joule-Thomson detent system, is then started up so as to lower the temperature of the cold finger to the value T1, the nominal operating temperature of the photodetector 3, here equal to the liquefaction temperature of the refrigerating fluid contained inside finger 1.
FIG. 2 shows the phase change diagram of the gas filling enclosure 6, whose volume is constant. Temperature T1 corresponds here to a balance of the solid-vapor phases, the saturating vapor pressure being established at the corresponding balance pressure P1. In FIG. 2 the temperature Ti is also shown which corresponds to the upper limit temperature above which it is considered that the photodetector 3 has unsatisfactory operation. Here, the temperature Ti corresponds to a balance of the liquid-vapor phases of the gas filling enclosure 6 and the corresponding saturating vapor pressure is Pi.
Thus, during cooling of finger 1, the gas filling enclosure 6 condenses, then solidifies, partially, to reach the solid-vapor balance at the final temperature T1.
After the refrigerant supply has been cut off or exhausted, the latent sublimation heat of the condensed gas is recovered and contributes to maintain the temperature of cold finger 1 during the phase change time. In fact, referring to FIG. 3, for the cryogenic system of the invention (continuous line), as for a conventional vacuum system of the prior art (broken line), the evolution of the temperature T during the refrigeration time θo is similar and the curve is substantially linear from the ambient temperature Ta to the intermediate temperature Ti, then rapidly bends to reach the liquefaction temperature T1 of the refrigerating fluid, during the phase changes of the gas contained in enclosure 6. When cooling of finger 1 ceases, in the conventional device, the temperature increases substantially linearly in time. The time of self-supporting operation θA corresponds to the duration of use of the photodetector. In the device of the invention, the temperature shows a second level portion corresponding to the latent sublimation heat of the gas filling enclosure 6. This results in artificially increasing the heat capacity of the cryogenic system of the invention and consequently in increasing the time of self-supporting operation θB of the detector as shown in the Figure.
FIG. 4 shows experimental results which confirm these predications, in the case where the intermediate temperature is 120° K. for example.
The time of self-supporting operation of the system of the invention may be essentially increased depending on the gas used. This gas may be xenon, krypton, argon, nitrogen, carbon dioxide, nitrogen protoxide or, also, a mixture of these gases, under suitably chosen partial pressures.
Since it is no longer necessary to have a double wall under a sealed vacuum, the mechanical structure of the enclosure may be simpler and lighter. The seals and the electric connections for the photodetectors may be designed more easily. The system of the invention also allows more reliable storage.
It is of course, possible, without departing from the spirit of the invention, to use the vaporization heat of the gas depending on the gas mixture chosen. It is sufficient to choose a mixture such that the temperature T1 corresponds to a liquid-vapor instead of solid-vapor balance.
The system of the invention may be modified so as to recover at the outlet of finger 1, at least a part of the refrigerating fluid used for the refrigerant supply of this finger 1 and to channel the resulting cold gas into a jacket 10 (shown in phantom lines) fixed to the wall 4 by way of channel 12 (also shown in phantom lines).
Such thermalization of wall 4 of the cryogenic system on the one hand reduces the temperature difference between the outside and the inside of the system, thus reducing the heat losses and increasing correspondingly the time of self-supporting operation and, on the other hand, ensures possible demisting of window 7.
The cryogenic system of the invention has very numerous other advantages such as the suppression of getters for maintaining the vacuum; it finally allows different organic products to be used inside the cryogenic device (epoxy adhesives, organic blacks, . . . ) which are better performing but perhaps more degasifying and thus unusable in a vacuum.
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A cryogenic device for radiation detectors is provided comprising an enclosure situated between a cryogenic cold finger supporting a detector and an external wall. After a brief degasification under vacuum of said enclosure, at least one gas is therein introduced, whose liquefaction or solidification temperature is higher than the temperature reached by said cold finger.
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